

; ff^lg^ 


Plate 1. 


A MANUAL 


FOR THE 


STUDY OF INSECTS 

REVISED EDITION 


BY 


JOHN HENRY COMSTOCK 

Emeritus Professor of Entomology in Cornell University 


AND 


ANNA BOTSFORD COMSTOCK 

Emeritus Professor of Nature Study in Cornell University 


AND 


GLENN W. HERRICK 

Professor of Entomology in Cornell University 


tKtoenttetl) Ctottton 


ITHACA, NEW YORK 
THE COMSTOCK PUBLISHING COMPANY 

i93i 


Copyright, 189s, 

BY 

JOHN HENRY COMSTOCK 

Revised Edition 
Copyright, 1930, 

BY 

JOHN HENRY COMSTOCK; 


fey* *•* 

ilLIBRAR' 

PREFACE TO ORIGINAL EDITION 

For many years the most pressing demand of teachers and learners in 
entomology in this country has been for a handbook by means of which 
the names and relative affinities of insects may be determined in some 
such way as plants are classified by the aid of the well-known manuals 
of botany. But, as the science of entomology is still in its infancy, the 
preparation of such a handbook has been impossible. Excellent treatises 
on particular groups of insects have been published; but no general work 
including analytical keys to all the orders and families has appeared. It 
is to meet this need that this work has been prepared. 

The reader must not expect, however, to find that degree of complete- 
ness in this work which exists in the manuals of flowering plants. The 
number of species of insects is so great that a work including adequate 
descriptions of all those occurring in our fauna would rival in size one of 
the larger encyclopaedias. It is obvious that such a work is not what is 
needed by the teachers and students in our schools, even if it were pos- 
sible to prepare it. An elementary work on systematic entomology will 
always of necessity be restricted to a discussion of the characteristics of 
the orders and families, and descriptions of a few species as illustrations. 
Complete synopses of species will be appropriate only in works treating of 
limited groups. It is believed, therefore, that it would not be wise to 
materially change the scope of the present work even if it were possible 
to describe all of our species. 

Although much pains has been taken to render easy the classification 
of specimens, an effort has been made to give the mere determination of 
the names of insects a very subordinate place. The groups of insects 
have been fully characterized, so that their relative affinities may be 
learned; and much space has been given to accounts of the habits and 
transformations of the forms described. As the needs of agricultural 
students have been kept constantly in view, those species that are of 
economic importance have been described as fully as practicable, and 
particular attention has been given to descriptions of the methods of 
destroying those that are noxious, or of preventing their ravages. 

An effort has been made to simplify the study of insects as much as 
possible without sacrificing accuracy in the descriptions. Only such 
morphological terms have been used as were necessary to accomplish the 
object of the book in a satisfactory manner. And so far as possible a 
uniform nomenclature has been used for all orders of insects. The fact 
that writers on each order of insects have a peculiar nomenclature has 
been a serious obstacle to the progress of entomology; this is especially 
true as regards the nomenclature of the wing-veins. It has been neces- 
sary for the student in passing from the study of one order of insects to 
that of another to learn a new set of terms ; and in many cases writers on 
a single family have a peculiar nomenclature. 

The present writer has endeavored to remove this obstacle by making 
a serious study of the homologies of the wing-veins, and by applying the 


iv PREFACE TO ORIGINAL EDITION 

same term throughout the work to homologous veins. The result is that 
the student is required to learn only one set of terms; and in applying 
these terms there will be brought to his attention in a forcible manner the 
peculiar modifications of structure characteristic of each order of insects. 
Heretofore, with a different nomenclature for the wing-veins of each 
order such a comparative study of the various methods of specialization 
has been beyond the reach of any but the most advanced scholars. 

The principal features of the method of notation of wing-veins pro- 
posed by Josef Redtenbacher has been adopted. But as the writer's 
views regarding the structure of the wings of primitive insects are very 
different from those of Redtenbacher, the nomenclature proposed in this 
book is to a great extent original. The chief point of difference arises 
from the belief by the present writer that veins IV and VI do not exist 
in the Lepidoptera, Diptera, and Hymenoptera; and that, in those or- 
ders where they do exist, they are secondary developments. The reasons 
for this belief are set forth at length in my essay on Evolution and 
Taxonomy. 

In this essay there was proposed a new classification of the Lepidop- 
tera, which was the result of an effort to work out the phylogeny of the 
divisions of this order. This classification has been further elaborated in 
the present work. In the other orders but few changes have been made 
from the more generally accepted classifications. It is more than prob- 
able however, that when the taxonomic principles upon which this classi- 
fication of the Lepidoptera is based are applied to the classification of the 
other orders radical changes will be found to be necessary. 

A serious obstacle to the popularization of Natural History is the 
technical names that it is necessary to use. In order to reduce this diffi- 
culty to a minimum the pronunciation of all of the Latin terms used has 
been indicated, by dividing each into syllables and marking the accented 
syllable. In doing this the well-established rules for the division of Latin 
words into syllables have been followed. It seems necessary to state this 
fact in order to account for differences which exist between the pronunci- 
ations given here and some of those in certain large dictionaries recently 
published in this country. 

Nearly all of the wood-cuts have been engraved from nature by the 
Junior Author. As the skill which she has attained in this art has been 
acquired during the progress of the work on this book, some of 
the earlier-made illustrations do not fairly represent her present standing 
as an engraver. But it does not seem worth while to delay the appear- 
ance of the book in order to re-engrave these figures; especially as it is 
believed that they will not be found lacking in scientific accuracy. The 
generous appreciation which the best engravers have shown towards the 
greater part of the work leads us to hope that it will be welcomed as an 
important addition to entomological illustrations. 

Although the chief work of the Junior Author has been with the pencil 
and graver, many parts of the text arc from her pen. But in justice to 
her it should be said that the plan of the book was changed after she had 
finished her writing. It was intended at first to make the book of a much 
more elementary nature than it is in its final form. It has seemed best, 
however, to leave these parts as written in order that the work may be of 
interest to a wider range of readers than it would be were it restricted to 
a uniform style of treatment. 


PREFACE TO ORIGINAL EDITION 


The figures illustrating the venation of the wings of insects have been 
drawn with great care under the writer's direction by Mr. E. P. Felt and 
Mr. R. H. Pettit. About one half of those in the chapter on Lepidoptera 
were drawn by Mr. Felt; the others in this chapter and those in the 
chapters on Diptera and Hymenoptera were drawn by Mr. Pettit. 

I wish also to acknowledge the help of my Assistant Mr. A. D. Mac- 
Gillivray, to whom I am indebted for much aid in bibliographical re- 
searches and in many other ways; also, that of Dr. A. C. White of the 
Cornell University Library, who has generously given much time to 
determining the etymologies of many of the more obscure words the pro- 
nunciations of which are indicated in the text. 

To the authorities of Cornell University the authors of this book are 
under deep obligation for aid and encouragement. The preparation of 
the work would not have been possible but for the liberal grants which 
they have made for the purchase of specimens and books. 


John Henry Comstock 


Entomological Laboratory, 

Cornell University, 

December, 1894 


01 


FOREWORD 

The Manual for the Study of Insects, published in 1895, was written 
to meet the needs of teachers of Entomology when that science was in its 
infancy as an academic study. It was well received and accomplished its 
purpose, and there has been a continuous call for it since; it is now in 
its eighteenth edition. Owing to the rapid development of the science it 
became necessary to revise the book and I began this before my retire- 
ment in 19 14. However, so great has been the growth of Entomology 
that this intended revision of the Manual resulted in a new textbook, 
An Introduction to Entomology. 

I still had it in mind to revise the Manual, making it more elemen- 
tary, when failing health prevented. It is with relief and confidence that 
I pass this task on to Professor Glenn W. Herrick, whom I trained when 
he was an undergraduate and who has now many years of successful 
teaching and careful research to his credit. 

John Henry Comstock 

April 5, 1929. 


INTRODUCTION 

Some time during the year 1895, a package containing the 
first volumes of "A Manual for the Study of Insects" fresh from the 
press, came to the Insectary at Cornell University where the writer lived 
and worked as a student in entomology. Professor Mark Vernon Slinger- 
land and the writer rushed with feverish haste to open the box in order 
to see and handle as quickly as possible, this wonderful book, the publi- 
cation of which we had awaited with such great anticipation and interest. 
The event, because of its inspirational value, was almost as significant in 
the life of the writer as it was, for other reasons, in that of the author of 
the book; and now after thirty-odd years it becomes a peculiar pleasure 
to have the opportunity of revising that first Manual of Professor Com- 
stock's. 

The aim of the revision has been to keep the Manual in form and 
arrangement practically as it was first written. The attempt has been 
made, of course, to bring the subject-matter down to date, to simplify it 
and to condense it somewhat in order to bring it within the horizon of 
the beginning student. The more advanced student in entomology has 
been adequately cared for by Professor Comstock's much more extended 
work, "An Introduction to Entomology," and by other works of somewhat 
similar character. 

The writer acknowledges with gratitude, the interest and hearty aid 
of his colleagues, notably that of Dr. O. A. Johannsen who compiled the 
simplified table of the Diptera and who read the manuscript on that 
order; that of Dr. W. T. M. Forbes who formulated the shorter table of 
the Lepidoptera and also read and criticised the text treating of this 
order; that of Dr. J. C. Bradley with the Hymenoptera; and of Dr. 
J. G. Needham from whose' papers and works on the aquatic forms the 
writer has drawn freely. 

Some of the old figures of the Manual have been omitted, notably 
several of those illustrating wing- venation. The need of these is not so 
great at this time for the Comstock-Needham system of naming the 
wing- veins of insects is now thoroughly established and familiar to stu- 
dents and teachers of entomology. Many new figures have been added. 
The writer is indebted to Doubleday, Page and Company for permission 
to use figures 11, 21, 23, 24, 25, 27, 28, 29, and 35, from the "Spider 
Book" by J. H. Comstock, to H. Holt and Company, for figures 270, 
302, and 564, from the "Manual of Injurious Insects," by Glenn W. 
Herrick, to MacMillan Company for figures 13, 30, and 510, from Her- 
rick's "Insects Injurious to the Household" and to Dr. Grace H. Gris- 
wold for figure 598a. 

Glenn W. Herrick 

Ithaca, N.Y. 
Dec. 2, 1929. 


■ • (1 * • 


CONTENTS 

CHAPTER PAGE 

I. Insects and their near relatives: Branch Arthropoda; Class 
Crustacea, Crabs, Lobsters, Crayfish, and others; Class Arach- 
nida, Spiders, Scorpions, Mites, and others; Class Diplop- 

ODA, millipedes; and Class Chilopoda, centipedes I 

II. Class Hexapoda or Insects: characteristics of the class; meta- 
morphoses of insects; external anatomy of insects; internal 
anatomy of insects; table for determining the orders of insects; 

list of the orders of insects 22 

III. Order Thysanura, Bristle-tails, Fish-moths, and others 45 

IV. Order Collembola, Spring-tails 47 

V. Order Orthoptera, Cockroaches, Crickets, Grasshoppers, Locusts, 

and others 49 

VI. Order Zoraptera 62 

VII. Order Isoptera 63 

VIII. Order Neuroptera, the Dobson, Aphis-lions, Ant-lions, and 

others 66 

IX. Order Ephemerida, Mayflies 74 

X. Order Odonata, Dragonflies 77 

XL Order Plecoptera, Stoneflies 81 

XII. Order Corrodentia, Book-lice and others 83 

XIII. Order Mallophaga, Bird-lice 85 

XIV. Order Embiidina 87 

XV. Order Thysanoptera,. Thrips 89 

XVI. Order Anoplura, Sucking Lice 92 

XVII. Order Hemiptera, Bugs 94 

XVIII. Order Homoptera, Plant-lice, Scale-insects and others 109 

XIX. Order Dermaptera, Earwigs 125 

XX. Order Coleoptera, Beetles 127 

XXL Order Strepsiptera, Stylopids 176 

XXII. Order Mecoptera, Scorpion-flies and others 178 

XXIII. Order Trichoptera, Caddice-flies 180 

XXIV. Order Lepidoptera, Moths, Skippers, and Butterflies 183 

XXV. Order Diptera, Flies 286 

XXVI. Order Siphonaptera, Fleas 326 

XXVII. Order Hymenoptera, Bees, Wasps, Ants, and others 329 

Index 385 


12 793 


EXPLANATION OF PLATES 
PLATE I. (Frontispiece) 

FIGURE PAGE 

1. The Carpet Beetle 150 

2. The Twelve-spotted Diabrotica 165 

3. The Adalia bipunctata 153 

4. The Silver-spotted Skipper 260 

5. The American Copper 283 

6. The Red Admiral 270 

7. The Painted Beauty 270 

PLATE II. (Page 34) 
The internal anatomy of a caterpillar. 

PLATE III. (Page 35) 
The internal anatomy of a cockroach. 


CHAPTER I 


INSECTS AND THEIR NEAR RELATIVES 


PHYLUM ARTHROPODA 

The Arthropods 

Zoologists recognize at least twelve great groups or phyla of animals, 
— Protozoa (one-celled animals), Porifera (sponges), Ccelenterata (hy- 
dras, sea-anemones), Platyhelminthes (flatworms), Nemathelminthes 
(roundworms), Trochelminthes (rotifers), Molluscoidea 
(lampshells) , Annulata (earthworms, et al.), Echinoder- 
mata (starfish), Mollusca (clams, oysters), Arthropoda 
(spiders, insects), and Chordata (fishes, birds, mam- 
mals). In organization and development the phylum 
Arthropoda, stands high in the series as indicated in the 
foregoing linear arrangement. Indeed, the arthropods 
stand next to the fishes, reptiles, birds and mammals, 
the highest forms in the animal kingdom. 

If an insect, a spider, a scorpion, a centipede, or a 
lobster be examined, the body will be found to be com- 
posed of a series of more or less similar rings or seg- 
ments joined together; and some of these segments 
will be found to bear segmented legs (Fig. i). All the 
animals possessing these characteristics are classed to- 
gether as the phylum Arthropoda. 

A similar segmented form of the body is found 
among worms; but these are distinguished from the 
arthropods by the absence of legs. It should be re- 
membered that many animals commonly called worms, 
as the tomato-worm, apple-worm, etc., are not true 
worms, but are the larvae of insects (Fig. 2). The earthworm is the 
most familiar example of a true worm. 

In the case of certain arthropods the distinctive characteristics of the 


Fig. 1. — An insect 
showing segmented form 
of body. 


Fig. 2. — Larva of butterfly, Papilio thoas. 


phylum are not evident from a cursory examination. This may be due to 
a very generalized condition; but in most instances it is due to a second- 


THE STUDY OF INSECTS 


Fig. 3. — An Itch-mite: a, from 
below; b, from above. 


ary modification of form, the result of adaptation to special modes of 
life. Thus the segmentation of the body may be obscured, as in spiders 

and in mites (Fig. 3); or the jointed appen- 
dages may be absent, as in the larvae of flies, 
of bees, and of many other insects. In all of 
these cases, however, a careful study of the 
structure of the animal, or of its complete life- 
history, or of other animals that are evidently 
closely allied to it removes any doubt regarding 
its being an arthropod. 

The phylum Arthropoda is the largest of 
the phyla of the animal kingdom, including many more known species 
than all the other phyla taken together. This vast assemblage of ani- 
mals includes forms differing widely in structure, all agreeing, however, 
in the possession of the essential characteristics of the Arthropoda. Several 
distinct types of arthropods are recognized ; and those of each type are 
grouped together as a class. 

The number of distinct classes that should be recognized, and the 
relation of these classes to each other are matters regarding which there 
are still differences of opinion; we must have much more knowledge 
than we now possess before we can speak with any degree of certainty 
regarding them. Some authorities recognize thirteen classes of arthro- 
pods; but since most of them contain forms which are rarely seen by 
most students only the more common representatives will be discussed. 
These are distributed among the following classes: Crustacea, Arachnida, 
Dipjopoda, Chilopoda, and Hexapoda. 


Class CRUSTACEA 


The Crustaceans 

The members of this class are aquatic arthropods, which breathe by true 
gills! They have two pairs of antenna 
and at least five pairs of legs. The 
position of the openings of the reproduc- 
tive organs varies greatly; but as a ride 
they are situated far forward. 

The most familiar examples of the 
Crustacea are the cray-fishes, the 
lobsters, the shrimps, and the crabs. 
Cray-fishes (Fig. 4) abound in our 
brooks, and are often improperly 
called crabs. The lobsters, the 
shrimps, and the true crabs live in 
salt water. 

The Crustacea are distinguished 
from nearly all other arthropods by 
their mode of respiration, being the 
only ones that breathe by true gills. 
Many insects live in water and are 
furnished with gill-like organs; but 
these are either tracheal gills or blood- 


FlG. 4. — A Cray-fish. 


INSECTS AND THEIR NEAR RELATIVES 3 

gills, organs which differ essentially in structure from true gills, as de- 
scribed later. The Crustacea also differ from other Arthropoda in having 
two pairs of antennae. Rudiments of two pairs of antennae have been 
observed in the embryos of many other arthropods; but in these cases 
one or the other of the two pairs of antennae fails to develop. 

The examples of crustaceans named above are the more conspicuous 
members of the class; but many other smaller 
forms abound both in the sea and in fresh water. 
Some of the more minute fresh-water forms are 
almost sure to occur in any fresh-water aquarium. 

In Figure (5) are represented three 

of these enlarged. The minute 

crustaceans form an important b, Y Cydop7i?, T Daphn?a. a,Cypris; 

element in the food of fishes. 

Some crustaceans live in damp places on land, and are 

often found by collectors of insects; those most often ob- 
Fig. 6. — a Sow- served are the sow-bugs (Oniscoida), which frequently 
bug " occur about water-soaked wood. ~ Figure (6) repre- 

sents one of these. 

Class ARACHNIDA 
Scorpions, Harvestmen, Spiders, Mites, and others 

The members of this class are air-breathing arthropods , in which the 
head and thorax are usually grown together, forming a cephalothorax, which 
has four pairs of legs, and which apparently has no antennas. The reproduc- 
tive organs open near the base of the abdomen. 

The Arachnida abound wherever insects occur, and are often mistaken 
for insects. But they can be easily distinguished by the characters given 
above, even in those cases where an exception occurs to some one of 
them. The more important of the exceptions are the following: in one 
order, the Solpugida, the head is distinct from the thorax; as a rule the 
young of mites have only six legs, but a fourth pair is added during 
growth; and in the gall-mites there are only four legs. 

The Arachnida arc air-breathing; but it is believed that they have 
been evolved from aquatic progenitors. Two forms of respiratory organs 
exist in this class: first, book-lungs; and second, tubular tracheae. Some 
members of it possess only one of these types; but the greater number 
of spiders possess both. 

The Arachnida lack true jaws. Therefore they do not masticate their 
prey and swallow the parts. They crush their victims and suck out the 
juices. The first pair of organs on the cephalothorax constitutes the 
principal crushing organs. They are modified antennae and are known as 
chelicerae. Other appendages, however, may aid in the crushing process. 
Each one of the second pair of appendages just behind the chelicerae 
is leglike in form. These are known as the pedipalps. Following the 
pedipalps are the four pairs of legs. Thus the cephalothorax of the 
Arachnida bears six pairs of appendages. The Arachnida have only 
simple eyes. 

The more familiar forms of this class are the scorpions, harvestmen, 
spiders, and mites. 


4 THE STUDY OF INSECTS 

Order PEDIPALPIDA 

The II 7/ ip -scorpions 

These strange creatures are found in our country only in the extreme 
southern part for they are tropical animals; but they are distributed 
from the Atlantic to the Pacific. In their general form they bear some 

resemblance to the scorpions; but 
they can be easily distinguished from 
the scorpions by the form of the first 
pair of legs and of the post-abdomen. 
The front legs are greatly elongated 
(Fig. 7) and have the tarsi broken 
up into many small slender segments 
giving this part of the leg a whip-lash- 
like appearance. In addition, the 
members of one family have the 
caudal end of the abdomen furnished 
with a slender, many-segmented ap- 
pendage resembling a tail. These 
forms are known as the " tailed whip- 
scorpions" (Fig. 7). There is, how- 
ever, but one species of this family 
in the United States, the giant tailed 
whip-scorpion, Mastigoproctus gigan- 
teus, which, when full-grown, attains 
a length of from four to five inches 
(Fig. 7). Its bite is said to be poison- 
ous but direct, authentic evidence of 
its supposed venomous quality is lack- 
ing. This species burrows in sand 
under logs or other objects lying on the ground ; it doubtless feeds on any 
insects that it can capture. 

There is another family of these creatures known as the tailless whip- 
scorpions because the individuals lack the tail-like appendage of the ab- 
domen so conspicuous in the tailed species. The front legs, however, of 
these tailless forms are even more whip-lash-like in appearance than those 
of the giant whip-scorpion but the body is relatively shorter and broader. 
There are only four species of this family found in this country and these 
are in the extreme South. They are smaller than the giant whip- 
scorpion. 

There is a third family represented by a single species in the United 
States Trithyreus pentapeltis, which is less than one-half an inch in length. 
It lives in the desert regions of Southern California. 


Fig. 7. — Mastigoproctus giganteus. 


Order SCORPIONIDA 

The Scorpions 

The scorpions (Fig. 8), have the body divided into a compact, un- 
segmcntcd cephalothorax, and a long, segmented abdomen. The ab- 
domen is divided into two portions: a broad pre-abdomen, consisting of 


INSECTS AND THEIR NEAR RELATIVES 


seven segments; and a slenderer tail -like division, the post-abdomen, 
consisting of five segments. At the end of the post-abdomen there is a 
large poison-sting, which appears like a segment. 
The chelicerae and the pedipalpi are provided with 
pincers. The pedipalpi resemble in a striking man- 
ner the great claws of lobsters. The cephalothorax 
bears from three to six pairs of eyes. Scorpions 
breathe by means of lung sacs, of which there are 
four pairs, opening on the lower side of the third 
to the sixth abdominal segments. 

Full-grown scorpions possess a pair of comb-like 
organs on the lower side of the second abdominal 
segment. The function of these organs may be 
tactile. 

The sexes of scorpions differ in that the male has 
broader pincers and a longer post-abdomen. Scor- 
pions do not lay eggs, the young being developed 
within the mother. After the birth of the young, 
the mother apparently shows great regard for them, 
carrying them about with her for some time, at- 
tached by their pincers to all portions of her body. 

Scorpions live in warm countries. They are com- 
mon in the southern portion of the United States, 
but are not found in the North. They are nocturnal, remaining concealed 
during the day, but leaving their hiding-places at dusk. When they run 
the post-abdomen of some species is bent upwards over the back. They 
feed upon spiders and large insects, which they seize with the large pin- 
cers of their palpi, and sting to death with their caudal poison sting. 

The sting of a scorpion rarely if ever proves fatal to a grown man, 
although the larger species, which occur in the Tropics, produce serious 
effects by their stings. 


Fig. 8. — A Scorpion. 


Order PSEUDOSCORPIONIDA 

The Pseudoscorpions 

The pseudoscorpions are small arachnids which resemble scorpions in 
the form of their pedipalps and of their body, except that the hind part 
of the abdomen is not narrow, as is the post-abdomen of scorpions, 
and they have no caudal sting. The abdomen is broad, 
flat, and thin and only one or two pairs of eyes are present 
on the cephalothorax. 

The pedipalps are enormously developed and are chelate, 
resembling those of the scorpions (Fig. 9). The pseudoscorp- 
ions are especially interesting because they possess silk glands 
in the cephalothorax which open near the tip end of each 
chelicera. The silk which they spin is used for making a 
fig. 0. — a Pseu- web or cocoon in which the pseudoscorpion can retreat dur- 
ing the moulting period and during the winter. 
There are many species of pseudoscorpions in the United States, found 
in the North as well as in the South. They live under stones, beneath 
the bark of trees, in moss, under leaves on the ground, in the nests of 


6 THE STUDY OF INSECTS 

bees, of ants, and of termites and in households where they are often 
found between the leaves of books. It is believed that they live on mites 
and minute insects. They are often found attached to flies and beetles 
and according to one observer they sometimes kill the flies and eat them. 

Order PHALANGIDA 
The Harvestmen, or Daddy-long-legs 

The harvestmen are very common in most parts of the United States. 
They are well known to children in this country under the name daddy- 
long-legs, but as this name is also sometimes applied to crane-flies, har- 
vestmen is preferable. In some sections of the country the harvestmen 
are known as grandfather graybeards. 

Most harvestmen can be recognized by their very long and slender 


Fig. io — The Striped Harvestman 


legs (Fig. io) although some species have comparatively short ones. The 
cephalothorax is indistinctly if at all segmented. The abdomen is short, 
broad, consists of nine segments, and is without a tail-like appendage; it 
is broadly joined to the cephalothorax. 

The eyes of the harvestmen are two in number, and are situated on a 
prominent tubercle near the middle of the cephalothorax. The chelicerae 
are pincer-like. Their pedipalpi are four-jointed, and are small compared 
with the pedipalpi of the preceding orders; they resemble in form the 
palpi of insects. The members of this order breathe by tracheae, which 
open by a single pair of spiracles, on the lower side of the body at the 
junction of the cephalothorax and abdomen. 

There seems to be some uncertainty regarding the food of harvestmen. 
Some writers say they live on dead insects while others aver that they 
feed on live aphids and other small insects. It seems clear that they 
also suck the juices of fruits and soft vegetables. 

In the North most harvestmen die in the autumn after they have 
deposited eggs under stones, or in crevices or in the ground. These eggs 
do not hatch until the following spring. In the South more of the adults 
hibernate under rubbish during the winter. 

No silk glands have been found in the harvestmen and they do not 
make webs like the spiders. 

Order ARANEIDA 

The Spiders 

The spiders differ from other Arachnida in having the abdomen un- 
segmented and joined to the cephalothorax by a short, narrow stalk. 


INSECTS AND THEIR NEAR RELATIVES 


The cephalothorax is also unsegmented ; and the abdomen bears at its 
end organs for spinning silk (Fig. n). 

The cheliceras (Fig. 12, md) consist of two segments, a strong basal 
one and a claw-shaped terminal 
one, at the tip of which a poison 
gland opens (Fig. 13). It is by 
means of these organs that spiders 
kill their prey. The pedipalpi are 
leg-like in form, but differ greatly 
according to sex. In the female 
the last segment of the pedipal- 
pus resembles a foot of the spider, 
and is usually armed with a well- 
developed curved claw. But in 
the male the corresponding seg- 
ment is more or less enlarged, and 
very complicated in structure 
(Fig. 14). The greater number of 
spiders have four pairs of eyes, but 
there may be only one, two, or 
three pairs; and certain cave 
spiders are blind. Spiders breathe by means of lung-sacs, of which there are 
one or two pairs ; and some have tracheae also. The lung-sacs open on the 


Fig. 11. — The banana spider showing division of body 
into cephalothorax and abdomen. 


Fig. 12. — Lower side 
of cephalothorax of a 
spider; md, chelicera; 
mx, maxilla; p, paipus; 
/, lower iip; s, sternum. 


Fig. 13. — Chelicera of a spider: p, 
poison gland; d, duct; o, opening at 
tip of fang; /, fang. 


Fig. 14. — Maxilla 
and palpus of male 
house-spider. 


Fig. 15. — End of abdomen 
of spider, showing six spinn-r- 
ets spread apart; in front of 


lower side of the abdomen near its base, 
and between them is the opening of the 
reproductive organs . The tracheae open 
through a single spiracle near the hind 
end of the body, usually just in front 
of the spinning organs. 

The spinning organs, which are sit- FlG l6 _ A Rroup 
these'^Thesp^cie.'and'behind uated near the end of the abdomen, of spinning tubes, 
them the opening of the aiimen- CO nsist of one or two or three pairs of gI 

tary canal. . l , . . 

spinnerets. These appendages (tig. 15) are more or 
less finger-like in form, and sometimes jointed. Upon the end of each spin- 
neret there are many small tubes, the spinning tubes, from which the silk is 
spun (Fig. 16). Some spiders have one hundred or more of these spinning- 


8 THE STUDY OF INSECTS 

tubes on each spinneret. The silk is in a fluid state while it is within 
the body, but it hardens as soon as it comes in contact with the air. 

Ordinarily the tips of the spinnerets are brought close together, so that 
all the minute threads that emerge from the numerous spinning tubes 
mite to form a single thread. This, however, may be so delicate as to be 
invisible, except in a favorable light. Sometimes a spider will spread its 
spinnerets apart, and thus spin a broad ribbon-like band. We have 
observed a spider seize a large grasshopper which was entangled in its 
web, and, rolling it over two or three times, completely envelop it in a 
sheet of silk spun from its spread-apart spinnerets. 

In the construction of their webs the orb- weaving spiders make use of 
two kinds of silk. One of these is dry and inelastic ; the other, viscid and 
elastic. This fact can be easily seen by examining an orb web. If the 
spiral line which forms the greater part of the web be touched, it will ad- 
here to the finger, and will stretch, when the finger is withdrawn, to several 
times the original length. But if one of the radiating lines or a portion of 
the outer framework be touched, it will neither adhere to the finger nor be 
stretched. If the spiral line be examined with a lens, it will be found to 
bear numerous bead-like masses of viscid matter (Fig. 17); 

~H-~ ~\^ this explains its adhesiveness. 

^-4 — - — — V"~ It is supposed that the two kinds of silk are spun from 

—J. \^ different spinnerets. When this silk is first spun the viscid 

matter forms a continuous layer of liquid on the outside of 

fig. 17.— viscid silk ft g u t verv soon this layer breaks up into 

from an orb web. , , ,-, • • -i 

the bead-like masses — ma way similar to \ 
that in which the moisture on a clothes-line on a foggy day 
collects into drops. 

Spiders of the two families Dictynidos and Uloboridce have FlG ™'"_ End of 
spinning organs differing from those of all other spiders, a b jj°™ e J? showin s cri - 
Thcy have in front of the usual spinnerets an additional 
organ, which is named the cribellum (Fig. 18). This bears spinning-tubes 
like the other spinnerets, but these tubes are much finer. These spiders 
C have also on the metatarsus of 

-^g^-^^^S^^^^^^^^#^ thc hind le S s one or . two TOW . s 
^^^^^^^^^^^^m^ of curved spines: this organ is 

^^^^^^^^^^^^^^^^^^^ the calamistrum (Fig. 19). By 

means of the calamistrum 

Fig. 19. — Metatarsus of hind leg of spider showing calamistrum, c. ,i SoiderS COmb from the 

cribellum a band of loose threads, which forms a part of their webs. 

Spiders make use of silk in the construction of their webs or snares, in 
the building of tubes or tents within which they live, in the formation of 
egg-sacs, and in locomotion. 

Figure 20 represents the large egg-sac of one of the orb weavers. This 
is made in the autumn, and contains at that season a large number of 
eggs — five hundred or more. These eggs hatch early in the winter; 
but no spiders emerge from the egg-sac until the following spring. If 
egg-sacs of this kind be opened at different times during thc winter, the 
spiders will be found to increase in size but diminish in _ number as the 
season advances. In fact, a strange tragedy goes on within these egg- 
sacs: thc stronger spiders calmly devour their weaker brothers, and in 
the spring those which survive emerge sufficiently nourished to fight their 
battles in the outside world. 


INSECTS AND THEIR NEAR RELATIVES 


The egg-sacs of the different species of spiders vary greatly in form. 
In some, as in that figured below, the outer covering is very dense, while 


Fig. 20. — Egg-sac of Argiope. 


Fig. 21. — Lycosa with thin egg-sac. 


in others the outer part consists of thin flossy silk (Fig. 21). One of the 
most common kinds is very flat, silvery in color, and is firmly attached 
to stones lying upon the ground (Fig. 22). 

Every one knows that a spider wishing to descend 
to some place beneath it simply fastens a line to the 
object which it is upon and then drops boldly off, regu- 
lating the rate of its descent by spinning the line 
rapidly or slowly; when the spider wishes to return, it 
has only to climb up the same line. 

Frequently spiders pass from point to point in a F IG - . ? 3 - — E es sac on 

, . 7 1 i- . • 1 r "11 i • 1 rr-M under side of a stone. 

horizontal direction by means of silken bridges. I hese 
are formed in this way: the spider spins out a thread, which is carried off 
by a current in the air. After a time the thread strikes some object and 
adheres to it; then the spider pulls the line tight, and fastens it where it 
is standing. It then has a bridge, along which it can easily run. 

But more remarkable than either of these uses of silk for locomotion is 
the fact that many spiders are able to travel long distances, hundreds of 
miles, through the air by means of these silken threads — 

"sailing mid the golden air 
In skiffs of yielding gossamere." — (Hogg.) 

The aeronautic spiders, or flying spiders, as they are more commonly 
called, are frequently very abundant, especially on warm autumn days. 
At such times innumerable threads can be seen streaming from fences, 
from bushes, and the tips of stalks of grass, or floating through the air. 
The flying spider climbs to some elevated point, which may be merely 
the tip of a stalk of grass, and then, standing on the tips of its feet, lifts 
its body as high as it can, and spins out a thread of silk. This thread is 
carried up and away by a current of air. When the thread is long enough 
the force of the air current on it is sufficient to buoy the spider up. It 
then lets go its hold with its feet and sails away. These spiders travel 
long distances over the sea far from land in this manner. 


IO 


THE STUDY OF INSECTS 


Representatives of thirty families of spielers are found in the United 
States but only a few common forms can be discussed here, those which 
best illustrate the habits of these most interesting animals. The spiders 
will, however, well repay one for further study of them. With the excep- 
tion of the hour-glass spider, common in the South and the tarantulas 
found in the Southwest, spiders are harmless creatures and as safe to 
observe and handle as beetles or ants. 


Family AViculariid^; 
The Tarantulas and the Trap-door Spiders 

Those who live in the warmer parts of our country know well the 
large spiders commonly called tarantulas. These are the giants among 
spiders, some of them being the largest known; but some species of this 
family are not very large. They arc dark-colored, hairy spiders, and can 
be distinguished from the other families mentioned here by the fact that 
the cheliceree work up and down instead of sidewise. 

The members of this family have various habits. Some live in the 
cracks of trees or under stones or rubbish on the ground or sometimes 
in a simple cell dug in the earth and lined with a slight web of silk. 
Others dig definite tunnels in the ground, line them with silk and in 
many cases close the opening with a door or lid. Others spin webs 
resembling those of the grass-spiders known as the funnel-web weavers. 

One of the best 
known of the tarantulas 
is Eurypehna hentzi. This 
species occurs in the 
southern and southwest- 
ern states, and is one of 
the largest of our spiders 
(Fig. 23). Several 
closely allied species are 

Fig. 23. - A Tarantula, Eurypdma hentzi. found in California. 

But the members of this family that have attracted most attention 
on account of their habits are the trap-door spiders. These dig a tube 
in the ground, as do many other members of this family; but thi s tube is 
lined with a denser layer of silk, and is provided 
with a hinged lid, which fits the opening of the 
tube with wonderful accuracy (Fig. 24). The 
spider hides in this nest when not seeking its 
prey. Some species take the precaution to build 
a branch to their nest, and to provide this 
branch with a door. As this door forms a part 
of one side of the main tube, it is not likely to 
be observed by any creature which may find 
its way past the first door of the nest. 

Several species of trap-door spiders occur in 
the southern and southwestern states. The hab- 
its of many of these spiders are not yet known. 
They should be studied much more. 


Fir.. 24. — Entrance to tunnel of 
trap-dooT spider. (From the Spider 
Book, Doubleday, Page and Co.) 


INSECTS AND THEIR NEAR RELATIVES 


ii 


Family Agelenid^e 
The Funnel-web Spiders 

Even the most careful observers seldom realize what an immense 
number of spider-webs are spun upon the grass in the fields. But oc- 
casionally these webs are made visible in the early morning by the dew 
which has condensed upon them. At such times we may see the grass 
covered by an almost continuous carpet of silk. 

The greater number of the webs seen at such times are of the form 
which we term funnel-webs. They consist of a concave sheet of silk, 
usually with a funnel-shaped tube at one side, and numerous lines extend- 


Fig. 25. — Web of Agelena. 

ing in all directions to the supporting spears of grass (Fig. 25). The 
tube serves as a hiding-place for the owner of the web; from this retreat 
the spider runs out on the upper surface of the web to seize any insect 
that alights upon it. The tube opens below, near the roots of the grass; 
so that the spider can escape from the web if a too formidable insect 
comes upon it. 

The funnel-web spiders are long-legged usually brownish individuals 
with the hind pair of spinnerets very long while the feet have three 
claws. The eyes of these spiders are eight in number and arranged in 
two rows. 

Probably the most common spider in our fauna is the grass-spider or 
funnel-web weaver (Agelena noma) whose webs are found everywhere 
during the summer spun on the grass. The webs are most conspicuous 
in the early morning when the dew has condensed on them. 

To this family also belongs the remarkable aquatic spider of Europe 
(Argyroneta aquatica) which lives among plants at the bottom of clear 
quiet ponds. It breathes air adhering to its body which it brings from 
above the surface of the water. 

Family Dictynid^e 

The Hackled-band Spiders with irregular webs 

Certain spiders are remarkable for using two kinds of silk in the for- 
mation of their webs. Thus, as explained later, the orbweavers build 


12 


THE STUDY OF INSECTS 


Fig. 26. — 
Curled thread of 
a Dictynid, en- 
larged. 


the framework of their orbs of dry and inelastic threads, and attach to 
this framework a thread which is sticky and elastic; while most spiders 
which make irregular webs use only one kind of silk. There are, how- 
ever, certain species of irregular web-weavers which use two kinds of 
silk. One of them is a plain thread like that spun by other spiders, and 
the other is a peculiar ribbon-like thread or band with curled threads 
running through it. This ribbon-like band with its curled threads we 
have called the hackled-band. 

The hackled-band weavers represent 
two families, one of which makes irregu- 
lar webs; the other, those which are of 
definite form. The first of these is the 
Dictynidag. 

The hackled-band is made in the same 
way by both families. It is composed of 
silk spun probably partly from certain of 
the spinnerets and partly 
from the cribellum (page 8); 
and is combed into its pecul- 
iar form by means of the 
comb of stiff hairs, the cala- 
mistrum, which is borne by 
the metatarsus of the hind 
legs (see page 8). In mak- 
ing the hackled-band the spider turns one 
of its hind legs under the abdomen so 
that the calamistrum is just under the 
spinnerets and makes a rapid combing 
motion. By the rapid combing motions 
of the hind legs the calamistrum finally 
combs out from the spinning-tubes a 
flat-thread and at the same time tangles 
through it some curled threads; but it is 
difficult to determine just how the 
hackled-bands are given their charac- 
teristic form and the whole process is 
not well understood. 

This band of tangled or curled threads 
is easily seen in the webs of these spiders, 
being wider than the ordinary threads 
and white in color. In old webs it becomes conspicuous by the large amount 
of dust which it collects. Figure 26 shows the appearance of this band when 
magnified, and the way in which it is attached to the plain threads. 

Our more common dictynids make webs of various shapes, on fences, 
under stones, in holes in rotten logs, and on plants. These webs are 
especially common among the flowers of golden-rod and other plants 
having clusters of small flowers (Fig. 27), and exhibit a slight degree of 
regularity. 


Fig. 27. — Web of dictynid. 


INSECTS AND THEIR NEAR RELATIVES 


13 


Family Uloborid^ 
The Hackled-band Spiders with regular webs 

We have already described the ribbon-like threads, or hackled-bands 
of the dictynids (p. 12), and the curious organs called cribellum and 
calamistrum, by which these curled threads are made (p. 8). Similar 
organs and a similar habit are possessed by the spiders of the family 
Uloboridae. These spiders, however, make webs which are regular in form. 
There are only two genera belonging to this family in the United States; 
but as the webs made by these are very different, we will describe both. 

The triangle spider, Hyptiotes cavatus. — This spider is common all 
over New England and the Middle States, and has been found as far to 
the Southwest as Texas. Its web is most often found stretched between 


Web of triangle spider. 


the twigs of a dead branch of pine or spruce. At first sight this web 
appears like a fragment of an orb web (Fig. 28); but a little study will 
show that it is complete. The accompanying figure, from a photograph 
of a web of the triangle spider spun between two dead twigs of a pine 
tree, illustrates the form of the web. It consists of four plain lines 
corresponding to the radiating lines of an orb web, and a series of double 
cross lines, which are spun by the cribellum and calamistrum. From the 
point where the radiating lines meet a strong line extends to one of the 
supporting twigs. Near this twig the spider rests, pulling the web tight 
so that there is some loose line between its legs, as shown in the enlarged 
figure. When an insect becomes entangled in one of the cross lines, the 
spider suddenly lets go the loose line so that the whole web springs for- 
ward, and the insect is entangled in other cross threads. The spider then 
draws the web tight and snaps it again. This may be repeated several 
times before the spider goes out upon the web after its prey. 


14 


THE STUDY OF INSECTS 


Uloborus. — The spiders of this genus make round webs which re- 
semble at first sight those of the orb weavers; but they differ from the 
ordinary orb webs in that the spiral thread is made of the hackled-band 
silk. These webs are nearly horizontal, and are usually made between 
stones or in low bushes. The spiders of this genus are not common, but 
they are widely distributed. 


Family Theridiidve 

The Comb-footed Weavers 

Many are the kinds of webs spun by different spiders. Some of them, 
as the orb webs and the funnel-webs, delight us with their wonderful 
regularity of form; while others appear to be a mere shapeless maze of 
threads. Such are the structures whose presence in the corners of our 
rooms torment thrifty housewives, and which arc disrespectfully termed 
cobwebs. The most common spinner of cobwebs is the abundant house- 
spider, Theridion tepidariorum, which spins its irregular webs composed 
of threads extending in all directions with no apparent regularity, in any 
convenient corner. The spider, which hangs in its web with its back 
downwards, will serve well as a representative of this family. 

These spiders have eight eyes and 
three tarsal claws. In addition, they 
have on the tarsus of the fourth pair 
of legs a distinct comb consisting of a 
row of strong, curved, and toothed 
setae (Fig. 29). As the presence of this 
tarsal comb distinguishes these spiders 
from all others, they may well be called 
the comb-footed spiders. The comb is 
used for flinging silk, often in a quite 
liquid state, over the entangled prey. 
Although the house-spiders are the most famil- 
iar members of this family, a large number of 
species spin their webs in the fields on bushes. 
These webs usually consist of a flat or curved 
sheet, under which the spider hangs back 
downward. This sheet is supported by threads 
running in all directions to the neighboring ob- 
jects. Frequently there is a large number of 
these supporting threads above the web, which 
serve the additional purpose of impeding the 
flight of insects, and causing them to fall into 
the web, where they are caught. A few species 
which do not live in webs and spin very little, 
are found under stones, or in the moss and 
leaves, and run with great rapidity. 

One spider of this family, Latrodcctits mac- 
lans, commonly known as the "black widow" 
or hour-glass spider is, outside of the tarantulas, the one poisonous spider 
in this country. It is a coal-black spider with a red marking in the form of 
an hour-glass on the underside of the abdomen (Fig. 30). The female is 


Fir,. 2Q. — Comb of Theridion; b, a tooth 
of comb, enlarged. (From the Spider Book, 
Doubleday, Page and Company.) 


Fig. ?o. — The hour glass spider. 
Ventral side aboye to show the red 

marking 


INSECTS AND THEIR NEAR RELATIVES 


15 


about one-half an inch in length. This spider is common all over the 
southern states and occurs as far north as Pennsylvania and Ohio, at least. 

Family Argiopid^e 
The Orb Weavers 

Few if any of the structures built by lower animals are more wonder- 
ful than the webs of orb-weaving spiders, but these beautiful objects are 
so common that they are often considered hardly worthy of notice. If 
they occurred only in some remote corner of the earth, every one would 
read of them with interest. 

The webs of the different species of orb weavers differ in the details of 
their structure, but the general plan is quite similar. There is first a 
framework of supporting lines. The outer part of this framework is 
irregular, depending upon the position 
of the objects to which the web is 
attached; but the more central part 
is very regular, and consists of a num- 
ber of lines radiating from the center 
of the web (Fig. 31). All of these sup- 
porting lines are dry and inelastic. 
But there is spun upon the radiating 
lines in a very regular manner a thread 
which is sticky and elastic (Fig. 17, 
p. 8). Usually this sticky thread is 
fastened to the radiating lines so as to 
form a spiral, but a few species make 
webs in which this thread is looped 
back and forth. 

Many of the orb weavers 
strengthen their webs by spinning a 
zigzag ribbon across the center. This 
ribbon is made by spreading the 
spinnerets apart so that the minute 
threads from the spinning-tubes do not unite to make a single thread, as 
is usually the case. 

Some of the orb weavers live in their webs hanging head downward, 
usually near the center of the web; others have a retreat near one edge 
of the web, in which they wait for their prey. While resting in these 
retreats they keep hold of some of the lines leading from the web, so 
that they can instantly detect any jar caused by an entrapped insect. 

When an insect in its flight touches one of the turns of the sticky 
line, the line sticks to it; but it stretches so as to allow the insect to 
become entangled in other turns of the line. If it were not for this elas- 
ticity of the sticky line, most insects could readily tear themselves away 
before the spider had time to reach them. 

In making its web an orb weaver first spins a number of lines extend- 
ing irregularly in various directions about the place where its orb is to be. 
This is the outer supporting framework. Often the first line spun is a 
bridge between two quite distant points. This is done as described on 
p. 9. Having a bridge across the place where the web is to be, it is an 


Fig. 31. — Partially completed web of Argiope. 


j 6 THE STUDY OF INSECTS 

easy matter for the spider to stretch its other lines where it wishes them. 
In doing this it fastens a thread to one point, and then walks along to 
some other point, spinning the thread as it goes, and holding it clear of 
the object on which it is walking by means of one of its hind legs. When 
the second point is reached the thread is pulled tight and fastened in 

place. 

After making the outer framework the radiating lines are formed. A 
line is stretched across the space so as to pass through the point which is 
to be the center of the orb. In doing this the spider may start on one 
side, and be forced to walk in a very roundabout way on the outer frame- 
work to the opposite side. It carefully holds the new line up behind it as 
it goes along, so that it shall not become entangled with the lines on 
which it walks; one or both hind feet serve as hands in these spinning 
operations. The spider then goes to the point where the centre of the orb 
is to be, and fastening another line there, it walks back to the outer 
framework, and attaches this line an inch or two from the first. In this 
way all of the radiating lines are drawn. The next step is to stay these 
radii by a spiral line which is begun at the center, and attached to each 
radius as it crosses it. The turns of this spiral are as far apart as the 
spider can conveniently reach, except at the center of the w r eb. All of the 
threads spun up to this stage in the construction of the web are dry and 
inelastic. The spider now proceeds to stretch upon this framework a 
sticky and elastic line, which is the most important part of the web, the 
other lines being merely a framework to support it. In spinning the 
sticky line the spider begins at the outer edge of the orb, and passing 
around it fastens this line- to each radius as it goes. Thus a second spiral 
is made. The turns of this spiral arc placed quite close together, and the 
first spiral, which is merely a temporary support, is destroyed as the 
second spiral progresses. Figure 3 1 represents a web in which the second 
spiral is made over the outer half of the radii. In this figure, aa repre- 
sents the temporary stay-line; 66 the sticky spiral; and cc the fragments 
of the first spiral hanging from the radii. 

The orb weavers arc 1 three-clawed, eight-eyed, sedentary spiders. The 
tarsi are more or less clothed with hairs; but they lack the comb charac- 
teristic of the Theridiidae. They are fairly common, many of our large 
garden spiders being common representatives. 

Family Thomisid^; 
The Crab Spiders 

There arc certain spiders which are called crab spiders, on account of 
the short and broad form of the body, and the curious fact that they 
can walk more readily sidewise or backward than forward. 

These spiders spin no webs, but lie in wait for their prey. They live 
chiefly on plants and fences, and in the winter hide in cracks and under 
stones and bark. Most of the species are marked with gray and brown, 
like the bark upon which they live. Some species conceal themselves in 
flowers, where they lie in wait for their prey. These are brightly colored, 
like the flowers they inhabit; so that insects visiting flowers may alight 
within reach of a spider before seeing it. 

In this family the legs arc turned outward and forward more than 


INSECTS AND THEIR NEAR RELATIVES 


17 


Fig. 32. — Misumena valia. 


downward; so that the body is carried close to the ground. The legs of 
the second pair are as long as or longer than those of the fourth pair. 
The eyes are small, nearly equal in size, and arranged in two rows. 

One of the best-known members of 
this family is the female of Misumena 
vdtia, which is frequently found in 
flowers (Fig. 32). She is remarkable 
for the change in the color of her body 
which takes place when she migrates 
from one flower to another of different 
color. In the spring the female frequents 
the white flowers of trillium, fleabanc, 
and other plants. She then has a ground 
color of white. Later in the season when 
she migrates to golden-rod or other yel- 
low flower her body becomes yellow in 
color. 

Family Lycosid^ 

The Running Spiders 

Every collector of insects who has searched for specimens under stones 
and logs is familiar with the large, dark-colored, hairy spiders often 
found in these places. These spiders frequently attract especial attention 

by dragging after them a 

large _ gray ball (Fig. 33); 

this is the egg-sac, which 

the female carries about 

with her attached to her 

spinnerets. These spiders 

run swiftly; and as they 

depend on the use of their 

legs for the capture of their prey, they are well termed running spiders. 

These spiders resemble in general appearance and in habits the 

tarantulas of the South and the West. But none of our species attain 

the great size of some of the tarantulas, and in the running spiders the 

claw of the chelicerae moves horizontally 
instead of vertically. 

In this family the body is hairy and 
usually much longer than broad. The eyes 
differ markedly in size, and are arranged in 
three rows. The larger eyes arc not in the 
front row. The legs are rather long and 
quite stout. 

Like the tarantulas, some of the running 
spiders build tubular nests in the ground, 
which they line with silk. Sometimes the 
entrance to these nests is concealed by small 
sticks and leaves, and sometimes the spider 
builds a regular turret over the entrance of 
■ its tube (Fig. 34). These nests are used 
mostly as retreats. A few species spin webs. 


Fig. 33. — Lycosa and egg-sac. 


Fig. 34. — Fntrnnce t 
spider, Lycosa. (After Marx.) 


1 8 THE STUDY OF INSECTS 

The larger members of our common species belong to the genus 
Lycosa. These drag after them their egg-sacs as described above; and 
when the young hatch they climb on their mother's back, and are carried 
about for a time. Whether the mother provides nourishment or not for 
the young during this period has not been definitely determined. 


Family Attid^e 
The Jumping Spiders 

The jumping spiders are of medium size, with a short body and short 

stout legs (Fig. 35). They are common on 
plants, logs, fences, and the sides of buildings. 
They are very apt to attract attention by 
their peculiar appearance; their short stout 
legs, bright colors, conspicuous eyes, and 
quick, jumping movements being very differ- 
ent from those of ordinary spiders. 

The eyes are arranged in three rows; 
those of the front middle pair are the largest, 
and are very conspicuous. These self-pos- 
sessed spiders are able to stare an ordinary 
observer out of countenance. They move 
sidewise or backward with great ease, and can 
jump a long distance. They make no webs 
except nests in which they hide in winter or 
when moulting or laying eggs. They are 
hunters, pursuing their prey or springing upon 
it when it comes near them. 

In certain members of this family the 
body is longer than in the typical forms, and 


. — A jumping spider, Salti- 
(From the Spider Book, 
Doubleday, Page and Company.) 


ant-like in appearance. 


Order ACARINA 
The Mites 


In this order the abdomen is unsegmented and broadly and closely 
joined with the thorax usually giving the entire body a more or less sac- 
like appearance. In many members of this order the body is divided into 
two regions which resemble the cephalothorax and abdomen of other 
arachnids but really the regions are not the same in their structure and 
make up. In many mites the body is marked by numerous transverse, 
fine lines, which are so impressed as to appear like the divisions between 
minute segments (Fig. 38). 

As a rule the cheliceras are of characteristic form and often chelate but 
in many of the mites and ticks they are modified into slender, nccdle-like 
organs, fitted for piercing and sucking. 

As in most arachnids the normal number of legs is eight but almost 
always the newly-hatched young have only six legs (3 pairs) while the 
adult members of the gall-mites, family Eriophyidce, have but two pairs 
of legs. With the exception of a few species the mites reproduce by 
laying eggs. 


INSECTS AND THEIR NEAR RELATIVES 


19 


The majority of mites are very small but a few, especially the ticks, 
are of considerable size. The mode of life of the different members of 
this order varies greatly; some are parasitic upon animals; others infest 
living plants; and many feed upon dead animal or vegetable matter, 
thus acting as scavengers. 

Among the mites that are parasitic upon animals are the various ticks, 


Fig. 36. — The southern 
cattle-tick, Bnophilus annulaius. 


Fig. 37. — An Itch-mite: 
below; b, from above. 


a, from 


which are very common in the warmer parts of our country. The com- 
mon cattle-tick (Fig. 36) of the southern states is a very injurious parasite 
of cattle because it not only sucks the blood of its host but it carries from 
one animal to another the organism which causes a serious fever among 
the cattle known commonly as Texas-fever but more properly splenic 
fever. 

The itch-mite is a well-known parasite, infesting man and causing 
the disease known as itch. The sensation characteristic of this disease 
is due to the burrowing of the mites in the skin; and the efficiency of 
sulphur ointment in checking this disease is due to the fact that by the 
use of it the mites are killed. Figure 37 represents an itch-mite greatly 
enlarged. 

Parasitic mites are frequently found attached to insects; a common 
species occurs beneath the wings of locusts. 

The best known of the mites that infest plants is the one commonly 
called the red spider. This lives upon house-plants; and in the warmer 
parts of the country, it infests fruit-trees, cotton, and other plants in 
the open air. On house-plants and in the greenhouse it can be subdued 
by a liberal use of water. 

Some of the mites that infest 
plants produce galls. These galls are ^x J*s?£$firi 

of various forms, but differ from those 
produced by gall-flies (Family Cynip- 
idce of the Order Hymenoptera) in 
having open mouths, from which the 
young mites escape. 

A common disease of the pear, 
caused by the pear-leaf blister-mite, 
is produced by a four-legged mite Phyllocoptes pyrl, (Fig. 38). The blisters 
characteristic of the disease are swellings of the leaf, within which there 


Fig. 38. — Phyllocoptes pyri, greatly enlarged. 


20 


THE STUDY OF INSECTS 


is a cavity affording a residence for the mites. Figure 39 represents a 

section of a leaf through one of these galls. Here the leaf is seen to be 

greatly thickened at the dis- 
eased part. On the lower side 
there is an opening through 
which the mite that started 
the gall entered, and from 
which young mites developed 
in the gall can escape, in order 
to start new galls. The in- 
fested leaves become reddish 
in color but finally turn black 
and drop off. Badly infested 
trees fail to develop good fruit 
and buds are not produced for 
the succeeding crop. Apple 

trees are also badly infested by this mite. The mite can be controlled 

by spraying the trees with lime-sulphur solution in the early spring before 

the buds burst. 

Among the scavenger mites there are some that infest food products. 

Thus mites arc sometimes found in cheese, in sugar, and in preserved 

meats. 


Fig. 39. — Diagram of gall of PhyUocoples pyri: g, gall; 
normal structure of leaf; o, opening of gall; e, eggs. 
Soraur). 


n, n, 
(After 


Class DIPLOPODA 
The Millipedes or Diplopods 

The members of this class are air-breathing arthropods in which the head 
is distinct, and the remaining segments of the body form a continuous region. 
The greater number of the body-segments are so grouped that each apparent 
segment bears two pairs of legs. The antenna are short and very similar to 
the legs. The openings of the reproductive organs are paired, and situated 
behind the second pair of legs. 

The Diplopoda and the Chilopoda were formerly grouped together in 
the class, Myriapoda. But this grouping has been abandoned, because it 
has been found that the Chilopoda are more closely allied to the insects 
than they are to the Diplopoda. Owing to the very general and long 
continued use of the term Myriapoda, the student who wishes to look up 
the literature on these two classes should consult the references under 
this older name. 

The most distinctive feature of the millipedes is that which sug- 
gested the name Diplopoda for the class, the fact that throughout the 
greater part of the 
length of the body 
there appear to be 
two pairs of legs 
borne by each seg- 
ment (Fig. 40). 

This apparent 


Fig. 40. — A millipede, Spirobolus marginatus. 

doubling of the legs is due to a grouping of the segments in pairs and cither 
a consolidation of the tcrga of each pair or the non-development of one 
of them; which alternative is the case has not been definitely determined. 


INSECTS AND THEIR NEAR RELATIVES 21 

Most of our more common millipedes possess stink-glands, which 
open by pores on a greater or less number of the body-segments. These 
glands are the only means of defence possessed by millipedes, except the 
hard cuticula protecting the body. 

The millipedes as a rule are harmless, living in damp places and feed- 
ing on decaying vegetable matter; but there are a few species that occa- 
sionally feed upon growing plants. 


Class CHILOPODA 
The Centipedes or Chilopods 

The members of this class are air-breathing arthropods in which the head 
is distinct, and the remaining segments of the body form a continuous region. 
The numerous pairs of legs are not grouped in double pairs, as in the 
Diplopoda. The antennce are long and many-jointed. 
The appendages of the first body-segment are jaw- 
like and function as organs of offense, the poison 
jaws. The opening of the reproductive organs is in 
the next to the last segment of the body. 

The animals constituting the class Chilopoda 
are commonly known as centipedes. They vary 
to a considerable degree in the form of the body, 
but in all except a few forms the body-segments 
are distinct, not grouped in couples as in the dip- 
lopods (Fig. 41). They are sharply distinguished 
from the preceding class in the possession of poison- 
jaws and in having the opening of the reproduc- 
tive organs at the caudal end of the body. The 
body is usually flattened. 

Many species of centipedes are venomous. 
The poison glands open through the appendages 
of the first body-segment. These organs are leg- 
like in form and are bent forward so as to act 
with the mouth -parts. These creatures abound 
in all parts of the United States ; those which are 
found in the North are comparatively small, and 
rarely, if ever, inflict serious injury to man; but 
the larger species, which occur in the warmer re- 
gions, are unquestionably venomous. 

The centipedes are predacious, feeding on in- 
sects; they usually live under stones, logs, and 
bark. There is one species, the house centipede, 
Scutigera forceps, which has fifteen pairs of very 
long legs and which is often present running on 
the walls of dwelling houses, especially in the 
warmer regions of the United States. It hunts 
for flies and other insects and appears to be harm- 
less to man. It prefers damp situations; in 
houses it is most frequently found 'in cellars, 
bathrooms, and closets. Sometimes it becomes 
very abundant in warm, moist conservatories. 


Fig. 41. — Scutigera forceps. 


CHAPTER II 

CLASS HEXAPODA 

The Insects 

The members of this class are air-breathing Arthropoda, with distinct 
head, thorax, and abdomen. They have one pair of antennce, threee pairs of 
legs, and usually one or two pairs of wings in the adult state. The opening 
of the reproductive organs is near the caudal end of the body. 

There are about us on every side myriads of tiny creatures that are 
commonly passed unnoticed, and even when observed, they are usually 
thought to be unworthy of serious consideration. But all life is linked 
together in such a way that no part of the chain is unimportant. Fre- 
quently the action of some of these minute beings seriously affects the 
material success or failure of a great commonwealth. The introduction 
and spread of a single species of insect (the cottony-cushion scale) in 
California threatened the destruction of the extensive orchards of that 
State; thousands of trees perished. The introduction of a few individuals 
of a particular kind of lady-bug (Rodolia cardinalis), which feeds upon 
this pest and multiplies rapidly, soon checked the pest, and averted the 
disaster. 

But insects are of interest to us for other reasons than the influence 
they may have upon our material welfare ; the study of them is a fruitful 
field for intellectual growth. It is not a small matter to be able to view 
intelligently the facts presented by the insect world, to know something 
of what is going on around us. And so extensive and complex is this 
field that no one gains more than a mere smattering concerning it. 

We know as yet comparatively little about the minute structure of 
insects; the transformations and habits of the greater number of species 
have not been studied; and the blood-relationship of the various groups 
of insects is very imperfectly understood. If, therefore, one would learn 
something of the action of the laws that govern the life and development 
of organized beings, and at the same time experience the pleasure de- 
rived from original investigation, he cannot find a better field than is 
offered by the study of insects. 

But it is not necessary that one should have the tastes and leisure 
required for careful scientific investigation in order to profit by this study. 
It can be made a recreation, a source of entertainment when we are tired, 
a pleasant occupation for our thoughts when we walk. Any one can find 
out something new regarding insect architecture — the ways in which 
these creatures build nests for themselves or for their young. It is easy 
to observe remarkable feats of engineering, wonderful industry, unremit- 
ting care of young, tragedies, and even war and slavery. 

The abundance of insects makes it easy to study them. They can be 
found wherever man can live, and at all seasons. This abundance is even 
greater than is commonly supposed. The number of individuals in a 


HEXAPODA 23 

single species is beyond computation: who can count the aphid s or the 
scale-insects in a single orchard, or the bees in a single meadow? 

Not only are insects numerous when we regard individuals, but the 
number of species is far greater than that of all other animals taken 
together. The number of species in a single family is greater in several 
cases than the number of stars visible in a clear night. 

The word insect is often applied incorrectly to any minute animal; 
but the term should be restricted to those forms possessing six legs and 
belonging to the class, Hexapoda. Thus spiders, which have eight legs, 
are not insects. 

The name Hexapoda is from two Greek words: hex, six; and pous, 
foot. It refers to the fact that the members of this order differ from 
other arthropods in the possession of only six feet. 

Insects breathe by means of a system of air-tubes (tracheae) which 
extends through the body. This is true even in the case of those that 
live in water and are supplied with gill-like organs (the tracheal gills; 
see p. 39). The head is distinct from the thorax, and bears a single pair 
of antennas; in these respects they are allied to the millipedes and centi- 
pedes although they are apparently more closely related to a small group 
of animals known as symphylids of the class, Sym phyla (see "An Introduc- 
tion to Entomology" by J. H. Comstock). 

They can be easily distinguished by the number of their feet, and, 
usually, also by the presence of wings. 

The Metamorphoses of Insects 

Nearly all insects in the course of their lives undergo remarkable 
changes in form. Thus the butterfly, which delights us with its airy 
flight, was at one time a caterpillar; the bee, which goes so busily from 
flower to flower, lived first the life of a clumsy, footless grub; and the 
graceful fly was developed from a maggot. 

In the following pages considerable attention will be given to descrip- 
tions of the changes through which various insects pass. It is our wish 
in this place merely to define certain terms which are used in describing 
these changes. 

Development without metamorphosis. — In two of the orders of insects, 
the Thysanura and Collembola, the young insect just hatched from the 
egg is of the same form as the adult insect. These insects. merely grow 
larger, without any more marked change in form than takes place in our 
own bodies during our life. They are said, therefore, to develop without 
metamorphosis. 

Incomplete or gradual metamorphosis. — There are many insects which 
undergo a striking change of form during their life, although the young 
greatly resembles the adult. Thus a young locust just out from the egg 
can be easily recognized as a locust. It is of course much smaller than 
the adult, and is not furnished with wings. Still the form of the body is 
essentially the same as that of the adult (Fig. 42). (The hair-line above 
the figure indicates the natural size of the insect.) After a time rudi- 
mentary wings appear; and these increase in size from time to time till 
the adult state is reached (Figs. 43 to 47). During this development 
there is no point at which the insect passes into a quiescent state corre- 
sponding to the chrysalis state of a butterfly. Those insects which, like 


24 


THE STUDY OF INSECTS 


the locust, when they emerge from the egg resemble in form the adult, 
but still undergo some change, are said to undergo an incomplete meta- 
morphosis. In other words, after leaving the egg they do not undergo a 
complete change of form. 

There are many other insects besides locusts which have an incom- 
plete metamorphosis. For example, crickets, cockroaches, aphids, the 
true bugs, cicadas, scale- insects, et al. 

The young of three orders of insects, the stoneflics (Plecoptera) , the 
mavrlies (Ephemerida) and the dragonflies (Odonata) are adapted for 


Fig. 42. — Nymph of Melanoplus, 
first stage. (After Emerton.) 


Fig. 45. — Nymph of Melanoplus, 
fourth stage. (After Emerton.) 


Fig. 4.?. — Nymph of Melanoplus, 
second stage. (After Emerton.) 


Fig. 46. — Nymph of Melanoplus, fifth 
stage. (After Emerton.) 


Fig. 44. — Nymph of Melanoplus, 
stage. (After Emerton.) 


third 


Fig. 47. — Melanoplus, adult. 


living in the water and most of them pass through somewhat more com- 
plicated changes than do the nymphs of locusts. For these reasons 
perhaps they ought to be included in a group by themselves and desig- 
nated as having a special phase of metamorphosis; but for the sake of 
simplicity we have placed them among the insects having a gradual or 
incomplete metamorphosis. 

The nymph. — The young of all insects with incomplete metamorphoses 
are known as nymphs. The term nymph is applied to all stages of such 
insects from the time they hatch until they shed their skin for the last 
time. When a nymph first hatches it has no signs of wings; but after it 
molts once or twice one or two projections appear on each side of the 
thorax in the case of those forms in which the adult has wings. These pro- 
jections become larger and larger and more wing-like in form with each 
successive molt. 

The important feature of insects having an incomplete metamorphosis 


HEXAPODA 


25 


Fig. 48. — Eggs of insects; 1, (Ecanthus nigricornis; 
2, (Enis semidea; 3, Piezosterum subulatum; 4, Hydrometra 
martini. 


is that the wings develop externally. That is, the wings of nymphs are 
sac-like outgrowths of the body-wall which appear early and grow larger 
as already explained. 

Complete metamorphosis. — Other insects, like the bees, butterflies, 
moths, flies, and beetles leave the egg in an entirely different form from 
that which they assume when 
they reach maturity. A butter- 
fly begins its active life as a 
caterpillar. It feeds and grows, 
and when full-grown changes to 
a chrysalis. In this stage it 
has very little resemblance to a 
caterpillar. After a time there 
bursts forth from the chrysalis 
shell the butterfly, which looks 
very little like the chrysalis and 
still less like the caterpillar 
from which it came. In a 
similar way, from the egg laid 
by a fly upon a piece of meat 
there hatches, not a fly, but a 
footless, worm-like maggot. 
This when fully grown changes 
to a quiescent object corres- 
ponding to the chrysalis of a 
butterfly. Later from this ob- 
ject there escapes a winged fly like that which laid the egg. Those insects, 
like the butterflies and flesh-flics which when they emerge from the egg 
bear almost no resemblance in form to the adult insect, are said to un- 
dergo a complete metamorphosis. In other words, the change of form 
undergone by the insect is a complete one, and it passes through the fol- 
lowing stages : — 

The egg. — This is the first stage in the existence of any insect, although 
in some instances the egg remains in the body of the mother till it hatches. 
But almost always the eggs are laid by the mother insect on or near the 
food which gives nourishment to the young. Many of the most interest- 
ing habits of insects are connected with the care of the eggs by the 
parent. The eggs may have smooth oval shells; but often the shells are 
beautifully ribbed and pitted (Fig. 48), and sometimes they are orna- 
mented with spines, and are frequently exquisitely colored. 

The larva. — This is the second stage of an insect with a complete 

metamorphosis and is the form that 
hatches from the egg. Familiar ex- 
amples of larvae are caterpillars (Fig. 
49), maggots, and grubs. In fact, many 
creatures popularly known as worms 
are larvae of insects. Away from the 
ocean we find but few worms, except earthworms, leeches, "hair- 
snakes," and worm-parasites in the intestines of men and animals. The 
larval stage is devoted to growth; the sole business of a larva being 
to eat and grow. All molting, because of increased size, is done in the 
larval stage, later molts are simply for change of shape. 


Fig. 49. — A caterpillar, the larva of a moth. 


26 THE STUDY OF INSECTS 

The pupa. — This is the third stage in the life of many insects, and is 
ordinarily a period of inaction, except that rapid and wonderful changes 
go on within the body. Very few pupae, like those of mosquitoes, arc 
active. Usually pupa? have no power of moving around, but many of 
them can squirm when disturbed. When the last skin of the larva is 
thrown off the pupa is revealed ; it is an oblong object, and frequently 
apparently headless and footless. In many pupae the skin is a shiny 
covering like porcelain. If a pupa be examined closely the antennas and 

legs and wings may be seen ; these are folded 
up closely and soldered to the breast in the 
case of the moths and butterflies (Fig. 50), 
but free in case of the bees, ants, and 
beetles. 

The chrysalis. — This term is often ap- 
plied to the pupa of a butterfly. The word 

Fig. 50. - A pupa of a large moth. fe derived from a Q reek WQrd mcan ing gold, 

and came into use because of the golden dots and markings on many of the 
butterfly pupae. 

The cocoon. — Many larvae, especially those of moths, when full 
grown, spin about the body a silken case, so that when they change to 
helpless pupae they may be protected from enemies, and from rain and 
snow; these silken cases are called cocoons. They are frequently made 
within a rolled leaf (Fig. 51), or beneath grass and rubbish on the ground, 
or in cells below the ground. Some hairy caterpillars make cocoons 
largely of their own hairs, which they fasten together with a film of silk. 

The important characteristic of 
insects having a complete metamor- 
phosis is that the wings develop in- 
ternally. The wings begin to form in 
the young larvae, caterpillars of but- 
terflies, as buds of the hypodermis 
underneath the cuticula and appear 
for the first time when the last larval ^ 
skin is shed. ( 

Imago. — A fully developed or „ J , . 

-. ,, . , . 11 j • TM Fig. 51. — A large cocoon wit hm a rolled leaf. 

adult insect is called an imago. I lie 

imagos of most insects except those of the orders Thysanura and.Col- 
lembola have wings although there are many eases where wings have 
been lost through disuse. An insect never grows or molts after it reaches 
the adult stage. There is a popular belief that a small fly will grow into a 
large fly, but this is not true, for after any insect gets its perfect wings it 
can grow no larger, except that in case of females the body may be 
distended by the growth of eggs within it. While many adults cat more 
or less, it is only to sustain life, and not for growth. Indeed, many adult 
insects take very little food, and some have lost their mouth-parts 
entirely, through disuse. The adult stage usually lasts for a considerably 
shorter time than the larval or nymph stages. In fact, it seems planned 
in the economy of nature that the grown-up insects should live only long 
enough to lay eggs, and thus secure the perpetuation of the species. For 
example, mayflies live but a few days or even but a few hours, — just long 
enough, apparently, to lay their eggs and provide for the perpetuation of 
the species. 


HEXAPODA 


27 


How Insects Grow 

It has already been pointed out that a small fly does not grow into a 
large fly. No insect grows after it becomes an imago. All growth of an 
insect takes place in the young stages and larval and nymphal stages; 
and growth in these immature stages is accompanied by a shedding or 
molting of the outer skin. 

Molting. — The outer skin of a nymph or of a larva consists in large 
part of a substance known as chitin. In the young insect this outer 
skin soon becomes so firm and hard that it will not stretch enough to 


Fig. 53. ■ — Leg of May-beetle. (After Straus-Durckhenn.) 


allow for the growth of the insect. The result is that 
from time to time the skin of the young insect becomes 
too small for it and must be shed. But before this is 
done a new skin is formed beneath the old one; then the 
old skin bursts open, and the insect crawls forth, clothed 
in a soft skin, which stretches to accommodate the in- 
creased size of the individual. Very soon, however, this 
new skin becomes hardened, and after a time it in turn 
must be shed. This shedding of the skin is termed molt- 
ing, and the cast skin is sometimes referred to as the 
exuvicz. Insects differ greatly as to the number of times 
they molt: many species molt only four or five times, 
known to molt more than twenty times. Figure 52 


Fig. 52. — Exuviae 
nymph of dragonfly. 

while others are 

represents the cast skin of a dragonfly clinging to a reed. 


The External Anatomy of Insects 

The subject of insect anatomy is separated into two divisions: one, 

treating of the structure of the 
body- wall or skeleton ; the other, 
of the internal organs. The for- 
mer is termed external anatomy; 
the latter, internal anatomy. 

In our own bodies we find a 
central framework or skeleton, 
about which are arranged the 
muscles, blood-vessels, nerves, 
and other organs. But insects 
are constructed on an entirely 
different plan; with them the 
supporting skeleton is outside, 
and the muscles, nerves, and 
— a section of the body-waii of an insect: other organs are within this 

/;, hypodermis; bm, basement membrane; 1 1 / rrvi tj?c u 

d, dermis; tr, tdchogen; s, seta. skeleton. The difference can be 


Fig. 54- 
<-, cuticula; 
e, epidermis. 


28 


THE STUDY OF INSECTS 


well seen if the figure showing the internal structure of the leg of a may- 
beetle (Fig. 53) be compared with one of our own limbs, either arm or leg. 

The body of an insect is built on the same 

plan as arc its legs. The outside of the body 

is more or less firm, and this firm outer wall 

supports the muscles and other organs, thus 

The skeleton is therefore, in general outline, a 


Fig. 55- — A Larva. 


Fig. 56. — An 

earwig. 


serving as a skeleton 
hollow cylinder. 

The outer body-wall is composed of three layers: (1) an outer pro- 
tective layer, the cuticula; (2) a middle layer, the hypodermis; 
and (3) an inner delicate thin layer, the basement membrane 
(Fig. 54). The cuticula is a tough sheet of chitin often hard- 
ened by the deposition in it of other substances. 

The cuticula is not hardened throughout but remains soft 
and flexible at certain transverse indentations running around 
the body. These soft places in the cuticula mark the divi- 
sions between the ring-like portions of the body called seg- 
ments. 

In this way provision is made for the various motions of 
the body. The ring-like nature of the segments of the body 
is best seen in larvae (Fig. 55), and in the abdomen of an 
adult insect (Fig. 56). The movements of the legs, antennae, and certain 
other appendages are provided for in the same way; each one is a cylin- 
der made up of several segments, and be- 
tween these segments the wall of the 
cylinder remains flexible. 

When a single segment of the body is 
examined, its cuticula is not found to be 
side-view of locust with wings a continuous ring, but is seen to be made 
up of several portions more or less mov- 
able upon each other. Such a hardened portion of the cuticula is termed 
a sclerite. 

The sclerites constitute the greater part of the cuticula, the soft 
membranous portions separating them being in 
most cases narrow. Usually these narrow por- 
tions are mere lines; they are then called su- 
tures. 

Frequently the sutures become entirely ef- 
faced. We are therefore often unable to distin- 
guish certain sclerites in one species of insect 
which we know to exist in another. In such cases 
the effaced sutures are said to be obsolete. 

If the central portion or thorax of an adult 
insect be examined, numerous sclerites and su- 
tures can be observed (Fig. 57). 

The subject of external anatomy of insects 
consists very largely in a study of the sclerites of 
which the different segments of the body and of 
its appendages are composed. This part of the 
subject is quite difficult, and will not be discussed 
here. It is treated, however, in the discussion 
of the characters used in the classification of the Coleoptera given on 


Fig. 58. — Wasp, with head, 
thorax, and abdomen separated. 


HEXAPODA 


29 


pages 128 to 130. These pages should be carefully studied before 
attempting to use the table that follows them. 

The segments of the body in a fully developed insect are grouped into 
three regions: head, thorax, and abdomen (Fig. 58). In the larval state 
this grouping of the segments is not well shown. 


The Head and its Appendages 

The head is the first of the three regions of the body formed of several 
body-segments grown together. 

The head bears the compound eyes, the simple eyes or ocelli, the an- 
tennae, and the mouth-parts. 

The compound eyes. — On each side of the head of an adult insect is 

an organ, which is 
recognized at once as 
an eye. But when 
one of these eyes is 
examined with a mi- 
croscope it is found 
to present an appear- 
ance very different 
from that of the eye 
of higher animals; its surface is divided 
into a large number of six-sided divisions 
(Fig. 59). A study of the internal struc- 
ture of this organ has shown that each of 
these hexagonal divisions is the outer 
^^npvC- end of a distinct portion or element of 

-| / II \ ^ the eye (Fig. 60). Hence what at first 

"X^vJLy^" a PP ears to De a single eye is really an 
1§Nf€* organ cc 


*/. 


Fig. 59. — Part of surface 
of compound eye, greatly 
enlarged. 


r-jpv 


omposed of hundreds of distinct 
structures; it is termed, therefore, a com- 
pound eye. Each of the small elements 
of which a compound eye is composed is 
termed an ommatidium (plural ommati- 
dia). The number of ommatidia of which 
a compound eye is composed varies 
greatly: there may be not more than 
fifty, as in certain ants, or there may be 
many thousand, as in a butterfly or a 
dragonfly. Compound eyes are not found 
in larvae, though they may possess a group 
of simple eyes on each side of the head. 
The simple eyes. — In addition to the 
compound eyes, many adult insects pos- 
sess simple eyes. These are situated be- 
tween the compound eyes. They vary in 
number from two to three; the most 

common number is three (see Fig. 58). The simple eyes are termed ocelli. 
Nymphs also possess ocelli but in the case of most larvae there are 

simple eyes which are different in origin from the ocelli of adult insects. 
The antennae. — The antennas are a pair of jointed appendages artic- 


FlG. 60. — An ommatidium of Machilis 
c, cornea; ky, corneal hypodermis; cc, crystal- 
line-cone-cells; :', iris-pigment cells; r, retin- 
ula cells; rh, rhabdom; b, basement mem- 
brane; ap, accessory pigment cells. 


3° 


THE STUDY OF INSECTS 


ulated with the head in front of the eyes or between them. They vary 
in form. In some insects they are thread-like, consisting of a series of 
similar segments; in others certain segments are greatly modified in 
form. 

The various forms of antennas arc designated by special terms. The 
more common of these forms are represented in Figure 61. These are as 
follows: 

i. Setaceous or bristle-like, in which the segments are successively 
smaller and smaller, the whole organ tapering to a point. 

2. Filiform or thread-like, in which each segment is of nearly 


Various forms of an- 


Fig. 62. — Mouth-parts of the red- 
legged Locust. 


uniform thickness throughout its length; and the antenna as a whole 
tapers gradually, if at all, towards the tip. 

3. Moniliform or necklace-form, in which the segments are more or 
less globose, suggesting a string of beads. 

4. Serrate or saw-like, in which the segments are triangular, and pro- 
ject like the teeth of a saw. 

5. Pectinate or comb-like, in which the segments have long processes 
on one side, like the teeth of a comb, or on both sides, like a feather. 

6. Clavatc or club-shaped, in which the segments become gradually 
broader, so that the whole organ assumes the form of a club. 

7. Capitate or with a head, in which the terminal segment or seg- 
ments form a large knob. 

8. Lamellate in which the segments that compose the knob are ex- 
tended on one side into broad plates. 

The mouth-parts . — No organs in the body of an insect vary in form 
to a greater degree than do the mouth-parts. Thus with some the 
mouth is formed for biting, while with others it is formed for sucking. 
Among the biting insects some are predacious, and have jaws fitted for 
seizing and tearing their prey; others feed upon vegetable matter, and 


HEX APOD A 31 

have jaws for chewing this kind of food. Among the sucking insects the 
butterfly merely sips the nectar from flowers, while the mosquito needs a 
powerful instrument for piercing its victim. In this place the typical 
form of the mouth-parts as illustrated by the biting insects is described. 
The various modifications of it presented by the sucking insects are 
described later, in the discussion of the characters of those insects. 

In the biting insects, the mouth-parts consist typically of an upper 
lip, the labrum (Fig. 62, 8); an under lip, the labium (Fig. 62, 12); and 
two pairs of jaws between them. These jaws open sidewise, instead of in 
a vertical direction, as do the jaws of the higher animals. The jaws of 
the upper pair are called the mandibles (Fig. 62, 10); the lower pair, the 
maxilla; (Fig. 62, 11). There may be also within the mouth one or two 
tongue-like organs, the cpipharynx and hypopharynx (Fig. 62, 13). The 
epipharynx is attached to the upper wall of the cavity of the mouth, 
and the hypopharynx to the lower. The position of the hypopharynx is 
quite analogous, therefore, to that of our tongue. 

The mandibles vary much in form, but usually each consists of a 
single sclerite. The maxillae of biting insects, on the « 

other hand, are very complicated organs, each com- ; W^*^1 

posed of several scleritcs. Each maxilla bears an appen- ^nH^, /»\' 
dage consisting of several segments; these appendages f^EU^i0^ 
are termed the maxillary palpi. In the maxillae of cer- ^fflrg^ 
tain biting insects, as the grasshoppers and the ground ^H^f 

beetles, there is an appendage usually consisting of two *^ Bp 

segments: this is the galea or outer lobe. In some of Wt~4 

these insects, as the ground-beetles and the tiger-beetles, *& 

the galea is shaped like a plapus, and thus there appear Fre. 63. — Maxilla of 
to be two pairs of maxillary palpi (Fig. 63). The la- 
bium is furnished with a pair of jointed appendages; these are the labial 
palpi (Fig. 62, 12, d). 

The Thorax and its Appendages 

The thorax is the second or intermediate region of the body; it is the 
region that bears, in the adult insect, the organs of locomotion, the legs, 
and the wings when they are present. This region is composed of three 
of the body-segments more or less firmly joined together; the segments 
are most readily distinguished by the fact that each bears a pair of legs. 
In winged insects, the wings are borne by the second and third segments. 
The first segment of the thorax, the one next to the head, is named the 
prothorax; the second thoracic segment is the mesothorax; and the third, 
the metathorax. 

The legs. — Each leg consists of the following parts, beginning with 
the one next to the body (see Fig. 64) : coxa, trochanter, femur, tibia, and 
tarsus. Each of these parts consists of a single segment except that in 
certain Hymenoptera the trochanter consists of two segments (Fig. 
64, t), and in most insects the tarsus consists of several segments. The 
number of segments of the tarsus usually varies from one to^ five. Fre- 
quently the first segment of the tarsus is much longer than either of the 
other segments, and it may also differ greatly in form from them ; under 
such circumstances it is sometimes designated the metatarsus (Fig. 64). 
The last segment of the tarsus usually bears one or two claws. 


32 


THE STUDY OF INSECTS 


Fig. 64. — Legs of insects: A, wasp; B, ichneu- 
mon-!ly; C, bee; c, coxa; tr, trochanter; /, femur; 
/;', tibia; la, tarsus; met., metatarsus. 


On the ventral surface of the segments of the tarsus in many insects 
are cushion-like structures termed pulvilli. In many insects the pulvilli 
of the last segment of the tarsus are circular pads beneath the tarsal 
claws. In most descriptive works these are referred to as the pulvilli, 
even though the other pulvilli are well developed. 

The pulvilli of some insects, notably those of the Diptera, bear fine, 

hollow hairs, called tenent hairs, from 
which an adhesive fluid exudes that 
enables the insect to walk on the 
undersides of objects. 

The wings. — The two pairs of 
wings are borne by the mesothorax 
and metathorax, but either or both 
pairs may be wanting. Thus the 
flies, or Diptera, have only the first 
pair of wings fitted for flight, the 
second pair being represented by a 
pair of knobbed threads; and with 
the earwigs and beetles each of the 
first pair of wings is hard and to- 
gether they form a cover for the hind 
pair. 

In form an insect's wing is a large, 
membranous, leaf-like appendage, 
which is thickened along certain lines. These thickened lines are termed 
the veins or nerves of the wing; and their arrangement is described as the 
venation or neuration of the wings. The thin spaces of the wings which 
are bounded by the veins are called cells. When a cell is completely 
surrounded by veins it is said to be closed; but when it extends to the 
margin of the wing it is said to be open. 

The wings of different insects vary greatly in structure, and thus 
afford excellent distinctions for the 
purposes of classification. The vari- 
ous parts of the wing have, there- 
fore, received special names. There 
is considerable lack of uniformity 
among entomologists as to the names 
applied to these parts; but we have 
adopted the set of terms defined be- 
low as representing the best usage. 

An insect's wing is more or less 
triangular in outline; it therefore 
presents three margins: the costal 
margin, or costa (Fig. 65, a-b); the 
outer margin (Fig. 65, b-c); and the inner margin (Fig. 65, c-d). 

The angle at the base of the costal margin (Fig. 65, a) is the humeral 
angle; that between the costal margin and the outer margin (Fig. 65, b) 
is the apex of the wing; and the angle between the outer margin and 
the inner margin (Fig. 65, c) is the anal angle. 

There have been many different sets of names applied to the veins of 
the wings. Not only have the students of each order of insects had a 
peculiar nomenclature, but in many cases different students of the same 


Fig. 65. 

angles. 


Diagram of a wing showing margins and 


HEXAPODA 


33 


order of insects have used different sets of terms. This condition of 
affairs was incident to the beginning of the science, the period before 
the correspondence of the veins in the different orders had been worked 
out. But now the time has come when it seems practicable to apply a 
uniform nomenclature to the wing veins of all orders; and the following 
set of terms is proposed for that purpose. 

The principal veins of the wing, those that arise at or near the base 
of the wing, are termed, beginning with the one lying on the costal mar- 
gin, the costa, the subcosta, the radius, the media, the cubitus, and the 
anal veins. The radius, media, and cubitus are usually branched, and 
there may be several anal veins. 

In addition to the principal or longitudinal veins, there may be a 
greater or less number of cross-veins — veins extending transversely from 
one longitudinal vein to another. 

The principal veins may be designated by numbers as well as by 
names ; the following table indicates the correspondence of the names and 
numbers : 


Costa = vein I. 
Subcosta = vein II. 
Radius = vein III. 
Media = vein V. 


Cubitus = vein VII. 
ist anal vein = vein VIII. 
2d anal vein = vein IX. 
3d anal vein = vein XI. 


It was formerly believed that in certain insects three other longitu- 
dinal veins were present; these were numbered IV, VI, and X respec- 
tively; hence these numbers are omitted in the above table. 

At the time the first edition of this book was written, it was thought 
best to designate the veins by numbers; but owing to a lack of uniform- 
ity in the numbering of the veins by different writers, it is now clear that 
the names are to be preferred. In the lettering of figures, abbreviations 
of the names can be used as is done in Figure 66. 


idA 

Fig. 66. — Wing of a fly, Antsopus. 


The divisions of a branched vein are numbered, beginning with the 
one nearest the costal margin of the wing; and these numbers are in- 
dicated by sub-figures. For example, the five branches of the typical 
radius are designated thus, Ri, R 2 , R3, R4, Rs- 

When two or more branches of a branched vein coalesce, the com- 
pound vein is designated by an expression indicating this coalescence, as 
R2+3. In this way it is possible to indicate some of the changes that 
have taken place in the development of the species; and to make use of 


34 


THE STUDY OF INSECTS 


them in working out the classification of the group to which the species 
belongs. 

The cells of the wing are designated by applying to each the number 
or the abbreviation of the name of the vein that forms its cephalic (front) 
margin. In Figure 06 the veins are designated by letters at the margin 
of the figure; the cells by letters within the figure. When a cell is 
divided by a cross- vein the parts are numbered, as in the case of cell M 2 
in Figure 66. 

The Abdomen and its Appendages 

The abdomen is the third or caudal region of the body. Its segments 
are more simple, distinct, and ring-like than those of the other regions. 
The number of segments of which it appears to be composed varies 
greatly. In the cuckoo-flies {Chrysididaz) there are usually only three or 
four visible, while in many other insects nine appear. Except in the 
lowest order of insects (Thysanura) the abdomen of the adult bears no 
locomotory appendages. But many larvas have fleshy appendages which 
aid in locomotion: these are termed prolegs. In the adult the end of the 
body in many families is furnished with jointed filaments — the cerci, and 
caudal setce. Frequently also the body is furnished in the male with 
organs for clasping — the claspers; and in the female with saws, piercers, 
or borers — the ovipositor. In the female of certain insects there is a 
sting, a modified ovipositor, which is used as an organ of defence; and 
the abdomen of plant-lice and certain other insects bears a pair of tubes 
or tubercles, through which a wax-like material is excreted: these are 
termed cornicles, or siphuncles; see page 115. 


The Internal Anatomy of Insects 

As has been shown in the preceding pages, the body-wall serves as a 
skeleton, being hard, and giving support to the other organs of the body. 
This skeleton may be represented, therefore, as a hollow cylinder. We 
have now to consider the arrangement and the general form of the organs 


Fig. 67. — Diagram showing the relation of the internal organs. 

contained in this cylinder. For the details of the structure of the internal 
organs the student is referred to more special works. 

The accompanying diagram (Fig. 67), which represents a vertical, 
longitudinal section of the body, will enable one to gain an idea of the 
relative position of some of the more important organs. The parts shown 
in the diagram are as follows: the body-wall, or skeleton (s); this is 
made up of a series of overlapping segments; that part of it between the 
segments is thinner, and is not hardened, thus remaining flexible and 
allowing for the movements of the body. Just within the body-wall, 


THE STUDY OF INSECTS 

PLATE II 


Internal Anatomy of a Caterpillar (Cossus ligniperda). 

Fig. 4. — Caterpillar opened on the ventral middle line. Fig. 5. — Caterpillar opened on the dorsal 
middle iine. 1, principal longitudinal tracheae; 2, central nervous system; 3, aorta; 4, longitudinal 
dorsal muscles; 5, longitudinal ventral muscles; 6, wings of the heart; 7, tracheal trunks arising near 
spiracles; 8, reproductive organs; o, vertical muscles; 10, last abdominal ganglion. (After Lyonet.) 


THE STUDY OF INSECTS 

PLATE III 


Internal Anatomy of a Cockroach (Periplaneta orientalis). 

a, antennae; 6i, bi, ft,?, legs; c, anal cerci; d, ganglion on recurrent nerve upon the crop; 

e, salivary duct; /, salivary bladder; g, gizzard; h, hepatic cceca; i, mid-intestine; /, Malpig- 

hian vessels; k, small intestine; /, large intestine; m, rectum; », first abdominal ganglion; o, ovary; 
p, sebaceous glands. (From Rolleston.) 


HEX APOD A 35 

and attached to it, are represented a few of the muscles (ra); it will be 
seen that these muscles are so arranged that the contraction of those on 
the lower side of the body would bend it down, while the contraction of 
those on the opposite side would act in the opposite direction. The 
alimentary canal (a) occupies the centre of the body, and extends from 
one end to the other. The heart (//) is a tube lying between the ali- 
mentary canal and the muscles of the back. The central part of the 
nervous system (n) is a series of small masses of nervous matter con- 
nected by two longitudinal cords: one of these masses, the brain, lies in 
the head above the alimentary canal; the others are situated, typically 
one in each segment, between the alimentary canal and the layer of 
muscles of the ventral side of the body; the two cords connecting these 
masses, or ganglia, pass one on each side of the oesophagus to the brain. 
The reproductive organs (r) lie in the cavity of the abdomen and open 
near the caudal end of the body. The respiratory organs are omitted 
from this diagram for the sake of simplicity. 

The muscular system. — We find in insects a wonderfully large number 
of muscles. Those that move the segments of the body form several 
layers just within the body-wall. The two figures on Plate II represent 
two caterpillars which have been split open lengthwise, one on the middle 
line of the back and one on the opposite side ; in each case the alimentary 
canal has been removed, so that only those organs that are attached 
quite closely to the body-wall are left. From a study of these figures 
some idea can be obtained of the number and arrangement of these 
muscles. It should be borne in mind, however, that only a single layer of 
muscles is represented in these figures — the layer which would be seen 
if a caterpillar were opened in the way indicated. When these muscles 
are cut away many other muscles are found extending obliquely in 
various directions between these muscles and the body-wall. 

The muscles of insects appear very differently from those (the lean 
meat) of higher animals. In insects the muscles are either colorless and 
transparent, or yellowish- white ; and they are soft, almost of a gelatinous 
consistency. The fibers of insect muscles are usually if not always of the 
striated type. 

As a rule, the muscles of insects are composed of many distinct fibres 
which are not enclosed in ten- 
dinous sheaths as with verte- 
brates. But the muscles that 
move the appendages of the 
body are furnished with a ten- 
don at the end farthest from the 

bnHv (Pier f\0>\ ^ IG ' ^ — ^eg °^ May-beetle. (After Straus-Durckheim.) 

Notwithstanding the soft and delicate appearance of the muscles 
of insects, they are really very strong. 

The alimentary canal. — The typical position of this is represented in 
the diagram (Fig. 67) ; and on Plate III, illustrating the anatomy of a 
cockroach, its form in that insect is shown. In larvae it is a nearly 
straight tube, extending from one end of the body to the other. But in 
adult insects it is usually much longer than the body, and is consequently 
more or less folded. It is composed of parts differing in form and use. 
To these parts names have been given similar to those used to designate 
the corresponding parts in higher animals; thus we distinguish a pharynx. 


36 


THE STUDY OF INSECTS 


an oesophagus, sometimes a crop, sometimes a gizzard, a stomach, a small 
intestine, and a large intestine. 

The adipose tissue, or fat. — On opening the body of an insect, espe- 
cially of a larva, one of the most conspicuous things to be seen is fatty 
tissue, in large masses. These often completely surround the alimentary 
canal, and are held in place by numerous branches of the tracheae with 
which they are supplied. Other and smaller masses of this tissue adhere 
to the inner surface of the abdominal wall, in the vicinity of the nervous 
system, and at the sides of the body. In a full-grown larva of Corydalus 
cornutus the adipose tissue is often greater in bulk 
than all of the other organs found inside of the mus- 
cular walls of the body. In adult insects it usually 
exists in much less quantity than in larvae. 

The circulatory system. — In insects the circula- 
tory system is not a closed one, the blood flowing in 
vessels during only a part of its course. The greater 
part of the circulation of this fluid takes place in the 
cavities of the body and of its appendages, where it 
fills the space not occupied by the internal organs. 

Almost the only blood-vessel that exists in insects 
lies just beneath the body-wall, above the alimentary 
canal (Fig. 67, h). It extends from near the caudal 
end of the abdomen through the thorax into the 
head. That part of it that lies in the abdomen is 
the heart; the more slender portion, which traverses 
the thorax and extends into the head is the aorta. 
On each side of the heart, there is a series of 
triangular muscles extending from the heart to the 
lateral wall of the body. These constitute the dorsal 
diaphragm or the wings of the heart. 

The heart is a tube, which is usually closed at its 
posterior end; at its anterior end it is continuous 
with the aorta. The heart is divided into chambers 
(Fig. 69). The number of these chambers varies 
greatly in different insects; in some, there is only 
one, in others, as in the cockroach, there are as many 
as thirteen, but usually there are not more than 
eight. The blood is admitted to the heart through slit-like openings, the 
ostia of the heart; usually there' is a pair of ostia in the lateral walls of each 
chamber. Each ostium is furnished with a valve-like structure which 
closes it when the chamber contracts. 

When a heart consists of several chambers, they contract one after 
another, the wave of contraction passing from the caudal end of the heart 
forwards. As the valves between the chambers permit the blood to move 
forward but not in the opposite direction, the successive contractions of 
the chambers cause the blood received through the ostia to flow toward 
the head, into the aorta. The blood flows from the open, cephalic end 
of the aorta and passes in quite definite streams to the various parts of 
the body-cavity and into the cavities of the appendages. These streams, 
like the ocean currents, have no walls but flow in the spaces between 
the internal organs. After bathing these organs, the blood returns to the 
sides of the heart, which it enters through the ostia. 


Fig. 69. — Heart of May- 
beetle (after Straus Durck- 
heim): a, lateral aspect of 
aorta; b, interior of heart 
showing valves; c, ventral 
aspect of heart and wins- 
muscles — the muscles are 
represented as cut away 
from the caudal part of the 
heart; d, dorsal aspect of 
heart. 


HEXAPODA 


37 


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The blood consists of two elements, a fluid plasma and cells similar to the 
white corpuscles of the blood of vertebrates, the leucocytes. It differs greatly 
in appearance from the blood of vertebrates, on account of the absence of red 
blood corpuscles. In most insects the blood plasma is colorless ; but in many- 
species it has a yellowish, greenish, or reddish color. 
The blood receives the products of digestion of 
food, which pass in a liquid form, by osmosis, through 
the walls of the alimentary canal. On the other 
hand it gives up to the tissues which it bathes the 
materials needed for their growth. In insects oxy- 
gen is supplied to the tissues and gaseous wastes 
are removed chiefly by the respiratory system and 
not by means of the blood as in vertebrates. 

The nervous system. — The central part of the 
nervous system consists of a ganglion in the head 
above the oesophagus, and of a series of double 
ganglia, typically one for each segment of the body, 
lying on the floor of the body cavity, and connected 
by two longitudinal cords. In the head, one of these 
cords passes on each side of the oesophagus, from 
the brain to another ganglion in the head below the 
oesophagus, thus forming a nervous collar about the 
alimentary canal. From each ganglion nerves arise, 
which supply the adjacent parts; and from the 
thoracic ganglia nerves extend to the legs and wings. 
This series of ganglia is really a double one; but 
the members of each pair of ganglia are more or less 
closely united on the middle line of the body, and 
often appear as a single ganglion. Figure 70 gives a general view of the 
central nervous system of Corydalus cornutus. 

In addition to the central nervous system there are two sympathetic 
nervous systems and the peripheral sensory nervous system, the latter 

composed of a network of fine 
nerves all around the body just 
beneath the hypodermis of the 
body walls. 

How insects breathe — The 
respiratory system. — A com- 
mon mistake made by begin- 
ners in the study of Entomology is to suppose that insects breathe through 
the mouth as do the higher animals. Many a beginner has carefully 
poured chloroform on the head of an insect in the expectation of killing it 
in that way, and has been surprised at his poor success. 

The truth is, insects breathe through their sides. If an insect be 
carefully examined, there can be found along the sides of the body a 
series of openings (Fig. 71). These are the openings through which the 
air passes into the respiratory system and are termed spiracles. 

The number of spiracles varies greatly in different insects. There is, 
however, never more than one pair on a single segment of the body. 
They do not occur on the head, but are borne by each of the last two tho- 
racic segments., and by the first eight abdominal segments. Thus ten seg- 
ments may bear spiracles, but usually one or more segments lack them. 


Fie. 70. — 

of Corydalus 


Nervous system 
(After Leidy.) 


Fig. 71. — Side-view of locust with wings removed. 


38 


THE STUDY OF INSECTS 


Fig. 72. — Tracheal 
system of cockroach. 
The alimentary canal re- 
moved to show the ven- 
tral tracheal communica- 
tions. (After Miall and 
Denny.) 


These spiracles are either simple openings into the respiratory system, 
or are provided with valves, sieves, or fringes of hair for the exclusion of 
dirt. They lead into a system of air-tubes termed trachea. The accom- 
panying figure will indicate the distribution of the main trunks of these 
trachea? in a cockroach (Fig. 72). There is a short trunk 
arising from each spiracle; these are all connected to- 
gether by a large longitudinal trunk on each side of the 
body, and by numerous transverse trunks. From these 
large tracheae there arise a great number of smaller ones, 
not shown in the figure, which branch and subdivide 
and extend to all parts of the body. Connected to the 
tips and sides of these small tracheae are minute tubes 
called tracheoles. The tracheoles appear to be ultimately 
connected with the various tissues and it is through these 
that air reaches the tissues of the body. 

Although insects are, strictly speaking, air-breathing 
animals, many of them, as is well known, live in the 
water. The study of the ways in which aquatic insects 
breathe is a very interesting one ; it presents to us many 
wonderful modifications of structure. Some of the 
more common of these are described in subsequent pages 
of this book; in this place we can only make a few 
generalizations. 

The various modes of respiration of aquatic insects may be classified 
under two heads: first, those in which the insects obtain air from above 
the surface of the water; second, those in which the insects breathe the 
air that is mechanically mixed with the water. 

With many aquatic in- 
sects the spiracles open be- 
neath the wings, which are 
folded upon the abdomen. 
The insect, by coming to the 
surface of the water and 
lifting the tips of its wings, 
forms a cavity beneath them, 
into which the air rushes. 
The insect can then swim 
through the water, carrying 
this air with it in a position 
where it can be respired. 
When the air becomes im- 
pure, the insect rises to the 
surface, forces out the air 
from beneath its wings, and 
takes in a new supply. Wa- 
ter beetles and aquatic bugs 
afford familiar examples of this mode of respiration. 

Some insects are provided with long tubes connected with their spira- 
cles, by means of which they can draw their supply of air from above 
the surface of the water while they crawl upon the bottom of shallow 
ponds. Our most common illustrations of this are bugs of the family 
Nepidce; but the most remarkable development of this kind is exhibited 


R 


Fig. 7.?. — Tracheal gill of a damselfly: A, en- 
tire gill showing the tracheae; B, part of gill more 
magnified, showing both tracheae (T) and tra- 
cheoles (I). 


HEX APOD A 39 

by certain dipterous larvae of the family Syrphidoe, known as rat-tailed 
maggots. 

Although there are many insects that live in the water and draw their 
supply of air from above it, many aquatic insects breathe, as do fishes, 
the air that is mixed with the water. This is accomplished by organs 
known as tracheal gills. These are hair-like or more or less plate-like 
expansions of the body-wall, abundantly supplied with tracheae (Fig. 73). 
These tracheae divide and subdivide, and their terminations or fine 
branches, tracheoles, are separated from the water that bathes the organ 
only by its thin walls. In this way the air contained in the tracheae is 
separated from the air in the water only by a delicate membrane, which 
admits of the transfer of gases between them. It will be observed that 
the difference between a tracheal gill and a true gill (as of fishes, Crus- 
tacea, etc.) is that the true gill is supplied with vessels containing blood, 
which is purified by being brought in contact with the air in the water, 
while the tracheal gill is supplied with tracheae containing air to be puri- 
fied. 

Tracheal gills are usually borne by the abdomen, sometimes by the 
thorax, and in case of some stoneflies by the head. They pertain al- 
most exclusively to the immature stages of insects; but stoneflies of the 
genus Pteronarcys retain them throughout their existence. 

Tracheal gills vary greatly in form; in Corydalus they are hair-like, 
and occur in tufts near the lateral margins of the abdominal segments; 
in the caddice-worms they are thread-like, more or less branched, and 
irregularly distributed over the surface of the abdomen; and in certain 
damselflies they are in the form of large plate-like caudal appendages. 

( Fi g- 73-) . ... 

The reproductive organs. — The reproductive organs are situated in 

the abdomen, as represented in Figure 67. There is a set on each side 
of the body; but the two sets usually open by a common tube near the 
caudal end of the body. In the mayflies and in the earwigs, however, 
the reproductive organs of each side have a distinct opening. Thus may- 
flies are often found with two bunches of eggs projecting from the caudal 
end of the body. 

All insects are developed from eggs; but there are some apparent 
exceptions. Thus many flies retain their eggs until after they are 
hatched, and in some flies the young attain a considerable development 
before they are born. In the plant-lice (Aphtdidce) there is a remarkable 
alternation of reproduction. This is described more fully in the account 
of that family. 

The Subclasses and Orders of the Hexapoda 

The class, Hexapoda, is divided into two subclasses, the Apierygota 
and the Pterygota. The primitive insects were undoubtedly wingless; 
and there are two orders of living insects, the Thysanura and the Col- 
lembola, which are still wingless. These orders constitute the subclass 
Apterygota. All other insects are believed to have descended from 
winged ancestors and are therefore placed in the subclass, Pterygota. 
Some of the forms in this subclass, for example the bird-lice, the sucking 
lice and the fleas have lost their wings during their sedentary parasitic 
lives but this wingless condition is certainly an acquired one. 


4 o THE STUDY OF INSECTS 

We have divided the Ilexapoda in this work into twenty-five orders 
and have arranged them in a linear series as must be done in a simple 
text-book; for it is impossible to indicate in a satisfactory way either the 
relation of the orders to each other or the relative rank of the orders. 
An effort is made to place near together closely allied orders, and to 
treat first those that are more simple or primitive or generalized in 
structure, and last those that are more specialized. But this plan could 
be fully carried out only by having several parallel columns on the pages 
of the book, each representing a distinct line of descent, an arrangement 
which, to say the least, is impracticable. 

The list below indicates the sequence in which the orders are discussed 
in the following chapters. 

subclass apterygota. — Wingless insects in which the wingless condition is 
believed to be a primitive one, there being no indication that they have descended from 
winged ancestors. 

1. order thysanura. — The Bristle-tails, p. 45 

2. order collembola. — The Spring-tails, p. 47 

subclass pterygota. — Winged insects and wingless insects in which the wing- 
less condition is believed to be an acquired one; i.e., those insects that have de- 
scended from winged ancestors. 

3. order orthoptera. — The Cockroaches, Crickets, Grasshoppers, and others. 

P- 49 

4. order zoraptera. — The genus Zorotypus. p. 62 

5. order isoptera. — The Termites or White Ants. p. 63 

6. order neuroptera. — The Dobson, Aphis-lions, Ant-lions, and others, p. 66 

7. order ephemerida. — The Mayflies, p. 74 

8. order odonata. — The Dragonflies and the Damselflies. p. 77 

9. order plecoptera. — The Stonefhes. p. 81 

10. order corrodentia. — The Psocids. p. 83 

11. order mallophaga. The Bird-lice. p. 85 

12. order embiidina. — The Embiids. p. 87 

13. order thysanoptera. — ■ The Thrips. p. 89 

14. order anoplura. — The Lice. p. 92 

15. order hemiptera. — The True Bugs. p. 94 

16. order homoptera. — The Cicadas, Leafhoppers, Aphids, Scale-bugs, and others. 

p. 109 

17. order dermaptera. — The Earwigs, p. 125 

18. order coleoptera. — The Beetles, p. 127 

19. order strepsiptera. — The Twisted Winged Insects, p. 176 

20. order mecoptera. — The Scorpion-flies, p. 178 

21. order trichoptera. — The Caddice-fties. p. 180 

22. order lepidoptera. — The Moths, the Skippers, and the Butterflies, p. 183 

23. order diptera. — The Flies, p. 286 

24. order siphonaptera. — The Fleas, p. 326 

25. order hymenoptera. — The Bees, Wasps, Ants, and others, p. 329 

TABLE FOR DETERMINING THE ORDERS OF THE HEXAPODA 

This table is merely intended to aid the students in determining to which of 
the orders a specimen that he is examining belongs. No effort has been made to 
indicate in the table the relation of the orders to one another. 
A. Winged. (The wing-covers, Elytra, of beetles and of earwigs are wings.) 
B. With two wings. 

C. Wings horny, leathery, or parchment-like. 

D. Mouth-parts formed for sucking. Wings leathery, shortened, or mem- 
branous at the tip. p. 94 Hemiptf.ra 

DD. Mouth-parts formed for biting. Jaws distinct. 


HEXAPODA 41 

E. Wings horny, without veins. Hind legs not fitted for jumping, p. 127 

COLEOPTERA 

EE. Wings parchment-like with a network of veins. Hind legs fitted for 
jumping, p. 49 . . Orthoptera 

CC. Wings membranous. 

D. Abdomen with caudal filaments. Mouth-parts vestigial. 

E. Halteres wanting, p. 74 Ephemerida 

EE. Halteres present (males of Coccidae). p. 109 Homoptera 

DD. Abdomen without caudal filaments. Halteres in place of second wings. 

Mouth-parts formed for sucking, p. 286 Diptera 

RB. With four wings. 
C. The two pairs of wings unlike in structure. 

D. Fore wings reduced to slender club-shaped appendages; hind wings fan- 
shaped with radiating veins. Minute insects, p. 176 Strepsiptera 

DD. Front wings leathery at base, and membranous at tip, often overlapping. 

Mouth-parts formed for sucking, p. 94 Hemiptera 

DDD. Front wings of same texture throughout. 

E. Front wings horny or leathery, being veinless wing-covers. {Elytra.) 
F. Abdomen with caudal appendages in form of movable forceps, p. 125 

Dermaptera 

FF. Abdomen without forceps-like appendages, p. 127 Coleoptera 

EE. Front wings leathery or parchment-like with a network of veins. 
F. Under wings not folded; mouth-parts formed for sucking. 

G. Beak arising from the front part of the head. p. 94 .... Hemiptera 
GG. Beak arising from the hind part of the lower side of the head. 

p. 109 Homoptera 

FF. Under wings folded lengthwise. Mouth-parts formed for chewing. 

p. 49 Orthoptera 

CC. The two pairs of wings similar, membranous. 

D. Last joint of tarsi bladder-like or hoof-like in form and without claws. 

Wings with fringe of long hairs, p. 89 Thysanoptera 

DD. Last joint of tarsi not bladder-like. 

E. Wings entirely or for the greater part clothed with scales. Mouth-parts 

formed for sucking, p. 183 Lepidoptera 

EE. Wings naked, transparent, or thinly clothed with hairs. 

F. Mouth-parts arising from the hinder part of the lower surface of the 
head, and consisting of bristle-like organs inclosed in a jointed sheath. 

p. 109 Homoptera 

FF. Mouth-parts in normal position. Mandibles not bristle-like. 
G. Wings net-veined, with many veins and cross-veins. 
H. Tarsi consisting of less than five segments. 

I. Antennae inconspicuous, awl-shaped, short and slender. 

J. First and second pairs of wings of nearly the same length; 
tarsi three-jointed, p. 77 Odonata 

J J. Second pair of wings either small or wanting; tarsi four- 
jointed, p. 74 Ephemerida 

II. Antennas usually conspicuous, setiform, filiform, clavate, capitate, 

or pectinate. 
J. Tarsi two- or three-jointed. 

K. Second pair of wings the smaller, p. 83 Corrodentia 

KK. Second pair of wings broader, or at least the same size as 

the first pair. p. 81 Plecoptera 

JJ. Tarsi four-jointed; wings equal, p. 63 Isoptera 

HH. Tarsi consisting of five segments. 

I. Abdomen with setiform, many-jointed anal filaments. (Certain 

mayflies), p. 74 Ephemerida 

II. Abdomen without many-jointed anal filaments. 

J. Head prolonged into a trunk-like beak. p. 178 Mecoptera 

JJ. Head not prolonged into a beak. p. 66 Neuroptera 

GG. Wings with branching veins and comparatively few cross-veins, or 
veinless. 
H. Each of the veins of the wing extending along the middle of a 

brown line. p. 87 _ Embiidina 

HH. Wings not marked with brown lines. 


42 THE STUDY OF INSECTS 

I. Tarsi two- or three-jointed. 

J. Hind wings smaller than the fore wings. 

K. Cerci present; body less than three millimeters in length. 

p. 62 ZORAPTERA 

KK. Cerci absent; larger insects, p. 83 Corrodentia 

JJ. Posterior wings as large as or larger than the anterior ones. 
(Certain stoneflies). p. 81 Plecoptera 

II. Tarsi four- or five-jointed. 

J. Abdomen with setiform, many-jointed anal filaments (Certain 

mayflies), p. 74 Ephemerida 

JJ. Abdomen without many-jointed anal filaments. 

K. Prothorax horny. First wings larger than the second, naked 
or imperceptibly hairy. Second wings without or with 
few, unusually simple, veins. Jaws (mandibles) well de- 
veloped. Palpi small, p. 329 Hymenoptera 

KK. Prothorax membranous or, at the most, parchment-like. 
Second wings as large as or larger than the first, folded 
lengthwise, with many branching veins. First wings 
naked or thinly clothed with hair. Jaws (mandibles) in- 
conspicuous. Palpi long. Moth-like insects, p. 180 

Trichoptera 

AA. Wingless or with vestigial or rudimentary wings. 

B. Insects with a distinct head and jointed legs, and capable of locomotion. 
C. Aquatic insects. 

D. Mouth-parts fitted for piercing and sucking. 

E. Free-swimming nymphs, p. 94 Hemiptera 

EE. Larvae parasitic in sponges (Sisyridas). p. 66 Neuroptera 

DD. Mouth-parts fitted for chewing. 

E. Either somewhat caterpillar-like larvae that live in portable cases or 
campodeiform larvae that spin nets for catching their food. (Caddice- 

worms). p. 180 Trichoptera 

EE. Neither case-bearing nor net-spinning larvae. 

F. Naiads, that is, immature insects that resemble adults in having the 
thorax sharply differentiated from the abdomen, and, except in very 
young individuals, with rudimentary wings. 
G. Lower lip greatly elongated, jointed, capable of being thrust forward, 

and armed at its extremity with sharp hooks, p. 77 Odonata 

GG. Lower lip not capable of being thrust forward. 

H. Usually with filamentous tracheal gills on the ventral side of the 

thorax, p. 81 Plecoptera 

HH. Tracheal gills borne by the first seven abdominal segments. 

p. 74 Ephemerida 

FF. Larvae, that is, immature forms that do not resemble adults in the 
form of the body, and in which the developing wings are not visible 
externally. 
G. Several segments of the abdomen "furnished with prolegs. p. 183 

Lepidoptera 

GG. With only anal prolegs or with none. 

H. With paired lateral filaments on most or on all of the abdominal 

segments. (Sialidae). p. 66 Neuroptera 

See also Haliplidae and Gyrinidae. p. 127 Coleoptera 

HH. Without paired lateral filaments on the abdomen, p. 127 

Coleoptera 

CC Terrestrial insects. 
D. External parasites. 

E. Infesting the honey-bee. (Braula). p. 286 Diptera 

EE. Infesting birds or mammals. 

F. Body strongly compressed. (Fleas), p. 326 Siphonaptera 

FF. Body not strongly compressed. 

G. Mouth-parts formed for chewing. (Bird-lice), p. 85 . . . Mallophaga 
GG. Mouth-parts formed for piercing and sucking. 

H. Antennae inserted in pits, not visible from above. (Pupipara). 

p. 286 Diptera 

HH. Antennas exserted, visible from above. 


HEXAPODA 43 

I. Tarsi with a single claw which is opposed by a toothed projection 
of the tibia. (Lice), p. 92 Anoplura 

II. Tarsi two-clawed, p. 94 Hemiptera 

DD. Terrestrial insects not parasites. 

E. Mouth-parts apparently retracted within the cavity of the head so that 
only their apices are visible, being overgrown by folds of the genae. 
F. Abdomen consisting of ten or eleven segments. (Campodeida; and 

Japygidae). p. 45 Thysanura 

FF. Abdomen consisting of not more than six segments, p. 47 

COLLEMBOLA 

EE. Mouth-parts mandibulate, either fitted for chewing or with sickle- 
shaped mandibles formed for seizing prey. (See also EEE.) 
F. Larvae with abdominal prolegs. 

G. Prolegs armed at the extremity with numerous minute hooks. 

(Caterpillars), p. 183 Lepidoptera 

GG. Prolegs not armed with minute hooks. 

H. With a pair of ocelli, one on each side. (Larvae of saw-flies). 

p.3 2 9 Hymenoptera 

HH. With many ocelli on each side of the head. p. 178. .Mecoptera 
FF. Without abdominal prolegs. 

G. Body clothed with scales. (Machilidse and Lepismatidae) . p. 45 

Thysanura 

GG. Body not clothed with scales. 
H. Antennae long and distinct. 

I. Abdomen terminated by strong movable forceps, p. 125 

Dermaptera 

II. Abdomen not terminated by forceps. 

J. Abdomen strongly constricted at base. (Ants, etc.) p. 329 

Hymenoptera 

JJ. Abdomen not strongly constricted at base. 

K. Head with a long trunk-like beak. (Boreus). p. 178 

Mecoptera 

KK. Head not prolonged into a trunk. 

L. Insects of small size, more or less louse-like in form, with 
a very small prothorax, and without cerci. (Book-lice 

and Psocids). p. 83 Corrodentia 

LL. Insects of various forms, but not louse-like, prothorax not 
extremely small; cerci present. 
M. Hind legs fitted for jumping, hind femora enlarged. 
(Wingless locusts, grasshoppers, and crickets), p. 49 

Orthoptera 

MM. Hind femora not greatly enlarged, not fitted for 
jumping. 
N. Prothorax much longer than the mesothorax; front 
legs fitted for grasping prey. (Mantidas). p. 49 

. Orthoptera 

NN. Prothorax not greatly lengthened. 
O. Cerci present; antennae usually with more than 
fifteen joints, often many-jointed. 
P. Cerci with more than three joints. 

Q. Body flattened and oval. (Blattidae). p. 49 

Orthoptera 

QQ. Body elongate. 
R. Head very large. {Termopsis). p. 63 

ISOPTERA 

RR. Head of moderate size. p. 49 

Orthoptera 

PP. Cerci short, with one to three joints. 

Q. Body linear with very long linear legs. 

(Walking-sticks), p. 49 Orthoptera 

QQ. Body elongate or not, if elongate the legs 
are not linear. 
R. Body elongate; front tarsi with first joint 
swollen, p. 87 Embiidina 


44 THE STUDY OF INSECTS 

RR. Front tarsi not enlarged. 

S. Minute insects, less than J of an inch in 
length; antenna,' nine-jointed, p. 62 

ZoRAPTERA 

SS. Larger insects; antenna: usually more 
than nine-jointed. (White-ants), p. 63 

ISOPTERA 

00. Cerci absent; antennas usually with eleven 

joints, p. 127 COLEOPTERA 

HH. Antenna? short, not pronounced; larval forms. 

I. Body cylindrical, caterpillar-like. p. 178 Mecoptera 

II. Body not caterpillar-like. 

J. Mandibles sickle-shaped; each mandible with a furrow over 
which the maxilla of that side fits, the two forming an organ 
for piercing and sucking. (Ant-lions, aphislions, hemero- 

biids). p. 66 Neuroptera 

JJ. Mouth-parts not of the ant-lion type. 

K. Larva of Raphidia. p. 66 Neuroptera 

KK. Larvae of beetles, p. 127 Coleoptera 

EEE. Mouth-parts haustellate, fitted for sucking; mandibles not sickle- 
shaped. 
F. Body covered with a waxy powder or with tufts or plates of wax. 

(Mealy-bugs, Orthezia). p. 94 Hemiptera 

FF. Body more or less covered with minute scales, or with thick long 
hairs; proboscis if present coiled beneath the head. (Moths), p. 183 

Lepidoptera 

FFF. Body naked, or with isolated or bristle-like hairs. 

G. Prothorax not well developed, inconspicuous or invisible from 

above, p. 286 Diptera 

GG. Prothorax well developed. 

H. Last joint of tarsi bladder-like or hoof-like in form and usually 
without claws; mouth-parts forming a triangular un jointed 

beak. p. 89 Thysanoptera 

HH. Last joint of tarsi not bladder-like, and furnished with one 
or two claws; mouth-parts forming a slender, usually jointed 
beak. 

I. Beak arising from the front part of the head. p. 94. Hemiptera 

II. Beak arising from the back part of the head. p. 109. Homoptera 
BB. Either without a distinct head, or without jointed legs, or incapable of loco- 
motion. 

C. Forms that are legless but capable of locomotion; in some the head is dis- 
tinct, in others not. Here belong many larvas representing several of the 
orders, and the active pupas of mosquitoes and certain midges. It is im- 
practicable to separate them in this key. 
CC. Sedentary forms, incapable of locomotion. 

D. Small abnormal insects in which the body is either scale-like or gall-like in 

form, or grub-like clothed with wax. The waxy covering may be in the 

form of powder, or large tufts or plates, or a continuous layer, or of 

a thin scale, beneath which the insect lives. (Coccidae). p. 94 Hemiptera 

DD. Pupae, the inactive stage of insects with a complete metamorphosis; 

capable only of a wriggling motion, and incapable of feeding. 

E. Obtected pupae, pupas in which the legs and wings are glued to the 

surface of the body; either in a cocoon or naked, p. 183. . . .Lepidoptera 

EE. Coarctate pupas, pupae enclosed in the hardened larval skin. p. 286 

Diptera 

EEE. Exarate pupae, pupas that have the legs and wings free; either in a 
cocoon or naked. This type of pupa is characteristic of all of the orders 
in which the metamorphosis is complete except the Lepidoptera and 
Diptera. 


CHAPTER III 
ORDER THYSANURA* 


The Bristle-tails 

The members of this order are wingless insects still in a primitive con- 
dition. The mouth-parts are formed for chewing and the adults resemble the 
young in form for they do not have marked metamorphosis. The segments 
of the abdomen are of the usual number, eleven, and the last one usually 
bears two or three long, segmented, filiform appendages. 

The members of this order are known as bristle-tails, a name sug- 
gested by the presence, in most of them, of either two 
or three many-jointed filiform appendages at the caudal 
end of the body (Fig. 74) . The paired caudal appendages 
are the cerci; the median one, when three are present, 
is the median caudal filament, a prolongation of the 
eleventh abdominal segment. 

The bristle-tails are most often found under stones 
and other objects lying on the ground ; but some species 
live in houses. While most species prefer cool situations, 
there is one, the fire-brat, that frequents warm ones, 
about fire-places and in bakehouses. The antennas are 
long and many-segmented. There are less than twenty 
species known in this country. 

In one family the compound eyes are very perfect 
but in all others they are more or less degenerate or are 
lost entirely. 

The mouth-parts are formed for chewing but in 
many of the forms the jaws are apparently sunk in the 
head due to being overgrown by folds of the cheeks, or 
■ genas. In two families the jaws are not overgrown and 
the mouth-parts project in a normal manner. 
An interesting feature of some members of this order is the short, 
slender, two-segmented appendages found on the ventral side of the 
abdomen and known as styli. The styli are believed to be vestiges of 
legs persisting from many-legged ancestors probably centipede-like 
animals, the symphylids (See, An Introduction to Entomology, p. 23.) 

A common representative of this order is the fish-moth or silver-fish 
(Lepisma saccharina) as it is variously called. 

Often the careful housekeeper sees in the ironing-basket, or upon the 
book-shelf where she is dusting, a flash of light like a tiny thread of quick- 
silver, that usually vanishes as soon as seen. 

If she is experienced she knows that this streak of light is a little 
animal, half an inch long, whose body is clothed in shining scales like 
* Thysanura: thysanos (dOa-avos), a tassel; our a, (ovpa), the tail. 

45 


— Lepisma 


46 


THE STUDY OF INSECTS 


those of a fish. Hence she calls it a fish-moth. It is especially abundant 
in warm climates, and often docs damage to starched clothing, book- 
bindings, and sometimes loosens wall-paper 
by eating out the paste. Under a micro- 
scope the fish-moth shows beautiful mark- 
ings on the shining scales; and at the 
caudal end of the body are three long 
bristle-like appendages (Fig. 74), which sug- 
gest the common name bristle-tail applied 
to members of this suborder. 

Another common form is the fire-brat 
(Thenndbia domestica), which resembles 
the fish-moth in general appearance. It 
is remarkable for frequenting warm, even 
hot places, about ovens, ranges, and fire- 
places. 
(Afte G r' Lubb7ck.)^ . Figure 75 represents Japyx, a bristle- 
tail in which the caudal appendages are in 
the form of horny forceps; and Figure 76 represents the lower 
side of Machilis, another bristle-tail found under stones and m ackUis, showing 
bark. This is the form that has vestigial legs on the ab- appendages 
domen. 


Fig. 76. — 
Ventral aspect of 


Fig. 76a. — Campodea slaphylinus. 

An illustration of a small, delicate, whitish thysanuran, Campodea 
slaphylinus, which lives in damp places under stones or in rotten wood 
and leaves. Note that the thorax and abdomen differ from each other 
very little in form. This is true of many of these simple insects. (After 
Lubbock.) 


CHAPTER IV 
ORDER COLLEMBOLA* 


The Spring-tails 

The insects of this order are wingless insects still in a primitive condition. 
The mouth-parts are formed either for chewing or for sticking. The adults 
resemble the young in form for they do not have a marked metamorphosis. 
The segments of the abdomen are reduced to six in number. On the ventral 
side of the abdomen in many species is a springing organ. 

The spring-tails are minute insects, often of microscopic size and 
rarely more than 1/5 of an inch in length. Most of the species live on 
decaying matter. They are common under stones and decayed leaves 
and wood, in the chinks and crevices of bark, among moss, and on 
herbage in damp places. Sometimes they occur abundantly in winter 
on the surface of snow where they appear as minute black specks which 
spring away at our feet on either side. Some species collect in great 
numbers on the surface of standing pools of water. 

There is, on the underside of the fourth 
abdominal segment of most of these insects 
a fork-like appendage, the springing organ 
(Fig. 77), which, when the insect is at rest, is 
bent forward beneath the body and caught 
and held under tension by a catch on the third 
segment. When this organ is released it sud- 
denly springs-backward and throws the insect 
high in the air several feet away. This action 
is like a spring-board jump, only these tiny 
insects always carry their spring-boards with 
them, and thus have won the name of spring- 
tails. 

Typically, the mouth-parts of the spring- 
tails are chewing with the jaws overgrown by 
the cheeks until they are hardly visible. In a few forms the 
mandibles and maxillae have become modified into needle- 
like organs which are used for piercing and sucking. 

These insects possess a peculiar organ called the ventral 
tube, or collophore. It may be wart -like or tube-like in form and it is sit- 
uated on the underside of the first abdominal segment. It exudes a 
viscid fluid by means of which the insects are enabled to cling to the 
lower surface of an object. 

A common species of spring-tail is the snow-flea, Achorutes nivicola 
(Fig. 78), which occurs abundantly in winter on the surface of the snow. 

* Collembola: colla (n6\\a), glue; embolon (e^oXov), a bolt, bar; — from their 
collophores. 

47 


Fig. 77. — The 
"spring" of Papi- 
rius: via. manu- 
brium; d, left dens; 
mu, left mucro. 
(After Lubbock.) 


Fig. 78. — The 
snow-flea, Achorutes 
nivicola. (After Fol- 
som.) 


4 8 


THE STUDY OF INSECTS 


It sometimes proves a nuisance in sugar-bushes by getting into the 
sap. 

Another tiny one-, the garden-flea, Sminthurus hortensis, often be- 
comes a pest by feeding on young cabbages, 
turnips, cucumbers, and squashes. 

Through a microscope, certain spring-tails 
appear very absurd. They have long antennae 
and large dark eye-spots on the face, which, to- 
gether with the long hair that sticks forward 
on the head and thorax, give the creature a 
look of solemn fierceness (Fig. 79). Different 
Fir.. 79 .-Papiri*sfusc«s. (After species may be found at almost any time of the 
Lubbock.) year in damp places. 


Fig. 70a. — Tomocerus plumbe.ns, 


A side view of a spring-tail, Tomocerus plumbens, showing that cu- 
rious organ, the collophore, co; and the catch, c, which holds the spring, 
s, in place and under tension when the latter is drawn beneath the ab- 
domen. 


CHAPTER V 
ORDER ORTHOPTERA* 

Grasshoppers, Crickets, Cockroaches, and others 

The winged members of this order have two pairs of wings; the fore 
wings are more or less thickened, but have a distinct venation; the hind 
wings are folded in plaits like a fan when at rest; there are many forms in 
which the wings are vestigial or even wanting. The mouth-parts are formed 
for chewing. The metamorphosis is incomplete; the nymphs are terrestrial. 

The order Orthoptera includes some of the very common and best- 
known insects. The most familiar representatives are those named 
above. 

Although the song of the katydid and the chirp of crickets are most 
often associated with recollections of pleasant evenings spent in the 
country, we cannot forget that to members of this order are due some of 
the most terrible insect scourges man has known. The devastations 
caused by great swarms of migratory locusts are not only matters of 
historical record, but are too painfully known to many of our own 
generation in the western states. 

With the exception of a single family (Mantidce), the members of this 
order are, as a rule, injurious to vegetation; and many species are quite 
apt to multiply to such an extent that their destruction of vegetation 
becomes serious. 

In the Orthoptera the two pairs of wings differ in structure. The fore 
wings are parchment -like, forming covers for the more delicate hind 
wings. These wing-covers have received the special name tegmina; they 
are furnished with a fine network of veins, and overlap at the tip at 
least. There are many species in which the wings are rudimentary, 
even in the adult state. Such adults resemble nymphs; but in the case 
of the jumping Orthoptera, where this peculiarity most often occurs, 
nymphs can be distinguished by the fact that the rudimentary hind wings 
are outside of the fore wings, instead of beneath them, as in the adult 
state. 

There are six families of well-known insects in the order Orthoptera 
which can be separated by the following table. 

A. Hind femora fitted for jumping, i.e., very much stouter or very much longer, 
or both stouter and longer, than the middle femora; organs of flight of immature 
forms inverted; stridulating insects. (The Saltatorial Orthoptera.) 
B. Antennae long and setaceous, except in the mole-crickets and sand-crickets; 
tarsi three- or four- jointed; organs of hearing situated in the fore tibiae; oviposi- 
tor elongate, except in the mole-crickets and sand-crickets, with its parts 
compact. 
C. Tarsi four-jointed; ovipositor, when exserted, forming a strongly compressed, 

generally sword-shaped blade, p. 50 Tettigoniid^e 

* OrthSptera: orthos (6p06s), straight; pteron (irrepov), a wing. 

49 


So THE STUDY OF INSECTS 

CC. Tarsi usually three-jointed, except in the pigmy mole-crickets where they 

arc reduced; ovipositor, when exserted, forming a nearly cylindrical, straight, 

or occasionally upcurved needle, except in the Trigonidiinae. p. 53 . . . Gryllid^e 

BB. Antennae short; tarsi three-jointed; organs of hearing situated in the first 

abdominal segment; ovipositor short, with its parts separate, p. 56 

_■ Locustid^: 

A.\. Hind femora closely resembling those of the other legs, and scarcely if at all 

stouter or longer than the other femora, i.e., not fitted for jumping; organs of 

flight in a normal position when immature; stridulating organs not developed. 

B. Body elongate; head free; pronotum elongate; legs slender, rounded; cerci 

jointed or without joints; walking insects. 

C. Front legs simple; cerci without joints, p. 58 Phasmid/E 

CC. Front legs fitted for grasping; cerci jointed, p. 59 Mantid/E 

BB. Body oval, depressed; head wholly or almost wholly withdrawn beneath the 
pronotum; pronotum shield-like, transverse; legs compressed; cerci jointed; 
rapidly running insects, p. 60 Blattid/E 

Family Tettigoniid^; 

The Long-homed Grasshoppers 

This family has usually been given the name Locustidag, but this 
name should be used for the family of short-horned grasshoppers or 
locusts. The members of this family are among the most attractive in 
appearance of the Orthoptera. In many of them the wings are graceful 
in form and delicate in color, and the antennae are exceedingly long and 
slender, looking more like ornaments than like organs of practical use. 
The tarsi are four-segmented and the ovipositor is sword-shaped. 

These beautiful creatures are much less frequently seen than are the 
crickets and locusts because of their protective green color, which renders 
them inconspicuous in their haunts among foliage or on the blades of 
grass. Their presence is most often indicated by the chirping of the 
males. 

Any one that is in the habit of lying in the tall grass of meadows or 
pastures and watching the insects that can be seen there is sure to be 

familiar with certain green grass- 
hoppers, which attract attention by 
the extreme delicacy and great 
length of their antennas. The 
antennas are much more slender 
than with the short -horned grass- 
hoppers or locusts, and much longer, 
exceeding the body in length. The 
tarsi are four-jointed. The ear- 
like organs, when present, are situ- 
ated near the base of the fore tibiae 
(Fig. 80), and the ovipositor is 
sword-shaped. 

In those species of this family 
„ „ _ r , ,. , , in which the wings are well de- 

ric. 80. — Leg of katydid, showing car-like organ. 1 -. c -, ,1 1 ■ • j„ j 

vol oped we find the males provided 
with an elaborate musical apparatus by means of which they call their 
mates. This consists of a peculiar arrangement of the veins and cells of a 
portion of each wing-cover near its base. This arrangement differs in the 
different species ; but in each it is such that by rubbing the wing-covers 


ORTHOPTERA 


5i 


Fig. 81. — Wing 
cover of male mead 
ow grasshopper. 


82. — Wing- 
of female 
meadow grasshopper. 


together they are made to vibrate, and thus produce the sound. Figure 
81 represents a wing-cover of the male of a common meadow grasshop- 
per, and Figure 82 that of a female of the 
same species. 

In order to facilitate the study of this 
family the more common representatives can 
be arranged in four groups; the katydids, 
the meadow grasshoppers, the cricket-like 
grasshoppers, and the shield-backed grass- 
hoppers. 


THE KATYDIDS 


The chances are that he who lies awake 
of a midsummer night must listen whether 
he wishes to do so or not, to an oft-repeated, FlG 
rasping song that says, "Katy did, Katy cover 
did ; she did, she didn't," over and over again 
There is no use of wondering what Katy did or didn't do, for no mortal 

will ever know. If, when the dawn comes, 
the listener has eyes sharp enough to discern 
one of these singers among the leaves of some 
neighboring tree, never a note of explana- 
tion will he get. The beautiful, finely- 
veined wings folded close over the body 
keep the secret hidden, and the long an- 
tennae, looking like threads of living silk, 
will wave airily above the droll, green eyes 
as much as to say, "Wouldn't you like to 
know?" The katydids live among the 
branches of trees and the song made by 
the male is heard at night and occasion- 
ally on dark cloudy days. The true 
northern katydid, Pterophylla camellifdlia, 
is the species commonly known as the 
"Katydid" owing to its characteristic 
strident call. It is found throughout the 
United States east of the Rocky Moun- 
tains; but in the North it lives in col- 
onies which occupy rather restricted areas 

(Fig- 83). 

There are several species of false katy- 
dids with broad leaf-like wings that live 
in trees and look much like the real katy- 
did. One of these is known as the an- 
gular-winged katydid, Microcentrum 
rhomb if olium. It deposits its large ellip- 
tical eggs in rows along the edge of a leaf or 
on a small branch (Fig. 84). 
There is another species of angular-winged katydid, Microcentrum 
retinerve, which is somewhat smaller than the preceding but closely re- 
sembles it in form and appearance. 


Fig. 83. — Pterophylla 
(After Harris.) 


camellifolia. 


52 


THE STUDY OF INSECTS 


Fig. 84. — The angular-winged katydid and its eggs. 


THE MEADOW GRASSHOPPERS 


From the middle of the summer to the autumn there can be found 
upon the grass in our meadows and moist pastures many light-green long- 


Fig. 85. — Conocephalus. 


Fig. 86 — Ceuthophilus. 


horned grasshoppers of various sizes; these, on account of the situations 
in which they are usually found, are termed the meadow grasshoppers. 
They are of medium size and are the most common members of this 
family (Fig. 85). Associated with the meadow grasshoppers and living in 
the same situations, are often found larger, longer-winged grasshoppers 
with pointed heads, called the cone-headed grasshoppers. 


THE CRICKET-LIKE GRASSHOPPERS 


These are the long-horned grasshoppers that bear some resemblance 
to the true crickets (Fig. 86). They have a short, thick body and re- 
markably stout hind femora, like a cricket, but are entirely destitute of 
tegmina and wings. The more common species are either of a pale 


ORTHOPTERA 53 

brown or a dirty white color and more or less mottled with either lighter or 
darker shades. Most of them fall in the genus Ceuthophilus (Fig. 86). 

These insects live in dark and moist places, under stones and rubbish, 
especially in woods, in cellars, in the walls of wells, and in caves. They 
are commonly called cave-crickets and some, because of the high arched 
back, camel-crickets. 

THE SHIELD-BACKED GRASSHOPPERS 

These are mostly wingless or nearly wingless, dull-colored insects 
which bear some resemblance to crickets. They present, however, a 
queer appearance, due to the pronotum extending backward over the 
rest of the thorax, like a sun-bonnet worn over the shoulders with the 
back side forward. These insects live in grassy fields or open woods. 
Most of them occur west of the Mississippi but a few of the genus Atldn- 


Fig. 87. — Atlanlicus. Fig. 88. — Stenopelmatus. 

ticus occur in the East (Fig. 87). Some of the shield-backed grasshop- 
pers of the genus Anabrus, popularly known as the western cricket, invade 
cultivated fields at times in the western states and destroy the crops. 

The sand-crickets of the Pacific Coast are not widely unrelated to the 
shield-backed grasshoppers. They are clumsy creatures with big heads 
that live under stones in loose soil. They belong to the genus, Sten- 
opelmatus (Fig. 88). 

Family Gryllid^e 
The Crickets 

In the more typical crickets the hind legs are fitted for leaping and the 
antennae are long and slender. The tegmina lie flat on the back and are 
bent down abruptly at the sides of the body like a box-cover. The 
ovipositor is spear-shaped and wings are absent in some species. 

There are crickets, however, which have short antennas, some in which 
the ovipositor is sword-shaped and a few without an ovipositor. 

With most species of crickets the males differ greatly in appearance 
from the females. The males have musical organs which are even more 
elaborate than those of the katydids and meadow grasshoppers. Here all 
that part of each wing-cover that lies on the back is occupied by them. 
This gives the males a very different appearance from the females, the 
wing-covers of that sex being veined simply. 

During the latter part of summer and in the autumn the air is filled 
with the chirping of crickets. It is an interesting thing to watch one of 


54 


THE STUDY OF INSECTS 


Mm 


these fiddlers calling his mate. By moving quietly in the direction from 
which the sound comes, and stopping whenever the insect stops chirping, 
but moving on again when he renews his song, one can get near enough 
to see how he does it. This can be done even in the 
night with the aid of a lantern, as the crickets do not 
seem to mind lights. 

Figure 89 represents the musical apparatus of a 
cricket. From this it will be seen that the large 
veins divide the wing-covers into disk-like membra- 
nous spaces. If the principal vein which extends 
diagonally across the base of the wing-cover be ex- 
amined with a microscope, it will be seen to be fur- 
nished with ridges like those of a file (Fig. 89, C). On 
the inner margin of the wing-cover, a short distance 
toward the base from the end of the principal vein, 
there is a hardened portion which may be called the 
scraper. This is shown enlarged at s in the figure. 
Each wing-cover is therefore provided with a file and 
a scraper. When the cricket wishes to make his call, 
he elevates his wing-covers at an angle of about 
forty-five degrees with the body ; then holding them 
in such a position that the scraper of one rests upon 
the file of the other, he moves the 
wing-covers back and forth sidewise 
so that the file and the scraper rasp 
upon each other. This throws the 
wing-covers into vibration, and pro- 
duces the call. 

The crickets do not constitute a 

Fig. 89. — Fore wing , -j ui 

of Gryiius; a, as seen large group yet there is considerable 
S^^SH^t diversity of form among them. The 
down on the side of the m ore common species may be placed 

abdomen is not shown; . , ,. L ... .. J ., 

s, scraper; /,/, tympana, in three rather distinct groups; the 
beio'wT t SET/fiE tree-crickets, the field-crickets, and the 

C, file greatly enlarged. mole-cricketS. „££ ^~ ^^ 


THE TREE-CRICKETS 

The common name of this group was suggested by the fact that these 
crickets are very apt to inhabit trees; but they occur also on shrubs, or 
even on high herbs and tall grass. They are delicate insects, many of 
which are of a light green color. Most of them belong to the genus 
(Ecanthus and the one that often attracts attention is the snowy tree- 
cricket, 0. mveus (Fig. 90). Although usually unseen the males arc evi- 
dent in late summer and in the autumn by their songs. Their song is 
begun early in the evening and is continued throughout the night; it 
consists of a monotonous scries of high-pitched trills rhythmically re- 
peated indefinitely. It is a remarkable fact that all of these crickets that 
are chirping in any locality chirp in unison. Except where the true katy- 
did is heard, this is the most conspicuous insect song heard in the night 
in the regions where this species occurs. 


ORTHOPTERA 


55 


Another species, 0. nigricornis, attracts attention because the female 
lays her eggs in a row in the stems of plants, especially in the canes of 
raspberries (Fig. 91). 

The field-crickets 

These are the common 
brown to almost black crickets 
with which we are probably 
most familiar. 

They abound everywhere, 
in pastures, meadows, and 
gardens; and certain species 
enter our dwellings . They lurk 
under stones or other objects 
on the ground or burrow into 


Fig. 92. — Gryllus 


Fig. 93. — Gryllo- 
lalpa hexadactyla. 


the earth. They are chiefly solitary, nocturnal in- 
sects; yet many can be seen in the fields in the 
daytime. They usually feed upon plants but are 
sometimes predacious. With most species the eggs 
are laid in the autumn, usually in the ground, and 
are hatched in the following summer. The greater 
number of the old crickets die on the approach of winter; but a few 
survive the cold season. In many of the species there are both short- 
winged and long-winged forms. In Figure 92 is shown a common short- 
winged form. The house cricket of Europe, Gryllus domesticus, is now 
present in the northeastern United States. 


Fig. 91. — Stem of black 
raspberry with the eggs of 
(Ecanlhus nigricornis: c, d, egg 
enlarged. (From Riley.) 


The mole-crickets 

These are called mole-crickets because they burrow in the ground like 
moles. The form of the body is suited to this mode of life. The front 
tibiae, especially, are fitted for digging; they are greatly broadened, and 
shaped somewhat like hands, or the feet of a mole (Fig. 93). 

The mole-crickets are not common insects in this country; but oc- 
casionally they are found in great numbers in a limited locality. They 
make burrows in moist places from six to eight inches below the surface 
of the ground, and feed upon the tender roots of various plants, and also 
on other insects. The eggs are deposited in a neatly constructed sub- 
terranean chamber, about the size of a hen's egg. 

In this country, at least, mole-crickets are nocturnal in habits, coming 
forth at night to feed and remaining hidden in their burrows during the 
day. 


56 


THE STUDY OF INSECTS 
Family Locustid/£* 


The Locusts or Short-honied Grasshoppers 

The family Locustida? includes the locusts or short-horned grass- 
hoppers. These are common and well-known insects. The antennas are 
much shorter than the body, and consist of not more than twenty-five 
segments. The ovipositor of the female is short and composed of separate 
plates; and the basal segment of the abdomen is furnished on each side 
with a tympanum, the external parts of the organs of hearing (Fig. 94). 

It is to these insects that the term locust is properly applied; for the 
locusts of which we read in the Bible, and in other books published in 
the older countries, are members of this family. Unfortunately, in the 
United States the term locust has been applied to the Periodical Cicada, 
a member of the order Homoptera, described later. 

Locusts lay their eggs in oval masses and cover them with a tough 


Fig. 94. — Side view of Locust with wings removed to show 
ear. See the arrow. 


Fig. 95. 

brum. 


Mclanoplus femur-ru- 


substance. Some species lay their eggs in the ground. The female makes 
a hole in the ground with her ovipositor, which is a good digging-tool. 
Some species even make holes in fence-rails, logs, and stumps; then, 
after the eggs are laid, the hole is covered up with a plug of gummy 
materials. There is but one generation a year, and in most cases the 
winter is passed in the egg-state. This family is of great economic im- 
portance, as the members of it usually appear in great numbers in every 
region where plants grow, and often do much damage. 

The males of many locusts are able to produce sounds. This is done 
in two ways: first, certain species rub the inner surface of the hind 
femora, upon which there is a row of minute spines, against the outer 
surface of the wing-covers. In this case each wing-cover serves as a 
fiddle, and each hindleg as a fiddle-bow. Second, other species rub to- 
gether the upper surface of the front edge of the hind-wings and the 
under surface of the wing-covers. This is done while the locust is flying 
and the result is a crackling sound. 

There are very many species of locusts in the United States. We 
have space to refer to only a few here. 

The most familiar member of the family is the red-legged locust, 
Mclanoplus femur-ruhrum (Fig. 95). It is more abundant than any 
other species throughout the United States, except in the high dry lands 
of the central part of the continent where the Rocky Mountain locust, 
Melanoplus sprctus, has its breeding grounds. 

The Rocky Mountain locust is only about one to one and a quarter 

* This family is termed the Acrididas by some writers, other writers use the fam- 
ily name Acridiidaj. 


ORTHOPTERA 


57 


inches long and resembles closely the red-legged locust but has somewhat 
longer wings. In past years when the food of this locust has become 
scarce in its high dry home, it has migrated to the lower and more fertile 
regions of Kansas, Iowa and Nebraska where it has devastated the crops 
over large areas. 

It will be remembered that at one time it almost produced a famine 
in Kansas and the neighboring states. Fortunately the young of this 
insect hatched in the low regions are not healthy, and die before reaching 
maturity. Consequently the plagues caused by the emigration of this 
insect are of short duration. There are several other species of Melano- 
plus common in this country, but they can be distinguished only by very 
careful study. One, the "big yellow locust", Meldnoplus dijjferentialis, is 
about if inches long, yellowish-brown in color and often so abundant 
in the middle West that it injures fields of grass and grain very seriously. 
The Carolina locust, Dissostclra Carolina, is common throughout the 
United States and Canada, and at the North is our largest species. It 
lives in roads and on bare places, and its color matches the soil on which 
it lives. It is usually pale yellowish or reddish-brown or slate color, with 
small dusky spots. The hind wings are 
black, with a broad yellow edge. It meas- 
ures from one inch and a half to nearly 
two inches in length. 

The clouded locust, Encoptolophus sor- 
didus (Fig. 96), is very common in the 
Eastern United States during the au- 
tumn. It abounds in meadows and pastures, and attracts attention by the 
crackling sound made by the males during flight. Its color is dirty brown, 
mottled with darker spots. 

The American locust, Schistocerca americana, is a fine species nearly 

3 inches long. It 
is found in the 
southern states 
and as far north 
as Connecticut 
and Iowa (Fig. 
97). The pellucid 
locust, Cam- 
nula pelliicida, 
scarcely an inch 
in length, has 
clear pellucid 
south to Arizona. 


Fig. q6. — Encoptolophus sordidus. 


It 


is a large, clumsy species 
it is confined to the cen- 


Fig. 07. — Schistocerca americana. (From Riley.) 

hind wings and occurs in the northern United States 
is often injurious to crops. 
The lubber grasshopper, Brachystola magna, 
in which the wings are vestigial 
tral portion of North America. 

The pigmy locusts. — There is a group of small locusts 
of which Acrydium (Fig. 98) is an example, which is no- 
table for the shape of the pronotum. This projects back- 
ward like a little roof over the wings, and often extends beyond the end of 
the abdomen. With these insects the wing-covers are reduced to small 
rough scales, the wings being protected by the large pronotum. These in- 


Fig. oS. — Acrydiur, 


58 


THE STUDY OF INSECTS 


sects arc commonly found in low, wet places, and on the borders i if streams. 
Their colors are usually dark, and are often protective, closely resembling 
that of the soil upon which they occur. These locusts are very active, 
jumping great distances. 


Family Phasmid^e 
The Walking-sticks and the Leaf -in sects 

The Phasmidae are of especial interest on account of the remarkable 

mimetic forms of the different species. In those species that are found in 

the United States, except one in Florida, the body 
is linear (Fig. 99), wingless, and furnished with 
long legs and antennas. This peculiar form has 
suggested the name walking-sticks which is com- 
monly applied to these insects. 

These insects are strictly herbivorous; they 
are slow in their motions, and often remain quiet 
for a long time in one place. They evidently de- 
pend on their mimetic form for protection. In 
addition to this some species have the power of 
ejecting a stinking fluid, which is said to be very 
acrid; this fluid comes from glands placed in the 
thorax. 

The eggs are scattered on the ground beneath 
the plants upon which the insects feed, the female, 
unlike most Orthoptera, making no provision for 
their safety. In our 
common northern 
species the eggs are 
dropped late in the 
summer and do not 
hatch till the follow- 
ing spring, or even 
till the second spring 
in some cases. 

Our common 
northern walking- 
stick is Diaphero- 
mera femorata (Fig. 
99). The range of 
this species extends 
quite common insect, 

and on several occasions has appeared in such 

great numbers as to be seriously destructive to 

the foliage of forest trees ; but these outbreaks 

have been temporary. 

Among the more striking in appearance of 

the walking-sticks found in the South are Mega- 

phasma dcntricus, our largest species, measuring from 5 to 6 inches in length, 

and Anisomorpha buprestoides, a yellowish brown species, about half as long 

as the preceding. 


Fig. gg. — A Walking-stick. 

into Canada. It is a 


Fig. 100. — Phyllium scythe. 
Sharp, after Westwood.) 


(From 


ORTHOPTERA 


59 


While our species are all wingless, except Aplopus mayeri, found in 
southern Florida, many exotic species are furnished with wings; and with 
some of these the wings resemble leaves. Among the more remarkable 
of the leaf-insects, as they are known, are those of the genus Phyllium 
(Fig. ioo), the members of which occur in the tropical regions of the 
Old World. 

Family Mantid^e 

The Praying Mantes or Soothsayers 

Certainly they are pious-looking fellows, with their front 
legs clasped together in front of their meek, alert faces, and 
it is no wonder that they are called praying mantes. But 
the only prayer that could ever enter the mind of a mantis 
would be that some unwary insect might come near enough 
for him to grab it with his hypocritical claws, and so get a 
meal. 

The praying mantes are easily recognized by the unusual 
form of the pro thorax and of the first pair of legs (Fig. 102). 
The prothorax is elongated and the front legs are large and 
fitted for seizing prey. The coxa? of the front legs are very 
long, and the femora and tibiae of these legs are armed with 
spines ; the tibia of each leg can be folded back against the 
femur so that the spines of the two will securely hold any 
insect seized by the praying mantis. 

With some species the wings resemble leaves of plants in 
form and coloring. 

All of the species are carnivorous, feeding on other in- 
sects. They do not pursue their prey but wait patiently 
with the front legs raised like uplifted hands in prayer, until 
it comes within reach, when they seize it. 

The eggs of the Mantidas are encased in chambered 
ooth ecas, which are usually fastened to the stems or twigs 
of plants (Fig. 101). 

Most of the members of this family are tropical insects; a few species, 
probably less than twenty, live in the southern half of the United States; 
and one of our native species, Stagmomantis Carolina (Fig. 102), is found 
as far north as Maryland and southern Indiana. 


Fig. ioi. — Egg- 
cases of Stagmoman- 
tis Carolina. (From 
Riley.) 


6o 


THE STUDY OF INSECTS 


Recently two exotic species have been introduced into the Northern 
States, probably by the importation of oothecae on nursery stock, and 
have become established here. These are the Mantis religiosa of Europe, 
which was first observed in this country near Rochester, N. Y., in 1899, 
and Paratcnodcra sinensis of China and Japan, which was first observed 
here at Philadelphia about 1895. 

Family Blattid^; 
The Cockroaches 

The cockroaches are well-known insects with oval depressed bodies, 
long slender antennae and legs fitted for running. The head is bent 
downward and the mouth-parts project backwards between the first pair 
of legs. 

After every one is in bed at night and all is quiet in the kitchen where 
there are water-pipes, often a throng of these small creatures come forth 
from hiding-places and, like brownies, take possession of everything. 
They race around everywhere, trying to find something to eat, almost 
anything that comes in reach of their greedy jaws. They eat book-bind- 
ings and bedbugs, if they find them, with equal alacrity. 


Fig. 103. — The Croton-bug; a, first instar; b, second instar; c, third instar; 
d, fourth instar: e, adult; /, adult female with egg-case; 4', egg-case, enlarged; 
h, adult with wings spread. All natural size except g. (From Howard and 
Marlatt.) 

Not only are these insects very destructive to our possessions, but 
owing to their fetid odor merely the sight of them awakens disgust. 

The eggs of cockroaches are enclosed in purse-like capsules (Fig. 103, g). 
These capsules, or oothecae, vary in form in different genera, but are more 
or less bean-shaped. Within, the ootheca is divided into two parallel 
spaces, in each of which there is a row of separate chambers, each cham- 
ber enclosing an egg. The female often carries an ootheca protruding 
from the end of the abdomen for several days. It has been found that 
a single female may produce several oothecae. Probably the most effec- 
tive means of ridding premises of cockroaches is by dusting the places 
they frequent with commercial sodium fluoride. 

In the Northern States our native species are usually found in the 
fields or forests under sticks, stones, or other rubbish. But certain im- 
ported species become pests in dwellings. In the warmer parts of the 
country, however, native and foreign species alike swarm in buildings of 
all kinds, and are very common out of doors. 


ORTHOPTERA 


61 


The croton-bug, Blattella germanica, is the most common house cock- 
roach in the North. It came from Europe and was first found about 
water-pipes in New York City connected with the Croton aqueduct. 
It is pale brown and only a little over \ an inch long (Fig. 103). 


Fig. 104. — The American cockroach. 


The American cockroach, Periplancta americdna (Fig. 104), is a native 
of tropical or subtropical America that has become distributed both in 
tropical and mild climates over the entire world. This is a large species 
measuring from 1 to if inches in length. 

The oriental cockroach, Blatta orientalis, is supposed to have come to 
us from Asia. It measures from f of an inch to nearly an inch in 
length and is blackish-brown in color. The wings of the female are very 
short. 


CHAPTER VI 


ORDER ZORAPTERA 


So little is known of this order which was established in 1913, that it 
is impossible at this time to define with any certainty, the characters of 
the group. But a single genus, Zorotypus, is known, and at this time, 
only about half a dozen species have been discovered. These have been 
found as follows: one each in Africa, Ceylon, Java, and Costa Rica and 
two in Florida. One of the species from Florida has also been found in 
Texas. In addition, a colony of one species has been discovered in north- 
ern Virginia. 

The known species are all minute, the largest measuring only -fa 
of an inch in length. The Florida species contain both winged and wing- 
less forms, the former being females although there are also wingless 
females. 


Fig. 105. — Zorotypus hubbardi; /, winged adult female; 5, antenna of a wing- 
less individual. (From An Introduction to Entomology.) 

The wingless adults resemble small termites. They have strong man- 
dibles but are blind. The legs arc fitted for running and the antennas are 
nine-segmented. The winged females have compound eyes and two pairs 
of wings (Fig. 105). 

These insects are social and live in colonies of various sizes under the 
bark of logs and stumps and frequently near the galleries of termites. It 
was thought, at first, that they might live as inquilines in the nests of 
termites; but recent observations do not support this view. 

* Zoraptera: zoros (£vp6s), pure; apterous (din-epos), without wings. 

62 


CHAPTER VII 
ORDER ISOPTERA* 

The Termites or White-ants 

The members of this order are social insects, living in colonies like ants. 
Each species consists of several distinct castes, the number of which differs 
in different species. Each caste includes both male and female individuals. 
In most species there are four castes as follows: first, the first reproductive 
caste, in which the wings become fully developed and are used for a swarming 
flight and then shed; second, the second reproductive caste, in which the 
wing-buds remain short; the individuals are sexually mature but retain the 
nymphal form; third, the worker caste; and fourth, the soldier caste. Ex- 
cept in a single Australian genus, the two pairs of wings are similar in 
form and in the more general features of their venation; they are long and 
narrow, and are laid flat on the back when not in use. The abdomen is 
broadly joined to the thorax; the mouth-parts are formed for chewing; the 
metamorphosis is incomplete. 

The termites or white-ants are chiefly tropical insects; but some 
species live in the temperate zones. These insects can be easily recog- 
nized by the fact that they live in ant-like colonies, by the pale color of 
the greater number of individuals of which a colony is composed, and by 
the form of the abdomen, which is broadly joined to the thorax instead 
of being pedunculate as in ants. 

The termites are commonly called white-ants on account of their 
color and of a resemblance in form and habits to the true ants. In 
structure the termites and ants are widely separated. In habits there is 
little more in common than that both are social. 

The cuticula of termites is delicate even in adults; the mature winged 
forms can withstand exposure to dry air for a limited period, as is neces- 
sary during their swarming flight ; but other members of a colony quickly 
become shriveled and die if exposed. It is for this reason that they build 
tubes constructed of earth and excrement for passage-ways, and only 
rarely appear in the open, and then merely for a brief period. 

The mouth-parts resemble those of the grasshoppers; but in the case 
of the soldier caste the mandibles are very large. The members of the 
winged sexual caste have compound eyes and a pair of ocelli. The 
workers and soldiers of most termites are blind but in case of the march- 
ing termite of Africa both the workers and soldiers possess eyes. 

The wings are long and narrow and when folded on the back of the 
insect extend far beyond the end of the abdomen. The wings of the 
sexual forms are shed after their flight. The shedding of the wings is 
facilitated by the presence in each wing near its base of a curved trans- 
verse suture, the humeral suture. 

* Isfiptera: isos (tow), equal; pier on (irrcpov), a wing. 
63 


64 


THE STUDY OF INSECTS 


With the termites the number of castes is greater than with the social 
bees, social wasps, and ants; and each caste includes both male and 
female individuals. The termites differ also from other social insects in 
that there arc at least two and sometimes three castes whose function 
is reproduction. The following castes have been found among these 
insects. 

The first reproductive caste. —At a certain season of the year, late 
spring or early summer for our most common species in the eastern 
United States, there can be found in the nests individuals with fully 
developed wings. These are sexually perfect males and females and 
constitute what is known as the first reproductive caste. In these the 
cutieula is black or dark chestnut in color and the eyes arc functional. 
A little later, these winged individuals leave the nest in a body; some- 
times clouds of them appear. After flying a greater or less distance they 
alight on the ground, and then shed their wings. 

At this time the males seek the females and they become associated 
in pairs. Each of the more fortunate couples that have escaped their 
enemies, find a suitable place for the beginning of a nest and become 
the founders of a new colony. Such a pair are commonly known as the 
king and the queen of the colony; they are also known as the primary 
royal pair. 

After the nest has been begun, the abdomen of the female becomes 
greatly enlarged, as a result of the growth of the reproductive organs and 
their products ; this is greater in certain exotic species than 
it is in those found in this country. Figure 106 represents 
in natural size the queen of a species found in India. This 
queen is comparatively small. In some species the queens 
become 6 to 8 inches in length ; such queens are incapable 
of locomotion and rest in a cell with nothing to do but lay 
eggs. In our native species of termites the queens do not 
become so large and they do not lose their power of move- 
ment. 

The second reproductive caste. — There are 
frequently found in the nests of termites in- 
dividuals which arc sexually mature but 
which retain the nymphal form of the body, 
having short wing-buds which do not develop 
further. These individuals constitute the 
second reproductive caste, which is represented 
by both males and females. The members of 
this caste are pale in color; their compound 
eyes are only slightly pigmented; and they FlG . I07 ._ Wo rker 
TeTme's never leave the nest unless by subterranean of Reticuiitermes 
tunnels. If a primary king or queen dies, its 
place is taken by individuals of the second reproductive caste. For this 
reason, the members of this caste are commonly known as substitute kings 
and queens or as complemental kings and queens. 

The workers. — If a termite nest be opened at any season of the year 
there will be found a large number of wingless individuals of a dirty 
white color, usuallv blind, and of the form represented by Figure 107. 
These are named the workers, for upon them devolve nearly all of the 
labors of the colony. A study of the internal anatomy of workers has 


Fie. 106. — ^)ueen 
white-ant 
gilvus. 


ISOPTERA 65 

shown that both sexes are represented in this caste. The worker caste is 
not always present. 

The soldiers. — ■ Associated with the workers, and resembling them in 
color and in being wingless, there occur numerous representatives of 
another caste, which can be recognized by the enormous size 
of their heads and mandibles (Fig. 108); these are the sol- 
diers. They are so named because it is believed that their 
chief function is the protection of the colony; but they do 
not seem to be very effective in this. Among the soldiers, 
as among the workers, both sexes arc represented. 

The nest-building habits of these insects are remarkable. 
In the tropics certain species build mound nests ten or 
twelve feet or more in height. Other species build large 
globular masses upon the trunks or branches of trees or upon 
other objects. Owing to the delicacy of their cuticula and 
the consequent danger of becoming shriveled if exposed, the FlG Io8 _ So] . 
termites build covered ways from their nests to such places <jier of Retkuiitermes 
as they wish to visit, if they are in exposed situations. These 
exposed nests are composed chiefly of the excreted undigested wood upon 
which the insects have fed. This is molded into the desired form and on 
drying it becomes solid. 

The termites that live in the United States do not build exposed 
nests; and, as the queens do not lose the power of movement, there is 
no permanent royal cell, centrally located. Some of our species mine in 
the earth, their nests being made under stones or other objects lying 
on the ground; some burrow only in wood; and others that burrow in 
the ground extend their nests into wood. 

In the warmer parts of this country and in the tropics termites are a 
great pest for they destroy buildings by mining into the foundation 
beams and into the timbers of the framework. Certain methods have 
been devised for the construction of buildings in warm countries for the 
purpose of making them termite-proof. 

Termites also destroy furniture and books, especially when the latter 
are stored in basements. In - infesting anything composed of wood, they 
eat out the interior, leaving a thin film on the outside. Thus a table may 
appear to be sound, but crumble tc pieces beneath a slight weight, en- 
trance having been made through the floor of the house and the legs of 
the table. 

While termites infest chiefly dead wood, there are many records of 
their infesting living plants, especially young orange and pecan trees in 
the South. 

The common species of termite in the northeastern United States is 
Reticulitermes flavipes. It often infests the wooden benches in greenhouses 
and in some localities undermines buildings by eating out the inside of 
the foundation timbers and then burrowing into the framework. 


CHAPTER VIII 
ORDER NEUROPTERA* 


The Horned Corydalus, the Lacewing-flies, the Ant-lions and others 

The members of this order have four wings; these are membranous and 
are usually furnished with many veins and cross-veins. In most members 
of the order, the wings have been specialized by the addition in the preanal 
area of many supernumerary veins of the accessory type. The mouth-parts 
are formed for chewing. The tarsi are five-jointed. The cerci are absent. 
The metamorphosis is complete. 

The order Neuroptera as now restricted differs greatly in extent from 
the Neuroptera of the early entomologists. Formerly there were included 
in this order many insects that are no longer believed to be closely re- 
lated. 

The wings of the Neuroptera are membranous 
and are usually furnished with many wing-veins. 
The two pairs of wings are similar in texture and 
usually in outline; in some the fore wings are 
slightly larger than the hind wings, in others the 
two pairs of wings are of the same size. The anal 
area is small in both fore and hind wings; it is 
rarely folded (Sialidae), and then only slightly so. 
The mouth-parts are formed for chewing. In 
several families the larva? suck the blood of their 
prey by means of their peculiarly modified man- 
dibles and maxilla?. The mouth-parts of the larva 
of an ant-lion will serve to illustrate this type of 
mouth-parts (Fig. 109). 

In this insect the mandibles {md) are very 
long, curved at the distal end, fitted for grasping 
and piercing the body of the prey, and armed with 
strong spines and setae. On the ventral aspect of 
each mandible there is a furrow extending the 
entire length of the mandible ; and over this fur- 
row the long and slender maxilla (mx) fits. On 
the dorsal aspect of the maxilla there is also a 
furrow. These two furrows form a tube which 
extends from the tip of the combined mandible 
and maxilla to the base of this organ where it 
communicates with the mouth cavity. Through this tube the blood of the 
prey is conveyed to the mouth. 

The metamorphosis is complete. The larvae that are known are pre- 
dacious or parasitic; a few of them are aquatic, Sialidae, Sisyridae, and 
* NeurOptera: neuron (vtvpov), a nerve; pteron (Trrtpov), a wing. 

66 


ioq. — Ventral side 
mouth-parts of an ant-lion: md, 
mandible; mx, maxilla. Much en- 
larged. 


NEUROPTERA 67 

certain exotic forms, but more of them are terrestrial; some when full- 
grown enter the ground and make earthen cells in which they transform, 
but most of them spin cocoons. The silk of which these cocoons are 
made, in the case of those in which the silk-organs have been described, 
is secreted by modified Malpighian vessels and is spun from the anus. 

The known Neuroptera of the world represent twenty families. 
Thirteen of these families are represented in North America; these can 
be separated by the following table. 

TABLE OF THE FAMILIES OF NORTH AMERICAN NEUROPTERA 

A. Prothorax as long as or longer than the mesothorax and metathorax combined. 

B. Fore legs greatly enlarged and fitted for grasping, p. 71 Mantispuxe 

BB. Fore legs not enlarged and not fitted for grasping, p. 71 Raphidiid^e 

AA. Prothorax not as long as the mesothorax and metathorax combined. 

B. Hind wings broad at base and with the anal area folded like a fan when not in 

use. p. 68 Sialid^e 

BB. Hind wings narrow at base and not folded like a fan when closed. 

C. Wings with very few veins and covered with whitish powder, p. 73 

Coniopterygid^; 

CC. Wings with numerous veins and not covered with powder. 

D. Antennae gradually enlarged towards the end or filiform with a terminal 
knob. 
E. Antennae short; wings with an elongate cell behind the point of fusion 

of veins Sc and R x . p. 70 Myrmeleonid^e 

EE. Antennae long; wings without an elongate cell behind the point* of 

fusion of veins Sc and Ri. p. 73 AscalaphiD/E 

DD. Antennae not enlarged towards the end. 

E. Male with pectinate antennae; female with an exserted ovipositor. 

p. 7 2 •.■••: Dilarid^e 

EE. Antennae not pectinate in either sex; female without exserted ovi- 
positor. 
F. Radius of the fore wings with apparently two or more sectors. 

G. Radius of the fore wings with apparently two sectors, one of which is 

vein R.2+3 and the other vein R 4 +5. p. 72 Sympherobiid^e 

GG. Radius of the fore wings with three or more sectors. Veins R 4 
and R 5 arise separately from vein Ri; one or more definitive acces- 
sory branches of the radius of the fore wings present, p. 72 

• • HeMEROBIIDjE 

FF. Radius of the fore wings with a single sector. 

G. Radial sector of the fore wings without definitive accessory veins 
although marginal accessory veins are present, p. 72 .... Sisyrid^e 
GG. Radial sector of fore wings with definitive accessory veins. 
H. Transverse veins between the costa and subcosta simple, p. 69 

Chrysopid^e 

HH. Many of the transverse veins between the costa and subcosta 
forked. 

I. Humeral cross-vein recurved and branched; first radio-medial 
cross- vein of the hind wings longitudinal and sigmoid, p. 73 

POLYSTCECHOTIDiE 

II. Humeral cross- vein not recurved; first radio-medial cross- vein 
of the hind wings transverse, p. 73 Berothid^e 

Of the foregoing families but three are of common enough interest to 
justify any extended discussion in this brief work. These are the Sialidae 
which embraces the horned Corydalus and the fish-flies, the Myrmelionidae 
which includes the curious ant-lions, and the Chrysopidae or lacewing-flies. 
The lesser known families are grouped at the end of the chapter. A more 
extended discussion of them may be found in "An Introduction to 
Entomology" by J. H. Comstock. 


68 


THE STUDY OF INSECTS 


Family Sialid.-e 
The Sialids 

The members of the Sialidrc differ greatly in size and appearance; 
but they agree in having the hind wings broad at the base with the anal 
area folded like a fan when not in use. In this respect they differ from 
all other Neuroptcra. 

The larva? are aquatic, predatory, and possess paired, lateral fi la- 
ments on most or on all of the abdominal segments. They leave the 
water when full-grown and transform in earthen cells on the banks of 
the streams or lakes in which they lived as larvae. The eggs are deposited 
in clusters on any convenient support near the water, in such situations 
that the young larvae can easily find access to the water. The adults 
fly but little; they are most often found resting on some support near 
the water, with the wings folded over the abdomen. 

The smoky alder-fly, Sialis infumdta, is a dusky-brownish small 
insect with a wing-expanse of about one inch. Its eggs are laid in 
patches on objects near or over the water. The larva lives beneath 
stones in swiftly flowing streams. It has paired lateral filaments on the 


Fig. no. — Larva of 
the smoky alder-fly. 


Fig. in. — Corydalus cornulus. 


Fig. ii2. — Corydalus cor- 
nuius, larva. 


first seven abdominal segments and the last abdominal segment is pro- 
longed into a tapering lash-like filament (Fig. no). 

The species that is most likely to attract attention is the horned 
corydalus, Corydalus cornutus. This is a magnificent insect, which has a 
wing-expanse of from four to nearly five and a half inches. Figure in 
represents the male, which has remarkably long mandibles. The female 


NEUROPTERA 


69 


resembles the male, except that the mandibles are comparatively short. 
The larva? are called dobsons or hellgrammites by anglers and are used by 
them for bait, especially for bass. Figure 112 represents a full-grown 
dobson, natural size. These larvae live under stones in the beds of 
streams. They are most abundant where the water flows swiftest. They 
are carnivorous, feeding upon the nymphs of stoneflies, mayflies, and 
other insects. When about two years and eleven months old, the larva 
leaves the water, and makes a cell under a stone or some other object on 
or near the bank of the stream. This occurs during the early part of 
the summer; here the larva changes to a pupa. In about a month after 
the larva leaves the water the adult insect appears. The eggs are then soon 
laid; these are attached to stones or other objects overhanging the water. 
They are laid in blotch-like masses, which are chalky-white in color, and 
measure from half an inch to nearly an inch in diameter. A single mass 
contains from two thousand to three thousand eggs. When the larvae 
hatch they at once find their way into the water, where they remain until 
full-grown. 

There are other common species of the family which closely resemble 
Corydalus but are smaller, the larger ones measuring less than two and a 
half inches in length, and having a wing- expanse of not more than four 
inches. 

The comb-horned fish-fly Chaidiodes pectinicomis, has serrate antennae 
and grayish wings while a closely related fish-fly, Nigronia serricornis, 
also with serrate antennae, has darker, more brownish wings, spotted with 
white dots. 


Family Chrysopid^e 
The Lacewing-flies or Aphis-lions 

The family Chrysopidae includes the insects commonly known as 
lacewing-flies; these and their larvae, the aphis-lions, are common and 
well-known insects; they are found upon herbage and the foliage of 
shrubs and trees throughout the 
summer months (Fig. 113). 

The adults are easily recog- 
nized by their delicate lace-like 
wings (Fig. 114) and their green 
or yellowish-green color. Their 
eyes are large and shine like 
molten gold when alive. They 
are often called golden-eyed flies; 
and because some of them when 
handled emit a disagreeable odor 
they have been called stink-flies, 
an undesirable name for such 
beautiful insects. 

The larvae of the lacewing- 
flies are known as aphis-lions, 
because they feed upon aphids; 
they are found on the foliage of 


7o 


THE STUDY OF INSECTS 


plants infested by these pests ; they also feed upon other small insects and 
the eggs of insects; they are spindle-shaped (Fig. 113) and are furnished 
with piercing and sucking mouth-parts like those of ant-lions. 

Nearly all aphis-lions arc naked ; but a few species cover themselves 
with the skins of their victims and other debris. 

The cocoons are generally found on the lower sides of leaves or on the 
supports of plants; they arc spherical and white and composed of dense 
layers of silk. In order to emerge the insect cuts a circular lid from one side 
of the cocoon; this is done by the pupa by means of its mandibles. After 
emerging from its cocoon, the pupa crawls about for a short time before 
changing to the adult state. 


Fig. 1 1 a. — Fore wing of a lace-wing fly, Chrysopa. 

The adults are often attracted to lights at night. A remarkable fact 
in the life-history of these insects is the way in which the female cares 
for her eggs. When about to lay an egg she emits from the end of her 
body a minute drop of a tenacious substance; this she applies to the 
object on which she is standing and then draws it out into a slender 
thread by lifting the abdomen; then an egg is placed on the summit of 
this thread, which dries at once and firmly holds the egg in mid-air. 

The eggs are often laid in groups which appear like a tiny forest of 
white stems with a shining ball at the summit of each. 


Family Myrmeleonid^e 
The Ant-lions 

The members of the family Myrmeleonidae are commonly known as 
ant-lions. This name was suggested by the fact that the larvae of the 

best-known species, those 
that dig pitfalls, feed 
chiefly on ants. 

The adults are graceful 

creatures. The body is 

long and slender (Fig. 

115); the antennas are 

/ \ \J short and enlarged to- 

jj6«a BLj'^ tVjL// wards the end; the wings 

\3k ^P* eKtL are * OT1 S an d narrow and 

delicate in structure. 

The larvas have broad 

Fro. I1S .- Larva, cocoon with pupa-skin projecting, and adult of f nC |. SOmewhat depressed 

an Ant-lion. bodies which taper to- 


NEUROPTERA 71 

wards each end (Fig. 115). The mouth-parts are large and powerful and 
are of the piercing and sucking type; they are described on page 66. 
The pupa state is passed in a spherical cocoon, made of sand fastened to- 
gether with silk, and neatly lined with the same material (Fig. 115). 

The life-histories of comparatively few of the species are known; 
but certain species, the larvae of which dig pitfalls in sandy places, have 
attracted much attention since the earliest days of entomology. 

Ant-lions are much more common in the southern and southwestern 
States than they are in the North. The pitfalls of the larvae are usually 
found in sandy places that are protected from rain, as beneath buildings 
or overhanging rocks. In making these pitfalls the sand is thrown out 
by an upward jerk of the head, this part of the body serving as a shovel. 
The pits differ greatly in depth, according to the nature of the soil in 
which they are made. Their sides are as steep as the sand will lie. 
When an ant or other wingless insect 
steps upon the brink of one of these 
pits, the sand crumbles beneath its 
feet, and it is precipitated into the 
jaws of the ant-lion, which is buried 
in the sand, with its jaws at the 
bottom of the pit (Fig. 116). In case 
the ant does not fall to the bottom of „. , „ , ,. 

,. •, ,1 ,1- 1 • .,1 riG. 116. — Pitfall of an Ant-lion. 

the pit, the ant-lion undermines it by 

throwing out some sand beneath it. These larvae can be easily kept in 

a dish of sand, and their habits watched. 

The most common ant-lion in the North is Myrmeleon immaculatus ; 
the larva of this species makes a pitfall. 

For a fuller account of the following families of the Neuroptera the 
student is referred to "An Introduction to Entomology" by John Henry 
Comstock. 

Family Raphidiid^e 

The Snake-flies 

i e l% e . ll7 '~ Raphidia ' The members of the Raphidiidse are found in this 
country only in the far West. They are strange- 
appearing insects, the prothorax being greatly elongated, like the neck 
of a camel (Fig. 117). 

Family Mantispidje 

The Mantis-like Nenropterons 

The members of the Mantispidae are 
even more strange in appearance than are 
those of the preceding family. Here, as in 
that family, the prothorax is greatly elon- 
gated; but the members of this family can 
be easily recognized by their remarkable fore 
legs, which are greatly enlarged and resemble 
those of the praying mantes in form (Fig\ , FlG -. " 8 - ~ M «»<«/><j. in the specimen 

TT n\ <t>i 1 £,, i/- . . ° figured the fore legs were twisted somewhat 

T 15;. I nese legs are fitted tor Seizing prey. in order to show the form of the parts. 


72 


THE STUDY OF INSECTS 


Family Sisyrid^e 

The Spongilla-flies 

The Sisyridae include a very limited number of small, smoky brown 
insects. They are called spongilla-flies because the larvae live as paras- 
ites in fresh-water sponges, the typical genus of which is Spongilla. 

Family Sympherobiid^e 

The Sympherobiids 

This family includes certain insects which were formerly classed with 
the Hemerobiidae but which exhibit a type of specialization of the wings 
that is quite different from that which is distinctively characteristic of 
that family. 

Family Hemerobiidae 

The Hemerobiids 

The Hemerobiidae include insects of moderate size; in most of our 
species the wing-expanse is between ^ and | of an inch; in one species 
of Megalomus it is only \ inch. In most of the species the body is 


Fig. iiq. — Fore wing of Hemerobius. 

brown or blackish and is often marked with yellow; in some the body 
is pale yellow. The wings are usually hyaline or pale yellowish (Fig. 119). 

Family Dilarid.e 

The Dilaridae is a small family, representatives of which are found 
chiefly in the Old World. In this family the antennae of the male are 
pectinate; and the female is furnished with an exserted ovipositor. 

A single rare species, Dllar americdnus, has been found in North Amer- 
ica; and of this only a single female individual is known of which the 
body is scarcely £ of an inch in length. 


NEUROPTERA 


73 


Family Polysixechotid,e 

The family Polystoechotidas was established to receive the genus 
Polystoeckotes, of which only two species, both 
American, are known. These are larger in- 
sects than are the members of the allied 
families, measuring in wing-expanse from if 
inches to 3 inches. They are nocturnal in 

habits (Fig. I2o). Fig. 120. — Polystcecholes punctatus. 


Family Berothid^e 

The Berothidas is a small family, which is represented in North Amer- 
ica by a single genus, Lomamyia, of which only two species are known. 

Family Ascalaphid^e 
The Ascalaphids 


Fig. 121a. — Larva 
of an Ascalaphid. 


Fig. 121. — An Ascalaphid. 

The family Ascalaphidas is quite closely allied to the 
Myrmeleonidas ; but the members of this family can 
usually be distinguished from myrmeleonids by the greater 
length of the antennas. The larvae resemble ant-lions in 
form of the body and possess the same type of mouth- 
parts (Fig. 121). 


Family Coniopterygid^e 

The Mealy-winged Neuropterons 

The Coniopterygidas is a family of limited extent; and it includes 
only small insects, the smallest of the Neuroptera; the described Amer- 
ican species measure only 3 mm. or less in length. They have the body 
and wings covered by a whitish powder. 


CHAPTER IX 
ORDER EPHEMERIDA * 


The Mayflies 

The members of this order have delicate membranous wings, triangular in 
outline and with many cross-veins and usually extra longitudinal veins; 
the hind wings are smaller than the fore wings and are sometimes wanting. 
The mouth-parts of the adidts are vestigial; those of the nymphs are fitted for 
chewing. The metamorphosis is incomplete. 

The name of this order is from the Greek word ephemeros, lasting but 
a day. It was given to these insects on account of the shortness of their 

lives after reaching the adult state. The mayflies 
are easily distinguished from other net-winged 
insects by the peculiar shape of the wings and the 
relative sizes of the two pairs (Fig. 122). 

The mouth-parts are nearly wanting, as these 
insects eat nothing in the adult state; the an- 
tennas are very small ; the abdomen is long, soft, 
and terminated by two or three many-jointed, 
thread-like appendages. 

Mayflies exhibit a remarkable peculiarity in 
their development. After the insect leaves the 
water and has apparently assumed the adult form, 
that is, after the wings have become fully ex- 
panded, it molts again. These are the only insects 
that molt after they have attained functional 
wings. The term subimago is applied to the 
instar between the nymph and the final form of 
the insect, the imago. With some species the 
fig. 122. — Mayfly. duration of the subimago stage is only a few 

minutes ; the insect molts on leaving the water ; flies a short distance ; and 
molts again. In others this stage lasts twenty-four hours or more 

What is spoken of as the brief or ephemeral life of the mayflies is 
true only of their existence in the adult state. Strictly speaking, the 
mayflies are long-lived insects. A few species pass through their life- 
cycle in a few weeks in midsummer; but as a rule one, two or three 
years are required for the development of a generation. The greater part 
of this time is passed, however, beneath the surface of the water as a 
nymph and after the insect emerges and assumes the adult form its 
existence is very brief. With many species the individuals leave the 
water, molt twice, mate, lay their eggs and die in the course of an evening 
or early morning. In the case of other species the adults may live several 
days; yet the lives of these are short compared with those of other in- 
sects. 

* EphemeYida, Ephemera: ephemeron (k^rinepov), a Mayfly. 
74 


EPHEMERIDA 75 

The eggs of mayflies are laid on or in the water. Either the female 
alights at intervals on the water to wash off the eggs or she cieeps down 
into the water to lay her eggs upon the undersides of stones. In either 
case the eggs finally rest in the water and hatch there into the nymphs 
which always live in the water. The nymphs breathe by means of tra- 
cheal gills which are usually situated along each side of the abdomen. 
They are usually active and live on bits of plant food found in the 
water. Some burrow in the bottom silt, others climb actively over green 
vegetation in the water, while others live in swiftly flowing water where 
they cling closely to submerged logs and stones. 

With many species of mayflies there is great uniformity in the date 
of maturing of the individuals. Thus immense swarms of them will 
leave the water at about the same time, and in the course of a few days 
pass away, this being the only appearance of the species until another 
generation has been developed. The great swarms of "lakeflies," 
Ephemera simulans, which appear along our northern lakes about the 
third week of July, afford good illustration of this peculiarity. 

Family Ephemeridje 

The Mayflies 

The order Ephemerida includes a single family, the Ephemeridae; 
the characteristics of this family, therefore, are those of the order, which 
are given above. 

The appearance and habits of the mayflies are certainly well known 
by those who live in the vicinity of streams, ponds, or lakes. 

In river or lake towns, during the warm evenings of late spring or 
early summer, the electric lights or street lamps are often darkened by 
myriads of insects that dash against them, and the pavements are made 
slippery by their dead bodies which have been trampled under foot. 
They are not the ordinary night-flying moths: if an individual of the 
thousands that cling to the posts and buildings in the vicinity of the 
light be examined, it will prove to be a delicate creature with dainty, 
trembling wings and two or three long, thread-like organs on the end of 
its body; the body itself is so transparent 
that the blood within can be seen pulsating. 
The front wings are large and finely netted, 
and the hind wings are small or absent (Fig. 
123). So fragile are these pale beings that 
they seem like phantoms rather than real 
fig 12? —Canis i nsec ts. No wonder that poets have sung of 
a two-winged May- them as the creatures that live only a day. 
It is true that their winged existence lasts 
often only a day or even a few hours; but they have an- fig. 124. — Nymph 
other life, of which the poet knows nothing. Down on the of Mayfly - 
bottom of a stream, feeding on mud, water-plants, or small insects, 
lives a little nymph with delicate, fringed gills along its sides and two or 
three long, many-jointed, and often feathery appendages on the end of the 
body (Fig. 124). It has strong legs and can both walk and swim. After 
about the ninth molt — there may be twenty molts in all — there appear 
on its thorax four little sacs which are the beginnings of wings; with each 


76 


THE STUDY OF INSECTS 


molt these grow larger, until finally the last skin of the water-nymph is shed, 
and gills and mouth-parts arc all left behind, and the insect comes forth, a 
winged mayfly. But there is still another change to be undergone. The 
insect has not yet reached the adult state. After flying a short distance it 
alights and sheds its skin again, a thin layer coming off from all parts of its 
body, even from its wings. After this the delicate creature is more fragile 
than before. It now has but one duty to perform in its brief life in the air, 
and that is to lay its eggs. These are sometimes laid on the surface of the 
water, and sometimes the mother wraps her wings about her like a diving- 
bell and goes down into the water and deposits her eggs on stones and then 
dies. 


This excellent illustration after Needham, shows a characteristic may- 
fly (A), with its long front legs, triangular wings, and slender caudal 
setae. It has transformed from the nymph (B), which spent its long life 
in the water where it obtained air by means of the feathery gills along 
the sides of the abdomen. 


CHAPTER X 
ORDER ODONATA* 


Fig. 125. — A dragonfly. 


The Dragon flies and the Damselflies 

The members of this order have jour membranous wings, which are 
finely netted with veins; the hind wings are as large as or larger than the 
fore wings; and each wing 
has near the middle of the 
costal margin a joint-like 
structure, the nodus. There 
are no wingless species. 
The mouth-parts are formed 
for chewing. The metamor- 
phosis is incomplete. 

Dragonflies and damsel- 
flies are very common in- 
sects in the vicinity of 
streams, ponds, and lakes; 
they are well known to all 
who frequent such places. 
The dragonflies, especially, 
attract attention on ac- 
count of their large size (Fig. 125) and rapid flight, back and forth, over the 
water and the shores; the damselflies (Fig. 128) are less likely to be noticed, 
on account of their less vigorous flight. 

Suborder ANISOPTERA f 

The Dragonflies 

The dragonflies constitute a natural division of the Odonata, the sub- 
order, Anisoptera. The wings of dragonflies are usually extended hori- 
zontally when they are at rest and the hind wings are as large and often 
are larger than the front ones. The compound eyes are very large, often 
occupying most of the surface of the head. In many cases the upper 
facets of each eye are larger than the lower ones. It is probable that in 
such eyes the part of the eye with the large facets is for night vision 
while the part of the eye with the small facets is for day seeing. Most 
dragonflies appear to have very keen sight for they follow and catch 
mosquitoes, midges and other small flies while on the wing, much as a 
hawk swoops downward and captures a weaker bird. But dragonflies are 
entirely innocent of any harm to mankind. They neither sew up people's 

* Odonata: odous (65ous). a tooth. 

f Anisfiptera: anisos (avuros), unequal; pteron (irrepov), a wing. 

11 


78 


THE STUDY OF INSECTS 


ears, as northern children think; nor bring dead snakes to life, as colored 
people in the South believe; but they are very fierce enemies to their 
insect kindred. Their long, narrow, closely-netted wings are strong, carry- 
ing them swiftly; and their jaws are powerful, and their appetites good; 
so ii is an unfortunate insect that falls in their way. 

The nymphs of dragonflies are stout-bodied creatures usually resting 
among the weeds in the water or in the silt at the bottom of a pond or 
stream. The abdomen is wide and there are no external gills. They are 
aquatic, for the female dragonflies lay their eggs either 
in the stems of water-plants, in submerged logs, or in 
wet mud or they simply fly down to the water and 
wash off their eggs from the abdomen or, alighting on a 
plant-stem, they push the long abdomen down into the 
water and lay a mass of eggs on a submerged stem or 
leaf. In any case when the eggs hatch the nymphs find 
themselves in the water and at once swim off and hunt 
for some smaller creatures to eat, for they are all 
carnivorous and ferocious. 

They have strong legs and big jaws, and are real 
insect ogres. The lower lip when extended reaches far 
out, and is armed with powerful hooks with which to 
grab their prey (Fig. 126) ; but when folded up it is so 
large that it is called a mask and gives the insect's face 
a comical resemblance to that of a bull-dog. These 
nymphs have a peculiar method of breathing. The 
caudal end of the alimentary canal is enlarged into a 
chamber and lined with tracheae. The 
nymph alternately draws water into 
this cavity and expels it; and thus 
the air in these tracheae is purified, 
this part of the alimentary canal 
acting as a tracheal gill. This process also helps the 
insect in swimming, for the water may be expelled with 
such force that the whole body is sent forward. 

When the nymph of a dragonfly is fully grown it 
leaves the water to transform. The skin of the nymph 
splits open on the back of the thorax and head, and 
the adult emerges, leaving the empty skin of the nymph 
clinging to the object upon which the transformation 
took place (Fig. 127). 

There are two families of dragonflies, the Mschnidce, 
and the Libclhdidce. 


Fig. 126. — Under 
side of head of a 
nymph of a damsel- 
fly with labium un- 
folded. (After Sharp.) 


Family ^schnid^ 


Fig. 127. — Exuviae of 
nymph of dragonfly. 


The eeschnids are mostly large species; among them are the largest, 
fleetest, and most voracious of our dragonflies. Some of them roam far 
from water and are commonly seen coursing over lawns in the evening 
twilight; but most of them fly over clear water. Some of the adults are 
marked with bright blues and greens. The nymphs eat nearly any ani- 
mal they can capture and hold. 


DON ATA 


79 


Family Libellulid^e 

This is a large family including many of our commonest and best- 
known species of dragonflies; many of them are familiar figures flying 
over ponds and ditches and by roadsides. Most of them are of well- 
sustained flight, and are seen continually hovering over the surface of 
still water; this suggested the common name skimmers which has been 
applied to them. 

Suborder ZYGOPTERA * 


The Damselflies 

The damselflies differ so much from the dragonflies and are so much 
like each other that they also constitute a well-defined suborder, Zygop- 
tera, of the Odonata. 

The two pairs of wings of 

the damselflies are similar in 

form and are either folded 

parallel with the abdomen when 

at rest or are uptilted in a 

vertical position (Fig. 128). 

The head is small and the eyes 

project on each side while the 

females possess an ovipositor 

by means of which they place 

their eggs in the stems of 

aquatic plants sometimes be- 
neath the water. 

Unlike the dragonflies, the 

damselflies are comparatively 

slow and feeble of flight al- 
though they are graceful in 

their movements. They are 

found along the margins of 

streams and ponds in which the 
nymphs pass their lives. 

Many of the damselflies are very attractive because of their bright 
blue or green metallic colors. 

The nymphs of the damselflies are slender, long-bodied creatures 
which cling to weeds in the water (Fig. 129). The abdomen is narrow 
and bears at the caudal end three flat, leaf -like tracheal gills set on edge 
in a vertical position. 

There are two families of the damselflies, the Agrionidce and the 
Ccenagrionidce. 

Family Agrionidce 

Here belong the most -beautiful of our damselflies, whose metallic 
blue or green colors are sure to attract attention. They are feeble in 
* Zygoptera: zygon (^vyov), yoke; pier on (wTepov), a wing. 


Fig. 128. — A damselfly. 


Fig. i2g. — Nymph of 
a damselfly. 


8o 


THE STUDY OF INSECTS 


flight and do not go far from the banks of the pond or stream in which 
they were developed. 

Family Cosnagrionid^e 

The members of this family are easily recognized by the shape of 
their wings, which are long, narrow, and very distinctly petiolate. 

To this family belong the smallest of our damselflies; but while our 
species are of small or moderate size, there exist in the tropics species 
that are the largest of the Odonata. Some of our species are dull in 
color; but many are brilliant, being colored with green, blue, or yellow. 
This family includes the greater number of our damselflies. 


Cn 2 Cm 

Fig. 129a. — Wings of a dragonfly. 


This is an illustration of the fore and hind wings of a dragonfly, en- 
larged to show the fine network of veins with the nodus, n, at the middle 
of the costal margin and the black area near the apex of the wing, known 
as the stigma. 


CHAPTER XI 
ORDER PLECOPTERA* 

The Stoneflies 

The members of this order have four membranous wings, with compara- 
tively few or with many cross-veins; in most of the forms the hind wings are 
much larger than the fore ivings, and are folded in plaits and lie upon the 
abdomen when at rest. The mouth-parts are of the biting type of structure, 
but are frequently undeveloped in the adults. The metamorphosis is in- 
complete. 

The stoneflies are common insects in the vicinity of rapid streams 
and on wave-washed rocky shores of lakes; but they attract little atten- 
tion on account of their inconspicuous colors and secretive habits. They 
get their name, stoneflies, from the fact that the nymphs are abundant 
under stones in the beds of streams. 

The body of an adult stonefly is flattened and the end of the abdomen 
in most species, bears two, many-segmented bristles. The antennas are 
also long, tapering and many-segmented. The mouth-parts are usually 
greatly reduced. Indeed, in some, 
the mandibles are almost membra- 
nous and of little use as chewing 
organs. In other forms they are 
firm and well fitted for biting. This 
is especially true of certain species 
of the genus, Tceniopteryx. One 
species of this genus, T. pacifica, 
known as the "salmon fly" has be- 
come a pest in the Wenatchee 
Valley in Washington because it 
eats into the swelling buds of 
apricots, peaches, and plums and 
often destroys them. 

Adult stoneflies are not partic- 
ularly attractive insects for most of Fig. 130. — a stonefly. 
them are of sober hues, black, brown, or grav, although a few which 
frequent the foliage of plants are green (Fig. 130). As a rule, they are not 
strong fliers and are usually found crawling about on stones or on plants 
near streams. Interestingly enough, several of the smaller forms appear 
early during warm days in February and March while the snow is still on 
the ground. Several small species formerly of the genus, Capnia, but now 
renamed Allocapma, are early spring appearing individuals. A very 
common one, A. pygmcea, which is dark brown to black and only about 
4 of an inch long, is known as the snow-fly because it appears on the 
* PlecSptera: plecos (ttUkos), plaited; pteron {-wrtpov), a wing. 

81 


82 


THE STUDY OF INSECTS 


snow during warm days in winter and often enters the house where it 
may be found crawling on the window-panes. 

The nymphs of stonefiies cling to the undersides of flat stones in 
swiftly flowing streams. They are flat creatures from one-half inch or 
less to one and one-half inches in length. They 
cling so closely and are so nearly the color of the 
stone that they look almost like fossils. Their 
antennas and caudal bristles and three legs on each 
side extend out like the rays of a star; the six soft 
clumps of white hair-like gills, one behind each leg, 
alone show that they are not engraved upon the 
stone (Fig. 131). These nymphs of the stonefiies 
are the favorite food of fishes, especially of brook 
trout. If a nymph is fortunate enough to escape 
the fate of being a luncheon for fish, when it is full- 
grown it crawls forth from the water and transforms 
to an adult stonefly. The east nymph-skins are 
common objects on the banks of streams which 
these insects inhabit. 

The tracheal gills of some nymphs are borne 
either on the underside of the head or on the abdo- 
men while some nymphs possess no tracheal gills 
fig. 131. — Nymph of stone- whatever, their supply of air being absorbed through 
fly - the skin. 

According to a recent classification of this order, that of Tillyard, it 
includes seven families; but only four of these families are represented in 
our fauna. The four families of our fauna can be separated by the 
following table. Most of our species belong to the Perlidae, 

A. Anal area of the fore wings with two or more series of cross-veins. 

Pteronarcid^e 

AA. Anal area of the fore wings with not more than a single series of cross-veins, 
usually with no cross-veins beyond the basal anal cell. 
B. Media of the fore wings separating from radius gradually, the two forming 

a sharp angle Perlidae 

BB. Media of the fore wings separating from radius abruptly, the two forming a 
blunt angle. 
C. Anal area of the fore wings with a forked vein arising from the basal anal 

cell. Cerci vestigial Nemourid^e 

CC. Anal area of the fore wings with only simple veins arising from the basal 
anal cell. Cerci well developed Capniid^e 


CHAPTER XII 
ORDER CORRODENTIA* 

The Psocids and the Book-lice 


# • \ 


Fig. 13: 


Psoius venosus. 


The winged members of this order have four membranous wings, with the 
veins prominent, but with comparatively few cross-veins; the fore wings are 
larger than the hind wings; and both pairs when not in use are placed roof- 
like over the body, being almost vertical, and not folded in plaits. The 
mouth-parts are formed for chewing. The metamorphosis is incomplete. 

The best-known representatives of this order are the minute, soft- 
bodied insects which are common in old papers, books, and neglected col- 
lections and which have received the popular 
name of book-lice. These low, wingless creatures 
form, however, but a small part of the order. 
The more typical winged forms (Fig. 132) bear 
a strong resemblance to plant-lice or aphids. 
The body is oval, the head free, and the protho- 
rax small. The fore wings are larger than the 
hind wings ; and both pairs when not in use are 
placed roof-like over the body, being almost 
vertical, and not folded in plaits. The mouth- 
parts are plainly chewing. The mandibles are of the ordinary, strong, 
heavy, biting type. The maxillas consist each of a body piece, a weak ter- 
minal lobe, and a four-segmented palpus. 

The venation of the wings is characteristic in this order, see page 84. 
The venation is more or less reduced; but its most characteristic feature 
is the bracing of the wing by anastomoses of the principal veins instead 
of by cross-veins, although there are one or two cross-veins in some species. 

The Corrodentia of the United States and Canada represent two fam- 
ilies, which can be separated as follows. 

A. Wings well developed; ocelli present Psocids 

AA. Wings absent or vestigial; ocelli absent Atropine 

Family Psocids 

The Psocids 

The family Psocidae includes the more typical members of the Corro- 
dentia, those in which the wings are well developed (Fig. 132). Usually 
the wings extend much beyond the end of the abdomen; but short- 
winged forms occur in species which ordinarily are long-winged. Of 
course the young of all are wingless, and there is a gradual development 
as the insect matures. 

* Corrodentia: Latin corrodens, gnawing. 
83 


8 4 


THE STUDY OF INSECTS 


The psocids occur upon the trunks and leaves of trees, and on stones, 
walls, and fences. They feed upon lichens, fungi, and probably other 
dry vegetable matter. 

The eggs are laid in heaps on leaves, branches, and the bark of trunks 
of trees. The female covers them with a tissue of threads, the silk of 
which is spun from the labium. 


Family Atropid^e 

The Book-lice and their Allies 

The most commonly observed species of this family are those known 
as book-lice, which are the minute soft-bodied insects often 
found in old books (Fig. 133). 

Take down from the shelf a time-yellowed book and 
open its neglected leaves and watch the pale tiny creatures 
that scurry across its pages; examine one of them with a 
lens, look well at its alert, knowing, black eyes, and we are 
sure you will believe that it is in search of real literature and 
not merely a feeder upon paper, as we are taught. Anyway, 
scientists have concluded that these insects look wise 
enough to bear the name Troctes divinatorius. Another 
species with small convex scales representing the front wings is Atropos 
pulsatoria. It is pale yellowish white and only ^ s of an inch in length. 

The book-lice feed on the paste in bookbindings, wall-paper and 
photographs. One species sometimes occurs in enormous numbers in 
husk or straw mattresses, in which case it is very annoying. 


Fig. 133. — A book 
louse. 


/?4+5 


Fig. 133a. — Wings of a psocid. 


These enlarged wings of a psocid illustrate the anastomosing of the 
principal veins, a form of structure which strengthens the wings with- 
out the necessity of cross-veins. 


CHAPTER XIII 
ORDER MALLOPHAGA* 

The Bird-lice 

The members of this order are wingless parasitic insects with chewing 
mouth-parts; cerci absent. Their development is without metamorphosis. 

The bird-lice are small wingless insects. The more common species 
range from -£- s of an inch to | of an inch in length. The bodies of 
these insects are flattened and usually have broad distinct heads with the 
antennas short and either exposed or hidden in grooves on the underside 
of the head. Bird-lice vary in color from almost white to yellow, tan, 
brown or nearly black with or without distinctive markings. The mouth- 
parts are on the underside of the head. The mandibles are large and 
prominent and the clypeus is enlarged into a conspicuous flap. Degen- 
erate eyes are present on the margins of the head. 

The bird-lice resemble the true lice in form and in being parasitic 
but they feed upon hair, feathers and dermal scales, while the true lice 
(Anoplura) have sucking mouth -parts and feed upon blood. 

The Mallophaga infest chiefly birds and on this account the term, 
bird-lice, is applied to the entire group; a few forms, however, are para- 
sitic upon mammals. For the most part the tarsi of those species that 
live upon mammals have but one claw which can be clamped against the 
tibia thus forming a structure well adapted for clinging to hairs. Those 
species which infest birds have two claws on the tarsi which are better 
adapted to running among feathers. The white eggs of the bird-lice are 
glued singly or in groups to the feathers and the development takes 
place on the body of the host. 

Bird-lice injure their hosts through the constant irritation which 
they cause by feeding on the dermal scales and by scratching the skin 
with their sharp claws during their incessant movements over the body 
of the host. It is to free themselves from these pests that birds wallow 
in dust. When poultry are kept in closed houses they should be provided 
with a dust bath. In addition the fowls should be treated with a pinch 
of sodium fluoride on the head, beneath each wing, on the back and 
underside of the abdomen, and two or three pinches beneath the tail 
feathers. It has also lately been discovered that nicotine-sulphate 
smeared on the perches just before the fowls go to roost will destroy all 
of the lice. 

The body-louse of the hen, Menopon biseriatum, is the largest louse 
on the hen; it is about -^ of an inch in length. It is yellowish in color 
and is found all over the body of the hen and is probably the most 

* Mallophaga: mallos (na\\6s), wool; phagein (4>aytli>) , to eat. 

85 


86 THE STUDY OF INSECTS 

serious louse on older chickens and young fowls (Fig. 134). It lays its eggs 


Fig. 135. — Goniodes stylifer. 
(From Law.) 


Fig. 136. — Tri 
chodectes scalaris 
(From Law.) 


The body-louse of the 


in clusters at the bases of feathers, especially 
about the vent of its host. 

The feather louse, Menopon pallidum, is 
another louse on the hen. It frequents the 
feathers commonly, although it is found on 
the skin of its host. 

The large turkey louse, Goniodes stylifer, 
is common on the turkey. It frequents the 
feathers on various parts of the body, espe- 
cially on the neck and breast (Fig. 135). 

Another and smaller species which in- 
fests the ox is known as, Trichodectes 
scalaris (Fig. 136). 


CHAPTER XIV 
ORDER EMBIIDINA* 

The Embiids 

This order is composed of small and feeble insects in which the body is 
elongate and depressed. The winged members of the order have two pairs 
of wings, which are quite similar in form and structure; they are mem- 
branous, extremely delicate, and folded on the back when at rest; the vena- 
tion of the wings is considerably reduced. The mouth-parts are formed for 
chewing. Cerci are present and consist each of two segments. The meta- 
morphosis may be considered as incomplete. 

This is a small order of insects, only 61 species being listed in a late 
monograph of the order. Only the males are winged and some species of 
these are wingless. The wings are usually rather long but have com- 


Fig. 137. — Embia sabulosa, male. (After Enderlein.) 

paratively few veins. Brownish bands run lengthwise of the wings along 
the courses of the longitudinal veins. The antennas are filiform and com- 
posed of 16 to 32 segments, while ocelli are wanting (Figs. 137 and 138). 

The metamorphosis of the winged males is more than incomplete and 
less than complete. It is peculiar because of this intermediate character. 

The embiids are small insects and not often seen. They live in silken 
burrows or galleries made beneath stones or other objects on the ground 
and sometimes in old decayed logs. Often there is extensive and con- 
* Embiidina: Embiidae, Embia, embios (e/j/3ios), lively. 
87 


88 THE STUDY OF INSECTS 

spicuous webbing of silk about the haunts and runways of the insects. 
There seems to be a difference of opinion regarding the position of the 


Fig. 138. — Wing of an embiid, enlarged. 

silk glands and the source of the silk. Further study of the production 
of the silk should be made. 

The embiids are widely distributed in the warmer parts of the world. 
A few species have been found in Florida, Texas, and California. They 
apparently live on decayed organic matter obtained with their chewing 
mouth-parts. 


Fig. 138a. — A female embiid. 

A female embiid, shown in this illustration, is wingless but has long, 
slender antennae. It must be remembered, however, that this insect is 
very small — it is only about § of an inch in length. 


CHAPTER XV 
ORDER THYSANOPTERA * 


The Thrips 

The members of this order are minute insects with wings or wingless. 
The winged species have jour wings; these are similar in form, long, narrow, 
membranous, not plaited, with but few or with no veins, and not commonly 
with cross-veins; they are fringed with long hairs, and in some species are 
armed with spines along the veins or along the lines from which veins have 
disappeared. The mouth-parts are formed for piercing and sucking. The 
tarsi are usually two- jointed and are bladder-like at the tip. The metamor- 
phosis is incomplete, but deviates from the usual type. 

The species of thrips occurring in our fauna are of small size, rarely 
more than ^ to \ of an inch in length. They can be obtained easily, 
however, from various flowers, especially those of the daisy and clover. 
Ordinarily it is only necessary to pull apart one of these flowers to find 


Fig. 139. — Thrips. 


Fig. 140. ■ 
original. 


Fore wing of Mlothrips nasturlii. (After Jones.) The lettering is 


several thrips. They are in many cases very active insects, leaping or 
taking flight with great agility. 

The body is long (Fig. 139). The antennas are filiform or moniliform 
and consist of from six to nine segments; they are always longer than 
the head and may be two or three times as long. The compound eyes 
are large, with conspicuous facets, which are circular, oval, or reniform 
in outline. Three ocelli are usually present in the winged forms. The 
mouth-parts are fitted for piercing and sucking; they are in the form 
of a cone which encloses the piercing organs. The cone is composed of 
the clypeus, labrum, maxillary sclerites, and labium. The piercing organs 
consist of the left mandible (the right mandible is vestigial) and the 
two maxillse. The mouth-parts of the Thysanoptera bear a striking 
resemblance to those of the Hemiptera. The wings are laid horizontally 
on the back when not in use; they are very narrow, but are fringed with 
long hairs (Fig. 140). The fringing of the wings suggested the name 
Thysanoptera. 

* ThysanSptera: thysanos (dvaavoi), fringe; pier on (irrepov), a wing. 

89 


9° 


THE STUDY OF INSECTS 


In some species one or both sexes are wingless in the adult state; 
and in others, short-winged forms occur. The cerci are absent. 

The legs are well developed, but are furnished with very peculiar 
tarsi. These are usually composed of two segments; the last segment 
terminates in a cup-shaped or hoof-like end and is usually without claws. 
Fitted into the cup-shaped end of the tarsus there is a very delicate, 
protrusile, membranous lobe or bladder, which is withdrawn into the cup 
when not in use but is protruded when the tarsus is brought into contact 
with an object. This is one of the most distinctively characteristic 
features of the members of this order. It was this feature that suggested 
the name Physopoda which is applied to this order by some writers. 

In one suborder, the Terebrantia, the female has a saw-like ovipositor 
with which she cuts slits in the tissues of plants and then deposits her 
eggs therein. In the other suborder, the Tubulifera, 
the female does not have a saw-like ovipositor and 
evidently deposits her eggs on the surfaces of objects. 
The metamorphosis of thrips is interesting because 
it approaches in some respects the type of com- 
plete metamorphosis. There is a quiescent stage 
resembling a pupa preceding the imago (Fig. 141). 

The different species of thrips vary greatly in 
habits, some being injurious to vegetation, while 
others are carnivorous, feeding on aphids and other 
small insects, the eggs of insects, and mites, especially 
the "red spider." Their most important economic 
role, however, is that of pests of cultivated plants. 
The thrips that infest plants puncture the tissue of 
the plant by their piercing mouth-parts and suck out 

Fig. 141. — Last nym- ,1 
phal stage of a thrips. tne Sap. 


Suborder TEREBRANTIA 

Among those thrips having saw-like ovipositors are found the more 
important economic species. The onion thrips, Thrips tabaci, is seriously 
injurious to onions, and often attacks cucumbers, tobacco, cabbage, and 
cauliflower. 

The greenhouse thrips, Heliothrips hczmorrhoidalis, is a tropical in- 
sect, which is often a serious pest in greenhouses; it is also found out 
of doors in the milder California climate. 

The bean thrips, Heliothrips fasciattis, is a serious pest on oranges, 
alfalfa, pear trees, and various garden crops in California. 

The orange thrips, Sctrtothrips citri, is a serious orange pest in Cali- 
fornia and Arizona; it deforms the new growth of foliage and causes 
scabbing and scarring of the fruits. 

The pear thrips, Tmnothrips inebnsequens , infests pears, prunes, 
peaches, and other deciduous fruits, both in California and in the East. 
It infests the opening buds and blossoms, stunting the leaves and blast- 
ing the blossoms. 

The strawberry thrips, Franklhriella tritici, was first described as a 
pest of wheat. It is found in the flowers of almost all wild and cultivated 
plants and is the commonest and most widely distributed of all American 
species of thrips. It is especially injurious to the strawberry. 


THYSANOPTERA 


91 


Suborder TUBULIFERA 

Those thrips which lack the saw-like ovipositor are not of great eco- 
nomic importance in our country, at least. One of the more common forms 
is the mullein thrips, Neoheegeria verbasci, the black individuals of which 
may usually be found in numbers during the fall among the rosettes of 
woolly leaves of our common mullein. 

The camphor thrips, Cryptothrips floridensis , is particularly abundant 
in Florida, where it is injurious to the camphor tree, especially to those 
individuals that have been cut back or pruned severely. 


Fig. 141a. — Trillium. 


One of our fine, large species of thrips, Ctenothrips bridwelli, is found 
on trillium and mandrake. 


CHAPTER XVI 
ORDER ANOPLURA* 


The True Lice 

The members of this order are wingless parasitic insects with piercing 
and sucking mouth-parts. Their development is without metamorphosis. 
Cerci absent. 

The order Anoplura is composed of the true lice. These are small 
wingless insects, which live on the skin of mammals and suck their blood. 
They are sharply distinguished from the Mallophaga or 
bird-lice by the possession of piercing and sucking 
mouth-parts. 

The body is more or less flattened (Fig. 142). The 
head is free and horizontal. The compound eyes are 
vestigial or are wanting. There are no ocelli. The 
antennas are three-, four-, or five-jointed. The mouth 
is furnished with a fleshy, unjointed proboscis, which 
can be withdrawn into the head or extended to a con- 
siderable length. Within this proboscis are two knife- 
like stylets; and at its base, when extended, there is a 
wreath of recurved hooks. These hooks serve to anchor 
firmly the proboscis when inserted in the skin of the in- 
fested animal. 

There is a single tarsal claw, which is opposed by a 
toothed projection of the tibia, forming an efficient 
organ for clinging to the hairs of the host. The abdomen consists of nine 
segments; there are no cerci. 

The eggs of the true lice are commonly known as "nits." They are 
attached to the hairs of the host by a glue-like substance. The young 
lice resemble the adults except in size. 

The order Anoplura is a small one of not more than 100 species at the 
present time. The most familiar forms are those infesting man and the 
domestic animals, horses, cows, sheep, swine, dogs and cats. 

The three species of lice parasitic on man belong in the family Pedi- 
culidas. They have comparatively large, convex, pigmented eyes and the 
proboscis is short. 

The most common species on man is the head -louse, Pediculus capitis. 
It lives among the hairs of the head and attaches its white eggs, or 
"nits" to the hairs. It is most common on the heads of children who 
live under unsanitary conditions. 

The body-louse, Pediculus corporis, (Fig. 143), lives on the body, espe- 
cially on the chest and back. It increases enormously among soldiers who 
are unable to bathe frequently. During the world war the "cooties," as the 
* Anoplura: anoplos (avoirXos), unarmed; oura (ovpa), tail. 

92 


Fig. 142. — Louse of the 
horse. (From Law.) 


ANOPLURA 


93 


soldiers called them, were extremely troublesome. They laid their eggs on 
threads of the clothing but it was found that both lice and eggs were 
destroyed during a proper laundering process. 

The crab-louse, Phthirius pubis, which is nearly as broad as long, 
lives in the armpits and pubic regions of the body. 

The common lice on cattle, swine, dogs and cats belong to the family 
H&matopinidce. These lice have long probosces and the eyes are vestigial 
or wanting. The short-nosed ox-louse, Hosniatopinus eurystemus, (Fig. 144) 


Fig. 143. — The body louse, 
Pediculus corporis, much en- 
larged. 


Fig. 144. — E. euryster- 
nus. (From Law.l 


Fig. 14s. — The 
louse. (homLaw.) 


is found principally on the neck and shoulders of mature cattle. It is of 
a bluish-slate color and about f of an inch long. Sodium fluoride applied to 
the infested places with a tin shaker and then rubbed in among the hairs 
with the hand is an effective remedy for these cattle-lice. 

The dog-louse, Linognaihus piltferus, has a broad abdomen and a com- 
paratively short proboscis (Fig. 145). The hog-louse, Hcematopinus suis, 
is the largest louse affecting domestic animals and is common on swine, 
especially if their quarters are neglected and allowed to become un- 
reasonably filthy. 


CHAPTER XVII 
ORDER HEMIPTERA* 

The True Bugs 

The winged members of this order have four wings; the wings of the 
first pair are thickened at the base, with thinner extremities which overlap 
on the back. The mouth-parts are formed for piercing and sucking; the 
beak arises from the front part of the head. The metamorphosis is incom- 
plete. 

People who know but little regarding entomology are apt to apply 
the term bug to any kind of insect; but strictly speaking, only members 
of the order Hemiptera are bugs. 

The bugs are very common insects. Many species abound on grass 
and on the foliage of other plants; some species live on the surface of 
water; others live within water; and a few are parasitic on birds and 
mammals. 

This order is a very important one; it includes many species in- 
jurious to vegetation; among these are some of our more important 
pests of cultivated plants. On the other hand, some of the species are 
ranked among beneficial insects on account of their predacious habits; 
for many of them feed upon noxious insects. 

The name Hemiptera was suggested by the form of the front wings. 
In these the basal half is thickened so as to resemble the elytra of beetles, 
only the terminal half being wing-like. The hind wings are membranous, 
and are folded beneath the front wings. On this account the front wings 
are often termed wing-covers; they are also termed hemelytra, a word 
suggested by their structure. 

In the Hemiptera the front wings present characters much used in the 
classification of these insects; and consequently special names have been 

applied to the different parts of them. 
The thickened basal portion is com- 
posed of two pieces joined together 
at their sides; one of these is narrow 
and is the part next to the scutellum 
when 1;he wings are closed; this is 
distinguished as the clavus (Fig. 146, 

Fir,. 146. — Diagram of a front wing of a bug: C l) \ the Other part is the COrium (Fig. 
d, clavus; co, cerium; *, membrane. ^ ^ The terminal portion of the 

front wing is termed the membrane (Fig. 146, m). In certain families, 
the Anthocoridae for example, a narrow piece along the costal margin of the 
wing is separated by a suture from the remainder of the corium; this is the 
embolium (Fig. 149, e). In certain other cases, as the Miridas for example, a 
* Hemiptera: hemi- (17/u). half; pteron (irrepov), a wing. 
94 


HEMIPTERA 


95 


triangular portion of the terminal part of the corium is separated as a dis- 
tinct piece; this is the cuneus (Fig. 148, cu). 

The mouth-parts are formed for piercing and sucking. Without 
dissection, they usually appear as a slender segmented beak arising from 
the front part of the head (Fig. 149). The beak consists of the labium 


Fig. 147. — Diagram of a front wing of an antho- 
corid: e, embolium. 


Diagram of a front wing of a mirid: 


Fig. i4g. — Head of Lethocerus: c, clypeus; /, la- 
brum; Ip, labial palpi; y, y, maxillary sclerites. 


with possibly vestiges of the labial palpi combined with it. The beak is 
deeply grooved on the dorsal surface forming a channel in which are four 
long, slender setae or bristles, two of which are the much 
modified mandibles and two the greatly changed maxilla?. 
The beak is not a piercing organ; its function is to protect 
and direct the seta? and to determine, by means of tactile 
hairs at its tip, the place where the puncture should be made 
by the setae (Fig. 150). 

The mandibular and maxillary setae when in use, are 
pushed beyond the tip of the beak in order to pierce the 
tissues of the plant on which the insect is feeding. 

Most of the Hemiptera protect themselves by the emis- 
sion of a fluid having a disagreeable odor. In the stink- 
bugs, PentatomidcB, the fluid is excreted through two 
openings on the ventral side of the thorax near the middle 
coxae. In the bedbugs the openings are in the dorsal wall of FlG lso _ Mouth . 
the first three abdominal segments. p arts of Bu e- ( After 

In the Hemiptera the metamorphosis is incomplete ; the 
newly-hatched young resembles the adult in the form of its body but lacks 
wings. After one or two molts the wing-buds appear and become 
larger and larger at successive molts. With the last molt there takes 
place a great expansion of the wings, the change at this time being much 
greater than at either of the previous molts. There are many wingless 
forms in this order. In some species all individuals are wingless; in 
others there are two forms of adults, the winged and the wingless. 


9 6 THE STUDY OF INSECTS 

TABLE FOR DETERMINING THE FAMILIES OF THE HEMIPTERA 

A. Antennae shorter than the head, and nearly or quite concealed in a cavity beneath 
the eyes. 

B. Hind tarsi with indistinct setiform claws (except in Plea, of the family No- 
tonecitidae, which are less than 3 mm. in length). 
C. Fore tarsi consisting of one segment, which is flattened or shovel-shaped, and 

without claws; head overlapping the prothorax dorsally. p. 97. . . .CORlxiDiE 
CC. Fore tarsi of the usual form, and with two claws; head inserted in the 

prothorax. p. 98 Notonectid^e 

BB. Hind-tarsi with distinct claws. 

C. Caudal end of the abdomen furnished with a respiratory tube composed of a 
pair of grooved, thread-like organs; tarsi one-segmented, p. 98. . . .Nepid.e 
CC. Caudal end of abdomen without long respiratory tube. 

D. Legs flattened, fitted for swimming; caudal end of the abdomen furnished 
with a pair of strap-like appendages (these appendages are retractile and 
are frequently withdrawn from sight) ; tarsi two-segmented, p. 99 

BELOSTOMATID/E 

DD. Legs fitted for walking; abdomen without strap-like caudal appendages. 

E. Without ocelli, p. 107 Kaucorid/e 

EE. Ocelli present, p. 100 Gelastocorid/E 

AA. Antennae at least as long as the head, usually free, rarely (Phymatidce) fitting in 
a groove under the lateral margin of the pronotum. 
B. Body linear; head as long as the three thoracic segments, p. 107 

HYDROMETRID/E 

BB. Body of various forms, but, when linear, with the head shorter than the 

thorax. 

C. Last segment of the tarsi more or less split, and with the claws of at least 

the front tarsi inserted before the apex. 

D. Hind femora extending much beyond the apex of the abdomen; the 

middle and hind pairs of legs near together and very distant from the 

front pair; beak four-jointed, p. 101 Gerrid.e 

DD. Hind femora not extending much beyond the apex of the abdomen; 
middle pair of legs about equidistant from front and hind pairs (except in 

Rhagovelia); beak three-jointed, p. 101 Veliid^e 

CC. Last segment of the tarsi entire, and with the claws inserted at the apex. 
D. Antennae four-jointed.* 

E. Hemelytra resembling network, and very rarely with any distinction 

between the corium and the membrane, p. 104 Tingid/E 

EE. Hemelytra of various forms or absent, but not of the form presented 
by the Tingidae. 

F. Beak three-jointed. 

G. Hemelytra when well developed with an embolium (Fig. 147); those 

forms in which the adult has vestigial hemelytra have no ocelli. 

H. Hemelytra vestigial; parasitic bugs preying on man, bats, and 

birds, p. 102 Cimicid.^ 

HH. Hemelytra usually well developed; not parasitic bugs. p. 102 

Anthocorid^e 

GG. Hemelytra when well developed without an embolium; those 
forms in which the adult has vestigial hemelytra have ocelli. 
H. Ocelli wanting. 

I. Body greatly flattened, p. 108 Aradid.e 

II. Body not greatly flattened, p. 103 Reduvud/E 

HH. Ocelli present, though sometimes difficult to see. 

I. Beak long, reaching to or beyond the intermediate coxae; an- 

tennae not whip-like; membrane of hemelytra with looped 
veins, p. 100 . . Saldid/E 

II. Beak not reaching the intermediate coxae. 

J. Front legs with greatly thickened femora, p. 104. .PHSTMATHME 

JJ. Front femora somewhat thickened, but much less than half 

as wide as long. p. 103 Reduviid^e 

* In some cases there are minute intermediate joints between the principal joints 
of the antennae; for the purposes of this table these intermediate joints are not counted. 


HEMIPTERA 97 

FF. Beak four-jointed. 

G. Front legs fitted for grasping prey, the tibiae being armed with 
spines and capable of being closed tightly upon the femora, which 
are stout. In the forms with long wings the membrane is usually 
furnished with four long veins, bounding three discal cells which are 
often open. From these cells diverge veins which form several 

marginal cells (Fig. 165). p. 103 Nabid^e 

GG. Front legs fitted for walking. 

H. Hemelytra with cuneus; membrane with one or two closed cells 

at its base; tarsi furnished with an arolium. p. 101 . . . . Mirid^e 

HH. Hemelytra without cuneus. Membrane with four or five simple 

or anastomosing veins arising from the base; or with a large 

number of veins arising from a cross-vein at the base. 

I. Ocelli wanting. 

J. Exceedingly flat bugs. p. 108 Aradid^e 

JJ. Rather stout and heavily formed bugs. p. 104 

PYRRHOCORID/E 

II. Ocelli usually present. 

J. Head with a transverse incision in front of the ocelli, which 

are always present, p. 107 Neidid.e 

JJ. Head without transverse incision. 

K. Membrane with four or five simple veins arising from 
the base of the membrane, the two inner ones sometimes 

joined to a cell near the base (Fig. 173). p. 105 

LyCEIDjE 

KK. Membrane with many, usually forked veins, springing 
from a transverse basal vein (Fig. 175). p. 106 

COREID/E 

DD. Antennae five-jointed.* 

E. Tibiae armed with strong spines; hemelytra with the clavus markedly 

thicker than the membrane, p. 108 Cydnid^e 

EE. Tibiae smooth or with small spines. 

F. Scutellum narrowed behind, only rarely almost covering the abdomen. 

p. 106 Pentatomid;e 

FF. Scutellum not narrowed as in the Pentatomidae, very convex, nearly 
or quite covering the abdomen, p. 108 Scutellerid^e 

* In some cases there are minute intermediate joints between the principal joints 
of the antennae; for the purposes of this table these intermediate joints are not 
counted. 

Family Corixid^e 

The Water-boatmen 

The family Corixidae includes oval, gray-and-black mottled bugs, 
usually less than half an inch in length, which live in lakes, ponds, and 
streams, in both stagnant and running water. The 
characteristic form and markings of these insects are 
shown in Figure 151. 

The beak is very short, the middle legs are very 
long and slender, and end in two claws, while the hind 
legs are long, flattened and fringed for swimming. The 
water-boatmen have the body flattened on the dorsal 
side and they swim on the ventral side in normal posi- 
tion. 

The body of these insects, as they swim through 
the water, is almost completely enveloped in air, which 
glitters like a silver armor. This air is purified by contact with the fine 
particles of air scattered through the water; so that the insects can breathe 


9 8 THE STUDY OF INSECTS 

their coats of air again and again if they are in clean water. If the insects 
are in stagnant water they have to come to the surface at intervals for a 
fresh supply of air. 

In their favorite attitude the water-boatmen are anchored to some 
object near the bottom of the water by their long middle legs. The body 
of these insects, with the air which clings to it, is much lighter than water; 
consequently whenever they lose hold upon the object to which they have 
been clinging, they rise quickly to the surface, unless they prevent it by 
swimming. They occasionally float on the surface of the water, and can 
leap into the air from the water and take flight. 

These insects feed upon the vegetable matter in the ooze at the bot- 
toms of ponds and at the same time consume the minute animals which 
are present in this plant material. 

Both the adults and eggs of species of the genus Corixa are used as 
food for man and for birds. It is said that in Mexico the natives bind 
the stalks of a sedge into bundles which are then floated on the water of 
a lake where the bugs will deposit their eggs on them in great abundance. 
The bundles are then removed and dried and the eggs beaten off on to a 
cloth and then ground into flour for baking. The adults and eggs of 
Corixa mercendria are said to be imported into England by the ton as 
food for birds, game, and fish. 

Family Notonectid^; 

The Back-swimmers 

The back-swimmers have the back shaped like the bottom of a boat 
instead of being flat like that of the water-boatmen and they differ from 
all other aquatic bugs in that they always swim on their backs. 

The favorite attitude of the back-swimmers is floating on the surface 
of the water, back downward, with the hind end of the body projecting 
sufficiently to admit of air being drawn into two air chambers on the 
ventral side of the body. There are two longitudinal furrows on the 
ventral side of the abdomen arched over by long hairs thus forming two 
tubes into which air is taken. The spiracles open into these tubes. 

The hind legs are long and act as oars and when the back-swimmers 
are disturbed they dart away toward the bottom of the 
pond. They do, however, lie right side up on the sur- 
face of the water occasionally and often take flight into 
the air. 

fig. 152. — a back- The species of the genus, Notonecta, are most com- 
swimmer - mon (Fig. 152). They have sharp piercing mouth-parts 

and sometimes sting with them unless handled carefully. 

Family Nepid^e 

The Water-scorpions 

The water-scorpions have two long filaments on the end of the body, 
which are grooved on the inner side. By putting these filaments together 
a long tube is formed, which the insects can project to the surface of the 
water, and thus obtain air for breathing, while resting on the bottom of 


HEMIPTERA 


99 


the pond. This tube conducts the air to two spiracles at the caudal end 
of the abdomen. 

The most common members of this family- 
belong to the genus Rauatra (Fig. 153). These 
are long, slender bugs with long, slender legs. 
The only other representative of the family 
found in the United States is Nepa apiculata. 
In this species the body is oval, flat, and thin, and 
measures about two-thirds of an inch in length, 
not including the breathing-tube (Fig.. 154). 
s*^ ^ -v^ The water-scorpions live 

^*»w^ g^^ among rubbish or on the stems of 
^~v Jtty-^ water-plants, in ponds and in the 
^f quiet parts of our streams. They 
JSjL Ib^ are carnivorous, and have the 
I ■ H ] first pair of legs fitted for seizing 
/ ^Hr I P ,v . v - ^n these legs the coxa is 
▼ very long, and the femur is fur- 

nished with a groove into which 
I the tibia and tarsus fit like the 

blade of a pocket-knife into the 
epa handle. 

The eggs of these bugs are in- 
serted in the decaying tissues, often stems, of 
aquatic plants. Although these insects are aquatic the second and hind 
pairs of legs are fitted for walking rather than for swimming. 


Fig. 154. 
apiculata. 


Fig. 153. — A water-scorpion. 


Family Belostomatid^; 
The Giant Water-bugs 

The common name "giant water-bugs" was applied to this family 
because it contains the largest of the Hemiptera now living. 

The members of this family are all wide and 
flat-bodied aquatic insects. The fore legs are 
for grasping, the middle and hind legs are 
fitted for swimming. At the caudal end of the 
body there is, in the adult, a pair of narrow, 
strap-like respiratory appendages, which are 
retractile. 

These insects are rapacious creatures, feed- 
ing on other insects, snails, and small fish. Like 
other water-bugs, they fly from pond to pond 
and are frequently attracted to lights. This 
is especially the case where electric lights 
are used, into which they sometimes fly and are 
killed by hundreds. On this account they are 
known in many parts of the country as ' ' electric- 
light bugs." 

Figure 155 represents Lethocerus americanus. 
In Lethocerus, the front femora are grooved 
for the reception of ,the tibia?, as in the pre- fig. 155. — Lethocerus americanus. 


THE STUDY OF INSECTS 


Fie. 156. — Belos- 
toma jluminea. 


Fig. is7 — Eggs on 
back of Abedus. 


ceding family. Another common rep- 
resentative of the family is Bendcus 

griseus. This resembles Lethocems 

americanus very closely but can be 

distinguished from it by the absence 

of the femoral groove. 

There are other smaller species of 

this family which belong to the genus 

Belostoma. Our most common species 

is Belostoma fluminea (Fig. 156). 

In this genus and in Abedus the 

eggs are carried by the males on their 
backs, where they are placed by the females, some- 
times in spite of vigorous opposition on the part of 
the male (Fig. 157). 

Family Gelastocorid^ 

The Toad-shaped Bugs 

The Gelastocoridae was formerly known as the Galgulidas. 
In these insects the body is broad and short, and the eyes are promi- 
nent and projecting; the form of the body and the protuberant eyes 
remind one of a toad (Fig. 158). Ocelli are present. The antennae are 
short and nearly or quite concealed beneath the eyes. The beak is short, 
stout, and four-segmented. The fore legs are raptorial. 

The toad-shaped bugs live on the muddy margins of 
streams or other bodies of water. Some of them make holes 
for themselves, and live for a part of the time beneath 
the ground. They feed upon other insects, which they cap- 
ture by leaping suddenly upon them. Their colors are pro- 
Fig. 158. — Gdas- tective and vary so as to agree with the color of the soil 

tocaris oculalus. Qn ^^ they ^ The ^ ^ buried ^ the ^d. 

The most common and most widely distributed representative of the 
family found in this country is Gelastocoris oculatus (Fig. 149). 


Family Saldid/E 

The Shore-bugs 

These are certain small bugs, of dark colors with white or yellow 
markings, which abound in the vicinity of streams and 
lakes, and upon damp soils, especially of marshes near our 
coasts. The shape of these shore-bugs is shown by Figure 
159. The antennas are long and conspicuous. The beak is 

three-segmented and very long. shore^u! 9 " ~~ A 

Some of the shore-bugs dig burrows, and live for a part of the 
time beneath the ground. They take flight quickly when _ disturbed, but 
alight after flying a short distance, taking care also to slip quickly into 
the shade of some projecting tuft of grass or clod where the soil agrees 
with the color of their bodies. 

Thirty-three species belonging to this family have been found in the 
United States and Canada; these represent eight genera. 


HEMIPTERA 101 

Family Veliid^; 
The Broad-shouldered Water-striders 

The Veliidae includes insects which are closely related to the water- 
striders of the next family. The bodies of these insects are usually 
stout, oval and broadest across the prothorax. The legs 
are not extremely long and the second pair is about 
equidistant from the front and hind pairs except in the 
genus Rhagovelia (Fig. 160). 

The broad-shouldered water-striders are found both 
on the banks of streams and ponds and on the surface of 
the water. The small, plump-bodied species of Micro- Fig. 160. — Rhago- 
velia are found at the water's edge but run out on the 
water when disturbed. Those of Rhagovelia which arc larger, run on the 
surface of rapid streams. 

These water bugs are dimorphic, for both fully winged and short- 
winged to wingless adults occur in the same species. 

Family Gerrid^e 

The Water-striders 

On the quiet pools of streams or calm waters of ponds one may 
usually find numbers of rather long-bodied insects with long slender legs, 

skimming about over the surface of the 
water. These are the true water-striders. 
The long middle and hind legs are near 
together and distant from the front legs 
(Fig. 161). It should be noted that some 
water-striders have comparatively short 
oval bodies. 

These insects are predacious and feed 

on other insects which happen to fall in 

fig. 161. - a water-strider. t j ie . wa t er ; they of ten jump from the water 

to capture flies. In the fall, the water-striders hide away beneath the banks 

of the streams or at the bottoms of the pools and there they remain until 

spring. 

There are commonly winged and wingless forms of the same species. 
Thus these insects are dimorphic. 

Twenty species of water-striders are known from our fauna and those 
of the genus, Halobates, are deep sea forms for they live on the surface 
of the ocean, often hundreds of miles from land. 

Family Miridve 

The Leaf-bugs 

This family, formerly known as the Capsidas, is the largest family of 
the Hemiptera. The species are small or of medium size but they vary 
greatly in form and markings. The hemelytra are rather characteristic 


io2 THE STUDY OF INSECTS 

for they are nearly always complete with clavus, corium, cuneus and 
membrane. The family contains several well-known economic forms. 

The four-lined leaf-bug, Pcecilocapsus linedtus, is a bright, 
yellow bug about § of an inch long, with four longitudinal 
black lines along its back (Fig. 162). It attacks various 
plants but is most injurious to currants, gooseberries, deutzia, 
dahlia, and weigelia. Its eggs are laid in groups of 6 to 8 in 
the stems of the food plants. There is one generation each 
fig. 162. — Poecii- year. 
ocapsus hmatus. /pj^ Garnished plant bug, Lygus pratensis, is a greenish to 

dull brown bug about -5- of an inch long with a V-shaped yellowish mark on 
the scutellum. It has been recorded on about fifty different plants and is 
often seriously injurious to asters, dahlias, and celery and to apple and 
peach trees in the nursery row. No satisfactory method of control is 
yet known. 

The apple redbug, Lygidea mendax, is another injurious species of this 
family. The nymphs are bright red in color but the adults are lighter 
and not so conspicuous. Both the nymphs and adults puncture the 
young apples with their beaks, thereby causing the fruit to become knotty, 
deformed and misshapen. The bugs can be controlled by spraying the 
trees after the petals have fallen with nicotine-sulphate at the rate of 
f of a pint to 100 gallons of water. 

Family Anthocorid^e 

The Flower-bugs 

The flower-bugs are small insects living on flowers, often on trees 
and sometimes under bark or rubbish. They are predacious and happily 
some of them prey upon injurious species of insects. The most common 
one is the insidious flower-bug, Triphleps insidiosus, which is black and 
only about ^ of an inch in length. It is common on flowers as well as 
in other situations. It preys on Phylloxera on the leaves of grapes and 
sometimes on the chinch-bug. 

Family CimicidjB 

The Bedbug Family 

The members of this family are parasitic bugs, which are either wing- 
less or possess only vestigial hemelytra. In these insects the ocelli are 
absent, the antennas are four-jointed, the beak is three-jointed, and the 
tarsi are three-jointed. Only four species belonging to this family have 
been found in America north of Mexico. These are the bat bedbug, 
Clmex pilosellns , which is parasitic on the bat, the species found in the 
nests of swallows, CEciacus vicarius, the species which infests poultry in 
the Southwest, Hamatoslphon inodorous, and the common 
bedbug, Clmex lectuldrius, which sometimes attacks poultry 
as well as man. The bedbug is a well-known pest over the 
greater part of the world. It is reddish brown in color, and 
measures when full-grown from one-sixth to one-fifth inch 
in length. The body is ovate in outline and very flat (Fig. 
1 63). It is wingless, or has very short vestigial hemelytra. 


HEMIPTERA 


103 


The begbug is nocturnal in habits, hiding by day in the cracks of 
furniture and beneath various objects. The white oval eggs are laid in 
batches in cracks and crevices of bedsteads and furniture, under seams of 
mattresses and in other places. They hatch in from six to ten days and 
the nymphs, under favorable conditions, become grown in 35 to 48 days. 
In well-heated houses the bugs will multiply all the year round. 


Family Nabid^e 
The Nabids 


and somewhat oval behind. In 
short-winged and a long-winged 


Fig. 164. — Nabis 
subcoleoptratus. 


Fig. 165. — Hemelytron of Nabis ferus. 


In this family the body is oblong 

some species there are two forms, a 
form. In case of one of 
the most common spe- 
cies, Nabis subcoleop- 
tratus, the short-winged 
form (Fig. 164), in 
which the hemelytra 
barely reach to the 
second abdominal segment, is much more abundant than 

the long-winged form. It is of a shining jet-black color with yellowish 

legs. 

Family Reduviid^; 
The Assassin-bugs 

This is a large family containing bugs of very diverse form. They 
are predacious on other insects and sometimes on the higher animals, 
even attacking man. The beak is three-segmented and very efficient as a 
puncturing instrument. 

The masked bedbug hunter, Reduvius personatus, has become noto- 
rious as a "kissing bug" for it often inflicts painful wounds on the cheeks 
and lips of human beings with its beak. The nymphs of this bug are 
masked with lint and dust which adhere to the body by reason of a 
sticky substance secreted by the insect. These nymphs frequent houses 
and often destroy bedbugs when the latter can be found. The adult 
(Fig. 166) is very dark brown and about § of an inch in length. 
The big bedbug, 
Triatoma sanguisilga, 
which occurs in the 
southern states is nearly 
an inch long. It attacks 
man as well as chickens 
and sucks the blood. 

The wheel -bug, Ari- 
lus cristatus, is of inter- 
Redu- est because of the 
cogwheel-like crest on 
See page 108. w 
The thread-legged bug, Emesa brevipennis, is a curious form with its 
long, slender body and thread-like legs (Fig. 167). 


Fig. 166.— 

vius personatus 


its prothorax. 


Fig. 167. — Emesa brevipennis. 


io4 


THE STUDY OF INSECTS 


Family Phymatid^ 

The Ambush-bugs 

The ambush-bugs are notable for the form of the front legs which are 
modified into grasping organs. The antennae are also notable because 
the terminal segment of each is more or less enlarged into a knob-like 
form. 

The most common member of this family is Phymata erosa 
(Fig. 1 68). It is a greenish insect, with a black band across 
the broadly expanded abdomen. It conceals itself in flowers, 
fig. i 68.— and captures the insects which come to sip nectar. It is es- 
Phymata erosa. p ec j a iiy abundant among the flowers of golden-rod. It over- 
powers and captures insects like cabbage butterflies, honey-bees and large 
wasps. 


Family Tingid^; 

The Lace-bugs 

The Tingida? are doubtless the most easily recognized of all Hemip- 
tera. The lace-like structure of the hemelytra, usually accompanied by 
expansions of the prothorax of a similar structure, gives these insects a 
characteristic appearance which 
needs only to be once seen to be 
recognized in the future (Fig. 169 
and 170). They are generally very 
small insects. But they occur in 
great numbers on the leaves of 
trees and shrubs, which they 
puncture in order to suck their 
nourishment from them. 'Their 
eggs are fastened to leaves, and 
covered by a brown, sticky sub- 
stance ; they appear more like fungi 
than like the eggs of other insects. 


Fig. i6q. — A tingid, Cory 
/'mi ha iircuala. 


Fig. 170. — Eggs and 
nymph of the tingid, C 
arcuata. 


Family Pyrrhocorid^ 
The Cotton-stainer Family 

The members of this family are rather stout and heavily formed 
bugs, and are generally black or brown, marked with red. In this family 
there are two or three large cells at the base of the membrane, and from 
these arise branching veins (Fig. 171). 

The most important member of this family is the cotton-stainer, 
Dysdercus suturellus, which is about § of an inch long (Fig. 172). 
The head, front part of thorax, and underside of the abdomen are red 
while the dark brown hemelytra are marked with light yellow lines. The 
nymphs are red. The insect punctures the immature bolls and the seeds 
within. The seeds exude a material which stains the lint an indelible 


HEMIPTERA 


105 


yellowish color. The colonies of red nymphs may be brushed off into pans 
of kerosene or the bugs may be trapped in the fall under and on heaps 
of cotton seeds placed here and there in the field and then destroyed. 

The bordered plant-bug, Enryophthal- 
rnus succinctus, is probably the most widely 
distributed species of this family. It is 
found from New Jersey to Mexico. It is 
brownish-black with the sides of the pro- 
thorax margined with orange or red. It has, 
under certain conditions, become injurious 
to cotton. 


Fig. 171. — Hemelytron of Euryophthalmus suc- 
cinctus. 


Fig. 172. — Dysdercus su- 

lurellus. 


Family Lyg.^eid^ 
The Chinch-bug Family 

This, too, is a large family, about two hundred species being known to 
occur in the United States. Here the membrane of the wing-covers is 
furnished with four or five simple 
veins, which arise from the base of 
the membrane; sometimes the two 
inner veins are joined to a cell near 
the base (Fig. 173). 

This family contains the chinch- 
bug, BllSSUS leucopterus, the most FiG.173— Hemelytron of Ly S *«s. 

destructive member of the family occurring in the United States. Al- 
though quite widely distributed, its injuries have attracted 
most attention in the Mississippi Valley, where it has de- 
stroyed many million dollars' worth of grain. It is a small 
bug, measuring less than one-sixth of an inch in length. 
It is blackish in color, with snowy-white wing-covers, each 
marked with a dark spot and Y-shaped line, as shown in 
the Figure 174. The species is dimorphic, there being a 
short-winged form. 

There are two generations of the chinch-bug each year; they winter 
as full-grown insects and hide in stools of grasses. In the early spring 
they come forth and lay their eggs in fields of grain upon the roots or 
stems beneath the ground. The eggs hatch in about two weeks. The 
nymphs are red, and feed at first upon roots; afterwards they attack the 
stalks of the plants they infest. In about 45 days they get their growth. 
About this time the whole brood starts out to find new pastures, and 
they all march on foot in one direction, like an army. Although they are 
tiny insects they number millions, and so attract much attention. As 
soon as they find a new field of grain they lay their eggs for another brood. 


io6 


THE STUDY OF INSECTS 


Family Coreid^e 

The Squash-bug Family 

This family is also a very extensive one, including many species of 
various forms. They may be distinguished by the venation of the 
membrane of the hemelytra. This part is furnished with many veins, 

most of which spring 
from a cross-vein near its 
base (Fig. 175). 

The squash-bug, An- 
asa tristis, is a good 
example of this great 
family. These when full- 
grown are brownish-black bugs, with some yellow spots along 
the edges of the abdomen (Fig. 176), and are dirty yellow on 
the under side. This bug winters in the adult state, and takes the first 
opportunity in the spring to lay its eggs on the leaves of squash and 
pumpkin vines. As soon as they hatch, the young bugs attack the vines 
and are apt to destroy them entirely. 


FlG. 175. — Hemelytron of Leptocoris Irivillalus. 


Fig. 176. — Anasa 
iristis. 


Family Pentatomid^e 

The Stink-bug Family 

This is a family the taste and odor of which most of us know to our 
sorrow. We learn the flavor in one experience, and conclude that once is 
enough for a lifetime. 

It should not be concluded, however, that only members of this 
family possess this disagreeable odor; for most of the Hemiptera protect 
themselves by rendering their bodies unpalatable in this way. 

This nauseous odor is caused by a fluid which is excreted through 
two openings, one on each side of the under side of the body near the 
middle coxas. 

In this family the antennae are five-jointed; the scutel- 
lum, although large, is usually less than half as long as the 
abdomen (Fig. 177). 

Some species of this family feed upon other insects, and 
so are very helpful to the farmer, one species especially 
{Perillus bioculatus) being a gallant fighter against the 
potato-beetle. Other species feed entirely upon vegeta- 
fig. 177— a bles, while others live upon both vegetable and animal 

pentatomid. matter . 

The harlequin cabbage-bug or calico-back, Murgdntia histrionica, 
is very destructive to cabbages, radishes, and turnips in the southern 
states and on the Pacific coast. It is black with bands, stripes, and 
margins of red or orange or yellow. The full-grown bugs live through 
the winter, and in the early spring each female lays on the under surface 
of the young leaves about twelve eggs in two parallel rows. The young 
bugs are pale green, with black spots. They mature in a few days, so 
there are many generations in one season. 


HEMIPTERA 


107 


Other Families of the Hemiptera 

For a more detailed discussion of the following families the student is 
referred to "An Introduction to Entomology" by J. H. Comstock. 

Family Naucoridce. The creeping water-bugs are flat-bodied mod- 
erate-sized insects living in water. The front legs are fitted for grasping 
and the insects live among reedy or grassy, quiet waters where they creep 
about among the plants. There are only two genera in our fauna, Pelo- 
coris and Ambry sus, with but a few species. 

Family Ochteridce. These are shore-inhabiting bugs with only a few 
species in the United States, all of the genus Ochterus. 

Family Mesoveliidce. There are only two species of this family known 
in our fauna. Both are small insects less than one-fourth of an inch in 
length. One, at least, lives on the surface of the water in quiet ponds. 
Family Hebrides. This is a family of small plump-bodied bugs meas- 
uring less than one-eighth of an inch in length. There are two genera, 
Hebrus and Merragdta, containing but six species in our fauna at the 
present time. 

Family Hydrometridce. At least three species of these long, narrow- 
bodied insects with long, slender legs and antennae occur 
in the United States (Fig. 178). They creep slowly upon 
the surface of the water in quiet weedy places. 

Family Schizopteridce. But a single species of this 
family has yet been found in the United States. This 
one is only about -jV of an inch in length. It lives among 
fallen leaves, rubbish, and earth. 

Family Dipsocorida. There are only two or three 
species of this family and they are all small, less than 
1*2 of an inch in length. 

Family Isometopidce. Two species of this family 
have been found in the Southwest and two in the East. 
Both of the eastern forms are rare and all of them are 
small measuring not more than -^ of an inch in length. 

Family Termatophylidce. This family, although small 
in number, is world wide in distribution. One species 

has been found in the United States, but only 
the female of this one has been described. 

Family Polyctenidce. The many-combed bugs 
are rare but are of interest because they are 
parasitic on bats. One species, Hesperoctenes 
longiceps, has been described from a bat in 
southern California. The hemelytra are vestigial. 
Family Enicocephalidce. These are called 
the unique-headed bugs because the head 
differs in form from all other Hemiptera. Ap- 
parently but two species have been found up 
to this time in the United States. 

Family Neididce. The Neididae, known as 

stilt-bugs, are striking in appearance because 

the body is long and narrow and is furnished 

fig. no. — jaiysmspinosus. with long slender antennae and legs (Fig. 179). 


Fig. 178. — Hydrometra. 


io8 


THE STUDY OF INSECTS 


Of the few species in our country but two are widely distributed. These 
are sluggish insects found in the undergrowth of woods and in meadows 
and pastures. The most common representative is J&lysus spindsus which 
is widely distributed in the United States and Canada. It has been found 
to be a serious pest of tomatoes in some localities for it punctures the stems 
and fruit and sucks out the juices. 

Family Aradidcs. The members of this family are known as the flat- 
bugs because their bodies are very flat and thin. They live in the cracks 
or beneath the bark of dead trees and logs. They are usually brownish 
to black and the hemelytra are reduced in size. Some of them somewhat 
resemble bedbugs and because of this there was an old idea prevalent in 
the days of log houses that bedbugs got into the house from the logs used 
in constructing it. There are several genera in this family and at least 
fifty-nine species are known in this country. 

Family Cydnidce. This family includes two fairly well defined groups 
of bugs, the burrower-bugs and the negro-bugs. Of the first group the 
species are generally black or very dark brown and they 
burrow in sandy places or beneath sticks or stones or at the 
roots of grasses. 

The negro-bugs are short, broad, and very convex. 
They are mostly black and beetle-like in appearance. They 
infest various plants. There are only a few species. 

Family Scutelleridce. These are known as the shield- 
backed bugs because the scutellum covers nearly the 
whole of the abdomen. The body is short, broad, and 
convex (Fig. 180). 


Fro. 

shield-backed bu; 


Fig. 180a. — The wheel-bug, Arilus cristatus (From Glover). See page 103. 


CHAPTER XVIII 
ORDER HOMOPTERA* 


Cicadas, Leaf hoppers, Apkids, Scale-bugs, and others 

The winged members of this order have four wings, except in the family 
Coccidce; the wings are of the same thickness throughout, and usually are 
held sloping at the sides of the body when at rest. The mouth-parts arc 
formed for piercing and sucking; the beak arises from the hind part of the 
lower side of the head. The metamorphosis is incomplete except in some highly 
specialized forms. 

Although the Homoptera is a well-defined order, the families of which 
it is composed differ greatly in the appearance of their members. For 
this reason there is no popular name that is applied to the order as a 
whole. 

The wings of the Homoptera are usually membranous, but in some 
the front wings are subcoriaceous. In these cases, however, they are of 
quite uniform texture throughout, and not thickened at the base as in the 
Hemiptera. 

Many wingless forms exist in this order; in the family Coccidas the 
females are always wingless; and in the family Aphididas the males may 
be either winged or wingless, while usually the sexually perfect females 
and certain generations of the agamic 
females are wingless. In the Coccidce 
the males have only a single pair of 
wings, the hind wings being represented 
by a pair of club-like hal teres. 

In the Homoptera the front part of 
the head is bent under and back so that 
the beak arises from the hind part of the 
lower side of the head. 

The mouth-parts are formed for 
piercing and sucking. The piercing 
organs consist of four long, bristle-like 
setae, the mandibular and maxillary 
setas; these are enclosed in a long, 
jointed sheath, which is the labium. 
The labium and the enclosed setas con- 
stitute what is commonly termed the 
beak. 

As an example of the homopterous ««• maxill] ,7 f , seta A ; , c \ c \ y t pe ^ l \ labi T, ; ,'A epi ; 

... * r pharynx. (After Marlatt with changed lettering.) 

type ot head and mouth-parts those of a 

cicada are probably the most available, on account of the large size of these 
insects and the comparative ease with which the parts of the head can be 
distinguished. Figure 181 represents a front view of the head. 
* HomSptera: homos (6/j.os), same, pteron (irrepop), a wing. 

IOQ 


Fir,. 181. — Head of cicada: mi. rmndibularseta; 


no THE STUDY OF INSECTS 

TABLE FOR DETERMINING THE FAMILIES OF THE HOMOPTERA 

A. Beak evidently arising from the head; tarsi three-jointed; antennae minute, 
bristle-like. 
B. With three ocelli, and the males with musical organs. Usually large insects, 

with .-ill the wings entirely membranous, p. i 10 Cicadid/E 

BB. ( kvlli only two in number or wanting; males without musical organs. 

C. Antennae inserted on the sides of the cheeks beneath the eyes. p. 113 

Fulgorid^e 

CC. Antenna' inserted in front of and between the eyes. 
I '. 1'rothorax not prolonged above the abdomen. 
E. Hind tibiae armed with one or two stout teeth, and the tip crowned with 

short, stout spines, p. 1 1 1 Cercopid^e 

EE. Hind tibiae having a row of spines below, p. 112 CicadelliDjE 

DD. Prothorax prolonged into a horn or point above the abdomen, p. 112 

Mkmbracid/e 

AA. Beak apparently arising from between the front legs, or absent; tarsi one- or 
two-jointed; antennae usually prominent and threadlike, sometimes wanting. 
B. Tarsi usually two-jointed; wings when present four in number. 
C. Wings transparent. 

D. Hind legs fitted for leaping; antennae nine- or ten-jointed, p. 114 

Chermid.e 

DD. Legs long and slender, not fitted for leaping; antennae three- to seven- 
jointed, p. 114 and 118 Aphidid^e and Phylloxerid.e 

CC. Wings opaque, whitish; wings and body covered with a whitish 

powder, p. 1 18 Aleyrodioe 

BB. Tarsi usually one-jointed; adult male without any beak, and with only 
two wjfigs; female wingless, with the body either scale-like or gall-like in 
form, or grub-like and clothed with wax. The waxy covering may be in the 
form of powder, of large tufts or plates, of a continuous layer, or of a thin 
scale beneath which the insect lives, p. 119 Coccid^e 

Family Cicadid^e 

The Cicadas 

The large size and well-known songs of the more common species of 
this family render them familiar objects. It is only necessary to refer to 
the periodical cicada and to the harvest-flies, one of which is represented 
by Figure 182, to give an idea of the more striking 
characteristics of this family. 

The species are generally of large size, with a 
subcorneal body. The head is wide and blunt, with 
prominent eyes on the outer angles, and three bead- 
like ocelli arranged in a triangle between the eyes. 
They are notable for the complex musical organs of 
of the males with which they produce their so-called 
song, a loud, sustained, usually high-pitched noise 
emitted during the warm days of summer. There 
are over seventy species of cicadas in our fauna. 

They are several species of cicadas that are 
commonly known as dog-day cicadas or harvest-flies ; 
a common one of these is the species that has re- 
ceived the popular name of the lyreman; this is 
Tibicen linnet (Fig. 182). The shrill crv of this 

Fig. ito.-TMcenlmnei. spccies> wWch ig the most prominent of the various 

insect sounds heard during the latter part of the summer, has made its 
author familiar to many. This insect varies both in size and colors. It 


HOMOPTERA in 

commonly measures two inches to the tip of the closed wings; it is black 
and green, and more or less powdered with white beneath. 

The member of this family that has attracted most attention is the 
periodical cicada, Magicicada septcndecim. This species is commonly 
known as the seventeen-year locust; but the term locust when applied 
to this insect is a misnomer, the true locusts being members of the order 
Orthoptera. This species is remarkable for the long time required for it 
to attain its maturity. The eggs are laid in the twigs of various trees 
by the female. Sometimes this cicada occurs in such great numbers that 
they seriously injure small fruit trees, by ovipositing in the twigs and 
smaller branches. The nymphs hatch in about six weeks. They soon 
voluntarily drop to the ground, where they bury themselves. Here they 
obtain nourishment by sucking the juices from the roots of forest and 
fruit trees. And here they remain till the spring of the seventeenth year 
following. They emerge from the ground during the last half of May, at 
which time the empty pupa-skins may be found in great numbers, cling- 
ing to the bark of trees and other objects. It is at this period that the 
cicadas attract attention by the shrill cries of the males. The insects 
soon pair, the females oviposit, and all disappear in a few weeks. 

Seventeen distinct broods of this species have been traced out; so 
that one or more broods appear somewhere in the United States nearly 
every year. In many localities, several broods co-exist, each brood 
appearing in distinct years. There is a race of the species in which the 
period of development is only thirteen years. This variety is chiefly a 
southern form, while the seventeen-year broods occur in the more north- 
ern states. 

Family Cercopid^e 
The Spittle-insects or Frog-hoppers 

During the summer months one often finds upon various shrubs, 
grass, and other herbs, masses of white froth. In the midst of each of 
these masses there lives a young insect, a member of this family. In 
some cases as many as four or five insects inhabit the same mass of froth. 
It is asserted that these insects undergo all their transformations within 
this mass; that when one is about to molt for the last time, a clear 
space is formed about its body and the superficial part of the froth dries, 
so as to form a vaulted roof to a closed chamber within which the last 
molt is made. 

The adult insects wander about on herbage, shrubs, and trees. They 
have the power of leaping. The name frog-hoppers has doubtless grown 
out of the fact that formerly the froth was called "frog-spittle" and was 
supposed to have been voided by tree-frogs from their mouths. The 
name is not, however, inappropriate, for the broad and depressed form 
of our more common species is somewhat like that of a frog. 

Most of the froth of spittle insects is voided from the anus but a 
mucilaginous material excreted by large hypodermal glands on the 
seventh and eighth abdominal segments is added to the mass which 
renders it viscous and helps to retain the air bubbles introduced into it 
by the insect. The froth is evidently a means of protection. 

In this family the antennae are inserted in front of and between the 
eyes; the prothorax is not prolonged over the abdomen, as in the Mem- 


THE STUDY OF INSECTS 


bracida? ; 


Fig. 183. - 
Lepyronia quad 
rangularis. 


the tibiae are armed with one or two stout teeth, and the tip is 
crowned with short, stout spines, as shown in Figure 183. 

One of the more common and very widely distributed 
species is Lepyronia quadrangular is (Fig. 183). The adult 

of this species is a brownish insect, densely covered with 
microscopic hairs, and black beneath; the hemelytra are 
marked with two oblique brown bands. 


Family Membracid^e 

The Tree-hoppers 

In the tree-hoppers, the prothorax extends backward like a roof over the 
body, often quite covering it. In some cases the prothorax is 
elevated above the head, so that it looks like a horn (Fig. 184) ; 
in others it is shaped like a tam-o'-shanter; and sometimes 
it has horns, one on each side, which have given one species fig. is 4 . — .En- 
the name of the buffalo tree-hopper. chenopa binotata. 

Many species of this family live upon bushes or small trees, and all 
are good leapers; hence the common name, tree-hoppers. Some species 

excrete honey-dew, and are attended by ants. 
All feed upon plants, but they seldom appear 
in sufficient numbers to do much damage. 
Sometimes the females of the buffalo tree- 
hopper, Ceresa bubalus, injure apple trees by 
laying their eggs in large numbers in the 
bark of the smaller branches (Fig. 185). 
The tree-hoppers of the genus, Telamona, have a hump-backed ap- 
pearance (Fig. 186). In many of the tree-hoppers, the eyes have a keen, 


Fie. 185.— 
Ceresa bubalus. 


iS6.— Tcla- 


Fig. 187. — Tree-hoppers. 


droll look, and the line that separates the head from the prothorax 
gives them the appearance of wearing glasses (Fig. 187). 


Family Cicadellid^e 

The Leaf hoppers 

The most abundant members of the Homoptera, except perhaps the 
aphids, are the leafhoppers. Large numbers of them can be easily col- 
lected by sweeping grass, herbage, or the foliage of shrubs. 


HOMOPTERA 


113 


The leafhoppers are slender, small insects, distinguished by the form 
of the hind tibiae, which are nearly or quite as long as the abdomen, 
curved, and armed with a row of spines on each margin (Fig. 
188). 

Among the leafhoppers that have attracted attention on 
account of their injuries to vegetation are the following: the 
destructive leafhopper, Euscelis exitiosus, which is represented 
greatly enlarged by Figure 189, sometimes infests 
grains to a serious extent. The grape-vine leaf- 
hopper, Erythroneura comes, is a well-known pest 
that infests the leaves of the grape. It is about i4 J 
one-eighth inch in length with varied markings fig. i8q — 
of yellow and red on its back. Eleven varieties Eu ^ dis cxlti 
of this one species have been described. The rose 
leafhopper, Empoa rosce, is also a well-known pest, as it often swarms 
on the leaves of roses, doing great damage. Its presence is usually in- 
dicated by numerous white cast skins adhering to the lower side of the 
leaves. The potato leafhopper, Empoasca fabcr, is one of the chief pests 
of the potato. In addition to injuring the plants, it disseminates a disease 
of the foliage known as "hopperburn." The adults are about | of an inch 
long and of a pale yellowish-green color. 


Fig. 188. — On 
comctopia undata 


Family Fulgorid^e 

The Lantern-fly Family 

This family is remarkable for certain exotic forms which it contains. 
Chief among these is the great lantern-fly of Brazil. Scarcely less strange 
are the candle-flies of China and the East Indies. The popular names of 
these insects refer to the fact that they were thought to be phosphorescent, 
but we know of no native species that possesses this peculiarity. There 
does not seem to be any typical form of the body characteristic of this 
family. The different genera differ so greatly, that on superficial exami- 
nation they appear to have- very little in common. Some even resemble 
butterflies and moths, while others might easily be mistaken for neuropter- 
ous genera. 

The most useful character for recognizing these insects is the form 
and position of the antennae. These have two large basal segments and a 
bristle-like terminal portion. They are situated on the side of the cheek 
beneath the eyes. Although the Fulgoridae are vegetable feeders, none 
of our species has attracted the attention of agriculturists. There are, 
however, certain exotic species which do great injury to crops. 
The two accompanying fig- 
ures will serve to show the 
wonderful variations in form of 
these insects ; many other types 
exist. Figure 190 represents a 
common species of Scolops, 
which occurs in grassy places, fig. 191.- 
In this genus the head is greatly prolonged, as with tnonalis - 
the exotic candle-flies. Figure rgi represents Ormenis septentrionalis , a 
beautiful pale-green species powdered with white, which feeds on wild 


Fig. 190. — Scolops. 


■ Ormenis seplen- 


ii 4 THE STUDY OF INSECTS 

grape-vines, drawing nourishment from the tender shoots and midribs of 
the leaves during its young stages. 

Family Chermid^e 

The Jumping Plant-lice 

The jumping plant-lice are comparatively small insects; our more 
common species measuring only from one-twelfth to one-sixth inch in 
length, and it is rare that we find any twice that size. 
When examined with a lens they appear like tiny cicadas 
(Fig. 192). Their hind legs are formed for jumping; their 
antennae are ten-jointed or rarely nine- or eleven-jointed. 
They are very active creatures, jumping and taking flight 
when disturbed. 

The Chermidse subsist entirely upon the juices of 
plants, and some of them cause serious injuries. Many 
species form galls; one of the larger of these infests the 
leaves of hackberry. 

The most destructive member of this family in the 

-The near- United States is the pear-tree psyllia, Psyllia pyricola. 

^Psyiiia, greatly This is a minute species, measuring only one-twelfth inch 

in length to the tip of the folded wings (Fig. 192). 
The eggs are laid early in the spring in the creases of the bark and in 
the leaf-scars of the smaller branches. The young nymphs migrate to 
the axils of the leaf petioles and the stems of the forming fruit; later 
they spread to the under side of the leaves. They secrete large quan- 
tities of honey-dew, upon which a blackish fungus grows. There are at 
least four generations each year. Badly infested trees shed their leaves 
and young fruit in midsummer. In some cases orchards have been so 
badly injured by this pest that they have been cut down by their owners. 

Family Aphidid^j 
The Plant-lice or Aphids 

The plant-lice or aphids are well-known insects; they infest nearly 
all kinds of vegetation in all parts of the country. Our most common 
examples are minute, soft-bodied, green insects, 
with long legs and antenna?, which appear on various 
plants in the house and in the field. Usually, at 
least, in each species there are both winged and 
wingless forms (Fig. 193). There are many species 
of aphids, nearly all of which are of small size ; some 
measure less than -^ of an inch in length; and our fig. i 93 . — a group of aphids. 
largest species, only \ or \ of an inch. 

The body is usually more or less pear-shaped. The winged forms 
have two pairs of delicate, transparent wings. These are furnished with 
a few simple or branched veins. The first pair of wings is larger than the 
other, and the two wings of each side are usually connected by a com- 
pound hooklet or several hamuli. The beak is three-jointed, and varies 
greatly in length; sometimes it is longer than the body. The compound 


HOMOPTERA 115 

eyes are prominent, and ocelli are also usually present. The antennas are 
from three- to seven-jointed. On the back of the sixth abdominal seg- 
ment there is, in many species, a pair of tubes, the cornicles, through 
which a wax-like material is excreted. In some genera these organs are 
merely perforated tubercles, while in still other genera they are wanting. 

Many species of aphids excrete a sweet substance known as honey- 
dew from the posterior end of the alimentary canal. It is sometimes 
produced in such quantities that it forms a glistening coating on the 
leaves of the branches below the plant-lice, and stone walks beneath 
shade-trees are often densely spotted with it. This honey-dew is fed 
upon by bees, wasps, and ants. The bees and wasps take the food 
where they find it, paying little if any attention to its source; but the 
ants recognize in the plant-lice useful auxiliaries, and often care for them 
as men care for their herds. This curious relationship will be discussed 
further in the chapter on ants. 

In addition to honey-dew, many aphids excrete a white waxy sub- 
stance. This may be in the form of powder, scattered over the surface of 
the body, or it may be in large flocculent or downy masses; every grada- 
tion between these forms exists. 

The plant-lice are remarkable for their peculiar mode of development. 
The various species differ greatly in the details of their transformation, 
but the following generalizations illustrated by the life history of the 
cabbage aphid, Brevicoryne brassicce, may be made. 

The stem-mother. — In the spring there hatches from each surviving 
egg which was laid on a cabbage stump in the fall, a female aphid known 
as the stem-mother because she gives rise to all of the succeeding genera- 
tions during the summer. She brings forth her young alive and is there- 
fore viviparous. She also bears young aphids without having mated 
(there are no male aphids in the spring) and is therefore parthenogenetic. 

The wingless agamic form. — This stem-mother gives birth to young 
which do not develop wings and which are all females. These reproduce 
parthenogenetically and are known as the wingless agamic forms. These 
reproduce their kind for a variable number of generations and then pro- 
duce the next form. 

The winged agamic form. — After a variable number of generations of 
the wingless agamic form have been developed and the food-plant has be- 
come overstocked by them, there appears a generation which is winged. 
These are all parthenogenetic, viviparous females. They are known as 
the winged agamic forms. These migrate to ether cabbage plants which 
are not overstocked with the wingless pi ant -lice. 

When the migrating winged agamic form becomes established on fresh 
plants, it produces young which are all females of the wingless agamic 
form. After a variable number of generations of the winged and wing- 
less forms have been developed and fall approaches, the egg-laying (ovip- 
arous) females and the males are produced. 

The males and oviparous females. — These are the true sexual forms. 
They pair and each female lays one or more eggs on the cabbage stump 
which rest over the winter. In the case of the cabbage aphid the ovip- 
arous female is wingless and the male is winged. Other aphids differ 
in this respect. In some species the females are winged and in a few the 
males are wingless. 

Primary and secondary host plants. — Some aphids deposit their eggs in 


7J 


116 THE STUDY OF INSECTS 

the fall on a certain plant which is called the primary host plant; but in 
the spring when the stem-mothers have appeared and have given rise to 
winged forms in the second and third generations these winged aphids 
become migrants and fly to another perhaps totally unrelated plant, 
which is called the secondary host plant. On this plant the aphids live 
during the summer but return to the primary host plants in the fall on 
which the sexes are produced and the eggs are laid. 

The potato aphid, Illinoia solanifolii, deposits its eggs in the fall on 
the rose, its primary host plant; but in the spring the winged migrants 
leave the rose and go to the potato to pass the summer. Toward fall 
winged forms appear and return to the rose where the sexual forms are 
produced and the eggs are laid. 

The rosy apple aphid, Anuraphis roseus, is another example of this 
habit. The eggs of this aphid are deposited on the apple in the fall but 
in the spring winged migrants fly to the narrow-leaved and broad-leaved 
plantains and on these plants the insects pass the summer. 

Some aphids are bark-feeding. For example, the giant hickory aphid, 
Longistigma carycz, is found feeding on the branches of hickory, maple, 
and other forest trees. It is the largest aphid known, 
measuring nearly ^ of an inch to the tips of its wings (Fig. 
194). 

Other aphids are leaf-feeding like the potato aphid al- 
fig 194. — The ready mentioned and the spring grain aphid, or "green 

Kiant hickory aphid. 1 ,, ^ „ .. „ 1 • 1 • • • • j. 1 

bug, 1 oxoptcra graminum, which is so injurious to wheat 
and oats in some seasons in the Mississippi Valley. 

There are also root-feeding species. For instance the corn-root aphid, 
Anuraphis maidiradicis, which is such a pest on the roots of corn in the 
Mississippi Valley; and the strawberry-root aphid, Aphis forbesi, which 
infests the roots of strawberry plants. Both of these species are attended 
by ants and placed upon the roots of corn and strawberries by the ants. 

Some aphids secrete great quantities of white waxy threads which 
cover their bodies like wool. These are known as the woolly aphids. 
One of these woolly aphids which occurs on the apple, is known as the 
woolly apple aphid, Eriosoma lamgera. It has a complex life history. 
Its eggs are deposited on the bark of the elm. There they hatch in the 
spring and the young crawl to the leaves and by their presence produce 
rosettes at the ends of branches. Later, winged forms go to the apple 
where several generations are produced, some of which live on the 
branches and some on the roots underground. The root form may be 
very injurious to the trees, especially in sandy soil. Finally in the autumn, 
the winged forms on the apple fly back to the elm where the sexual 
individuals are produced and the eggs are laid. It should be said that 
some of the aphids remain on the apple trees all winter. 

Large numbers of a woolly aphid are often found crowded together on 
the under side of the branches of alder. This species is known as the 
alder-blight, Prociphilus tessellata. In addition to the white excretion 
with which the body is covered this insect excretes large quantities of 
honey-dew. The result is that the branches infested by this insect, and 
those beneath the clusters of aphids, become blackened with fungi that 
grow upon this secretion. There is also a curious fungus which grows in 
large spongy masses beneath the clusters of plant-lice; this is known as 
Scorias spongiosa. It grows in the honey-dew that falls upon it. 


HOMOPTERA 


117 


The beech-tree blight, Proctphilus imbricator, infests both the twigs 
and leaves of beech. Like the preceding species it occurs in clusters of 
individuals, each of which is clothed with a conspicuous downy excretion. 
These clusters often attract attention by the curious habit that the in- 
sects have of waving their bodies up and down, the plume-like masses of 
excretion rendering them very conspicuous. When an infested limb is 
jarred the aphids emit a shower of honey-dew. Owing to the abundance 
of this secretion, the branches and leaves of an infested tree become 
blackened by growths of fungi, as with the preceding species. 

Other aphids produce galls of various shapes and sizes on the leaves 
of plants. 

The cockscomb elm-gall, Colopha ithnicola. — There are two species of 
aphids that make similar galls on the leaves of elm. These galls are 
commonly known as cockscomb elm-galls on account of their shape. 
Those made by the two species of aphids are so similar that a description 
of one will apply to the other. In each case the gall is an excrescence 
resembling a "cock's comb" in form, which rises abruptly from the upper 
surface of the leaf. It is compressed, and has its sides wrinkled perpen- 
dicularly and its summit irregularly gashed and toothed. It opens on 
the under side of the leaf by a long slit-like orifice. 

The poplar-leaf gall aphid, Thecabius populicaulis . — This aphid is 
common on several species of poplar. It makes a swelling the size of a 
small marble on the leaf at the junction of the petiole with the blade. 
This gall is of a reddish tint, and has on one side a slit-like opening. 


Fig. 195. — The witch-hazel cone-gall: a, natural size; b, section of 
gall, enlarged. (From Pergande.) 


The witch-hazel cone-gall aphid, Hormaphis hamamelidis , causes cone- 
like galls on the leaves of witch-hazel (Fig. 195). 


n8 


THE STUDY OF INSECTS 


Family Phylloxerid^ 
The Adelgids and the Phylloxerids 

In this family both the sexually perfect females and the partheno- 
genetic forms lay eggs. Moreover, the cornicles are wanting and the 
venation of the wings differs from that of the true aphids. 

Some members of this family live on conifers and cause galls on them. 
One species, Adelges abietis, lives on the Norway spruce and causes 
pineapple-shaped galls sometimes all over the tree (Fig. 196). 


Fig. 

abietis. 


196. — Gall of Adelges 


Fig. 197. — Phylloxera, root-inhabiting form: a, roots of 
Clinton vine showing the swellings; b, nymph as it appears 
when hibernating; c, d, antenna and leg of same; e,f, g, forms 
of more mature lice. (From Riley.) 


The most notorious and serious pest of this family is the grape 
phylloxera, Phylloxera vitifolice, which is a native insect on the American 
wild grape. Some of these aphids live on the foliage of the vines and 
cause small hollow galls on the leaves. Others live underground on the 
roots and cause swellings or nodules to form on the roots (Fig. 197). 
The infested roots may decay and the vines may die. In France where 
the aphid has been such a serious pest on the European type of grape it is 
the custom to use rootstocks of the native American wild grape on which 
to grow the European vines. The American rootstocks are resistant to 
the attacks of the phylloxera. 

Family Aleyrodid^e 
The Aleyrodids or White Flies 

The members of this family are small or minute insects; our more 
common species have a wing-expanse of about § of an inch. In the adult 
state both sexes have four wings, differing in this respect from the Cocci- 
dae, with which they were classed by the early entomologists. The wings 
are transparent, white, clouded or mottled with spots or bands. The 
wings, and the body as well, are covered with a whitish powder. It is 
this character that suggested the common name white flies. 


HOMOPTERA 119 

In the immature stages, these insects are scale-like in form and often 
resemble somewhat certain species of the genus Lecanium of the family 
Coccidae. Except during the first stadium, the larva? remain quiescent 
upon the leaves of the infested plant and in most species are surrounded 
or covered by a waxy excretion. In Figure 198 there 
is represented one of the many forms of this excre- 
tion. 

The members of this family feed exclusively on 
the leaves of the host-plants. With few exceptions 
they are not of economic importance ; and also with 
few exceptions, the injurious species are not widely 
distributed over the world as are many aphids 
and coccids. They are most abundant in tropical 
and semi-tropical regions. FlG - iq8 - — Ale y° des - 

The greenhouse white fly, Aster ochiton vapor ariorum, is an important 
pest of the greenhouse. It infests very many species of plants that are 
grown under glass; and sometimes it is a serious pest in the open on 
tomato and other plants that are set out after the weather is warm. 

The citrus white fly, Dialeurodes citri, is a well-known pest in the 
orange-growing sections of our country, and is also found in greenhouses 
in the North. It infests all citrus fruits grown in this country and is 
found on several other plants. 


Family Coccidae 
The Scale-insects or Bark-lice, Mealybugs, and others 

The family Coccidae includes the scale-insects or bark-lice, the mealy- 
bugs, and certain other insects for which there are no popular names. 
To this family belong many of the most serious pests of horticulturists; 
scarcely any kind of fruit is free from their attacks; and certain species 
of scale-insects and of mealybugs are constant pests in greenhouses. 
Most of the species live on the leaves and stems of plants; but some 
species infest the roots of the host-plants. The great majority of the 
species remain fixed upon their host during a part of their life-cycle, and 
can thus be transported long distances while yet alive, on fruit or on nurs- 
ery stock; this has resulted in many species becoming world-wide in dis- 
tribution. 

Happily some scale insects are useful to man. The lac-insect, Tachar- 
dia lacca, furnishes the stick-lac of commerce, from which shellac is 
made. Formerly, a red dye was obtained from the dried bodies of the 
cochineal insect, Coccus cacti, but recently this dye has been largely 
supplanted by the coal-tar dyes. China-wax is an excretion of the pe-la 
insect, Ericerus pe-la, and was formerly used in China in making candles. 

In the adult state, the two sexes of coccids differ greatly in form. The 
males are usually winged (Fig. 199, ib); in a few species they are either 
wingless or have vestigial wings. The fore wings are usually large, com- 
pared with the size of the body; the hind wings are always greatly 
reduced in size; usually they are a pair of club-shaped halteres, but in a 
few forms they are more or less wing-like. Each hind wing is furnished 
with a bristle, which is hooked at the end and fits into a pocket or fold 


120 


THE STUDY OF INSECTS 


Fig. igg. — Chionaspis furfura: i , scales on pear, natural size; ia, scale of male, ib, adult 
male, ic, scale of female, enlarged. 

on the inner margin of the fore wing of the same side; in a few species 
there are two or three or more of these hamuli. 

The legs are wanting in many adult females, having been lost during 
the metamorphosis. In adult males they are of ordinary form; except 
in a few species, the tarsi are one-jointed, and each is furnished with a 
single claw. 

The caudal end of the abdomen of the male usually bears a slender 
tubular process, the stylus. 

The female coccid is always wingless, and the body is either scale- 
like or gall-like in form, or grub-like and clothed with wax. The waxy 
covering may be in the form of powder, of large tufts or plates, of a con- 
tinuous layer, or of a thin scale, beneath which the insect lives. The 
antennas in many species are entirely wanting in the adult females. 

The mouth-parts of the adult males are lacking and they do not take 
food. In the case of the females of the more common species the maxil- 
lary and mandibular seta? are long and well developed for penetrating 
the tissues of plants. 

THE MOTILE COCCIDS 

We usually think of scale insects as fixed on a host-plant and unable 
to move about. There are, however, several subfamilies of coccids, the 
members of which are so generalized that the nymphs and adults possess 


HOMOPTERA 


normal, functional legs and are capable of movement over the host-plant 
although the amount of movement by these forms is usually not great. 
Jn fact some of the tortoise scales are practically fixed. 

The division into motile and non-motile forms is a purely artificial 
one used for the sake of a clearer understanding of these important insects. 

The cottony-cushion scale, Iccrya purchasi. — This beautiful insect 
(Fig. 200) was at one time the most dangerous insect pest in California, 
and did a great amount of injury. It is an introduced Australian species, 
and has been subdued to a great extent by the introduction of an Aus- 
tralian lady-bug, Rodolia cardinalis , which preys upon it. The body of 
the adult female is scale-like, dark orange-red, and has the dorsal surface 
more or less covered with a white or yellowish-white powder. The insect 
secretes a large egg-sac, which is beautifully ribbed. 


Fig. 200. — Icerya purchasi. 
and young, on orange. 


Females, adult 


Fig. 201. — Orthezia, enlarged. 


Orthezia. — The 


■ Pseadococcus longi- 
enlarged. 


threads like wool. 


members of this genus occur not uncommonly on 
various weeds. They are remarkable for the 
calcareous secretion with which the body is 
clothed. This is in the form of long plates. Fig- 
ure 201 represents a nymph; in the adult female 
the secretion becomes more elongated posteriorly, 
and forms a sac containing the eggs mixed with 
a fine down. Later, when the young are born, 
they remain in the sac till they have themselves 
secreted a sufficient amount of the lamellar mat- 
ter to cover them. 

The mealybugs. — The mealybugs are com- 
mon pests in greenhouses all over this country, 
especially the long-tailed mealybug, Pseudococcus 
longispinus (Fig. 202). In California there are 
several species which live in the open and become 
serious pests to citrus trees. Mealybugs excrete 
a white waxy material which may be in the form 
of a white powder over the body or of white 


122 


THE STUDY OF INSECTS 


The tortoise or soft scales. — The tortoise scales are so-called because 
the bodies of the females are usually shaped like the shell of a tortoise. 
The body of the female is cleft at the caudal end and, in our more 
common forms, is unprotected by wax or other form of covering. They 
are, therefore, often called soft scales. 

Legs are present in the first and usually in the second stage nymphs 
and the first stage nymphs are especially active. The adult females 
are usually well fixed to their host-plant. 

Many of them excrete very little wax, the body being practically 
naked, and the eggs, or the young in the viviparous species, are deposited 
beneath the body; in other species, although the body is nearly naked, 
the adult female excretes a large, cottony egg-sac; and in still others the 
body is deeply encased in wax. 

The soft scale, Lecanium hesperidum, is the commonest and most 
widely spread member of this subfamily; it infests a great variety of 
plants; in the North, it is very common in greenhouses; in the warmer 
parts of the country it lives out of doors. See Figure 206b, page 124. 

The members of the genus, 
Puhinaria, include species in 
which the body of the fe- 
male resembles Lecanium but 
which excrete a large cottony 
egg-sac. The cottony maple 
scale, Puhinaria vitis, is 
common on the maple, osage 
orange, grape, and other 


Fig. 203. — Puhinaria vitis. 
sacs, on grape, natural size 

plants (Fig. 203). 


Females, with large cottony egg- 


THE NON-MOTILE COCCIDS 

The greater number of the common 
scale insects of this country, especially 
those which are of economic importance, 
are fixed to the host-plant in the adult 
(female) stage. The legs of the newly 
hatched female nymphs are lost in the first 
molt and the adult female becomes incap- 
able of movement. 

The armored scales. — The great ma- 
jority of the common scale insects of this 
country differ from the forms already de- 
scribed in that the body of the insect, 
except for a very short period after birth, 
is covered with a scale composed in part 
of a waxy excretion of the insect and 
partly of molted skins. In the lecaniums 
the scale-like object is the body of the 
insect ; but in the case of the oyster-shell 
bark-louse (Fig. 204), the San Jose scale 
and of many other forms, the scale-like object commonly seen is not the 
insect, but a waxy armor beneath which it lives. 

The young insects of this group resemble in general appearance those 


Fig. 204. — The oyster-shell bark louse, 
Lepidosaphes ulmi; the young appear as white 
dots. 


HOMOPTERA 


123 


of other scale insects. Their active stage, however, is much shorter. 
After crawling about over the twigs of a tree for a few days, the young 
scale insect settles upon a suitable place and immediately begins to 
excrete fine threads of wax which soon become compacted into a thin 
pellicle covering the body. As the insect grows and sheds its skin, this 
cast skin is joined to the excretion and forms a part of the scale. This is 
the bright-colored, nipple-like prominence, seen in the center of the San 
Jose's scale and of the red scale of the orange; and two of them may be 
seen at the smaller end of the scale of the oyster-shell bark-louse. The 
position of the cast skins in the scale differs in different genera, and forms 
a good character for classification. 


JbamM. 


Fig. 205. — Chionaspis pinifoliir: 2, scales on Pinus strobus, natural size, leaves stunted; 2a, leaves 
not stunted by coccids; 2b, scale of female, usual form, enlarged; 2c, scale of female, wide form, en- 
larged; 2d, scale of male, enlarged. 

Closely allied species differ but little in the form of the scale. To 
distinguish these it is necessary to study the insects themselves, which are 
found beneath the scales. The distinctions between closely allied species 
are such that it requires very close observation and much skill in this 
particular line to make the determinations, a careful preparation of the 
specimens and an excellent microscope being necessary requisites. 

The different species of scale-insects vary as regards their food 
habits. We find that certain species infest particular plants and will feed 
upon no others; thus, the red-scale of the orange does not trouble decid- 
uous fruits. On the other hand, other species have a wide range of 
food plants. This is true of the San Jose scale, which infests a great 
variety of both cultivated and wild plants. 

Figure 205, represents the well-known pine-leaf scale, Chionaspis 


124 


THE STUDY OF INSECTS 


pinifolice, which occurs on various species of pine wherever these trees 
grow in the United States; Figure 199 represents the scurfy scale Chionaspis 
furfura, which is very destructive to apples and pears; while the San Jose 
scale, Aspidiotus pernicidsus, which is one of the most serious pests of vari- 
ous fruit trees in this country, is shown in Figure 206. 


Fig. 206. — San Jose scale, 
much enlarged. 


Fig. 206a, — Pseudococcus cilri, 
a mealybug that is a pest in green- 
houses and of orange trees in warm Fig. 200b, 
regions. natural size. 


Lecanium hcspcridum, adult females, 


CHAPTER XIX 
ORDER DERMAPTERA* 


The Earwigs 

The winged members of this order usually have four wings; but in some 
of them the hind icings are -vestigial or wanting; the fore wings are leathery, 
very small, without veins, and when at rest meet in a straight line on the 
back; the hind wings, when well developed, are large, with radiating veins, 
and when at rest are folded both lengthwise and crosswise. The mouth- 
parts are formed for chewing. The caudal end of the body is furnished with 
a pair of appendages, the cerci, which resemble forceps. The metamorphosis 
is incomplete. 

These are long, narrow-bodied insects with short, 
thickened fore wings which, when at rest, meet in a 
straight line on the back (Fig. 207). They Can be 
distinguished from beetles by the pair of forceps-like 
appendages, the cerci, at the caudal end of the body. 
The common name, earwig, was given these in- 
sects in England, and has reference to a widely 
spread fancy that these insects creep into the ears 
of sleeping persons. The earwigs are more common 
in this country in the South and on the Pacific Coast. 
They are nocturnal in habits and feed on flowers, 
fruits and vegetables and some species feed on ani- 
mal matter, especially dead 
insects. 

The fore wings resemble 
the elytra of beetles but the 
hind wings are very different 
from those of any other in- 
sects. Figure 208 represents one of these; 
are furnished with radiating veins which extend 
from a point some distance from the base of the wings. When the wing is 
not in use that part over which these veins extend is folded in plaits like a 
fan, after which the wing is folded twice crosswise. 

The most distinctive feature of the earwigs is the form of the cerci 
which are forceps-like and usually prominent. They are usually larger 
in the male than in the female. 

There are only about fifteen known species of earwigs in America 
north of Mexico and some of these are exotic forms which have come 
into the country through the channels of commerce. 

The little earwig, Labia minor, is only about \ of an inch long but it 
is widely distributed in the United States and has become established in 
Canada (Fig. 207). 

* Dermaptera: derma (Stpua), skin; pteron (irrepov), a wing. 
125 


Fig. 207. — An 
wig, Labia minor. 


Fig. 208. — Wing of earwig. 


they 


126 


THE STUDY OF INSECTS 


The seaside earwig, Anisolabis marliima, which is about f of an 
inch in length, is found along the Atlantic Coast from Maine to Texas. 
Both pairs of wings are absent in this species. 

The handsome earwig, Prolabia pulchella, is a shining chestnut-brown 


Fig. 209. — A , Male with short forceps; 
B, forceps of female; C, long type of forceps 
of male. (After Morse.) 

species found in the southern United States under the bark of dead trees. 
It is about \ of an inch in length. 

The European earwig, Forjicula auriculdria, (Fig. 209), was found at 
Newport, Rhode Island, in 191 1 and has now become established in the 
vStates of New York, Oregon, Washington and California. It is about f of 
an inch in length and of a rich reddish-brown with the wing-covers and legs 
a dull yellowish-brown. This earwig is nearly omnivorous although it is 
especially injurious to flowers and green plants. It often occurs in great 
numbers and becomes a serious pest. 


CHAPTER XX 
ORDER COLEOPTERA* 

The Beetles 

The winged members of this order have four wings; but the wings of the 
first pair are greatly thickened, forming "wing-covers" or elytra, beneath 
which the membranous hind wings are folded when at rest. The elytra meet 
in a straight line along the middle of the back and serve as armor, protecting 
that part of the body which they cover. The mouth-parts are formed for 
chewing. The metamorphosis is complete. 

The order Coleoptera includes only the beetles. 
These insects can be readily distinguished from all 
others except the earwigs by the structure of the 
fore wings, these being horny, veinless " wing- 
covers " or elytra, which meet in a straight line 
along the middle of the back (Fig. 210); and they 
differ from earwigs in lacking pincer-like ap- 
pendages at the caudal end of the body. Beetles 
also differ from earwigs in having a complete 
metamorphosis. FlG - 2I °- 

The hind wings are membranous, and in most species very efficient 
organs of flight. But in some of the pre-eminently running beetles the 
hind wings are wanting, and the elytra serve only as a protection to the 
abdomen. With some of these insects the elytra are even grown together 
where they meet on the middle line of the back; and in some of the 
Meloidae the elytra do not meet in a straight line. 

The venation of the wings of the Coleoptera has become greatly 
modified, and, consequently, the determination of the homologies of the 
wing veins is a difficult matter. The transformation of the fore wings 
into elytra has resulted in a great reduction of their venation; and the 
foldings of the hind wings interrupt the veins and cause distortions in 
their courses. 

The different mouth-parts are very evenly developed; we do not find 
some of them greatly enlarged at the expense of others, as in several 
other orders of insects. The upper lip, or labrum, is usually distinct; the 
mandibles are powerful jaws fitted either for seizing prey or for gnawing; 
the maxillae are also well developed and are quite complicated, consisting 
of several distinct pieces; the maxillary palpi are usually prominent; 
and the lower lip, or labium, is also well developed and complicated, con- 
sisting of several parts and bearing prominent labial palpi. 

The larvas are commonly called grubs. They are usually furnished 
with six thoracic legs, and often with a single proleg at the caudal end of 
the body; some, however, as the larvae of the snout-beetles, are entirely 
* Coleoptera: coleos (/coXeos), a sheath; pteron (wrepov), a wing. 

127 


128 


THE STUDY OF INSECTS 


Fig. 211. 


destitute of jointed legs. The pupae have the partially developed elytra, 
wings, and legs folded upon the breast, but in distinct sheaths (Fig. 211). 
These insects usually transform in rude cocoons made of earth or 
of bits of wood fastened together by a viscid substance excreted 
by the larvae. Many wood-burrowing species transform in the 
tunnels made by the larvae; and some of the dermestids as well 
as some of the lady-bugs transform in the last larval skin. 

Both larvae and adults present a very wide range of habits. 
While the majority of the species are terrestrial, the members of 
several families are aquatic; and while some feed on vegetable 
matter, others feed upon animal matter. The vegetable feeders 
include those that eat the living parts of plants, those that bore in dead 
wood, and those that feed upon decaying vegetable substances. Among 
the animal feeders are those that are predacious, those that feed on dried 
parts of animals, and those that act as scavengers, feeding on decaying 
animal matter. Viewed from the human standpoint, some species are 
very beneficial, others are extremely noxious. 

In the classification of beetles much use is being made of the varia- 
tions in form of the ventral and lateral sclerites of the thorax. Figure 
215 will serve as an illustration of these sclerites. One feature merits 
special mention: the coxae of the hind legs are flattened and immovably 
attached to the thorax so that they appear to be a part of the thorax 
instead of the basal segment of an appendage. 

The Coleoptera is a very large order, the latest catalogue listing 
18,547 species representing 109 families. The order is divided into two 
suborders, the Adephaga and the Polyphaga. 

CLASSIFICATION OF THE COLEOPTERA 

In order to use the table for determining the families of beetles it is 
necessary that the student should become familiar with certain terms not 
defined in the discussion of the external anatomy of insects. The follow- 
ing notes are therefore given as a supplement to that discussion. 

The head. — One of the sclerites that enters into the 
composition of the external wall of the head is frequently 
referred to in descriptions of beetles; this is the gula. 
The gula is the central portion of the ventral wall of the 
head, and is the part which bears the labium (Fig. 212, g). 

The sutures which bound the 
gula, one on each side, are 
termed the gular sutures (Fig. 
2 1 2 , gs) . In the Rhynchop- 
hora the gula appears to be 
wanting, and there is a single 
suture on the middle line of 
the head (Fig. 213, gs.) 

The antenna. — The 
more common types of an- 
tennae have been described. 
In many insects however, (£ r ^ t J s e ' s c 
the first segment of the an- 
tenna is long and the an- 
tenna is bent suddenly at the joint between the first and second seg 
ments; such antennae are said to be elbowed or geniculate. 


Fig. 212. — Head of Ilarpalus, ventral 
aspect: a, antenna; g, g, gula; ga, galea 
or outer lobe of the maxilla; gs, gular 
suture; //>, labial palpus; m, m, mandibles; 
mp, maxillary palpus; s, submentum. 


Fig. 213. — Head and 
prothorax of Rhyn, lio- 


proster- 
em, epimerum; 

/, femur. 


COLEOPTERA 


129 


The mouth-parts. — Much use is made of the form of the parts of the 
labium or lower lip in descriptions of beetles. When fully developed the 
labium consists of three principal parts and a pair of appendages. The 
principal parts are the submentum, the mentum, and the Ugula; the ap- 
pendages are the labial palpi. The basal part of the labium, the part 
which is joined to the gula, is the submentum (Fig. 214, sm). By an un- 
fortunate error this sclerite is almost invariably described in works on 
the Coleoptera as the 'mentum. This fact should be borne in mind by 
the student when using any of the older books on this subject. The 
intermediate portion of the labium is the mentum (Fig. 214, m); and the 
distal portion the Ugula. 

The ventral aspect of a beetle. — In the classification of beetles much 


Fig. 214. — Labium of Harpalus: sm, sub- 
mentum; in, mentum; lig, ligula; P, labial 
palpus. 


Fig. 215. — Ventral aspect of a beetle, Enchroma gigantea: 
Fig. 214a. — Maxilla of beetle; a, cardo; A, prothorax; B, mesothorax; C, metathorax; c, c, c, coxae; 
■ stl .P f r s ; c . palpifer; d, palpus; /, galea; em, em, em, epimera; es, es, es, episterna; s, s, s, sterna; /, I, 
g, lacinia; /;, digitus. trochantins; x, elytrum; y, antecoxal piece of metasternum. 

use is made of certain sclerites and sutures present on the ventral side 
of the insect. The student should study Figure 215 to become familiar 
with these structures. In some beetles the metasternum is divided 
into two unequal portions by a suture which extends transversely a short 
distance in front of the caudal margin ; the smaller sclerite which borders 
the posterior coxas in front and often passes between them is called 
the ante-coxal piece of the metasterum (Fig. 215, y). 


13° 


THE STUDY OF INSECTS 


The openings in the thoracic segments in which the legs are inserted 
are termed the coxal cavities. Much use is made in the classification of 


Fig. 216. — Prothorax of IJarpalus, ven- 
tral aspect: c, coxa; em, epimerum; es, 
episternum; /, femur; n, pronotum; s, s, 
s, prosternum. 


Fig. 217. — Prothorax of Pentlie; c, 
coxa; cc, coxal cavity; /, femur; s, pros- 
ternum; tr, trochanter. 


beetles of the form of the coxal cavities of the prothorax. When the 
epimera of the prothorax extend behind the coxae and reach the pros- 
ternum, the coxal cavities are said to be closed (Fig. 216); when the 
epimera do not extend behind the coxae to the prosternum, the coxal 
cavities are described as open (Fig. 217). 

The tarsi of certain beetles. — In the suborder, Polyphaga, there is a 
group of beetles, the Phytophaga, in which the tarsi appear to be four- 
segmented. The fourth segment is a very small one situated deep in be- 
tween the lobes of the third segment and is firmly united with the fifth 
segment (Fig. 218, A). Other types of tarsi in the series Palpicornia, Poly- 
formia, and Clavicornia are shown in Figure 218. 


Fig. 218. — Tarsi of beetles: A. PhytophaRa; B, C, 
D, of the series Palpicornia, Polyformia, and Clavicornia. 


TABLES FOR DETERMINING THE FAMILIES OF THE 

COLEOPTERA DISCUSSED IN THIS MANUAL 

TABLE I. — THE SUBORDERS 

A. Ventral part of the first segment of the abdomen divided by the hind coxal 
cavities, so that the sides are separated from the very small medial part. Suture 


COLEOPTERA 131 

present between pronotum and episternum. Suborder Adephaga; see Table II. 
AA. Ventral part of the first segment of the abdomen visible for its entire breadth. 
Suture between pronotum and episternum not present. Suborder Polyphaga; 
See Table III. 

TABLE II. — ADEPHAGA, THE FAMILIES OF THE SUBORDER 

A. Metasternum with an aritecoxal piece, separated by a well-marked suture reaching 

from one side to the other and extending in a triangular process between the 

hind coxae. Hind coxa? mobile, and of the usual form; habits terrestrial; 

legs fitted for walking. 

B. Antennas inserted on the front above the base of the mandibles. p. 135. 

ClCINDELIDyE 

BB. Antennas arising at the side of the head between the base of the mandibles 
and the eyes. Beetles with long flat bodies and with the scutellum visible. 

p. 136 CARABID/E 

AA. Metasternum without an antecoxal piece; legs fitted for swimming. 

B. With only two eyes; antennas filiform, p. 138 DytisciDjE 

BB. With four eyes, two above and two below; antennas short and modified in 
form. p. 139 Gyrinid^e 

TABLE III. — POLYPHAGA, THE SERIES OF FAMILIES OF THE 

SUBORDER 

A. Head not prolonged into a narrow beak, palpi always flexible; two gula sutures 
at least before and behind (Fig. 212); sutures between the presternum and the 
episterna and epimera distinct (Fig. 216); the epimera of the prothorax not 
meeting on the middle line behind the presternum (Fig. 216). 
B. Abdomen with at least three corneous segments dorsally, and exposed more or 
less by the short elytra. Hind wings with simple, straight veins; antennas 
variable, but never lamellate. Series Brachelytra; see Table IV. 
BB. Abdomen with at most two corneous segments dorsally, usually completely 
covered by the elytra; hind wings with veins in part connected by recurrent 
veins. 
C. Antennas clubbed or not, but if clubbed not lamellate. 

D. Tarsi usually apparently four-jointed, the real fourth segment being 
reduced in size so as to form an indistinct segment at the base of the 
last segment, with which it is immovably united (Fig. 218, A); the first 
three segments of the tarsi dilated and brush-like beneath; the third 
segment bilobed. Series Phytophaga; see Table VII. 
DD. Tarsi varying in form and in the number of the segments, but when 
five-jointed not of the type described under D above, the joint between 
the fourth and fifth segments being flexible. Series Palpicornia, Poly- 
formia, and Clavicornia; see Table V. 
CC. Antennas with a lamellate club. Series Lamellicornia; see Table VI. 
AA. Head either prolonged into a beak or not; palpi usually short and rigid; 
gular sutures confluent on the median line (Fig. 213, gs); prosternal sutures 
wanting; the epimera of the prothorax meeting on the middle line behind the 
presternum (Fig. 213, em). Series Rhynchophora; see Table VIII. 

TABLE IV. — THE FAMILIES OF THE BRACHELYTRA 

A. Elytra short, leaving the greater part of the abdomen exposed; the suture between 
the elytra when closed straight; wings present, and when not in use folded 
beneath the short elytra; the dorsal part of the abdominal segments entirely 
horny; abdomen flexible, and with seven or eight segments visible below; an- 
tennas not clubbed at the ends, p 143 Staphylinid/e 

AA. Elytra usually longer, covering the greater part of the abdomen ; when short the 
wings are wanting or, if present, may or may not be folded under the short 
elytra when at rest; the dorsal part of the abdominal segments partly mem- 
branous; antennas usually clubbed at the ends. 
B. Hind tarsi five-segmented, antennas rarely elbowed, abdomen with six or more 
ventral segments, anterior coxas conical. 


i32 THE STUDY OF INSECTS 

C. Posterior coxa' widely separated, eyes wanting or inconspicuous, p. 142. 

SlLPHIDJE 

CC\ Posterior coxae approximate, and not laminate, eyes with small facets. 

p. 142., SlI.PHID/E 

BB. All tarsi four-segmented ; hind coxae contiguous and with plates covering 
the femora entirely or in part. p. 142 Silphid^e 

BBB. Hind tarsi with only four segments; the fore tarsi, and almost always the 
middle tarsi with five segments, p. 142 SilphiDjE 

TABLE V. — THE FAMILIES OF THE PALPICORNIA, POLYFORMIA, 

AND CLAVICORNIA* 

It is impracticable to separate these three series of families in these tables, owing 
to the fact that characters sharply separating them have not been found. 
A. Hind tarsi five-jointed. 

B. Maxillary palpi as long as or longer than the antennas, p. 141 .. . .HvDROPHiUDyE 
BB. Maxillary palpi much shorter than the antennae. 

C. Tarsal claws very large; the first three abdominal segments grown together 

on the ventral side Psephenidce, Dryopida, Elmida 

CC. Tarsal claws of usual size; ventral abdominal segments usually free, some- 
times (Buprestidae) the first two grown together. 
D. Abdomen with not more than five ventral segments. 

E. Femur joined to the apex or very near the apex of the trochanter. 

Ptinida, Anobiidce, Bostrichida, Lyctida 

EE. Femur joined to the side of the trochanter. 

F. Anterior coxae globular or transverse, usually projecting but little from 
the coxal cavity. 
G. Anterior coxa transverse, more or less cylindrical, posterior coxae 
grooved for the reception of the femora. 

Nosodendridcc, Byrrhidce, Chelonariidce, et al. 

GG. Anterior coxae globular. 

H. Presternum with a process which extends backward into a groove 
in the mesosternum. 

I. Eye continuing the general line of the head, the head usually 

buried in the thorax up to the eye. Prothorax closely dove- 
tailed into mesothorax below. First ventral suture of abdomen 
much weaker than the others, usually partly lost. p. 148. 

BUPRESTID/E 

II. Eye usually prominent, frequently separated by a space from 
prothorax; articulation between pro- and mesothorax usually 
freely movable; first three ventral sutures of abdomen similar 
and deep. ( Not movable as usually reporte.) p. 147 . . . Elaterid/e 

HH. Presternum without a process received by the mesosternum, 
although it may be prolonged so as to meet the mesosternum. 

I. Posterior coxae contiguous Phalacridce 

II. Posterior coxae separated. 

J. Body depressed; middle coxal cavities not closed externally 
by a meeting of the mesosternum and metasternum. p. 152. 

CuCUJIDjE 

JJ. Body more or less convex; middle coxal cavities entirely 
surrounded by the sterna. 

Mycetophagidce, Cryptophagidcc, ErotylidcB 

FF. Anterior coxae conical, and projecting prominently from the coxal 
cavity. 
G. Posterior coxae dilated into plates partly protecting the femora, at 
least at their bases. 

H. Antennae serrate or flabellate Rhipiceridce 

HH. Antennae with the last three segments forming a large club. 

I. Tarsi with second and third segments lobed beneath. . . .Byturida 

II. Tarsi simple, p. 150 Dermestid^e 

DD. Abdomen with six or more ventral segments. 

E. Anterior coxae globular Cebrionidce, Plastoceridce 

EE. Anterior coxae conical. 

* Families italicized are not discussed in this manual. 


COLEOPTERA 


i33 


F. Posterior coxas not prominent, flat, covered by the femora in repose. 

Cleridce, Corynetida 

FF. Posterior coxas more or less conical and prominent at least internally, 
not covered by the femora in repose. 
G. Anterior coxae long, with distinct trochantins. 
H. Abdomen with seven or eight ventral segments. 
I. Middle coxae contiguous; epipleurae distinct. 

J. Episterna of metathorax sinuate on inner side, epipleurae 
usually wide at the base. 
K. Head more or less covered; antennae approximate or 
moderately distant; metathoracic epimera long. p. 144. 

Lamfyrid^e 

KK. Head exposed; antennae distant; metathoracic epimera 

wide PhejigodidcB 

JJ. Episterna of metathorax not sinuate on the inner side; 

epipleurae narrow at the base. p. 145 Cantharid^e 

AA. Hind tarsi either only three-jointed, or four-jointed but apparently only three- 
jointed, the third joint being small and concealed in a notch at the end of the 
second joint. (See also AAA.) 
B. Wings fringed with long hairs. A minute aquatic species from S. Cal. and 

Ariz. {Hydroscapha.) p. 141 Hydrophiud^e 

BB. Wings not fringed with hairs. 

C. Tarsi with second segment dilated. 

D. Tarsal claws appendiculate or toothed; first ventral abdominal segment 

with distinct curved coxal lines, p. 152 Coccinellid^e 

DD. Tarsal claws simple; first ventral abdominal segment without coxal 

lines Endomychidce 

AAA. Hind tarsi with only four segments; the fore tarsi, and almost always the 
middle tarsi also, with five segments. 
B. Anterior coxal cavities closed behind. 
C. Tarsal claws simple. 

D. Abdomen with five ventral segments. 

E. Ventral abdominal segments in part grown together. 

F. Next to the last segment of the tarsi spongy beneath Lagriidce 

FF. Penultimate segment of tarsi not spongy, p. 151 Tenebrionid^e 

BB. Anterior coxal cavities open behind. 

C. Head not strongly and suddenly constricted at base. 
D. Middle coxas not very prominent, antennas free. 
E. Prothorax margined at the sides. 

F. Middle coxal cavities entirely surrounded by the sterna. 

Cryptophagidce 

FF. Epimera of mesothorax reaching the coxae. 

G. Metasternum long; epimera of metathorax visible. .Melandryida 
GG. Metasternum quadrate; epimera of metathorax covered, p. 152. 

Cucujid^e 

EE. Prothorax not margined at the sides Pythidce 

DD. Middle coxas very prominent (Edemeridtz 

CC. Head strongly constricted at base. 

D. Head prolonged behind and gradually narrowed Cephaloidcc 

DD. Head suddenly narrowed behind. 

E. Hind coxas not prominent or but slightly so, anterior coxas globular, not 

prominent, p. 152 Cucujid^e 

EE. Hind coxas large, prominent. 

F. Tarsal claws simple; head horizontal Pyrochroidce 

FF. Claws cleft or toothed, front vertical, p. 145 .Meloide: 


TABLE VI. — THE FAMILIES OF THE LAMELLICORNIA 

A. Plates composing the club of the antennas flattened and capable of close apposi- 
tion. 

B. Abdomen with six visible ventral segments, p. 154 Scarab,eid.e 

BB, Abdomen with five visible ventral segments. 


134 


THE STUDY OF INSECTS 


C. Epimera of mesothorax attaining the oblique coxae, p. 154 . . . . Scarab/Eid^e 

CC. Epimera of mesothorax not attaining the coxae, p. 159 Trogid^e 

AA. Plates composing the club of the antennae not capable of close apposition, and 
usually not flattened. 
B. Men turn deeply emarginate, ligula filling the emargination. p. 160. .Passalid.^ 
BB. Mentum entire, ligula covered by the mentum or at its apex. p. 159. 

LuCANIDvE 

TABLE VII. — FAMILIES OF THE PHYTOPHAGA 

This series includes three families, which are so connected by intermediate forms 
that it is not easy to separate them. The . following table will aid the student in 
separating the more typical forms. 
A. Body elongate; antennae almost always long, often as long as the body or longer. 

The larvae are borers, p. 160 CerambyciDjE 

AA. Body short and more or less oval; antennae short. 

B. Front prolonged into a broad quadrate beak; elytra rather short so that the 
tip of the abdomen is always exposed. The larvae live in seeds, p. 167. 

Mylabrid^e 

BB. Front not prolonged into a beak; usually the tip of the abdomen is covered 
by the elytra. Both larvae and adults feed on the leaves of plants, p. 164. 
ChRYSOMELIDjE 

TABLE VIII. — THE FAMILIES OF THE RHYNCHOPHORA 
(Compiled from Blatchley and Leng) 
A. Beak rarely absent, usually longer than broad; tibiae never with a series of teeth 
externally. 
B. Antennae straight without a distinct club, though with the outer joints often 
more or less thickened; beak present at least in the female and pointing 
directly forward; form usually very slender and elongate, p. 169. . . Brentid/E 
BB. Antennae straight or elbowed, always with a distinct club. 

C. Palpi flexible; antennal club rarely compact; beak always short and broad; 
labrum present; thorax with a transverse raised line which is either ante- 
basal or basal, p. 169 Platystomid/e 

CC. Palpi rigid and labrum wanting except in the subfamily, Rhinomacerinae 
antennal club usually compact; beak variable in length, often long and 

curved downwards, p. 169 Curculionid^e 

AA. Beak absent or extremely short and broad; tibiae with a series of teeth ex- 
ternally, or, if these are wanting, with a prominent curved spine at apex; an- 
tennae short, but little longer than the head, always elbowed, and with a compact 
club except in Phthorophoelus where the club is lamellate; palpi rigid; body 
short, subcylindrical or rarely oval. 
B. Anterior tarsi with the first segment longer than the second, third and fourth 

together, p. 171 Platypodia: 

BB. Anterior tarsi with the first segment shorter than the second, third, and fourth 
together, p. 172 Scolytid^e 

THE CARNIVOROUS BEETLES 

Suborder Adephaga * 

The name of this suborder, Adephaga, was 
suggested by the predacious habits of its 
members. These beetles are distinguished 
from other Coleoptera by the presence of a 
suture on each side of the prothorax separat- 
ing the pleurum from the notum, and by the 
fact that the ventral part of the first segment 
of- the abdomen is divided by the hind 
coxal cavities so that the sides are separated 
from the very small medial part (Fig. 219). 

The larvae are campodeiform, and differ from all other beetle larvae in 
* Adephaga: adephagous (kb-qdyayos) , voracious. 


1 st A 


Fig. 2iq. — Ventral aspect of part of 
thorax and abdomen of Galerita janus: 1st 
A, first abdominal segment; 2d, A, second 
abdominal segment. 


COLEOPTERA 


i35 


that their legs are six-jointed except in a single exotic species; this is 
one more segment than is found in the legs of other beetle larvae. The 
legs are usually furnished with two claws, whereas the legs of other coleop- 
terous larvas are one-clawed. 

This suborder is represented in North America by less than ten fam- 
ilies. 

Family Cicindelid^; 

The Tiger-beetles 

The graceful forms and beautiful colors of the greater number of the 
tiger-beetles, those of the genus Cicindela, have made the family one of 
the favorites of students of Coleoptera. Their popular name is suggestive 
of their predacious habits, and of the stripes with which many are 
marked. They are usually a metallic green or bronze, banded or spotted 
with yellow. Some are black; and some that live on white sand are 
grayish-white, being exactly like 
the sand in color. Figure 220 
represents a common species of 
Cicindela. 

A useful character for distin- 
guishing the members of this 
family is the fact that the terminal 
hook of the maxilla (the digitus) 
is united to this organ by a mov- 
able joint (Fig. 221, h). FlG ' 22a FlG - 22T - FlG ' 222 " 

The tiger-beetle larvas (Fig. 222) are as ugly and ungraceful as the 
adults are beautiful. The two have only one habit in common — their 
eagerness for prey. The larvae live in vertical burrows in sandy places or 
in beaten paths. These burrows occur also in ploughed fields that have 
become dry and hard. They often extend a foot or more in depth. The 
larva takes a position of watchfulness at the mouth of its burrow. Its 
dirt-colored head is bent at right angles to its lighter-colored body and 
makes a neat plug to the opening of the hole. Its rapacious jaws extend 
upward, wide open, ready to seize the first unwary insect that walks 
over this living trap, or near it; for a larva will throw its body forward 
some distance in order to seize its prey. On the fifth segment of the 
abdomen there is a hump, and on this hump are two hooks curved for- 
ward. This is an arrangement by which the little rascal can hold back 
and keep from being jerked out of its hole when it gets some large insect 
by the leg, and by which it can drag its struggling prey down into its 
lair, where it may eat it at leisure. It is interesting to thrust a straw 
down into one of these burrows, and then dig it out with a trowel. The 
chances are that you will find the indignant inhabitant at the remote end 
of the burrow, chewing savagely at the end of the intruding straw. 

One hundred and fourteen species of tiger-beetles are now listed in 
our fauna; these represent four genera, the principal one of which is the 
genus Cicindela containing at least 76 species and many varieties. 

The members of this genus, unlike most other members of the family, 
are diurnal in habit. They are found on bright, hot days in dusty roads, 
in beaten paths, and on the shores of streams. They are the most agile 
of all beetles; and they are not merely swift of foot, but are also able to 


i 3 6 THE STUDY OF INSECTS 

fly well. When approached, they remain still until we can see them well 
but are still out of reach; then like a flash they fly up and away, alight- 
ing several rods ahead of us. Before alighting they usually turn so 
that they face us, and can thus watch our movements. They hide by 
night and in cloudy or rainy weather in holes in the ground or beneath 
stones or rubbish. The beetles have been found hibernating, each in a 
separate burrow extending under a stone. We have seen 
them in September digging burrows in a hillside; these 
descended slightly and were about five inches deep. The 
beetles kicked the dirt out behind them as they dug, so 
that it lay in a heap at the opening of the hole. 

There are two species of the genus Tetracha (Fig. 223) 
widely distributed in the United States. The species, Am- 
blycheila cylindriformis , found from Kansas to New Mexico 
is a very large one for it is nearly 1? inches long. Over 
Fig. 22.?. — Tetra- thirty species of the genus ( huus are found along the Pacific 
coast. These beetles are nocturnal : they search for their 
prey at night. 

Family CarabievE 
The Ground-beetles 

The ground-beetles are so called because they are very common on 
the surface of the ground, lurking under stones or rubbish, where they hide 
by day. At night they roam about in search of their prey. Our more 
common species are easily recognized by their shining black color and 
long legs. On the Pacific Coast, however, the darkling beetles (Family 
Tenebrionidae) , which are also black and have long legs, abound under 
stones and fragments of wood on the ground. But the two families can 
be easily distinguished by the fact that in the ground-beetles all the tarsi 
are five-jointed, while in the darkling beetles the hind tarsi are only 
four-jointed; and the darkling beetles do not run rapidly as do the 
ground-beetles. 

With the ground-beetles, the antennae are thread-like, tapering gradu- 
ally towards the tip, and each segment is of nearly uniform thickness 
throughout its length; the legs are fitted for running, and the antennas 
are inserted between the base of the mandibles and the eyes. Although 
most of the species are black, there are those that are blue, green, or 
brown, and a few that are spotted. The wing-covers are almost always 
ornamented with longitudinal ridges and rows of punctures. 

Most members of this family are predacious, feeding upon 
other insects, which they spring upon or capture by chase. A few 
species use vegetable food ; but their depredations are rarely of eco- 
nomic importance. As there are more than two thousand described 
North American species, and as many of the species are very com- 
mon, this family may be considered the most important family of 
the predacious insects. 

The larvae of ground-beetles are generally long, with the body of 
nearly equal breadth throughout (Fig. 224). They have sharp pro- 
jecting mandibles ; and the caudal end of the body is usually furnished with 
a pair of conical bristly appendages. They live in the same obscure situa- 


COLEOPTERA 


i37 


tions as the adult insects, but are more shy, and are consequently less 
frequently seen. Like the adults, they are predacious. 

Among the more common ground-beetles are the following. 

The searcher, Calosoma scrutator. — This is one of the larger and more 
beautiful of our ground-beetles; it has green or violet wing-covers 
margined with reddish, and the rest of the body is marked with violet- 
blue, gold, green, and copper (Fig. 225). This beetle and the two follow- 
ing have been known to climb trees in search of caterpillars. 


Fig. 225. 


Fig. 226 


Calosoma sycophanta, a common species in Europe, has been intro- 
duced and successfully colonized in New England, as a means of com- 
bating the gipsy-moth and the brown-tail moth. This species is 
somewhat smaller than the preceding, and lacks the reddish band on 
the margins of the elytra. 

The fiery hunter, Calosoma cdlidum, is easily recognized by the rows 
of reddish or copper-colored pits on the wing-covers (Fig. 226). 

The bombardier-beetles,' Bracklnus. — There are many species of 
beetles that have at the hind end of the body little sacs in which is 
secreted a bad-smelling fluid, which is used as a means of defence. These 
beetles spurt this fluid out onto their enemies when attacked. But in 
the case of the bombardier-beetles this fluid changes to a gas, which looks 
like smoke as soon as it comes in contact with the air, and is ejected 
with a sound like that of a tiny pop-gun. When some larger insect tries 
to capture one of these insect-soldiers, and gets very near it, the latter 
fires its little gun into the face of its enemy. The noise astonishes the 
pursuer, and the smoke blinds him. By the time he has recovered from 
his amazement, the little bombardier is at a safe distance. 
These beetles have quite a store of ammunition ; for we have 
often had one pop at us four or five times in succession, 
while we were taking it prisoner. The bombardier-beetles 
belong to the genus Brachinus, of which we have in this 
country twenty-seven species. They are very similar in ap- 
pearance; the head, prothorax, and legs are reddish-yellow, 
and the wing-covers are dark blue, blackish, or greenish-blue (Fig. 227). 

There is a common beetle which resembles the bombardier-beetles 


138 


THE STUDY OF INSECTS 


quite closely in size and color, but which may be distinguished by the 
comb-like form of the tarsal claws; this is Lebia grandis (Fig. 228). 
It has been reported more often than 
any other insect as destroying the Col- 
orado potato-beetle. 

What is perhaps the most common 
type of ground-beetle is illustrated by 
Harpalus caliginosus, which is represented 
natural size in Figure 229. It is of a 
pitchy black color, and is one of the most 
common of our larger species. There are 
one hundred and thirty-six described 
species of Harpalus in this country. Most 
of them are smaller than this one, are 
flattened, and have the prothorax nearly 
square. 

The most common of all ground-bee- 
tles, in the Northeastern States at least, 
is Pcecilus lucublandus. In this species 
(Fig. 230) the narrow, flat margin on each 
side of the prothorax is widened near the hind angle of this segment. 


Fig. 22g. 


Fig. 228. — Lebia gran- 
dis, natural size and en- 
larged 


Fig. 230. 


Family Dytiscid^ 

The Predacious Diving-beetles 

If one will approach quietly a pool of standing water, there may be 
seen oval, flattened beetles hanging head downward, with the tip of the 
abdomen at the surface of the water. Such beetles belong to this family. 
The predacious diving-beetles are usually brownish black and shining, 
but are often marked indefinitely with dull yellow. They can be dis- 
tinguished from the water scavenger-beetles, which they resemble in 
general appearance, by the thread-like form of the antenna?. The hind 
legs are the longest and are fitted for swimming, being flattened and 
fringed with hair. The middle and the hind 
pair of legs are widely separated. In the 
males of certain genera the first three seg- 
ments of the fore tarsi are dilated and form 
a circular disk, upon the under side of which 
are little cup-like suckers (Fig. 231). The 
females of some species exhibit an interesting 
dimorphism in that some of the individuals 
have the elytra furnished with a number of deep furrows (Fig. 232), 
while others of the same species have them smooth. 

The diving-beetles abound in our streams and ponds, but they are 
more often found in standing water than in streams. When at rest they 
float in an inclined position, head downward, with the tip of the hind end 
of the body projecting from the water. The spiracles open on the dorsal 
side of the abdomen beneath the elytra. By lifting the elytra slightly a 
reservoir is formed for air, which the beetle can breathe as it swims 
through the water. When the air becomes impure the beetle rises to the 
surface, forces it out, and takes a fresh supply. 


Fig. 232. 


COLEOPTERA 


i39 


These beetles are very voracious. They destroy not only other in- 
sects, but some of them will attack larger animals, as small fish. When 
kept in aquaria they can be fed upon any kind of meat, raw or cooked. 
They fly from pond to pond, and are often attracted to light at night. 
Many of the species make sounds, both under the water and in the air. 
In some cases this is done by rubbing the abdominal segments upon the 
elytra; in others, by rubbing the hind legs upon a rough spot on the lower 
side of the abdomen. 

The females deposit their eggs singly in punctures in the tissues of 
living plants. The larva? are 
known as water-tigers, be- 
cause of their blood-thirsti- 
ness. They are elongated, 
spindle-form grubs (Fig- 233). fig. 233. 

The head is large, oval or rounded, and flattened; the mandibles are 
large and sickle-shaped; in each there is a slit-like opening near the tip; 
from this opening a canal leads along the inner surface to a basal opening 
on the upper surface, which communicates with the corner of the mouth 
when the mandible is closed. The mandibles are admirably fitted for 
holding prey and at the same time sucking juices from its body. The 
thorax is furnished with six well-developed legs. The abdomen is termi- 
nated by a pair of processes; at the tip of the abdomen there is a pair of 
large spiracles, which the larva protrudes into the air at intervals, in 
order to breathe. 

When a larva is fully grown it leaves the water, burrows into the 
ground, and makes a round cell, within which it undergoes its transforma- 
tions. The pupa state lasts about three weeks in summer ; but the larva? 
that transform in autumn remain in the pupa state all winter. 

This is the largest of the families of water-beetles; more than three 
hundred North American species are known. 

The best way to obtain specimens is to sweep the vegetation growing 
on the bottom of a quiet pool with a dip-net. 

The larger of our common species belong to Cybtster, 
Dythcus (Fig. 234), and allied genera. 

The most common of the diving-beetles which are 
of medium size belong to the genus Acilius. 

There are also common diving-beetles which are of 
about the same size as the preceding, but which have 
the wing-covers marked with numerous very fine trans- 
verse striae; these belong to the genus Colymbetes. 

Of the smaller diving-beetles, measuring less than 
I of an inch in length, many species can be found in 
almost any pond. These represent many genera. 


Fig. 234. — A Dytis- 
cus beetle. 


Family Gyrinid^e 

The II li irl i gig-beetles 

As familiar to the country rover as the gurgling of the brook or the 
flecks of foam on its " golden-braided centre," "or the trailing ferns and 
the rustling rushes on its banks, are these whirligigs on its pools. Around 
and around each other they dart, tracing graceful curves on the water, 


140 


THE STUDY OF INSECTS 


which vanish almost as soon as made. They are social fellows, and are 
almost always found in large numbers, either swimming or resting motion- 
less near together. They rarely dive, except when pursued; but are so 
agile that it is extremely difficult to catch them without a net. Many of 
them when caught exhale a milky fluid having a very disagreeable odor. 
They feed upon small flies, beetles, and other insects that hill into the 
water, and are furnished with well-developed wings, with which they 
fly from one body of water to another. 

This is one of the most easily-recognized families of the whole 
order Coleoptera. The members of it are oval or elliptical in form 
(Fig. 235), more or less flattened, and usually of a very brilliant 
bluish-black color above, with a bronze metallic lustre. The fore 
legs are very long and rather slender; the middle and hind 
Fig. 235- legs are short, broad, and very much flattened. These insects 
are remarkable for having the eyes completely divided by the margin of 
the head, so that they appear to have four eyes — a pair upon the upper 
surface of the head with which to look into the air, and a pair upon the 
under side for looking into the water. The antenna? are very short and 
peculiar in form. The third segment is enlarged, so as to resemble an ear- 
like appendage, and the following ones form a short spindle-shaped 
mass. The}* are inserted in little cavities in front of the eyes. 
The eggs of these insects are small, of cylindrical form, and 
are placed end to end in parallel rows upon the leaves of aquatic 
plants. The larvae (Fig. 236) are long, narrow, and much flat- 
tened. Each abdominal segment is furnished with a pair of 
tracheal gills, and there is an additional pair at the caudal end 
of the bod}-. The elongated form of the body and the con- 
spicuous tracheal gills cause these larva? to resemble small cen- 
tipedes. When a larva is full-grown it leaves the water and 
spins a gray, paper-like cocoon attached to some object near the 
water. The pupa state of those species in which it has been ob- 
served lasts about a month. 

The family is a small one. At present only forty-one North American 
species are known. These represent three genera. The genus Gyretes is 
distinguished by having the last ventral segment of the abdomen elon- 
gated and conical. It is represented by two species. In the other two 
genera the last ventral segment is flattened and rounded at the tip. In 
Dineutus the scutellum is invisible; there are thirteen species of this 
genus. In Gyrinus the scutellum is visible; of this genus we have twenty- 
six species. 


THE HERBIVOROUS BEETLES 

Suborder Polyphaga * 

In the suborder Polyphaga the ventral 
part of the first segment of the abdomen 
is visible for its entire breadth (Fig. 237); 
the first three ventral segments are im- 
movably united (except in the Cupesida?), 
and the notum of the prothorax is not sepa- 
rated from the pleura by distinct sutures. 
polyphagus, eating many kinds of food. 


Fig. 236. 


FlG. 237. — Ventral aspect of part of 
tborax and abdomen of Enchroma giganlea: 
1 j 1, first abdominal segment. 


Polyphaga : 


COLEOPTERA 


141 


The larvae vary greatly in form; some are campodeiform, some are 
scarabeiform, and others are vermiform; in none are the legs more than 
five-jointed, and in none are the legs two-clawed. 

This suborder includes all but the few preceding families of the 
Coleoptera. 


Family Hydrophilid^ 

The Water-scavenger Beetles 

The water-scavenger beetles are common in quiet pools, where they 
may be found swimming through the water, or crawling among the 
plants growing on the bottom. They can be easily taken by sweeping 
such plants with a dip-net. 

They are elongated, elliptical, black beetles, resembling the preda- 
cious diving-beetles in appearance; but they are usually more convex, 
and differ also in having club-shaped antennas and very long palpi. As 
the antennae are usually concealed beneath the head, it often happens 
that the inexperienced student mistakes the long palpi for antennae. 

These beetles are supposed to live chiefly upon the decaying vegeta- 
tion in the water; but a number of species have been known to catch 
and eat living insects. They breathe by carrying a film of air on the 
lower surface of the body. This film gives them a silvery appearance 
when seen from below. They obtain the air by bringing the head to 
the surface of the water and projecting the antennae, which they again 
fold back with a bubble of air when they descend. The female makes a 
case for her eggs out of a hardened silk-like secretion. j^ 

Some species deposit as many as a hundred eggs in one of 
these water-proof packages (Fig. 238). The egg-cases in 
some instances are fastened beneath the leaves of aquatic 
plants; in others they are provided with floats and let 
loose in the water ; and in still other species the cases are 
carried by the mother underneath her body and steadied 
with her hind legs. Frequently some of the young larvae 
devour their companions; in -this way the size of the fam- 
ily is decreased before it escapes from 
the egg-case. Later they live upon insects that fall 
into the water, and upon snails. These larvae re- 
semble somewhat those of the Dytiscidae; but the 
body is much more plump, and the mandibles are 
of moderate size. 

The family Hydrophilidae is represented in North 
America by one hundred and ninety species. The 
largest of our common species is Hydrous trian- 
gularis (Fig. 239). In the genus Hydrous the met- 
asternum is prolonged backward into a spine 
between the hind legs, and the sternum of the protho- 
rax bears a deep furrow. 

Next in size to Hydrous are several species of 
Hydrophilus. In this genus the metasternum is 
prolonged somewhat, but does not form a long, sharp spine as in Hydrous 
and the sternum of the prothorax bears a keel-shaped projection. Our 


M 


:• '.'< 


^ 


'' /" 


,!i 


w 


J ' V 


Fig. 2,38. 


i 4 2 THE STUDY OF INSECTS 

most common species is Hydrophilus obtusdtus; this measures about f of 
an inch in length. 

Some of the smaller species of this family are not aquatic, but live 
in moist earth and in the dung of cattle, where, it is said, they feed on 
dipterous larvae. 

Family Silphid^e 

The Carrion-beetles 

The carrion-beetles are mostly of medium or large size, many species 
attaining the length of if inches while the smaller species of the more 
typical genera are nearly \ inch in length; some members of the fam- 
ily, however, are minute. The segments near the tip of the antennae 
are usually enlarged so as to form a compact club, which is neither comb- 
like nor composed of thin movable plates; sometimes the antennas are 
nearly filiform. 

These insects usually feed upon decaying animal matter; some, how- 
ever, feed upon fungi; some on vegetables; and a few species have been 
known to be predacious when pressed by hunger, destroying living snails 
and insects, even members of their own species; while a few occur only 
in the nests of ants. 

It is easy to obtain specimens of these insects by placing pieces of 
meat or small dead animals in the fields and examining them daily. 
There are several other families of beetles the members of which can be 
attracted in this way. 

The larvae also live upon decaying flesh and 
are found in the same situations as the adults. 

We have in this country more than one hundred 
species of this family. Our larger and more famil- 
iar species represent two genera, Necrophorus and 
SUpha. 

The burying-beetles, Necrophorus. — To this 
genus belong the larger members of the family. 
The body is very stout, almost cylindrical (Fig. 
240). Our common species have a reddish spot on 
each end of each wing-cover; these spots are often 
so large that they appear as two transverse bands. 
In some species the prothorax and the head are 
FlG - 2 4°- also marked with red. 

These insects are called burying-beetles because they bury carrion. 
When a pair of these beetles discover a dead bird, mouse, or other small 
animal, they dig beneath it. removing the earth so as to allow the carrion 
to settle into the ground. This they will continue until the object is 
below the surface of the ground. Then they cover it with earth, and 
finally the female digs down to it and lays her eggs upon it. The larvae 
that hatch from these eggs feed upon the food thus provided for them. 
There are many accounts of exhibitions of remarkable strength and sa- 
gacity by burying-beetles. A pair of these insects have been known to 
roll a large dead rat several feet in order to get it upon a suitable spot 
for burying. 


COLEOPTERA 

The members of the genus Sttpha are very much flattened (F 
The prothorax is round in outline, with very thin edges which 
the wing-covers somewhat. The body is not nearly as stout 
as that of a burying-beetle, being fitted for creeping under 
dead animals instead of for performing deeds requiring great 
strength. Silpha bituberosa, which is known as the spinach 
carrion-beetle, feeds on spinach, beets, and other plants, in 
the West. 

In some of the minute members of this family the body 
is nearly hemispherical. 


143 

ig. 241). 
overlap 


Fig. 242. 


Family Staphylinid^ 

The Rove-beetles 

The rove-beetles are very common about decaying animal matter, 
and are often found upon the ground, under stones or other objects. 
They are mostly very small insects; a few species, however, are of larger 
size, measuring \ inch or more in length. Their appear- 
ance is very characteristic, the body being long and slender, 
and the wing-covers very short (Fig. 242). The wings, 
however, are fully developed, often exceeding the abdomen 
in length ; when not in use the wings are folded beneath the 
short wing-covers. The abdominal segments are freely 
movable. 

It is interesting to watch one of these insects fold its 
wings; frequently they find it necessary to make use of the 
tip of the abdomen or of one of the legs in order to get the 
wings folded beneath the wing-covers. 

The rove-beetles can run quite swiftly; and they have the curious 
habit, when disturbed, of raising the tip of the abdomen in a threatening 
manner, as if they could sting. As some of the larger species resemble 
wasps somewhat in the form of the body, these threatening motions are 
often as effective as if the creatures really had a sting. William Becbe 
states (Atlantic Monthly, October, 1919) that when some rove-beetles 
were attacked by ants they raised their tails and ejected a drop or two 
of a repellent fluid which drove the ants away. This observation indi- 
cates the probable explanation of the actions of these beetles when dis- 
turbed. 

As these insects feed upon decaying animal and vegetable matter, 
they should be classed as beneficial. The larvas resemble the adults 
in the form of the body and are found in similar situations, about decay- 
ing animal and vegetable matter, beneath bark and in fungi. Some 
species are guests in the nests of ants, and others in the nests of termites. 
Nearly three thousand North American species of rove-beetles have 
been described. The great majority are small and exceedingly difficult to 
determine. Among the large species that are common are the following. 
Creophilus maxillosus. — This species varies from \ an inch to nearly 
an inch in length. It is of a shining black color, spotted with patches of 
fine gray hairs. There is a conspicuous band of these across the middle 
of the wing-covers, and another on the second and third abdominal seg- 


i44 THE STUDY OF INSECTS 

ments; this abdominal band is best marked on the lower side of the 
body. 

Staphylinus maculosus is a larger species, which often measures fully 
an inch in length. It is densely punctured, and of a dull brown color, 
with the scutellum black, and a row of obscure, square, blackish spots 
along the middle of the abdomen. 

Staph yllii us vulpinus resembles the preceding somewhat, but it has a 
pair of bright yellow spots at the base of each abdominal segment. 

Ontholestes cingulatus is of about the same size as the preceding. It 
is brown, speckled with brownish-black spots, and the tip of its abdomen 
is clothed with golden hairs. 

Family Lampyrid^e 

The Firefly Family 

During some warm, moist evening early in our northern June we are 
startled to see here and there a tiny meteor shoot out of the darkness 
near at hand, and we suddenly realize that summer is close upon us, 
heralded by her mysterious messengers, the fireflies. A week or two later 
these little torch-bearers appear in full force, and the gloom that over- 
hangs marshes and wet meadows, the dusk that shrouds the banks of 
streams and ponds, the darkness that haunts the borders of forests, are 
illumined with myriads of flashes as these silent, winged hosts move 
hither and thither under the cover of the night. 

The fireflies are soft-bodied beetles of medium or small size, with 
slender, usually eleven-jointed, saw-like antennae. The prothorax is 
expanded into a thin projecting margin, which in most cases 
completely covers the head (Fig. 243). The wing-covers are 
rather soft, and never strongly embrace the sides of the abdo- 
men, as with most other beetles. 

The fireflies are nocturnal insects and are sluggish by day. 

fig" 243. The property of emitting light is possessed by adults of both 

sexes and by larvae. The latter and the wingless females of 

certain species are known as glow-worms. The light-organs of the winged 

adults are situated on the lower side of one or more of the abdominal 

segments ; but they are lacking in some genera. 

There have been many speculations as to the usefulness of the light- 
producing power of various organisms to the organisms themselves; and 
as regards many of these photogenic creatures no definite conclusions 
have been reached. But there is considerable evidence to show that in 
the case of adult lampyrids it serves to enable these insects to find their 
mates. It has been found that females enclosed in a perforated opaque 
box do not attract males, while those enclosed in a glass vial do; thus 
showing that it is the light emitted by the female, and not its odor, that 
attracts the male. It has also been shown that in some cases at least 
there are specific differences in the method of flashing which enables the 
insects to distinguish at a distance their proper mates. 


COLEOPTERA 145 

Family Cantharidae 

The Soldier-beetles and others 

The family Cantharidae includes those genera that were formerly 
included in the family Lampyridse as the subfamily Telephorinas. 

The application of the name Cantharidae to this family is the result 
of one of those unfortunate changes in generic names rendered necessary 
by our code of nomenclature. In this case the change is especially un- 
fortunate, as the generic name Cantharis has been commonly applied to 
certain blister-beetles and is used in that sense in many medical works 
and in most text-books of entomology. The change is sure to result in 
much confusion. 

The most common members of this family are the soldier-beetles, 
Chauliognathus. These are very abundant in late summer and autumn 
on various flowers, but especially on those of goldenrod. The most com- 
mon species in the East are the Pennsylvania 
soldier-beetle, Chauliognathus pennsylvanicus, 
which is yellow, with a black spot in the mid- 
dle of the prothorax and one near the tip of 
each wing-cover (Fig. 244); and the margined 
soldier-beetle, C. margindtus. This species 
(Fig. 245) can be distinguished from the for- 
mer by the head and lower parts of the 
femora being orange. The beetles of this genus FlG ' 245 ' 

are remarkable for having an extensible, fleshy filament attached to each 
maxilla. These filaments are probably used in collecting pollen and 
nectar from flowers. 

This family is represented in our fauna by nine genera which include 
more than one hundred and fifty species. 

Family Meloid^e 
■The Blister-beetles 

The blister-beetles are of medium or large size. The body is com- 
paratively soft; the head is broad, vertical, and abruptly narrowed into 
a neck; the prothorax is narrower than the wing-covers, which are soft 
and flexible; the legs are long and slender; the hind tarsi are four- 
jointed, and the fore and middle tarsi are five-jointed. 

These beetles are found on foliage and on flowers, on which they feed 
in the adult state; some of the species are very common on goldenrod in 
the autumn; and several species feed on the leaves of potato. 

The blister-beetles are so called because they are used for making 
blister-plasters. The beetles are killed, dried, and pulverized, and the 
powder thus obtained is made into a paste, which when applied to the 
skin produces a blister. The species most commonly used is a European 
one, commonly known as the Spanish-fly; but our American species 
possess the same blistering property. 

The transformations of blister-beetles are remarkable; not only do 
these insects undergo wonderful changes in form, but the number of 
these changes is greater than is usual with insects. On this account their 
mode of development is termed hyper metamorphosis. 


146 


THE STUDY OF INSECTS 


The beetles lay their eggs in the ground. The newly hatched larva 
is active, running about in search of its food, which consists, in some 
species, of the eggs of locusts, in others of the egg and honey of some 
solitary bee. 

In the case of those species that live in the nests of bees the larva 
climbs a plant, and remains near a flower till it has a chance to seize 
hold of a bee visiting the flower. The larva clings to the bee until she 
goes to her nest, then, letting go of the bee, it remains in the cell and is 
shut up there with the egg of the bee and the store of food which the 
bee provides for her young. The beetle larva then devours the egg; after 
which it moults and undergoes a change of form, becoming a clumsy 
creature, which feeds upon the honey. Several other changes in form 
occur before the beetle reaches the adult stage. 

The wonderful instinct by which the larva? of these blister-beetles find 
their way to the nests of solitary bees has not yet reached perfection ; for 
many of the larvae attach themselves to flies, wasps, honey-bees, and other 
flower-visiting insects, and merely gain useless transportation thereby. 

The life cycle of the striped blister-beetle, Epicauta vittata, illustrates 
the hypermetamorphosis through which the blister-beetles pass. The 
female deposits her eggs in a mass of a hundred or more in a hole in the 
soil. They hatch into very active larvae each of which is known as a 
triungulin. The triungulin has long legs and runs about in search of 
eggs of grasshoppers. It feeds ravenously on the eggs and in about eight 
days molts to the second stage, called the caraboid stage, because it then 
resembles the larva of a carabid beetle. In another week it molts and 
assumes the appearance of a scarabaeid larva and is therefore called the 
scarabasidoid stage of the second larva. In a short time it molts again to 
the ultimate stage of the second larva. In about ten days more it molts 
again and becomes the pseudo-pupa or the coarctate larva. This form 
usually hibernates and in the spring transforms to the third larval stage. 
In a few days this larva transforms to the pupa in an earthen cell and in 
five or six days the pupa transforms to the adult beetle (Fig. 246). 


f\. 


FlO, 246. — liypermctamorphosis of the striped blister-beetle; A, triungulin; B, caraboid stage; D, scara- 
baeidoid stage; C, coarctate larva; E, pupa; F, adult beetle. 


COLEOPTERA 


i47 


More than two hundred species of blister-beetles have been found in 
this country. Our most common species in the East belong to the genus 
Epicauta. These insects feed in the adult state on the leaves of various 
plants, but especially those of potato, and upon the pollen of goldenrod; 
the larvae, so far as is known, are parasitic in the egg-pods of 
locusts. In addition to Epicauta vittata, discussed above, our 
more common species are the Pennsylvania blister-beetle, 
Epicauta pennsylvdnica, which is of a uniform black color 
(Fig. 247); and Epicauta cinerea, which is sometimes clothed 
throughout with an ash-colored pubescence, and sometimes 
the wing-covers are black, except a narrow gray margin; 
the two varieties were formerly considered distinct species; 
the first is commonly known as the gray blister-beetle, the 
last as the margined blister-beetle. 

The beetles of the genus Melee present an exception to 
the characters of the Coleoptera in that the wing-covers, 
instead of meeting in a straight line down the back, overlap 
at the base (Fig. 248). These wing-covers are short, and 
the hind wings are lacking. These beetles are called oil- 
beetles in England, on account of the yellowish liquid 
which oozes from their joints when they are handled. 
Our most common species is the buttercup oil-beetle, 
Melos angusticollis . It is found in meadows and pastures 
feeding on the leaves of various species of buttercups. 


Fig. 247. 


Fig. 248. 


Fig. 249. 


Family Elaterid^e 
The Click-beetles or Elaters 

There is hardly a country child that has not been entertained by the 
acrobatic performances of the long, tidy-appearing beetles called snap- 
ping-bugs, click-beetles, or skip-jacks (Fig. 249). Touch one of \/^ 
them and it at once curls up its legs, and drops as if shot; it 
usually lands on its back, and lies there for a time as if dead. 
Suddenly there is a click, and the insect pops up into the air 
several inches. If it comes down on its back, it tries again and 
again until it succeeds in striking on its feet, and then it 
runs off. 

Our common species of click-beetles are mostly small or of medium 
size, ranging from -fa to f of an inch in length. A few species are 

> — m- , <*■ larger, some reaching the length of nearly 2 inches. The 

^jr' \(^/ majority of the species are of a uniform brownish color; 
/8k Hv s< line are bl ac k " r grayish, and some are conspicuously 

^^ >/liJ\V s P°tted (Fig. 250). The body is elongated, somewhat flat- 
/ /^Byy tened, and tapers more or less toward each end; the 
antennae are moderately elongated and more or less ser- 
rate; the first and second abdominal segments are not 
grown together on the ventral side ; and the hind coxae are 
each furnished with a groove for the reception of the femur. 
Adult elaters are found on leaves and flowers, and are exclusively 
phytophagous; the larvae live in various situations; most of them are 
phytophagous, but some species are carnivorous. 


Fig. 250. — A click- 
beetle, Aeolus dorsalis, 
natural size and en- 
larged. 


t 4 8 THE STUDY OF INSECTS 

The larvae are long, narrow, worm-like creatures, very even in width, 
with a very hard cuticula, and are brownish or yellowish in color (Fig. 

251). They are commonly known as wire- 
\v< >rms, a name suggested by the form 
and hardness of the body. 

Some wireworms live under the bark 
of trees and in rotten wood; but many 
of them live in the ground, and feed on 
seeds and the roots of grass and grain. In fact there is hardly a culti- 
vated plant that they do not infest, and, working as they do beneath the 
surface of the ground, it is extremely difficult to destroy them. They 
are very apt to attack the plants at the most susceptible period of 
their growth, before they have attained sufficient size and strength to 
withstand the attack; and often seed is destroyed before it is germinated. 
There is a vast number of species of click-beetles; more than five 
hundred have been described from North America alone. It is quite 
difficult to separate the closely allied species, as there is but little varia- 
tion in shape and color. 

The corn wireworm beetle, Melanotics communis, is a graceful brown 
beetle about \ an inch in length (Fig. 249). The larva, or wireworm is 


about 1 j inches in length, cylindrical and shining brown 
extends over a period of five years in most cases. 

The wheat wireworm beetle, Agriotes mancus, is a 
small brown beetle about § of an inch in length. The 
larva, or wireworm is about one inch long and as large 
as the lead in a pencil. The life cycle extends over a 
period of three years. 

The eyed elater, Alaus oculatus. — Although most 
of our click-beetles are of moderate size, we have a 
few species that are large. The most common of 
these is the eyed elater. This is the great pepper- 
and-salt-colored beetle that has two large, black, vel- 
vety, eye-like spots on the pro thorax (Fig. 252). These 
are not its eyes, however. The true eyes are situated 
one on each side of the head near the base of the an- 
tenna. This insect varies greatly in size, some individ- 
uals being not more than half as large as others. 
The larger larvae are about two and a half inches long 
fifths of an inch wide across the middle of the bodv. 


The life cycle 


Fig. 252. 


and nearly two- 
They are carniv- 


orous and are often found in the trunks of old apple-trees. 


Family Buprestids 
The Metallic Wood-borers or Buprestids 

The buprestids resemble the click-beetles somewhat in form, being 
rather long and narrow; but they are easily recognized by their metallic 
coloring. Their bodies are hard and inflexible, and usually appear as if 
made of bronze; but some species exhibit the brightest of metallic colors. 
The antennae are serrate; the first and second abdominal segments are 
grown together on the ventral side; and these beetles do not have the 
power of springing when placed on the back. 


COLEOPTERA 


149 


The adults are found upon flowers and upon the bark of trees, basking 
in the hot sunshine. Some of them fly very rapidly, with a loud buzzing 
noise; and some drop to the ground when disturbed, and feign death. 

Most of the larvae are borers, feeding beneath bark or within solid 
wood. In such species the body is of a very characteristic form, which 
is commonly designated as " flat-headed." The flattened portion, how- 
ever, is composed largely of the segments immediately following the head. 
The first thoracic segment is very wide and flat; the next two or three 
segments are also flattened, but are successively smaller; while the rest 
of the body is quite narrow and cylindrical. These " flat-headed" larvae 
are legless, and have been compared to tadpoles on account of their 
form. Their burrows are flattened, corresponding with the shape of the 
larger part of the body. In some of the smaller species the larvas are 
cylindrical, and are furnished with three pairs of legs. These are leaf- 
miners; and in the adult state the body is much shorter than in the 
more typical species. 

This family is represented in our fauna by nearly three hundred 
species; among the more important of those that infest cultivated plants 
are the following. 

The Virginian buprestid, Chalcophora virginica. — ■ This is the largest 
of our common buprestids (Fig. 253). It is 
copper-colored, often almost black, and has 
its upper surface roughened by irregular, 
lengthwise furrows. This beetle appears late 
in spring in the vicinity of pine-trees. The 
larvae bore in the wood of pine, and are often 
very injurious. 

Dicerca divaricdta is f of an inch or more 
in length, copper-colored or brassy above, with 
the wing-covers marked with square, elevated, black spots. 
The wing-covers taper very much behind, and are separated at the 
tips (Fig. 254). The larva bores in peach, cherry, beech, and maple. 

flat-headed apple-tree borer, Chrysobothris femorata. — This is 
one of the most injurious of all buprestids. The adult (Fig. 
255) is about I an inch long, and is very dark green above, with 
bronze reflections, especially in the furrows of the wing-covers. 
It appears during June and July, and lays its eggsupon the trunk and 
limbs of apple, peach, oak, and other trees. The larvae at first 
bore into the bark and sap-wood, and later into the solid 
wood. The transformations are completed in one year, 
red-necked agrilus, Agrilus ruficollis. — This beetle is 
of an inch long (Fig. 256). Its body is narrow and nearly 
cylindrical. The head is of a dark bronze color, the prothorax of 
a beautiful coppery bronze, and the wing-covers black. The larva 
bores in the stems of raspberry and blackberry, causing a large FlG - 256 - 
swelling, known as the raspberry gouty-gall. These galls should be collected 
and burned in early spring. 

The bronze birch-borer, Agrilus anxius, is a greenish-bronze beetle about 
^ of an inch long which appears in June and July and deposits its egg in 
cracks of the bark of the white birch and of other birches. The whitish, 
slender larvae bore through the sapwood and inner bark completely girdling 
the branches and trunk and usually killing the trees. 


Fig. 254. 


Fig. 253. 


The 


Fig. 255. 

The 
about x 


150 THE STUDY OF INSECTS 

Family Dermestid.-e 
The Dermestids 

There are several families of small beetles that feed on decaying 
matter, or on skins, furs, and dried animal substances. The most im- 
portant of these is the Dermestidae, as several species belonging to this 
family destroy household stores or goods. 

The dermestids can be distinguished from most of the other beetles 
with similar habits by the fact that the wing-covers completely cover the 
abdomen. They are chiefly small beetles, although one of the common 
species measures ^ of an inch in length. They are usually oval, plump 
beetles, with pale gray or brown markings, which are formed of minute 
scales, which can be rubbed off. These beetles have the habit of pretend- 
ing that they are dead when they are disturbed; they will roll over on 
their backs with their legs meekly folded and lie still for a long period. 

The larvae do much more damage than the adults. They are active, 
and are clothed with long hairs. These hairs are covered throughout 
their entire length with microscopic barbs. 

This family is represented in our fauna by about one hundred thirty 
species; the following are some of the more important to these. 

The larder-beetle, Dermestes lardarius. — This pest of the larder is 
the most common of the larger members of this family. It measures 
about \ of an inch in length, and is black except the basal half of its 
wing-covers, which are pale buff or brownish-yellow. This lighter 
portion is usually crossed by a band of black spots, three on 
K each wing-cover (Fig. 257). The larva feeds on dead animal 
[^ matter, as meat, skins, feathers, and cheese. It is often a 
serious pest where bacon or ham is stored. When full-grown it 
is about \ an inch in length, dark brown above, whitish below, 
and rather thickly covered with long, brown hairs. It is said that these 
insects can be attracted by baits of old cheese, from which they may be 
gathered and destroyed. 

The carpet-beetle, Anthrenus scrophularice. — This is a well-known 
household pest. It is an introduced European insect, which was first 
recognized as a serious pest in this country about 1874. It feeds in its 
larval state on carpets, woollens, furs, and feathers; and for a consider- 
able period was exceedingly destructive. The larva is well known to 
many housekeepers as the buffalo-moth. It is a short, fat grub, about 
I of an inch in length when full-grown, and densely clothed with dark 
brown hairs. It lives in the cracks of floors, near the edges of rooms, 
and beneath furniture, where it eats holes in the carpet. It also enters 
wardrobes and destroys clothing. The adult is a pretty little beetle 
which may be found in infested houses, in the spring, on the ceilings 
and windows. It measures from T *2 to \ of an inch in length and is 
clothed with black, white, and brick-red scales. There is a whitish spot 
on each side of the prothorax, and three irregular, whitish spots on the 
outer margin of each wing-cover; along the suture where the two wing- 
covers meet there is a band of brick-red scales, which is widened in 
several places. It is worth while to learn to know this beetle; for a 
lady-bug which often winters in our houses is frequently mistaken for it. 


COLEOPTERA 151 

The carpet-beetle in its adult state feeds on the pollen of flowers. Some- 
times it abounds on the blossoms of currant, cherry, and other fruits. 

The museum pests, Anthrenus verbdsci and Anthrenus musebrwm. — 
There are two minute species of this family that are a constant source of 
annoyance to those having collections of insects. The adult beetles 
measure from -^ to £ of an inch in length, and are very convex. They 
deposit their eggs on specimens in our collections; and the larvae feed 
upon the specimens, often destroying them. In order to preserve a 
collection of insects it is necessary that they should be kept in tight cases, 
so that these pests cannot gain access to them. Specimens should not be 
left exposed except when in use. And the entire collection should be 
carefully examined at least once a month. The injury is done by the 
larvae, which are small, plump, hairy grubs. Their presence is indicated 
by a fine dust that falls on to the bottom of the case from the infested 
specimens. These larvas can be destroyed by pouring a small quantity 
of carbon bisulphide into the case, and keeping it tightly closed for a 
day or two. Benzine poured on a bit of cotton in the box will cause the 
pests to leave the specimens, when they may be taken from the box and 
destroyed. But we have found carbon bisulphide the better agent for 
the destruction of these pests. 

Family Tenebrionid^e 

The Darkling Beetles 

The darkling beetles are nearly all of a uniform black color, although 
some are gray, and a few are marked with bright colors. The different 
species vary greatly in size and in the form of the body. The hind tarsi 
are four-jointed, and the fore and middle tarsi are five-jointed. 

These insects occur chiefly in dry and warm regions. Thus while 
we have comparatively few species in the northeastern United States, 
there are many in the Southwest. Most of the species feed on dry 
vegetable matter, and often on that which is partially decomposed; 
some live in dung, some in dead animal matter, others in fungi, and a 
few prey upon larvae. More than eleven hundred species occur in this 
country. The three following will serve to illustrate the variations in 
form and habits. 

The meal-worm, Tenebrio mblitor. — This is a well-known pest in 
granaries and mills. The larva is a hard waxy yellow, cylindrical " worm, " 
which measures when full-grown 1 inch or more in length, 
and closely resembles a wireworm; it feeds on flour and meal. 
The beetle is black and about f of an inch in length, (Fig. 258). 
The larvae and pupae are used for bird-food and are grown in 
quantity by bird-supply houses. 

The forked fungus-beetle, Bolitotherus cornutus, 
is common in the northeastern United States and 
in Canada about the large toadstools which grow 
on the sides of trees. The surface of the body and wing- 
covers is very rough, and the pro thorax bears two prominent 
horns (Fig. 2^0). The larva lives within the fungi referred to 

Fig. 250. \ t> jvt o 

above. 
The pinacate-bugs. — Several species of Elebdes are abundant on the 


152 


THE STUDY OF INSECTS 


Fig. 260. 


Pacific Coast, where they are found under stones and pieces 
of wood lying on the gr< lund. They are apt to congregate in 
large numbers under a single shelter, and are clumsy in 
their movements. They defend themselves when dis- 
turbed by elevating the hinder part of the body and 
discharging an oily fluid from it. They present an 
absurd appearance, walking off clumsily, and carry- 
ing the hind end of the body as high as possible. 
The most common species are large, smooth, club- 
shaped beetles (Fig. 260), and are commonly known 
as pinacate-bugs. These beetles and those belonging 
to several closely allied genera lack hind wings. 


Family Cucujid^e 
The Cucujids 

The insects of this family are very flat and usually of an elongate 
form; most of the species are brown, but some are of a bright red color. 
As a rule they are found under bark and are believed to be carnivorous 
both in the larval and adult states; but some feed in grain. There are 
nearly one hundred species in our fauna. 

The most important member of this family is the corn silvanus, 
Oryzaphilus sur in amen sis, which is one of the small beetles that infest 
stored grain. This species is readily distinguished from other small 
beetles with similar habits by its flattened form and the saw-like edges 
of the prothorax. Besides grain it often infests dried fruits and other 
stores. It measures from -^ to \ of an inch in length. The larva as well 
as the adult feeds on grain. It differs from the larva of the granary- 
weevil (Sitophihts) in the more elongate form of its body and in the 
possession of three pairs of legs. 


Family Coccinellid^e 

The Lady-bugs 

These insects are well-known to nearly everyone under the popular 
name given above. They are more or less nearly hemispherical, generally 
red or yellow, with black spots, or black, with white, red, or yel- 
low spots. 

The larva? occur running about on foliage; they are of- 
ten spotted, with bright colors and clothed with warts or 
with spines (Fig. 261). When ready to change to a pupa the 
larva fastens itself by its tail to any convenient object, and 
the skin splits open on the back. Sometimes the pupa 
state is passed within this split skin, and sometimes the skin is 
forced back and remains in a little wad about the tail (Fig. 
262). 

With very few exceptions, the lady-bugs are predacious, 
both in the larval and adult states. They feed upon small 
insects and upon the eggs of larger species. The larva? of certain species 


Fig. 261. 


Fig. 262. 


COLEOPTERA 


i53 


are known as " niggers " by hop-growers, and are greatly prized by them; 
for they are very destructive to the hop-louse. On the Pacific Coast lady- 
bugs are well-known as the most beneficial of all insects to the fruit-growers. 
In addition to the native species found there, several species have been 
introduced as a means of combating scale-insects. One of these, 
Rodolia cardinalis, has proved of very great value in subduing the 
cottony-cushion scale (Icerya purchasi). This lady-bug was introduced 
from Australia. 

A very common one is the two-spotted lady-bug, Adalia bipunctdta. 
This species is reddish-yellow above, with the middle of the prothorax 
black, and with a black spot on each wing-cover. It frequently passes 
the winter in our dwellings, and is found on the walls and windows in 
early spring. Under such circumstances it is often mistaken for the 
carpet-beetle, and, unfortunately, destroyed. (See Plate I,Figure3). 

The nine-spotted lady-bug, Coccinella novemnotdta, has yellowish 
wing-covers, with four black spots on each, in addition to a 
common spot just back of the scutellum (Fig. 263). fig. 263. 

There are two " black sheep " in this family of lady-bugs, namely, 
the squash lady-bug, Epildchna boredlis and the bean lady-bug, Epilachna 
corrupta. The adults and larvae of both of these species are herbivorous 
and injurious, especially those of the latter. The bean lady-bug from its 
former home in the south-western states, suddenly appeared in Alabama 
in 1 919 and has now spread over most of the eastern United States and 
into Canada. It is pale yellowish to orange-brown and from \ to § of an 
inch in length. Each wing-cover has eight black spots arranged in three 
transverse rows. The larva? and adults feed on bean plants and are very 
destructive. 


Fig. 264. 


The squash lady-bug lives on various cucurbitacecus plants but it 
prefers the squash and often becomes destructive (Fig. 264). 


i54 THE STUDY OF INSECTS 

Family Scarab^id^e 
The Scarabceids or Lamellicorn Beetles 

This very large family is represented in our fauna by nearly one thou- 
sand species, and includes beetles that exhibit a wide range of variation 
in size, form, and habits. They are mostly short, stout-bodied beetles, 
of which the well-known June-bugs or May-beetles represent the most 
familiar type. The most useful character for distinguishing these insects 
is the lamellate form of the club of the antennae, the segments constitut- 
ing it being greatly flattened, and capable of being brought close to- 
gether. It is this character that suggests the name lamellicorn beetles. 

According to their habits, the members of this family can be sep- 
arated into two well-marked groups — the scavengers and the leaf- 
chafers. 

THE LAMELLICORN SCAVENGERS 

The lamellicorn scavengers in both the larval and adult states feed 
upon decaying vegetable matter. Nearly all the species live in dung, 
chiefly that of horses and cows; but a few species feed upon fungi. The 
following are the more common representatives of this division. 

The tumble-bugs. — These are the most familiar of all dung-beetles, 
for their peculiar habits have attracted much attention from the earliest 
times. They are of rounded form, and the wing-covers are shortened so 
as to expose the tip of the abdomen. They are generally black, but 
some are colored with rich metallic hues. They vary greatly in size. 

The name tumble-bug refers to the habit which many species exhibit 
of forming round balls of dung, which they roll long distances and then 
bury. They often work in pairs and it was formerly believed that such a 
pair was a male and a female working together to make provision for 
their progeny; but Fabre found by dissecting the beetles that the two 
members of a pair often proved to belong to the same sex; and concluded 
that the eager fellow- worker, under the deceitful pretense of lending a 
helping hand, nurses the scheme of purloining the ball at the first oppor- 
tunity. 

According to the observations of Fabre, the balls made early in the 
year are devoured by the beetles, which bury themselves with them and 
feed upon them. Later, other balls are made and buried, upon each of 
which an egg is laid. The larva hatching from this egg feeds upon the 
ball of dung, and when full-grown transforms within the cavity in which 
the ball was placed. 

This strange habit of rolling these balls has occasioned much specula- 
tion as to its object, and has been the source of many superstitions, 
especially in ancient times. The only reasonable theory that we have 
met is that, as many predacious insects frequent the masses of dung from 
which the balls are obtained, in order to prey upon the larvae which live 
there, the more intelligent tumble-bugs remove the food for their larva? 
to a safe distance. 

The most noted member of this group of genera is the sacred beetle 
of the Egyptians, Ateuchus sdcer. This insect was held in high veneration 
by this ancient people. It was placed by them in the tombs with their 


COLEOPTERA 


i5S 


dead; its picture was painted on sarcophagi, and its image was carved 
in stone and precious gems. These sculptured beetles can be found in 
almost any collection of Egyptian antiquities. 

From the habits and structure of this scarabseid the Egyptians 
evolved a remarkable symbolism. The ball, which the beetles were sup- 
posed to roll from sunrise to sunset, represented the earth; 
the beetle itself personified the sun, because of the sharp pro- 
jections on its head, which extend out like rays of light; 
while the thirty segments of its six tarsi represented the 
days of the month. All individuals of this species were 
thought to be males, and a race of males symbolized a 
race of warriors. This latter superstition was carried over 
to Rome and the Roman soldiers wore images of the sacred t ^^^ 6s '~ Cm ' 
beetle set in rings. 

Our common tumble-bugs are distributed among three genera: 
Cdnthon (Fig. 265), Copris, and Phanceus. 


Fig. 266. 


THE LAMELLICORN LEAF-CHAFERS 

The leaf-chafers are herbivorous insects which in the adult state 
usually feed upon the leaves of trees, but many of the species devour the 

pollen and petals of flowers. In the larval 
state some of these insects are found in rot- 
ten wood; others live in the ground, where 
they feed upon the roots of grass and other 
plants. These larvse are thick, fleshy grubs, 
with well-developed legs (Fig. 266). The 
caudal segments of the abdomen are very 
large, and appear black on account of the 
large amount of dirt in the intestine. The 
body is strongly' curved, so that the larvae 
can crawl only with great difficulty; when 
in the ground they usually lie on their backs. 
The following groups include the more 
important representatives of this division. 

I. The May-beetles or June-bugs. — During the warm evenings of 
May and June we throw open our windows so that we may feel the 
refreshing coolness of the night air and the inspiration of the new sum- 
mer. _ Suddenly, as we sit working or reading, our peace is disturbed by a 
buzzing object which whirls above us. Then comes a sharp thud and 
silence. A little later the scratching of six pairs of tiny claws tells us the 
whereabouts of the intruder. But so familiar are we with his kind that 
we need_ not look to know how he appears, the mahogany-brown blun- 
derer, with yellowish wings sticking out untidily from under his polished 
wing-covers. 

Although these insects are beetles, and attract our attention each 
year m May, they have received the infelicitous title of June-bugs. They 
are more properly termed May-beetles. 

The May-beetles belong to the genus Phyllophaga, of which we have 
nearly one hundred species. The adults frequently do much injury by 
eating the foliage of trees. In the case of large trees this injury usually 
passes unnoticed; but small trees are often completely defoliated by 


i<6 


THE STUDY OF INSECTS 


Fig. 267. 


them. When troublesome, they can be easily gathered by shaking them 
from trees upon sheets. Figure 267 represents a common species. 

The larvae of the different species of May-beetles are 
commonly classed together under the name " white grubs." 
They are often great pests in meadows and in cultivated 
fields. We have known large strawberry plantations to 
be destroyed by them, and have seen large patches of 
ground in pastures from which the dead sod could be 
rolled as one would roll a carpet from a floor, the roots 
having been all destroyed and the ground just beneath the 
surface finely pulverized by these larvae. No satisfactory 
method of fighting this pest has been discovered as yet. 
If swine be turned into fields infested by white grubs they 
will root them up and feed upon them. We have destroyed great numbers 
of the beetles by the use of trap-lanterns, but many beneficial insects 
were destroyed at the same time. 

II. The rose-bugs. — The common rose-bug, Macrodactylus sub- 
spinosus, is a well-known pest. It is a slender beetle, taper- 
ing before and behind, and measuring f of an inch in length 
(Fig. 268). It is thickly clothed with fine, yellow, scale-like 
hairs, which give it a yellowish color; the legs are long, slender, 
and of a pale red color. These beetles appear in early summer 
and often do great injury to roses and other flowers, and to 
the foliage of various fruit-trees and shrubs. This is a very 
difficult pest to control. The larva- of rose-bugs feed on the roots of 
plants. 

III. The shining leaf-chafers. — These insects resemble the May- 
beetles in form, but can be distinguished from them by the position of 
the hind pair of spiracles, which are visible on the sides below the edges 
of the wing-covers; and they differ from the other leaf-chafers in which 
the spiracles are in this position in that the tarsal claws are of unequal 
size, one claw of each pair being larger than the other. These beetles 
are usually polished, and many of them are of brilliant colors. To this 
family belong the most beautiful beetles known, many appearing as if 
made of burnished gold or silver, or other metal. 

The goldsmith-beetle, Cotalpa lamgera. — This is one of our most 
beautiful species. It measures about one inch in length, 
and is a broad oval in shape. It is of a lemon-yellow 
color above, glittering like burnished gold on the top of 
the head and thorax; the under side of the body is 
copper-colored and thickly covered with whitish wool. 

The spotted pelidnota, Pelidnota punctata. — This bee- 
tle is reddish-brown above, with three black spots on 
each wing-cover and one on each side of the prothorax 
(Fig. 269). The scutellum, base of the head, and entire 
body beneath, are of a deep, bronzed-green color. The 
adult is commonly found feeding on the leaves of grape. 
The larva feeds upon decaying roots and stumps of various trees. 

The Japanese beetle, Popillia japonica. — This is a very serious pest 
which feeds in the adult state on the foliage of many cultivated and wild 
plants, being practically omnivorous, and in the larval state feeds on the 
roots of grasses. It was first observed in this country in a limited area in 


Fig. 269. 


COLEOPTERA 


iS7 


Burlington County, New Jersey, in 191 6, and has since spread into 
Pennsylvania and New York. The adult insect is about the size of the 
Colorado potato-beetle, but slightly longer 
(Fig. 270). The head and thorax are shin- 
ing bronze-green in color, with the wing- 
covers tan or brownish, tinged with green 
on the edges. Along the sides of the abdo- 
men are white spots, and two very distinct 
white spots at the tip of the abdomen below 
the wing-covers. The larva resembles the 
larva? of May-beetles. 

IV. The rhinoceros-beetles. — ■ The name 
rhinoceros-beetles was suggested for this group 
by the fact that in many species the male 
bears a horn on the middle of the head. In 
addition to this horn there may be one or 
more horns on the thorax. These beetles are 
of medium or large size; in fact, the largest beetles known belong to this 
group. As with the flower-beetles, the 
claws of the tarsi are of equal size, but 
the fore coxae are transverse, and not 
prominent. 

One of the largest of our rhinoceros- 
beetles is Dynastes tityrus. This is of 
a greenish-gray color, with scattered 
black spots on the wing-covers, or, if 
only recently transformed, of a uniform 
dark brown. The male (Fig. 271) bears 


Japanese beetle, enlarged 


Fig. 271. 


a prominent horn on the top of the 
head, and a large one and two small 
ones on the prothorax. The female has 
only a tubercle on the head. This in- 
sect is found in the Southern States ; the 
larva lives in rotten wood. In the far 
west there is a closely allied species, 
Dynastes grant it, in which the large 
horn on the thorax is twice as long 
as in D. tityrus. In the West Indies 
there occurs a species, Dynastes hercules, 
which measures 6 inches in length. 

The sugar-cane beetle, Euetheola 
rugiceps, is a serious pest in the cane- 


Fig. 272. 


Y\.H.U\GV\0\_S. 
- The sugar-cane beetle. 


fields of Louisiana, and it sometimes injures corn (Fig. 272). 


i58 


THE STUDY OF INSECTS 


Y. The flower-beetles. — The flower-beetles are so called because many 
o! them are often seen feeding upon pollen and flying from flower to 
flower. These beetles are somewhat flattened, or nearly level on the 
back; the claws of the tarsi are of equal size and the 
tore coxa' are conical and prominent. More than one 
hundred species occur in this country. 

The hermit flower-beetle, Osmoderma eremicola. — 
This is one of the larger of our flower-beetles (Fig. 
273). It is of a deep mahogany-brown color, nearly 
smooth, and highly polished. It is supposed that the 
larva lives on decaying wood in forest trees. 

The genus Euphoria represents well the form of 
the more typical flower-beetles, which are distinguished 
by the margin of each wing-cover having a large, wavy 
indentation near its base, which renders the side 
pieces of the mesothorax visible from above. This 
indentation makes it unnecessary for these insects to 
fig. 273. raise or expand their wing-covers when flving, as 

most beetles do, as they are able to pass the wings out from the sides. 

The bumble flower-beetle, Euphoria inda. — The most 
common of our flower-beetles, at least in the North, is a 
yellowish-brown one, with the wing-covers sprinkled all over 
with small, irregular, black spots (Fig. 274). It is one of the 
first insects to appear in the spring. It flies near the sur- 
face of the ground with a loud humming sound, like that of a 
bumblebee, for which it is often mistaken. During the 
summer months it is not seen; but a new brood appears 
about the middle of September. The adult is a general feeder 
occurring upon flowers, eating the pollen, upon corn-stalks 
and green corn in the milk, sucking the juices, and upon peaches, 
grapes, and apples. Occasionally the ravages are very serious. 

The green June-beetle or "fig-eater, Cotinus nitida. — This species 
extends over the Atlantic slope, and is very common in the South. It is 
a green, velvety insect, measuring about one inch in length. It is some- 
what pointed in front, and usually has the sides of the thorax and elytra 
brownish-yellow. These beetles often fly in great numbers at night, 
making a loud buzzing noise similar to that of the May-beetles. In fact, 
in the South the term June-bug is often applied to this insect. The 
larvae feed upon the vegetable mold of rich soils; sometimes they injure 
growing vegetables by severing the roots and growing stalks; but the 
chief injury is due to the upheaval of the soil around the plants, which 
disturbs the roots; the larvae are also often troublesome on lawns and 
golf greens by making little mounds of earth on the surface. Sometimes 
they leave the ground and crawl from one place to another. When they 
do so, they, strangely enough, crawl upon their backs, making no use of 
their short legs. On one occasion we saw them crawling over the pave- 
ments on the Capitol grounds at Washington in such numbers that 
bushels of _ them were swept up and carted away. The adults frequently 
attack fruit, especially figs, grapes, and peaches. 

A closely related beetle, Cotinus mutabilis, occurs in the Southwest and 
attacks fruits in a similar manner. So far as known, its habits and life his- 
tory arc much like those of the fig-eater. 


Fig. 274. 


COLEOPTERA 


159 


Family Trogid^e 
The Skin-beetles 

This is a small family, which is represented in this country by 
twenty-five species. Until recently these insects were included in the 
preceding family; they can be distinguished from scarabaeids by the fact 
that the epimera of the mesothorax do not extend to the coxae as they do 
in the Scarabaeidae. The members of this family are oblong, convex 
species, in which the surface of the body and wing-covers is usually very 
rough, and covered with a crust of dirt, which is removed with great 
difficulty. They are small or of medium size; our most common species 
measure from \ to \ an inch in length. The abdomen is covered by the 
elytra; the feet are hardly fitted for digging, but the femora of the front 
legs are greatly dilated. 

These beetles feed upon dried, decomposing animal mat- 
ter; many species are found about the refuse of tanneries, 
and upon the hoofs and hair of decaying animals. 

Except a few species found in the far west, all of our 
species belong to the genus Trox (Fig. 275). Fig. 275. 


Family Lucanid^e 

The Stag-beetles 

The stag-beetles are so called on account of their large mandibles 
which in the males of some species are branched like the antlers of a 
stag. They and the members of the following family are distinguished 
by the form of the club of the antennae, which is composed of flattened 
plates; but these plates are not capable of close apposition, as in the 
antennas of the lamellicorn beetles. In the stag-beetles the mentum is 
not emarginate and the ligula is covered by the mentum or is at its apex. 

The adult beetles are found in or beneath 
decaying logs and stumps. Some of them are 
attracted at night to lights. They are said to 
live on honey-dew and the exudations of the 
leaves and bark of trees, for procuring which the 
brushes of their jaws and lips seem to be de- 
signed; but it seems probable that some species, 
at least, feed upon decomposing wood . They lay 
their eggs in crevices of the bark of trees, espe- 
cially near the roots. The larvae feed upon juices 
of wood in various stages of decay. They re- 
semble the well-known larvae of May-beetles. 

The family is a small one ; only thirty North 
American species are now known. 

The common stag-beetle, Lucdnus dama. — 
The most common of our stag-beetles is this spe- 
cies (Fig. 276). It flies by night with a loud buz- 
zing sound, and is often attracted to lights in houses. The larva is a 
large, whitish grub resembling the larvae of the lamellicorn beetles. It is 
found in the trunks and roots of old, partially decayed trees, especially 


Fig. 276. 


i6o 


THE STUDY OF INSECTS 


apple, cherry, willow, and oak. The specimen figured here is a male; 
in the female the mandibles are shorter. 

The giant stag-beetle, Lin amis elafhus, is a large species found in the 
South. It measures from if inches to 2 inches in length, not including 
the mandibles, which in the case of the male are more than half 
as long as the body, and branched like the antlers of a stag. 
The antelope-beetle, Dorcus parallel us. — This beetle is 
somewhat smaller than the species of Lucanus, and differs 
in having the wing-covers marked with longitudinal stria? 
and the teeth on the outside of the fore tibiae much smaller 
(Fig. 277). 

Several species of stag-beetles that are much smaller 
Fie. 277. than Dorcus are found in this country. 


Family Passalid^e 

The members of this family resemble the stag-beetles in the form of 
the antenna?, but differ in that the mentum is deeply 
emarginate, with the ligula filling the emargination. 

A single, widely distributed species is found in the 
United States; this is the horned passalus, Passalus 
cormltus (Fig. 278). It is a large, shining, black bee- 
tle, with a short horn, bent forwards, on the top of the 
head. This beetle and its larva are found in decaying 
wood. The larva appears to have only four legs, the 
hind legs being shortened and modified so as to form 
part of a stridulating organ. 

The beetles of this genus are common throughout 
the tropics of both hemispheres. According to the 
observations of Ohaus, which have been confirmed by 
Professor Wheeler, these beetles are social. They form 
colonies, consisting of a male and female and their progeny, and make 
large, rough galleries in rather damp, rotten logs. The parent beetles 
triturate the rotten wood and apparently treat it with some digestive 
secretion which makes it a proper food for the larva?, since their mouth- 
parts are too feebly developed to enable them to attack the wood directly. 
All members of the colony are kept together by stridulatory signals. The 
stridulatory organ of the adult consists of patches of minute denticles on 
the dorsal surface of the abdomen, which may be rubbed against similar 
structures on the lower surface of the wings. 


Fig. 278. 


Family Cerambycid^; 

The Long-homed Beetles or Cerambycids 

This is a very large family, there being more than eleven hundred 
described species in North America alone. As a rule the beetles are of 
medium or large size, and graceful in form; many species are beautiful 
in color. The body is oblong, often cylindrical. The antenna? are long, 
often longer than the whole body; but except in one genus, Prionus, they 
are only eleven- jointed, as with most beetles. The legs are also long, and 


CO LEO PT ERA 


161 


the tarsi are apparently four-jointed, the fourth segment being very 
small and hidden; the third segment of the tarsi is strongly 
bilobed (Fig. 279). 

They are strong flyers and swift runners; but many of 
them have the habit of remaining motionless on the limbs 
of trees for long intervals, and when in this apparent trance 
they suffer themselves to be picked up. But, when once 
caught, many species make an indignant squeaking by 
rubbing the prothorax and mesothorax together. 

The larvae are borers, living within the solid parts of 
trees or shrubs, or beneath bark. They are white or yel- 
lowish grubs. The body is soft, and tapers slightly 
from head to tail (Fig. 280); the jaws are power- 
ful, enabling these insects to bore into the hardest 
wood. The larval state usually lasts two or three 
years. The pupa state is passed within the bur- 
row made by the larva ; frequently a chamber is 
made by partitioning off a section of the burrow 
with a plug of chips; but sometimes the larva 
builds a ring of chips around itself just beneath the bark before 
changing to a pupa. The pupal state is comparatively short, 
lasting only a few days or weeks. 


Fig. 


Fig. 2 


THE PRIONIDS 


The larger of the long-horned beetles constitute a subfamily. They 
are distinguished from other cerambycids by having the sides of the 
prothorax prolonged outwards into a thin margin, which is more or less 
toothed. The wing-covers are usually leathery in appearance, and of a 
brownish or black color. The following are our best-known species. 

The broad-necked prionus, Prionus laticollis. — This is the largest of 
our common species; but the individuals 
vary from 1 to 2 inches in. length. It is of 
a pitchy-black color, and of the form shown 
in Figure 281. The antennae are twelve- 
jointed in both sexes. The larva is a large, 
fleshy grub, and infests the roots of grape, ap- 
ple, poplar, and other trees. 

The tile-horned prionus, Prionus imbricornis, 
is very similar to the preceding species but 
can be distinguished at a glance by the form 
of the antennae. In the antennae of the male 
the number of segments varies from eighteen 
to twenty, while in the female the number 
varies from sixteen to seventeen. The popular 
name refers to the fact that the segments 

of the antennae of the male overlap one another like the tiles on a 
roof. The larva infests the roots of grape and pear, and also feeds upon 
the roots of herbaceous plants. A closely related species, Prionus califor- 
nicus, occurs on the Pacific Coast. The larva is from 2§ to 3 inches 
long. 


l62 


THE STUDY OF INSECTS 


Fig. 282. 


THE TYPICAL CERAMBYCIDS 

In this group the prothorax is rounded on the sides, the tibise 
of the fore legs arc not grooved, and the palpi are never acute at the tip. 
There are nearly four hundred American species, representing more than 
one hundred genera. The few species mentioned below are 
those that the beginning student is most likely to meet. 

The ribbed pine-borer, Rhagium lineatum. • — This is a 
gray beetle mottled with black, and has a narrow thorax, 
with a spine on each side (Fig. 282). It received its name 
because of the three ridges extending lengthwise on each 
wing-cover. Its larva bores in the wood of pine-trees. On 
one occasion the writer found many of them in a pine-tree 
eight inches in diameter, which they had bored through and through. 
When the larva is full-grown it makes a hole nearly through the thick 
bark of the tree, so that it may easily push its way out after its trans- 
formations; it then retreats a short distance and makes a little ring of 
chips around itself, between the bark and the wood, and changes to a 
pupa within this rude cocoon. The adult beetle remains in this pupal 
cell through the winter. 

The cloaked knotty-horn, Desmocerus palliatus. — This beautiful 
insect is of a dark blue color, with greenish 
reflections. The basal part 
of the wing-covers is orange- 
yellow, giving the insect the 
appearance of having a yellow 
cape thrown over its shoulders 
(Fig. 283). The segments in 
the middle of the antennae are 
thickened at the outer end, so 
that they look like a series of 

knots. The adult is quite COm- Fig. 283. — Desmocerus pallia- 

mon in June and July on elder, 

in the pith of which the larva bores. 

The beautiful maple-borer, Glycobius specibsus. — 
This is a handsome insect, marked with black and 
yellow, as indicated in Figure 284. It lays its eggs 
in midsummer on the trunks of sugar-maples, in the wood of which 
the larvae bore. If an infested tree be examined in the spring the pres- 
ence of these borers can be detected by the dust that 
falls from the burrows. The larvae can be destroyed at 
this time by the use of a knife and a stiff wire. 

The locust-borer, Cyllene robmice. — To the enthusiastic 
entomologist the goldenrod is a rich mine, yielding to the col- 
lector more treasures than any other flower. It gives up its 
gold-dust pollen to every insect-seeker ; and because of this 
generous attitude to all comers it is truly emblematic of 
the country that has chosen it as its national flower. 

Among the insects that revel in this golden mine in the 
autumn is a black beetle with numerous transverse or wavy yellow bands 
(Fig. 285). This beetle is also found on locust-trees, where it lays its 
eggs. The larvae bore under the bark and into the hard wood. 


Fig. 284. 


Fig. 28s. 


CO LEO PT ERA 


163 


The locust-trees have been completely destroyed in some localities 
by the depredations of these larvae. 

The painted hickory-borer, Cyllene caryce. — This beetle resembles the 
preceding so closely that the same figure will represent either. But the 
hickory-borer not only infests a different kind of tree, but appears in 
the spring instead of the autumn. In this species the second segment of 
the hind tarsus is densely pubescent beneath, while it is glabrous in the 
locust-borer. 


Fig. 286. 


THE LAMIIDS 

As in the preceding group, the prothorax is rounded with these 
beetles; but the lamiids are distinguished by having the fore tibia? 
obliquely grooved on the inner 
side, and the last segment of the 
palpi cylindrical and pointed. 
The following are some of the 
more important species. 

The sawyer, Monochamus 
notatus. — This beautiful brown- 
ish-gray beetle is about 1 ^ inches 
long, with antennae as long as 
the body in the case of the fe- 
male and twice as long in the 
case of the male (Fig. 286). 
The larva bores in the sound 
wood of pine and of fir, making, 
when full-grown, a hole h inch 
in diameter. The pupal state 
is passed within the burrow. It sometimes occurs in such numbers as 
to kill the infested trees. 

The round-headed apple-tree borer, Saperda Candida. — Excepting 
the codling-moth, which infests the fruit, this is the worst enemy of the 
apple that we have. Its common name is used to distinguish it from the 
flat-headed apple-tree borer, already described, the larva of this species 
being nearly cylindrical in form (Fig. 280). The eggs are laid on the 
bark of the trunk of the tree late in June or July. The larva at first 
bores in the soft sap-wood, making a disk-shaped mine; after this it 

works in an upward direction in the harder 
wood, and at the close of its larval existence 
comes to the surface several inches above the 
place it entered. It requires nearly three 
years for this larva to attain its growth; it 
changes to a pupa, near the upper end of its 
burrow, about the middle of May, and emerges 
as a beetle in June. The beetle (Fig. 287) is 
of a pale brown color above, with two broad 
white stripes extending the whole length of the 
body. Although the larva is found chiefly in 
apple, it infests many other trees. The presence of the borers can be de- 
tected by the sawdust-like castings which the larvae throw out at the 
entrances of their burrows. 


Fig. 287. 


i6 4 THE STUDY OF INSECTS 

The two-spotted oberea, Oberea bimaculata, is sometimes a serious 
pest, boring in the canes of blackberry and raspberry. The larva re- 
sembles that of the preceding species. The adult (Fig. 
288) is .about h of an inch in length and of a dee]) black 
color, except the prothorax, which is yellow. There are 
usually two or three black spots on the pronotum, but 
frequently these are wanting. 

The red milkweed-beetles, Tetrabpes. 
- There are several species of bright red 
beetles that are common on milkweeds (Asclepias). 
These belong to the genus Tetraopes. Our most com- 
mon species (Fig. 289) is T. tetraophthalmus . In this 
species there are four black spots on each wing-cover, and the antennae 
are black and not ringed with a lighter color. The larva bores in the 
roots and the lower parts of the stems of milkweeds. 

Family Chrysomelids 

The Leaf-beetles or Chrysomelids 

The leaf-beetles are so called because they feed upon the leaves of 
plants both as larvae and adults. They are usually short-bodied, and 
more or less oval in outline ; the antennas are usually of moderate length ; 
and the front is not prolonged into a beak. The legs are usually short, 
and are furnished with tarsi of the same type as those of the preceding 
family (see Fig. 279, p. 161). 

Although we are unable to cite any characteristic that will invariably 
distinguish these beetles from the preceding family, the student will 
rarely have any difficulty in making the distinction. The beetles of the 
genus Donacia, described below, are the only common ones that are 
liable to be misplaced. In other cases the more or less oval form of the 
body, and the comparatively short antennae, and the leaf-feeding habits, 
will serve to distinguish the chrysomelids. 

The leaf -beetles are nearly all comparatively small, the Colorado 
potato-beetle being one of our larger species. 

The eggs are usually elongated and yellowish, and are laid upon the 
leaves or stems of the plants upon which the larvae feed. Many of the 
larvae live exposed on the leaves of plants; others that live in similar 
situations cover themselves with their excrement; some are leaf -miners; 
and a few, as the striped squash -beetle, bore in the roots or stems of 
plants. 

This is a large family, of which nearly one thousand North American 
species are known. The following illustrations will serve to 
show the variations in form and habits. 

The long-horned leaf-beetles, Donacia. — These are the 
common leaf-beetles that are liable to be mistaken for ceram- 
bycids. They are of elongated form, with slender antennae 
(Fig. 290). They measure from | to f inch in length, and 
metallic color — either greenish, bronze, or purplish. The 
lower side of the body is paler and is clothed with very fine hair which 
serves as a water-proof coat when the insect is submerged. The larvae 
feed upon the roots or in the stems of aquatic plants; and the adults 


COLEOPTERA 


165 


are found on the leaves of the same plants. We have many species, but 
they resemble one another so closely that it is difficult to separate 
them. 

The asparagus-beetle, Crioceris aspdragi. — This 
is a small red, yellow, and black beetle, that gnaws 
holes in the heads of young asparagus, and lays 
oval, black eggs upon them. The larvae, which are 
small, brown, slug-like grubs, also feed upon the 
young heads in the spring, and later in the season a 
second brood feed upon the full-grown plant. Figure 
291 represents a head of asparagus bearing the eggs 
of this beetle, also a beetle and a larva enlarged. 
The beetle measures about \ of an inch in length. 

The grape rootworm, Fidia longipes. — This in- 
sect is the most destructive enemy of the grape 
occurring east of the Rocky Mountains. The adult 
is a small grayish-brown beetle, measuring about \ 
of an inch in length. It feeds on the leaves in July, 
eating out characteristic chain-like holes. The eggs 
are laid beneath the loose bark of the vines. On 
hatching, the larvas drop to the ground and burrow down to the roots, 
which they destroy, causing the death of the vine, Most of the larvae 
do not transform till the following spring. 

The Colorado potato-beetle, Leptinotarsa dectrrnlinedta. — A good 
many insect tramps have come to us from Europe and from the Orient, 
and appropriated whatever pleased them of our growing crops or stored 
grain. But two of our worst insect pests have swarmed out on us in 
hordes from their strongholds in the region of the Rocky 
Mountains. These are the Rocky Mountain locust and the 
Colorado potato-beetle (Fig. 292). The latter insect dwelt 
near the base of the Rocky Mountains, feeding upon the 
sand-burr (Solanum rostratum), until about the year 1859. 
At that time it began to be a pest in the potato-fields of the 
settlers in that region. Having acquired the habit of feeding upon the 
cultivated potato, it began its eastward march across the continent, 
spreading from potato patch to potato patch. At first the migration 
took place at about the rate of fifty miles a year, but later it was more 
rapid; and in 1874 the insect reached the Atlantic Coast. 

The adult beetles hibernate in the ground; they emerge early in April 
or May, and lay their eggs on the young potato plants as soon as they 
appear; both larvae and adult beetles feed on the foliage of the potato. 
The larvae enter the ground to transform. This pest is usually controlled 
by the use of Paris green. 

The diabroticas. Several very important pests belong to the genus 
Diabrotica. They are chiefly greenish-yellow beetles, marked with black 
stripes or spots. The striped diabrotica, D. vittdta, has two black stripes 
on each wing-cover. The adult feeds on the leaves of cucumber, squash, 
and melon; and the larva, which is a slender, worm-like creature, bores 
in the stems and roots of the same plants. The twelve-spotted diabrotica, 
D. duodecim punctata, and Diabrotica soror, agree in having six black spots 
on each wing-cover. The former is very common in the East; the latter 
occurs on the Pacific Coast, and is the most destructive of all of the 


Fig. 292. 


i66 


THE STUDY OF INSECTS 


Fig. 293. 


diabroticas. Diabrotica longicomis is a green species, which feeds on the 
pollen and silk of corn and on the pollen of other plants. Its larva is 
Known as the corn rootworm; it is very destructive to corn in the 
Mississippi Valley. Its injuries are greatest where corn is grown on the 
same land year after year; hence a rotation of crops should be practised 
where this pest is troublesome. 

The jlcabeetles. — There is a group of leaf-beetles, of which we have 
many species, in which the hind legs are fitted for leaping, the thighs 

being very large. These are commonly 
called the fleabeetles. 

The striped fleabeetle, Phyllotreta vit- 
tdta, is exceedingly common on cabbage, 
turnip, radish, mustard, and 
allied plants. It is a small, 
black, shining beetle, with a 
broad, wavy, pale, dull yel- 
low stripe upon each wing- 
cover (Fig. 293) ; it measures 
about -jV of an inch in length. 
These beetles eat numerous 
little pits in the thicker leaves that they 
infest, and minute perforations in the thin- 
ner-leaved plants. The larva is a slender, 
white worm, about | of an inch in length ; 
it feeds on the roots of the plants infested by the 
adult. 

The cucumber fleabeetle, Epitrix ciiciimeris, is a 
common pest of melon and cucumber vines ; it also 
attacks the leaves of potatoes, raspberry, turnip, 
cabbage, and other plants. This is a minute black 
species, measuring less than -^ of an inch in length. 
The body is finely punctured and clothed with a 
whitish pubescence ; there is a deep transverse furrow across 
the hind part of the prothorax; the antennae are dull yellow, 
and the legs are of the same hue, except the posterior femora, 
which are brown. The adult beetles 
feed on the leaves of plants in the 
same manner as the preceding spe- 
cies ; and the larvae on the roots of the t 
infested plants. 

The grape fleabeetle, Haltica 
chalybea. — This is a larger species 
than the two preceding, measuring 
about \ of an inch in length, and is of 
a dark, steel-blue color. It is a great pest in vine- 
yards, eating into the buds of grape in early spring, 
and later gnawing holes in the leaves (Fig. 294). In 
May and June the brown, sluggish larvae may also be found feeding upon the 
surface of the leaves. The full-grown larva is chestnut brown marked with 
black spots (Fig. 295) . It drops to the ground and makes a cell in the earth in 
which it transforms. The most important injury caused by this pest is the de- 
struction of buds in early spring, which causes a great loss of foliage and fruit. 


Fig. 


COLEOPTERA 167 

The wedge-shaped leaf-beetles. — These insects are characterized by the 
peculiar form of the body, which is narrow in front and broad behind. 
In most of the species the body is much roughened by deep pits, and 
usually the pits on the wing-covers are in regular rows. These insects 
and the tortoise-beetles differ from other leaf-beetles in having the fore 
part of the head prominent, so that the mouth is con- 
fined to the under surface. Some of the larvae feed ex- 
ternally upon the leaves and bear a parasol composed 
of their excrement; other species are leaf -miners. 
Baliosus rubra is a good representative of this group (Fig. 
296). It varies in length from £ to £ of an inch. It 
is of a reddish color, with the elevated portions of 
the elytra more or less spotted with black. The FlG - 2 <> 6 - 

larva mines in the leaves of apple, forming a blotch-mine; the transforma- 
tions are undergone within the mine. We have also found this species 
mining the leaves of basswood in great numbers. 

The tortoise-beetles. — Among the more beautiful Coleoptera are cer- 
tain bright golden, green, or iridescent beetles found on the leaves of 
sweet potato, morning-glory, nettle, and other plants. In these beetles 
the body is flattened below and convex above; the head is nearly or 
quite concealed beneath the prothorax; and the margins of the pro tho- 
rax and elytra are broadly expanded, forming an approx- 
imately circular or oval outline, and suggesting a 
resemblance to the shell of a tortoise (Fig. 297). Not all 
of the species are iridescent ; and in the case of those that 
are, the brightness of the colors is said to depend on the 
emotions of the insect. What a beautiful way to express 
one's feelings — to be able to glow like melted gold when 
one is happy! Unfortunately for the beauty of our collections, these bright 
colors disappear after the death of the insect. 

The larva? of the tortoise-beetles are flattened, and have the margin 
of the body fringed with spines. At the caudal end of the body there is a 
forked appendage which serves a very strange purpose. This fork is 
bent forward over the backhand to it are attached the cast-off skins of 
the larva and its excrement; these constitute a parasol. When about to 
change to the pupa state these larva? fasten the caudal end of the body 
to the underside of a leaf; the skin then splits open, and is forced back 
to this end of the body, where it remains. 

The black-legged tortoise-beetle, Cassida nigripes, is a beautiful 
golden species which lives on the vines of the sweet potato. It is a little 
over j of an inch in length and each wing-cover bears three black spots 
arranged in a triangle. The beetle loses its brilliant tone if disturbed 
and when it dies the golden color fades to a yellowish-brown. 


Family Mylabrid^e 

The Pea-weevil Family 

These are small beetles, the larva? of which live in the seeds of legu- 
minous plants. The head of the adult is prolonged into a broad beak; 
and the wing-covers are rather short, so that the tip of the abdomen is 


i68 


THE STUDY OF INSECTS 


always exposed (Fig. 298). This is a comparatively small family; ninety- 
three species are listed in our fauna, of which eighty-one belong to the 
genus Mylabris. 

The pea-weevil, Mylabris pisorum. — "Buggy peas " are 
well known in most sections of our country; but just how 
1 the " bugs " find their way into the peas is not so generally 
understood. The eggs of the pea-weevil are laid upon the 
pod while the peas are quite small; when the larvae hatch 
they bore through the pod into the young peas. Here they 
feed upon the substance of the seed, which ripens, however, and in some 
cases will germinate when planted. The larva before transforming eats a 
circular hole on one side of the seed, leaving only a thin scale, which is 
easily pushed away by the mature beetle. The adult is about \ of an 
inch in length; it is dark brown, with a few white spots on the wing- 
covers, and one on the prothorax near the middle. Sometimes the beetles 
leave the peas during the autumn or winter; but as a rule they remain 
in the seed till spring, and are often planted with it. Seed peas should 
be placed in water, and the infested ones, which will float, should be 
picked out and destroyed. This species is not known to oviposit on dry 
peas. 

The bean-weevil, Mylabris obtectus. — This species resembles the 
preceding quite closely; but it is a little smaller (Fig. 298), and lacks 
the white markings characteristic of M. pisorum. It infests beans, and 
often several individuals inhabit a single bean. The eggs are laid within 
the pod, being pushed through a slit which the female gnaws through 
the pod. This species will oviposit on dry beans, peas, and other grain, 
and will continue to breed for many generations in stored beans and 
peas. 


The Snout-Beetles 
The Group Rhynchophora * 

The five families included in this series constitute a well-marked 
division of the order, which has long been known as 
the Rhynchophora or snout-beetles. These names were 
suggested by the fact that in many of these insects the 
head is prolonged so as to form a snout or beak; but 
it should be remembered that, while these names are 
very appropriate for a large part of this series, in some 
members of it the head is not thus prolonged. This is 
especially true of the last two families, the bark-beetles 
and timber-beetles, in which the beak is either want- 
ing or extremely short and broad. 

The most distinctive features characterizing this se- 
ries of families are the following: the suppression of the 
gula, the gular sutures being confluent (Fig. 299, gs); 
the absence of sutures between the presternum and the 
episterna and epimera; the meeting of the epimera of 
the prothorax on the middle line behind the prosternum 
(Fig. 299, em); and the palpi being usually short and rigid. 


Fig. 299. 


* Rhynchophora: rhynchos (New Latin), snout; phoros (<t>bpos), bearing. 


COLEOPTERA 169 

Family Brentid^ 
The Primitive Weevils 

This family is confined chiefly to tropical regions; only six species 
are found in the United States, and but one of these in the North. 

The northern brentid, Eupsalis minuta. — In the female 
the head is prolonged into a slender snout ; but in the male 
the snout is broad and flat, and is armed with a pair of 
powerful jaws (Fig. 300). These are weapons of offence, 
for the males fight desperately for their mates; and too, the 
males are generally larger than the females. In these re- 
spects these insects resemble the stag-beetles, the males of Fig 5oo 
which also fight for their mates. 

The northern brentid is found beneath the bark of recently felled or 
dying oak, poplar, and beech trees in the solid wood of which the larvas 
bore; and is widely distributed over the United States and Canada. 

Family Platystomid.43 
The Fungus Weevils 

This family includes a small number of snout- beetles in which the 
beak is short and broad, and the labrum is present; the antennae are not 
elbowed, and the terminal segments rarely form a compact club; the 
palpi are flexible; and the prothorax bears a transverse elevated ridge at 
or near its base. 

The larva? of many species infest woody fungi, others breed in the 
smut of corn and wheat, and still others bore in dead wood. The larvae 
of one cosmopolitan species, known as the coffee-bean weevil, Arceocerm 
fascictddtus, attack seeds of various plants. 

Sixty-two species of this family are known to occur in America north 
of Mexico. This family is the Anthribidae of many authors. 

Family Curculionid^e 
The Curculios or Typical Snout-beetles 

The Curculionidae is a very large family; it is represented in America 
north of Mexico by more than eighteen hundred species; to it belong 
four-fifths of all our Rhynchophora. This family includes the typical 
snout-beetles, the head being prolonged into a well-defined beak, which 
is usually long and curved downward. 

The following are some of the more important members of this family. 

The sweet potato weevil, Cylas formicdrius , is an Asiatic species which 
has invaded the Gulf states. The beetle is somewhat ant-like in form, 
a fact which suggested its specific name. It is about f of an inch in 
length. The elytra, head, and snout are bluish-black while the prothorax 
is reddish -brown. Both larvas and adults bore into the stems and tubers 
of the sweet potato and sometimes do very serious damage. 

The imbricated snout-beetle, Epiazrus imbriedtus, is usually a dull, 
silvery white beetle with brown markings; but the species is quite vari- 


i;o THE STUDY OF INSECTS 

able in color. It is represented, somewhat enlarged, in Figure 301. It 
is omnivorous, gnawing holes in various garden vegetables, strawberry- 
plants, and other fruits. The greater part of the insect is 
clothed with imbricated scales, which suggested the spe- 
cific name. 

The New York weevil, Ithycerns noveboracensis. — This 
is a large species, measuring from f to | of an inch in 
length. It is black, rather sparsely clothed with a mix- 
ture of ash-gray and pale brown prostrate hairs which 
give it a black-spotted appearance. The beak is short and 
broad. The mandibles are prominent, not very stout, 
IG ' 301 ' and emarginate at the tip, with an inferior cusp. The 

antennae are not elbowed; the first segment is longer than the second; 
and the terminal segments form a small, oval club. 

This species breeds in the twigs and tender branches of oak, hickory, 
and possibly other forest trees. The adult beetles appear in early spring, 
and sometimes do much damage to fruit-trees by eating into buds, and 
gnawing the tender bark on new growth. They can be caught by jarring 
them on to sheets or by the use of a plum-curculio catcher. (This 
weevil is placed in a separate family, Belidcz, by some authors.) 

The strawberry crown-girdler, Brachyrhmus ovdtus. — This is a dark 
brown, almost black, snout-beetle, about £ of an inch in length, which 
often invades dwellings in search of shelter, in the Northern States and 
Canada. The larvae feed on the roots of the strawberry, cutting them 
off near the crown. The adults feed on the foliage. In the adult, the 
hind wings are wanting and the elytra are grown together. 

The black vine-weevil, Brachyrhinus sulcatus. — This beetle is larger 
than the preceding species, measuring % of an inch in length; it is black, 
with small patches of yellowish hairs on the elytra. The larvae destroy 
the roots of strawberries; and both larvae and adults infest various green- 
house plants. 

The plum-curculio, Conotrachelus nenuphar. — This is the insect that 
stings plums, often destroying a large portion of the fruit; the larva is 
also the well-known " worm " of " wormy " cherries. This species is the 
most destructive insect that infests plums, cherries, and other stone 
fruits; it also breeds in apple. Its presence in an orchard can be deter- 
mined early in the season by a peculiar mark it makes when laying its 
eggs in the young fruit. The female beetle makes an incision, with her 
snout, through the skin of the fruit. In this incision she lays a single 
egg, which she pushes with her snout to the bottom of the cavity that 
she has prepared. She then makes a crescent-shaped incision in front of 
the one containing the egg. This last cut undermines the egg. leaving it 
in a little flap. The larvae feed within the fruit. In the case of the plums 
the infested fruit falls to the ground; but not so with cherries. When 
full-grown the larvae go into the ground to transform. This species in- 
fests nectarines, apricots, and peaches, as well as plums and cherries. 

The strawberry -weevil, Anthonomus signdtus, infests strawberry, 
blackberry, raspberry, and dewberry. The female beetle, after laying an 
egg in the flower-bud, causes it to fall by cutting the pedicel; the larva 
develops within the fallen bud. 

The cotton-boll weevil, Anthonomus grdndis, is one of the most serious 
insect pests known in the United States. It infests only cotton. The 


COLEOPTERA 


171 


Fig. 302. — The Mexican cotton- 
boll weevil, much enlarged. 


Fig. 303. 


egg is deposited in a young boll, which the larva destroys. The adults 
(Fig. 302) also feed upon the young bolls and upon the leaves. This 
species is a native of Central America. It spread through Mexico, and 
entered Texas about 1890. Since that time it 
has spread over a large part of the cotton belt. 
Very extensive investigations of this pest have 
been made by the Federal Government and by 
several state governments ; and much literature 
regarding it is available to those interested. 

The acorn-weevil, Balaninus 

rectus, has a slender snout twice 

as long as the body (Fig. 303). 

The female drills a hole in the 

young acorn with this snout and then lays an egg in the 

opening afterwards pushing it to the bottom of the hole 

with her snout. The grub devours the interior of the 

acorn. 

The hickory-nut weevil, Balaninus nasicus, breeds 

in hickory nuts and the chestnut weevil, Balaninus 
probosctdeus, causes wormy chestnuts. Each of these weevils have a long 
slender snout, longer than the body. 

Among the smaller members of this family are two exceedingly im- 
portant pests of stored grains; these are the granary- weevil, Calandra 
granaria, and the rice-weevil, Calandra oryzce. The rice-weevil is so 
called because it was first found in rice in India; but it infests various 
kinds of stored grain ; and in the South it is fully as important a granary- 
pest as is the granary-weevil. 

The two species are quite similar in appearance; but the granary- 
weevil is the larger, measuring from f to } of an inch in length ; while the 
rice-weevil measures less than \ of an inch in length, and differs from the 
granary-weevil in having the elytra marked with four reddish spots. 
The thorax of the rice-weevil is closely pitted with round punctures; 
that of the granary- weevil, with sparse elongate punctures. 
The adult female of both of these species gnaws a tiny 
hole in a kernel of grain and then deposits an egg in it. 
The larva feeds on the grain, becomes full-grown, and 
transforms within the kernel. The adult continues the in- 
jury begun by the larva, eating out the inside of the kernel. 


Family Platypodid^e 

This is a small family, which is represented in our fauna 
by a single genus, Platypus, of which only five species have 
been found in America north of Mexico; these are found 
chiefly in the South and the far West. 

Formerly this group was classed as a subfamily of the 
Scolytidae. It is distinguished from the Scolytidae by the 
fact that the first segment of the anterior tarsi is longer 
than the second, third, and fourth together. The form 
of the body is cylindrical (Fig. 304); and the head is 
large, wider than the prothorax. 


Fig. 304. — Platy- 
pus wilsoni, female. 
(After Swaine.) 


172 


THE STUDY OF INSECTS 


The species of this genus attack many kinds of conifers and deciduous 
trees. They bore deeply into the heart-wood, making " pin-holes " that 
often render lumber useless. The eggs are deposited in the galleries; 
and the larvae feed on a fungus, which is cultivated by the beetles and is 
known as ambrosia. In this respect Platypus resembles several genera of 
the Scolytidae, which also bore in solid wood and feed on ambrosia; all 
of these are known as ambrosia-beetles. The galleries of ambrosia-beetles 
are usually blackened by the fungus. See further account of the ambro- 
sia-beetles in the discussion of the next family. 


Famil y Scolytidae 

The Engraver-beetles and the Ambrosia-beetles 

The members of the family Scolytidae are mostly of cylindrical form 
(Fig. 307) and of small or moderate size; some species measure only 
■^s of an inch in length, but others are much larger, attaining a length of 
I of an inch or more. They are usually brown, 
sometimes black, and with many the hind end 
of the body is very blunt, as if cut off. The an- 
tennae are elbowed or bent in the middle, and are 
clubbed at the tip; the tibiae are usually serrate; 
and the first segment of the -anterior tarsi is shorter 
than the second, third, and fourth together. 

A few members of this family infest herbaceous 
plants; our most important one of these is the 
following. 

The clover-root borer, Hylastinus obscurus. — 
This pest was introduced from Europe and has 
become the most serious enemy of clover, especially 
red clover and mammoth clover, in New York 
State and in other sections of the North. It bores 
in the roots of plants beginning their second year 
of growth and destroys them (Fig. 305). Where 
it is common it is practically impossible to keep 
fields in clover longer than the second summer 
after seeding. In these regions it is the common 
practice to seed with clover and timothy mixed; 
after the clover disappears the field becomes a 
timothy meadow. No practical method of control 
of this pest has been found. 

Most scolytid beetles infest woody plants; 
among them are some of the most destructive 
enemies of forest-trees, and a few attack fruit- 
trees. As a rule they are more liable to attack- 
sickly trees, but their injuries are not confined to 
these. 

The scolytid beetles exhibit two radically 

different types of habits; and from this point of 

view they can be grouped into two groups: first 

the engraver-beetles or bark-beetles; and second, 

7jE k wK«T the ambrosia-beetles or timber-beetles. These two 


\ 


COLEOPTERA 


i73 


Fig. 306. 


groups, however, do not represent a natural division of the family based on 
structural characters. The peculiar habits of the ambrosia-beetles are be- 
lieved to have arisen independently in different parts of the series of 
scolytid beetles. 

The Engraver-beetles or Bark-beetles 

If the bark be pulled from dead branches or trunks of trees, the inner 
layer and the sap-wood will be found, in many cases, to be ornamented 
with burrows of more or less regular form. The smoothly cut figures 
are the mines of en- 
graver-beetles, which 
are also known as 
bark-beetles. Many 
kinds of these en- 
gravings can be 
found, each char- 
acteristic of a partic- 
ular species of 
engraver-beetles. A 
common pattern is 
shown in Figure 306. 

The different species of engraver-beetles vary so greatly in the details 
of their habits that it is difficult to make generalizations regarding them 
in the space available here. In a common type, the adult beetle, after 
penetrating the bark, makes a tunnel in the inner layer of the bark or in 
the sap-wood or in both; this is known as the egg-tunnel, and may be 
either simple or branched. In the sides of the tunnel, most species make 
niches, the egg-niches, in which the eggs are laid. The larva when 
hatched feeds on the bark or sap-wood or both and thus makes a lateral 
tunnel. These lateral tunnels made by the larvae often extend parallel 
in a more or less regular manner. 

While most of the engraver-beetles infest forest-trees, the two follow- 
ing species are well-known pests of fruit-trees. 

The fruit-tree bark-beetle, Eccoptogaster rugulosus. 
— This species infests apple, quince, plum, peach, and 
other stone-fruits. It is sometimes called the shot- 
hole borer by fruit-growers on account of the small en- 
trance holes of its burrows. The adult beetle measures 
from x 1 ^ to yV of an inch in length, and is dark brown or 
nearly black. It infests chiefly sickly trees. 

The peach-tree bark-beetle, Phthorophlams limi- 
naris. — This species resembles the preceding in size 
and habits, except that its injuries are confined 
chiefly to peach and cherry. It can be distinguished 
from the fruit-tree bark-beetle by the fact that the club 
of the antennas is lamellate, an unusual feature in this family (Fig. 307). 

The Ambrosia-beetles or Timber-beetles 

Certain members of the family Scolytidas differ in habits from the 
engraver-beetles or bark-beetles in a remarkable manner; these are those 
known as ambrosia-beetles or timber-beetles. They are termed ambrosia- 


Fig. 307. - 
la-us liminaris. 


Phlhoroph- 


174 


THE STUDY OF INSECTS 


beetles because they cultivate fungi, commonly called ambrosia, upon 
which they feed; and timber-beetles, because they burrow in the solid wood. 

The galleries of the ambrosia-beetles can be distinguished from those 
of other wood-boring insects by the fact that in all of their ramifications 
they are of uniform size and free from wood-dust and other refuse, and their 
walls are stained black i >r 1 >r< >wn by the fungus that is grown upon them. 

The galleries of different species differ in form; but usually there is a 
main gallery, which extends deeply into the solid wood and is often 
branched; and extending from the sides of the main gallery there are 
short chambers, termed cradles, in each of which an egg is laid and a 
larva reared (Fig. 308) . In some species, the female deposits her eggs loosely 
in the galleries, and the young and old live together in the same quarters. 


Fig. 308. — Gallery of Monarthrum mail in maple. (From Hubbard.) 

The galleries are excavated by the adult beetles. In some species 
the gallery is started by a single female, in others the males assist the 
females in this work. The entrances through the bark to the galleries 
are similar to those made by the bark-beetles and like them are known 
as " shot-holes." Under favorable conditions colonies may continue their 
excavations during two or three generations. 

The fungi upon which these beetles feed are carefully cultivated by 
them. So far as is known, each species of ambrosia-beetle cultivates 
only a single species of fungus, and only the most closely allied species 
have the same food-fungus. The fungus is started by the mother-beetle 
upon a carefully packed bed or layer of chips. It is probable that some 
conidia are brought for this purpose from the gallery in which the female 
was developed. The excrement of the larvae is used in some and prob- 
ably in all the species to form new beds for the propagation of the fungus. 

In those species in which the larvae are reared in separate cradles, 
" the mother-beetle is constantly in attendance upon her young during 
the period of their development, and guards them with jealous care. 
The mouth of each cradle is closed with a plug of the food-fungus, and 
as fast as this is consumed it is renewed with fresh material. The larvae 
from time to time perforate this plug and clean out their cells, pushing 
out the pellets of excrement through the opening. This debris is promptly 
removed by the mother and the opening again sealed with ambrosia. 
The young transform to perfect beetles before leaving their cradles." 


COLEOPTERA 


i75 


While the ambrosia-beetles are chiefly injurious to forest-trees, there 
are certain species that injure wine and beer casks; and one species, 
the pear-blight beetle, Anisandrus pyri, sometimes infests the tips of 
pear and apple branches, causing an injury that is often mistaken for the 
bacterial disease known as pear-blight. 

Nearly four hundred species of scolytid beetles, representing many 
genera, have been described from America north of Mexico. 

FAMILIES OF COLEOPTERA NOT DISCUSSED 

The order Coleoptera includes a great number of families the mem- 
bers of which are rare or little known. The special student of the beetles 
is referred to " An Introduction to Entomology " by J. H. Comstock and to 
special treatises on the Coleoptera for an account of the families which we 
have not been able to discuss in this Manual. 


Omophronidae 

Haliplidee 

Amphizoidas 

Rhysodidas 

Clavigeridas 

Pselaphidae 

Histeridas 

Sphasritidae 

Scaphidiidas 

Platypsyllidag 

Leptinidae 

Scydmaenidae 

Clambidas 

Brathinidas 

Corylophidas 

Trichopterygidae 

Sphasriidae 

Psephenidas 

Dryopidae 

Elmidae 

Ptinidae 

Anobiidas 

Bostrichidas 

Lyctidae 

Nosodendridas 

Byrrhidae 


Chelonariidas 

Cupesidae 

Dascillidas 

Eucinetidae 

Helodidas 

Nitidulidae 

Rhizophagidae 

Ostomidas 

Eucnemidae 

Cerophytidas 

Throscidae 

Phalacridas 

Mycetophagidae 

Cryptophagidas 

Erotylidas 

Rhipiceridae 

Derodontidas 

Cleridas 

Corynetidae 

Melyridas 

Lymexylidae 

Cebrionidae 

Plastoceridas 

Phengodidas 

Lycidae 

Micromalthidas 


Endomychidae 

Lathridiidae 

Monotomidas 

Heteroceridae 

Colydiidae 

Murmidiidae 

Mycetaeidas 

Cisidae 

Georyssidag 

Lagriidas 

Othniidas 

Sphindidas 

Eurystethidae 

Alleculidas 

Monommidae 

Melandryidae 

Pythidae 

CEdemeridae 

Cephaloidae 

Pedilidas 

Anthicidas 

Euglenidae 

Pyrochroidas 

Rhipiphoridas 

Mordellidas 


CHAPTER XXI 
ORDER STREPSIPTERA * 


The Stylopids or Twisted-winged Insects 

The members of this order are small, endoparasitic insects, which prey 
on other insects. Only the males are winged; in this sex, the fore wings are 
reduced to club-shaped appendages; the hind wings are large compared with 
the size of the tiny body, fan-shaped, furnished with radiating wing-veins, 
and folded longitudinally when at rest. The adult female is larviform and 
legless. The mouth-parts are vestigial or wanting; the alimentation is 
probably by osmosis. Both sexes undergo a hypermetamorphos is . 

The order Strepsiptera comprises insects that were formerly classed 
as a family of the Coleoptera, the Stylopidae; for this reason, these in- 
sects have been known as the stylopids. Recently since the establish- 
ment of the order Strepsiptera, the name the twisted-winged insects, 
derived from the technical name of the order, has been proposed for them ; 
but the old name is less cumbersome, and will probably continue to be 
used. 

The stylopids are small insects which live par- 
asitically within the bodies of other insects, chiefly 
bees, wasps, digger wasps, and certain Homoptera. Their 
small size and the fact that nearly their entire ex- 
istence is passed within the bodies of their hosts re- 
sult in their being rarely seen except by those who 
are searching for them. During the first stadium the 
young larvae of both sexes are free, and the adult 
winged male leads a free existence for a brief period. 

The stylopids are most easily found by examining 
adult individuals of the species of insects that they in- 
fest, in which may be found adult females and male 
men of 'styiopjzed pupa? of the parasites. The presence of a stylopid is 
indicated by the projecting of the head end of the body 
from between two of the abdominal segments of the host (Fig. 309). 
Frequently a single host will contain several parasites. 

Figure 310 will serve to illustrate the appearance of an adult male 
stylopid. The more striking features are the flabellate antennas; the 
large, stalked, compound eyes; the shortness of the prothorax and the 
mesothorax, and the great length of the metathorax; the reduction of 
the fore wings to club-shaped appendages; and the large size of the 
hind wings. 

The antennas of adult males differ greatly in form in the different 
families of this order. The number of antennal segments varies from four 
to seven. 

* Strepsiptera: strepsis (arpkipis), a turning; pteron (irTepov), a wing. 

176 


Fig. 3og. — Abdo- 


STREPSIPTERA 177 

The mouth-parts of the males are greatly reduced and the mouth 
opening is small. The labrum and labium are wanting as distinct parts. 


Fig. 310. — A male stylopid. (After Pierce.) 

In some species the mandibles are slender, curved and scimitar-like while 
the maxillae are two-segmented. In others the mandibles are greatly 
reduced. 

The three pairs of legs are similar in form and the abdomen is com- 
posed of ten segments. 

The adult female is very degenerate in form. That part of the body 
which projects from the body of the host is the cephalothorax, the head 
and thorax being consolidated into a single disk-like region. The abdo- 
men, which is within the body of the host, is a great sac filled with eggs. 
The body of the adult female is inclosed in the skin of the last larval 
instar, which is termed the puparium; but there is no pupal stage in 
this sex. 

Owing to their parasitic life the development and life-cycles of these 
insects are very complex and remarkable. The young larva is very active 
for it must hunt around and find a host insect. Many of these larva;, of 
course, never find a host and therefore starve. This contingency is 
provided for, however, because a female stylopid has been known to 
produce as many as 2000 young. After the young stylopid finds a host 
it bores to the inside of the body and begins its parasitic life. The 
larvae pass through several molts and assume different forms in their 
progress toward maturity, the females after the early stages differing in 
their development from the males. The female remains larval-like in 
form even when full-grown. 

The order, Strepsiptera, is well represented in this country, ninety- 
seven species having been listed and probably there are many undis- 
covered species. 


CHAPTER XXII 


ORDER MECOPTERA* 


Head 


Fig. 311 
and tail of Panorpa 


The Scorpion-flies and Their Allies 

The winged members of this order have four wings; these are usually 
long, narrow, membranous, and furnished with a considerable number of 
cross-veins; the wings are wanting or vestigial in two genera. The head is 
prolonged into a deflexed beak, at the end of which chewing mouth-parts are 
situated. The metamorphosis is complete. 

This is a small order composed of very remarkable in- 
sects. The most striking character common to all is the 
shape of the head, which is prolonged into a deflexed 
beak (Fig. 311). The beak is formed from the greatly 
elongated clypeus, submentum, and stipes of the maxillae 
» with the rather small, slender mandibles situated at the 

t» K ti P- 

^^i The antennas are long, very slender, and many- 

segmented. The compound eyes are moderately large 
and the legs are long and slender with five-segmented 
tarsi. 

The wings are membranous and are usually long and narrow but in 
certain rare forms they are comparatively broad. The venation of the 
wings is generalized but with many cross-veins. 

The metamorphosis is complete. The larvae are caterpillar-like, with 
three pairs of thoracic legs and with or without abdominal prolegs. The 
pupae are exarate, that is, the wings and legs are free, as in the Coleop- 
tera and Hymenoptera. 

The scorpion-flies. — The most com- 
mon members of this order belong to the 
genus Panorpa, of which there are nearly 
twenty described North American species. 
Figure 312 represents a female of this 
genus. In our more common species the 
wings are yellowish, spotted with black, 
genus are remarkable for the peculiar Panorpa, female 
form of the caudal part of the abdomen (Fig. 313). This 
at first sight reminds one of the corresponding part of a scorpion, and 
suggested the common name scorpion-flies for these insects. But in re- 
ality the two are very different; the last segment of the male Panorpa, 
instead of ending in a sting, like that of a scorpion, is greatly enlarged 
and bears a pair of clasping organs. The tarsal claws are toothed. 

The adults are found resting on the surface of foliage of rank herbage 
growing on the banks of shaded streams and in damp woods where there 
* Mecoptera: mecos (/jljjkos), length; pteron (irrepov), a wing. 

178 


Fig. 313. — Abdomen of 
Panorpa ru/escens. 

The males of this 


MECOPTERA 179 

is a luxuriant undergrowth of herbaceous plants. They feed on dead or 
injured insects and upon fruits; it appears that they rarely if ever cap- 
ture living prey. 

The females lay their eggs in crevices in the earth. The larvae are 
caterpillar-like in form; they have three pairs of true legs and eight 
pairs of abdominal prolegs ; and the body is armed with prominent spines 


Fig. 314. — Larva of Panorpa rufescens, first instar. (After Felt.) 

(Fig. 314); the larvae are carnivorous. The transformation takes place 
in a cell in the ground. 

Boreus. — This genus includes small Mecoptera, our species measuring 
from jV to I of an inch in length, which are often found on snow in 
winter. The wings of the female are vestigial or wanting; those of the 
male, imperfectly developed. The ocelli are wanting. The female has a 
long, protruding ovipositor, which in some species is nearly as long as the 
abdomen. The larva differs from that of Panorpa in lacking the abdom- 
inal prolegs. The pupa state is passed in an earthen cell in the ground. 
Four American species have been described, two from the East and two 
from the West. 

BUtacus. — Insects belonging to this genus have long, narrow wings, 
long legs, and a slender abdomen. They resemble crane-flies very closely 
when on the wing, but can be distinguished by the 
presence of two pairs of wings. They are almost as 
common as Panorpa; and, like the scorpion-flies, are 
found among rank herbage growing on the banks of 
shaded streams and in damp woods where there is a 
luxuriant undergrowth of herbaceous plants. When at 
rest they hang suspended, by their front legs, from 
some support (Fig. 315). The members of this genus 
capture and eat living insects. They are enabled to 
capture their prey by means of their curiously modi- 
fied tarsi, the last two segments of which are armed 
with teeth, and the last segment can be folded back 
against the next to the last segment. In this way there 
fig. 31s. — Natural is formed an efficient grasping organ. It is an interest- 
(From Felt? Bittacus - ing fact that, while in other predacious insects the fore 
legs are the chief organs of prehension, in Bittacus 
the hind legs are used for this purpose fully as often as the others, espe- 
cially when the Bittacus is hanging suspended by its fore legs and cap- 
tures an insect that comes within reach of it. 

Nine North American species of Bittacus have been described. 


CHAPTER XXIII 
ORDER TRICHOPTERA* 


Fig. 316. — Caddice-fly. 


The Caddice-flies 

The members of this order have four wings; these are membranous and 
usually more or less densely clothed with long, silky hairs. In the more 
generalized members of the order, the venation of the wings corresponds 
closely to that of the hypothetical primitive type with but few or no accessory 
veins; in some of the more specialized members of the order, the venation of 
the wings is reduced. The mouth-parts of adults, except the palpi, are 
vestigial. The metamorphosis is complete. 

The caddice-flies are moth-like insects, which 
are common in the vicinity of streams, ponds, 
and lakes, and are frequently attracted to lights at 
night (Fig. 316). The larva? of these insects are the 
well-known caddice-worms ; these live in the water, 
and most of them build cases about their bodies. 
In the adult insect, the body-wall is soft, and is thickly clothed with 
hairs. The two pairs of wings are membranous and usually more or 
less clothed with long, silky hair. In a few forms the wings are naked. 
The hind wings are shorter than the fore wings; but they are usually 
broader. In one species the female is apterous, and in another the wings 
of the female are vestigial. When not in use the wings are folded roof- 
like over the abdomen. 

The eggs of caddice-flies are round or slightly oval in form, 
are laid either in water or upon objects above 
water from which the larvae when hatched can 
find their way into the water. Some species that 
lay their eggs in water descend below the sur- 
face in order to glue their eggs to some sub- 
merged support. So far as is known, most 
caddice-flies, lay their eggs in a mass enveloped 
either in a cement, by which the mass is glued 
to some support, or in a gelatinous covering. In 
the latter case, the covering absorbs water and 
thus increases greatly in size. The form of the gelatinous mass and the 
arrangement of the eggs within it are often characteristic of the species 

(Fig. 317). 

The larvae of caddice-flies, the caddice-worms, found in this country 
are aquatic and most of them build portable cases in which they live and 
which they drag about wherever they go projecting only the front end 
of the body and the legs from the case when they travel. The cases of 
different species differ greatly in form and in materials vised in their con- 
* Triehoptcra: trichos (Opi£, rplxos), the hair; ptcron (ttt(poi>), a wing. 

180 


They 


Fin. 317. — Two egg-masse? 
of caddice-flies: a, Phryganea in- 
terrupta- b, Trianodes sp. (From 
Lloyd.) 


TRICHOPTERA 181 

struction ; but silk is used in building all of them. This silk, like that of 
caterpillars, is secreted by modified salivary glands and is emitted 
through an opening in the labium. 

Some caddice-worms build their cases entirely of silk; but most of 
the case-building species use other materials also; these may be grains 
of sand, small stones, bits of wood, moss, or pieces of leaves; and some 
species fasten shells of small mollusks to their cases. The materials used 
are glued together with silk; and the case is lined with silk, so as to 
form a suitable protection for the soft abdomen. 

When the caddice-worms are full-grown they do not leave the water 
to transform, the pupae being as truly aquatic as the larvae. Some of the 
case-building species change the form and material of their cases at this 
time; and nearly all of them partly close their cases so as to keep out 
intruders and sift; but usually provision is made for the ingress of water 
for respiration. Some species merely cement a stone or grains of sand 
over each opening of the case; others build a silken lid with a slit in it; 
and still others build a silken grating in each end of the case. Within 
these modified cases the larvae transform to pupae. 

In the case of those caddice-flies that emerge from rapidly flowing 
water, as the net-building species, the wings expand instantly when the 
insect reaches the surface of the water and are then fitted for flight; it is 
evident that if much time were required for the wings to become fit for 
use, as is the case with most other insects, the wave succeeding that 
which swept the insect from the water would sweep it back again and 
destroy it. 

The Trichoptera can be regarded as beneficial insects, as the larvae 
form an important element in the food of fishes, and especially of the 
brook trout. Sometimes in cities near rivers, the adults are annoying on 
account of the great numbers of them that are attracted to lights. 

This is a large order and includes several families. Each species of 
those which make cases builds a par- 
ticular kind of tube. Some caddice- 
worms are carpenters, 
building their houses of _ _ „ , , ,. 

o - Fig. 318. — Case of caddice- worm. 

straws or sticks placed 

lengthwise of the body (Fig. 318); but certain species that 
make their houses chiefly of straws fasten the straws cross- 
wise like the logs of a log-house (Fig. 319). These log-house 
fig. 319— Log- builders often have the curious habit of decorating their 
. a m type o case. k ouses j-^ f as tening snail-shells to the outside. 

There are caddice-worm houses closely resembling in plan those just 
described but differing in appearance, being-made of bits of moss. Some- 
times the houses are built of leaves ; these may be fastened so as to form 
a flat case; or are arranged in three planes, so as to form a tube, a cross- 
section of which is a triangle. 

Other caddice-worms are masons, building their houses of grains of 
sand or of small stones. Sometimes these houses are tubes very regular 
in outline, being composed only of grains of sand fastened together with 
silk; but certain species of mason caddice-worms fasten larger stones on 
each side of this tube of sand (Fig. 320). Some of the species that build 
tubes of sand make spiral houses which very closely resemble in form 
snail-shells (Fig. 321). 


l82 


THE STUDY OF INSECTS 


Perhaps the most remarkable species are the net-spinning caddice- 
worms. The best-known of these are species of the genus Hydropsyche, 
the nets of which have been described by many writers. 


Fig. 32a. — Case of Gtrra 
calcarala. (After Lloyd.) 


Fig. 321. — Case 
of H elico psyche. 
(From Lloyd.) 


Fig. 322. — Net of Hydropsyche. 


The larvae of Hydropsyche live only in rapid streams and on the wave- 
beaten shores of lakes. They do not build portable cases, but live in 
tubes composed of silk and debris, and fastened permanently in place; 
sometimes they establish themselves in old worm-holes in submerged 
wood. The most striking feature in their habits, however, is the fact 
that each one builds a net for the capture of its food. This net is built 
adjacent to the tube in which the larva lives; it is funnel-shaped and has 
at its down-stream end an opening in which is built a strainer. This is a 
beautiful object, consisting of two sets of regularly spaced strands of 
silk extending across the opening at right angles to each other (Fig. 322). 
These nets are often built in crevices between stones; but fully as often 
they are built up from a flat surface, as on the brink of a waterfall. 
Much of the coating of dirt with which rocks in such places are clothed in 
summer is due to its being caught in these nets. Algae, larvae, and other 
small animals in the water that passes through the net are held by the 
strainer and thus made available to the caddice-worm for food. 


CHAPTER XXIV 
ORDER LEPIDOPTERA* 


The Moths, the Skippers, and the Butterflies ' 

The winged members of this order have four wings; these are mem- 
branous, and covered with overlapping scales. The mouth-parts are 
formed for sucking. The metamorphosis is complete. 

The members of this order, the moths, the skippers, and the butter- 
flies, are well known to every observer of nature. Their most easily 
observed distinguishing characteristic is that which suggested the name 
of the order, the scaly covering of the wings and body. Every lad that 
lives in the country knows that the wings of moths and butterflies are 
covered with dust, which comes off upon one's fingers when these insects 
are handled. This dust when examined with a microscope is found to be 
composed of very minute scales of regular form. The body, the legs, 
and other appendages are also covered with scales. 

The scales of Lepidoptera are modified setas. That is, they are setae 
which, instead of growing long and slender as setae usually do, remain 
short, but grow very wide as compared with their length. Every grada- 
tion in form can be found from the ordinary hair-like form, which occurs 
most abundantly upon the body, to the short and broad scale, which is 
best seen upon the wings. 

There is a great difference among the 
insects of this order regarding the regular- 
ity of the arrangement of the scales upon 
the wings. With some of the lower moths 
the scales are scattered irregularly over the 
wings. But if the wing of one of the higher 
butterflies be examined with a microscope, 
the scales will be found arranged in regu- 
lar, overlapping rows; the arrangement be- 
ing as regular as that of the scales on a fish 
or of the shingles on a roof (Fig. 323). In 
the upper part of the figure the membrane 
is represented with the scales removed. 

The chief use of the scales on the body is for the protection of the 
insect. Another use of the scales may be to strengthen the wings. 
A secondary use of the scales is that of ornamentation; for the beautiful 
colors and markings of the moths and butterflies are due to the scales. 
If the scales are removed the colors of the insects are destroyed. 

The mouth-parts of moths and butterflies are especially adapted for 
sucking nectar from flowers. If the head of a butterfly be examined, 

* Lepidfiptera : lepido {\tirls, \inl5os), scale; pteron (irrepov), a wing. 

183 


t a- s A -£-*-" ■ 


slmAArtJFJf: 


Fig. 323. — Part of wing of butterfly, 
greatly magnified. 


184 


THE STUDY OF INSECTS 


Fig. 324. — Maxillae of cotton-moth, and tip of same enlarged. 


Fig. 325. — Cross-section of maxillae. 


there will be found a long sucking tube, which when not in use is coiled 
on the lower side of the head between two forward-projecting appendages. 
This long sucking tube is composed of the two maxillae, greatly elongated, 

and fastened together side by 
side. In Figure 324 there is 
represented a side view of the 
maxillae of a moth; and in 
Figure 325 a cross-section of 
these organs. Each maxilla is 
furnished with a groove, and 
the two maxillae are so fastened 
together that the tw r o grooves 
form a tube through which 
the liquid food is sucked. As 
a rule the maxillae of insects 
of this order are merely fitted 
for extracting the nectar from 
flow r ers, but sometimes the tips 
of the maxillae are armed with 
spines, as shown in Figure 324. 
This enables the insect to 
lacerate the tissue of ripe fruits 
and thus set free the juice, 
which is then sucked up. 
Many moths do not eat in 
the adult state ; with these the 
maxillae are wanting. The two forward projecting organs between which the 
maxillae are coiled when present are 
the labial palpi. In some moths the 
maxillary palpi are also developed. 
The larvae of Lepidoptera are 
known as caterpillars. They vary 
greatly in form and appearance; 
but are usually cylindrical, and pro- 
vided with from ten to sixteen legs, 
— six thoracic legs, and from four 
to ten abdominal legs. The thoracic 
legs, which are finally developed 
into the legs of the adult, have a 
hard external skeleton; and are 
jointed, tapering, and armed at the 
end with a little claw. The abdom- 
inal legs, which are shed 
with the last larval skin, 
are thick, fleshy, without 
joints, elastic or contrac- 
tile, and are generally 
furnished at the extrem- 
ity with numerous, min- 
ute hooks (Fig. 326); they are termed prologs. 

Most caterpillars, except the larvae of nearly all butterflies, spin 
cocoons (Fig. 327). In some instances, as in case of the silkworms, a 


Fig. 326. — Larva of a hawk-moth. 


LEPIDOPTERA 


185 


great amount of silk is used in the construction of the cocoon; in others 
the cocoon is composed principally of the hairs of the larva, which are 
fastened together with a fine web of silk. 


Fig. 328. — Pupa of a moth. 


Fig. 327. — Cocoon of a moth. 

The pupae of the Lepidoptera are typically of the obtected type; that 
is, the developing wings, legs, mandibles, maxilla?, and antennae are 
glued to the surface of the body (Fig. 
328); but in some of the more general- 
ized forms these appendages are free. 

The members of this order as a rule 
feed upon plants, and are not aquatic; 
some, as the clothes-moth and the species 
that destroy scale-insects, feed on animal 
matter, and a very few feed upon plants 
below the surface of the water. 

More than nine thousand species of Lepidoptera are known to occur 
in America, north of Mexico. These represent more than sixty families. 

We commonly divide the Lepidoptera into two groups; the moths 
and the butterflies. There is, however, a group within the division of 
butterflies known as the skippers, which constitutes a fairly well-defined 
assemblage of forms. 

The moths. • — These are the insects commonly called millers. 
Most of the species fly by night and are frequently attracted to lights. 
When at rest the wings are either wrapped around the body, or are 
spread horizontally, or are folded roof -like on the abdomen; except in a 
few cases they are not held in a vertical position above the body. The 
antennae of moths are of various forms; they are usually thread-like or 
feather-like; only in rare cases are they enlarged towards the tip. 

The butterflies. — All of our species of butterflies fly in the daytime; 
and, with few exceptions, they fold the wings together above the back in 
a vertical position when at rest. The antennae are thread-like, and 
usually with a club at the tip. It was this feature that suggested the 
term Rhopalocera, which is applied to them. 

The group of butterflies as defined here includes the representatives of 
two quite distinct superfamilies, the Hesperioidea or skippers, and the 
Papilionoidea or true butterflies. 

The skippers are so called on account of their peculiar mode of flight. 
They fly in the daytime and dart suddenly from place to place. When at 
rest they usually hold the wings erect in a vertical position like the true 
butterflies; often the fore wings are thus held while the hind wings are 
extended horizontally. The antennae are thread-like, and enlarged to- 


1 86 THE STUDY OF INSECTS 

wards the tip ; but in most cases the extreme tip is pointed and recurved, 
forming a hook. The abdomen is usually stout, resembling that of a 
moth rather than that of a butterfly. 

CLASSIFICATION OF THE LEPIDOPTERA 

The first step to be taken in the study of the classification of these 
insects is to become thoroughly familiar with the nomenclature of the 
wing veins; this is given on pages 32 to 33. It is a good plan to take 
several of the larger moths and butterflies and make drawings showing 
the courses of the veins of the wings in each, carefully indicating the 
names of the veins on the drawings. 

As the scales on the lower surface of the wings are more closely ap- 
plied to the wings than are those on the upper surface, the veins can be 
best seen when the wings are examined from below. The veins can be 
rendered more distinct for a few seconds by putting a little 95 % al- 
cohol or benzol on the part of the wing to be examined; this can be 
easily done by means of a camel's-hair brush. 

Sometimes it is necessary to remove the scales from a small part of 
the wing in order to determine the nature of some characteristic; this 
can be easily done by scratching them off lightly with a pin on the under- 
side only. 

The above methods are all that are needed in the majority of cases 
where the mere determination of an insect is the object. But when a 
very careful study of the venation of a wing is to be made, it should be 
bleached and mounted on a card or on a glass slip in order that it may 
be studied with a compound microscope. The following is the method of 
bleaching wings : — 

1. Remove the wings carefully so as not to break the frenulum if 
there be one. 

2. Dip the wings in alcohol in order to wet them. 

3. Immersion for an instant in hydrochloric acid, one part acid to 
nine parts water, will help but usually not necessary, 

4. Put them in Labaraque solution and leave there till the color has 
been removed from the scales. If a wing bleaches slowly, the process 
can be hastened by dipping it in the dilute acid and returning it to the 
Labaraque solution from time to time. This solution can be procured of 
most druggists. It deteriorates if left exposed in strong light. If it can- 
not be obtained, use an aqueous solution of chloride of lime. 

5. When a wing is bleached put it in alcohol and leave it there three 
to five minutes. This is to wash off the Labaraque solution. The wing 
can then be mounted on a card. But it is better to mount it as described 
below. 

6. Put wing on slide in alcohol, blot off excess alcohol, add a drop or 
two of oil of lavendar, let stand several minutes, put on balsam and 
cover with thin glass. 

Wings bleached and mounted in this way make an important addition 
to a collection. The slides should be carefully labelled to correspond with 
the rest. 

There are a few special terms used in describing the wings of the 
Lepidoptera which should be learned : — 

Frenulum. — In most moths there is a strong spine or a bunch of 


LEPIDOPTERA 


187 


bristles borne by the hind wing at the humeral angle (Fig. 329, /); this 
is the frenulum. Its use is to insure the acting together of the two wings 
of one side. As a rule the frenulum of the male consists of a single 
strong spine and that of the female when present of two or more bristles. 

Jugum. — In one suborder, including only a few rare moths, there 
exists, instead of a frenulum, a lobe borne near the base of the inner 
margin of the fore wing (Fig. 333, p. 193) ; this is the jugum. See suborder 
Jugatse. 


/?, *, 


/?, ^ 


Fig. 32g. — Wings of a moth: J h, frenulum-hook. 


Fig. 330. — Wings of Hemerocampa leucostigma. 


Discal cell. — Near the centre of the basal part of the fore wing there 
is a large cell lying between veins R and Cu (Fig. 330); this is the 
discal cell. In the more generalized Lepidoptera this cell is divided into 
two parts by the base of vein M (Fig. 330, hind wing); in such cases the 
cell lying immediately behind vein R is cell R, and that lying immedi- 
ately behind vein M is cell M. 

Patagia. — At the base of each fore wing there is a scale-like ap- 
pendage; these are the patagia or tegulae. 

In descriptions of Lepidoptera reference is often made to the palpi. 
These form the double beak-like projection which extends forward from 
the lower surface of the head. In most Lepidoptera only the labial 
palpi are well developed; but in some of the more generalized forms the 
maxillary palpi are also present. 

The presence or absence of ocelli is a character which is sometimes of 
considerable importance. These organs are situated, one on each side, 
above the compound eye and near its margin. But it requires some skill 
to find them when they are present, on account of the long scales clothing 
the head. 

The eye cap is also a character of some importance. The first seg- 
ment of the antennas of some moths is much broadened and hollowed out 


188 THE STUDY OF INSECTS 

and when such moths are at rest with the antennae folded back this seg- 
ment covers the eye like a cap. 

SIMPLIFIED KEY TO FAMILIES TO LEPIDOPTERA* 

A. Hind wing with eleven veins (counting along the margin) besides anals. 

B. Expanse' over i inch; mouth-parts rudimentary, p. 192 Hepialid^e 

BB. Expanse about .'. inch; mouth-parts functional. 

C. Mouth-parts for biting; middle tibia unarmed, p. 192 . . . . MlCROPTERYGIDjE 
CC. Mouth-parts for sucking (the usual spiral tongue), middle tibia ending in a 

single spur. p. 192 Eriocraniidje 

AA. Hind wing with only seven veins (or less) besides anals. 

B. Membrane of hind wing lanceolate or linear, narrower than its own fringe. 
C. First joint of antenna? very large and spoon shaped, completely covering the 
eye when folded back (an "eye-cap"). Cell of fore wing at least fully 
formed; palpi rudimentary, drooping, apex of fore wing sharply bent up or 

down. p. 202 Lyonetiid/E 

CC. No eyecap. 

D. A row of bristles on outer side of labial palpus (besides the usual hair and 
scales). Maxillary palpi usually conspicuous at base of tongue (between 
labial palpi), and folded, but absent in common clothes-moth. Head very 
rough. 
E. Wing-membrane with microscopic spinules between the sockets of the 
scales; female with piercing ovipositor; Sc of hind wing usually ap- 
parently forked into equally stout branches at base, or very stout; 
antenna smooth-looking (either with both rows of scales on each seg- 
ment lying flat, or finely pubescent) or else longer than fore wing. p. 195 

InCURVARIIDjE 

EE. Wing-membrane not spinulated; female with an extensible, tubular, 
soft and hairy ovipositor; Sc of hind wing apparently simple, connected 
by a weak vein to base of R or none; antenna with outer whorl of 
scales on each segment usually raised; rough-looking, not longer than 

fore wing. p. 199 Tineid^e 

DD. No bristles distinct from the usual hair and scales. Maxillary palpus 
inconspicuous, or projecting straight forward. 
E. Fore tibia without an epiphysis (antenna-cleaner) on its inner face. p. 204. 

COLEOPHORID^E 

EE. Fore tibia with an epiphysis along its middle part. 

F. Fore wing with four veins running from discal cell to costa, and five 

or six to below apex (inner margin), p. 207 Yponomeutid/E 

FF. Fore wing with at least as many veins running to costa as to inner 
margin from discal cell. 
G. Hind tibia hairy above; cell of fore wing very large, with an ac- 
cessory cell cut off from it by a weak vein. p. 202 . .Tischeriid^e 
GG. Hind tibia smooth-scaled, or with a regular series of bristles; 
cell of fore wing narrow, accessory cell (1st R3) not distinguishable. 

p. 203 Gracilariid/e 

BB. Hind wing (membrane) notched below apex, frequently narrower than its own 

fringe, p. 206 Gelechiid,e (part) 

BBB. Hind wing divided in 3 feathers, p. 217 Pterophorid^e 

BBBB. Hind wing broad, not notched, and broader than its own fringe. 
C. Antennae swollen toward tip (clubbed), no frenulum. 

D. Bases of antenna? separated by a space wider than their own thickness, 

fore wing with all branches of R, M, and Cu, (10 in all) present and arising 

separately from discal cell. 

E. Large butterflies, thorax much wider than head. p. 258. . . MEG ATH YMIDjE 

EE. Medium or small butterflies, expanding rarely over 2 inches; head 

wider than body. p. 259 Hesperiid/E 

DD. Antenna? closer together at base, branches of R partly stalked or united, 

there being only 9 (usually 8 or less) veins arising separately from discal 

cell. 

E. Fore wing with 3d A short and curved but running down free to inner 

margin, hind wing with only I anal. Cu apparently 4-branched. p. 262. 

PAPILIONID.E 

* This key was drawn up by Dr. W. T. M. Forbes. 


' LEPIDOPTERA 189 

EE. Fore wing without a free 3d A, hind wing with 2 anal veins. Cu (in 
our species) apparently 3-branched. 
F. Fore legs normal in size, used for walking. Usually 1 radial vein lost. 
G. M2 arising from middle of end of discal cell. Head very narrow, the 

antennae slightly encroaching on the eye. p. 281 Lyc^enid^e 

GG. M2 arising from upper angle of discal cell or even (usually) 
stalked with R3-5. Head wider, the eye a complete circle, p. 265. 

Pieridae 

FF. Fore legs reduced, often brush-like (except some 9's), not used for 
walking. Fore wing with all veins (except 1st A and 3d A) almost 

always preserved, p. 268 Nymphalid^e 

CC. Antennas not swollen toward tip, or if so (Sphingidae, Agaristidas, etc.) with 

frenulum well developed. 

D. Hind wing with Sc and R closely parallel or fused beyond where R leaves 

the discal cell. (Closer than they are along the discal cell); base of M 

not preserved in cell. 

E. Wings long and narrow, fore wing 4 x as long as wide; wings interlocked 

by rows of spines near inner edge of fore wing and costa of hind wing. 


p. 207 


. .^GERIID/E 


EE. Wings relatively broader, hind wing but little longer than broad. 
Wings not interlocked. 
F. Hind wing with three anal veins, 1st A being preserved, p. 212. 

Pyralidid^e 

FF. Hind wing with 1 or 2 anal veins. Body extremely stout, projecting 

far beyond the wings which are narrow, p. 218 Sphingidae 

DD. Hind wing with Sc and R widely separated beyond end of discal cell 

(Sc rarely wholly lost) ; or (some Cossidae) with base of M fully preserved, 

forked in cell. 

E. Fore wing with M2 arising more than one-third of the distance from M3 to 

M 1 , so that Cu appears to be 3-branched. 

F. Hind wing with Sc and R touching, closely parallel or fused no 

second quarter of discal cell, then diverging before end of discal cell. 

G. Base of Sc sharply angled, and connected by a more or less distinct 

humeral vein to base of frenulum. Usually slender moths, p. 223. 

Geometridae 

GG. Sc gently curved at base, not connected to frenulum-base. Stout 
moths. 
H. Radius pectinate (with Ri, 2, 3, 4 given off successively from the 
stem that leads to R5); frenulum rudimentary, p. 255. . Bombycid^e 
HH. R3 and 4 most closely associated; frenulum functional, con- 
spicuous in male. p. 227 Notodontid^e 

FF. Sc and R of hind wing diverging sharply almost from base. 

G. Hind wing with- two anal veins, upper discocellular vein (the portion 
of vein bounding the discal cell between the points where R s 

and Mi leave it) short and transverse, p. 246 Citheroniid.e 

GG. Hind wing with only one anal vein or upper discocellular vein 

long and longitudinal (usually both), p. 249 Saturniid,e 

EE. Fore wing with M2 associated with Cu-stem, Cu therefore apparently 
4-branched. 
F. Sc and R of hind wing fused for second fourth of discal cell or more. 
G. Vein 1st A preserved in both wings. 

H. Wings light colored, tongue absent, p. 197 Megalopygidae 

HH. Wings largely blackish, tongue strong, p. 197. . . Pyromorphid/E 
GG. Vein 1st A lost in both wings (fore wing with 1 anal, hind wing 

with two) . p. 242 . Arctiim: 

FF. Sc and R more shortly fused, or not at all. 

G. Vein 1st A, preserved in one and usually both wings. 

H. Vein 1st A, a well-marked tubular vein (i.e., an ordinary vein) 

on fore wing, at least toward margin. 

I. Spurs of tibiae longer than width of tibia;, normally over twice as 

long, if somewhat shorter with base of media (in cell) simple, 

dividing the cell into two parts. 

J. Fore wing with R3 and 4 stalked (forking over apex) or 

united, in the latter case with only two radial veins running 


1 9 o THE STUDY OF INSECTS 

to costa, and the third preserved vein to the apex.* p. .198 

ElCLEID/E 

JJ. pure wing with all veins preserved and separate, or with R4 
and 5 stalked or united, in that ease with three veins running 
to co ta before the one thai goes to apex. 
K. Fore wing with R5 running to costa. 

L. Palpus upturned and sickle-shaped, with long, pointed 

third joint, p. 205. (in part) CEcophorid^e 

LL. Palpus with third joint blunt, and either projecting 
forward or very short. 
ft 1 . Cu2 arising not far from middle of inner margin of 
cell; palpus without bristles (Peronea) p. 209. 

TORTRICIDjE 

MM. C112 arising more than I way out on cell; palpus 
normally with stiff bristles on outer side of second 
joint, p. 199, 195 . . . . Tineid^e and Incurvariid^e 
KK. Fore wing with R5 running to outer margin below apex. 
L. Fore wing with R4 and 5 strongly stalked or united (one 
vein missing); hind wing with R and Mi widely sepa- 
rated at origin from cell; palpus upturned, sickle-shaped, 
with third joint long and pointed, p. 205 

(Ecophorid^e (part) 

LL. Fore wing with R4 and 5 separate at origin or (rarely) 

with them stalked, but with R and Mi of hind wing 

stalked or closely approximate at origin; palpus with 

third segment usually short and blunt. 

M. Head smooth; palpus closely scaled, the third joint 

usually upturned and continuing the curve of the 

palpus; base of M (in cell) rarely preserved, and if 

so, bisecting cell. p. 207 Yponomeutid^e 

MM. Head and palpus rough-scaled, the third joint 
projecting forward, or stumpy and well set off; base of 
M running diagonally, in its outer part close to hind 

margin of cell, rarely lost. p. 209 Tortricid^e 

II. Spurs of tibia rudimentary, or if about as long as width of 
tibia, with M forked in cell. 
J. Base of M forked in cell, enclosing an intercalated cell (1st 

M2); spurs of tibiae distinct, p. 196 Cossid^e 

JJ. Base of M simple, dividing the cell in two parts. Tibiae 

normally with spurs absent, p. 200 Psychid^e 

HH. Vein 1st A, absent in fore wing. Palpus sickle-shaped, usually 

smooth, with long, pointed third joint, p. 205 GelechiiDjE 

GG. Vein 1st A, lost in both wings. 
H. Frenulum present. 

I. "Micros" (wings soft and loosely scaled) fringe lengthened at 

anal angle of hind wing, hind wing with Ri preserved as a 
strong vein connecting Sc and R near base, and palpi long and 
sickle-shaped, p. 205 Gelechiid/e 

II. "Macros" (wings strong) fringe hardly longer at anal angle 
of hind wing, Ri of hind wing lost by fusion of Sc and R or 
else palpi very short. 

J. Ocelli absent, hind wing with Sc and R merely touching J to 
I way out on discal cell or entirely separate, p. 232. 

Lymantriid^e 

JJ. Ocelli present (easily visible behind eye without denuding) 
Sc and R fused a short distance, or touching much nearer to 
base. 

K. Antennae swollen toward apex. p. 241 Agaristid^e 

KK. Antenna; regularly tapering, p. 234 NoctuiDjE 

HH. Frenulum absent, p. 256 Lasiocampid/E 

* If the wing is bluntly rounded the middle of the curving tip is viewed as the apex. 


LEPIDOPTERA 


191 


THE MOTHS 

There are thousands of species of moths many of which are commonly 
known as millers. Most of them are nocturnal in their activities and 
frequently come to lights in large numbers. When the individuals are at 
rest the wings are nearly always either wrapped around the body, or are 
spread horizontally, or are folded roof-like on the abdomen. Although 
the antennas are of various forms, they are usually thread-like or feather- 
like and only rarely are they enlarged at the tip. 

Suborder JUGATE 

The Jugate Lepidoptera 

The American representatives of this suborder are rare moths, which 
the student beginning the study of insects is not likely to meet. They 
can be easily recognized by the peculiar structure of the hind wings, 
which resemble the fore wings in form and in venation (Fig. 331). Inall 
other Lepidoptera, the two pairs of wings differ in form, and the hind 
wings are furnished with fewer veins than are the fore wings. 


Fig. 331. — Wings of Micropteryx. 

The most important character of the suborder, and the one to which 
its name refers, is the organ which aids in holding the two wings of each 
side together. There projects backward from the inner margin of the 
fore wing near its base a small lobe (Fig. 331, /), which extends, under or 
over the costal margin of the hind wing; while the greater part of the 
inner margin of the fore wing overlaps the hind wing. This arrangement 
assures the acting together of the two wings, at least in the downward 
stroke. 

This projecting lobe in its typical form is named the jugum or yoke; 
and the moths possessing this projection are termed the Jugatae or the 
Jugate Lepidoptera. 

The suborder Jugatas, as now more commonly limited, includes several 
families, representatives of three of which have been found in America; 
these are the Micropterygidae. the Eriocraniidae, and the Hepialidas. 


i 9 2 THE STUDY OF INSECTS 

Family Micropterygid^e 
The Mandibulate Jugatcs 

The members of this family are small insects which resemble tineid 
moths in general appearance. As with other members of the suborder 
Jugatae, the venation of the hind wings closely resembles that of the fore 
wings (Fig. 331). But these insects differ from all other Lepidoptera in 
that the adult moths have well-developed and efficient mandibles. This 
remarkable character, together with the lack of certain internal organs, 
has caused some authorities to take these moths out of the Lepidoptera 
and to put them in a separate order. 

The abdomen of the female has ten segments but there is no oviposi- 
tor. The adults feed on pollen. The larva? of our American forms do 
not seem to have been observed. 

Family Eriocraniid^e 
The Haustellate Jugates 

The members of this family, like those of the preceding one, are small 
insects which resemble tineid moths in general appearance. In this 
family the mandibles of the adult are vestigial; the maxilla? are formed 
for sucking, each maxilla forming half of a long sucking-tube, as in higher 
Lepidoptera; and the females have a piercing ovipositor. The jugal 
lobe of the fore wing extends back above the base of the hind wing and 
is clasped over an elevated part of the hind wing, thus being of the type 
described as a fibula. 

The best known species, Mnewomca auricyanea, is gold with purple 
spots and has a wing-expanse of about \ an inch. The larva mines in 
the leaves of chestnut, oak and chinquapin, making a large blotch mine. 
When grown it goes into the ground, spins a cocoon and changes to a pupa 
in the following winter. 

The pupa has long, arm -like toothed mandibles, with which it cuts 
the tough cocoon and with which it digs its way up to the surface of the 
ground; the adult emerges in April. 

Family Hepialid^e 
The Swifts or the Macrojugata, 

The members of this family are of medium or large size. Figure 332 
represents in natural size one of the larger of the American species, but 
many exotic species are larger than this one. Our smaller species have a 
wing-expanse of at least one inch. Our best-known species are brown or 
ashy-gray in color, with the wings marked with silvery-white spots. 

It is said that these moths fly near the earth, and only in the evening 
after sunset, hiding under some low plant, or clinging to the stalk of an 
herb during the day. Some of them fly with extreme rapidity, with an 
irregular mazy flight, and have, therefore, been named swifts by col- 
lectors. 

In the Hepialidae the posterior lobe of the fore wing is a slender. 


LEPIDOPTERA 


i93 


finger-like organ, which is stiffened by a branch of the third anal vein, 
and which projects beneath the costal margin of the hind wing. As 


Fig. 332. — Sthenopis purpurascens. 


the greater part of the inner margin of the fore wing overlaps the hind 
wing, the hind wing is held between the two. This is the type of pos- 
terior lobe of the fore wing to which the term jugum is applied (Fig. 333). 


Fig. 333. — Wings of a hepialid, seen from below; a, accessory vein. 

The larvae are normal caterpillars and furnished with sixteen legs; 
they feed upon wood or bark, and are found at the roots or within the 
stems of plants. They transform either in their burrows, or, in the case 
of those that feed outside of roots, within loose cocoons. The pupae have 
transverse rows of teeth on the abdominal segments; these aid them in 
emerging from their burrows. 

This family is represented in our fauna by two genera, Hepialus and 
Sthenopis. 


194 


THE STUDY OF INSECTS 


Suborder FRENAT^ 

The members of the Frenatae arc most easily recognized by the fact 
thai the venation of the hind wings (lifters markedly from that of the 
fore wings, being much more reduced. In this suborder, vein Ri of the 
hind wings coalesces with subcosta, the two appearing as a single vein, 
except that, in some cases, a short section of the base of Ri is distinct 


5r__£i__£ 


Fig. 334. — Wings of Prionoxyslus robinicB. 

presenting the appearance of a cross-vein between radius and subcosta 
(Fig. 334. Ri)-. 

The essential characteristic of the Frenatas is that they are de- 
scendants of those primitive Lepidoptera in which the two wings of each 
side were united by a frenulum. This fact should be clearly understood, 
for in many of the Frenatas the frenulum has been lost. The loss of the 
frenulum in these cases is due to its having been supplanted by a substi- 
tute for it, by an enlarged humeral area of the hind wings, which causes 
the two wings of each side to overlap to a great extent. This overlapping 
of the two wings insures their synchronous action; and the frenulum, 
being no longer needed for this purpose, is lost. 

As a rule the frenulum of the female, when present, consists of several 
bristles, while that of the male consists of a single strong, spine-like 
organ . 

The frenulum-hook, which is present in the males of most moths, is a 
membranous fold on the lower surface of the fore wing for receiving the 
end of the frenulum, and thus more securely fastening the two wings 
together (Fig. 329, / /?). As a rule, the frenulum hook arises from the 
membrane of the wing near the base of cell C. 


LEPIDOPTERA 


i95 


Leaf infested by the maple-leaf 


Family Incurvariid^e 

An interesting representative of the family Incurvariidae is the maple- 
leaf cutter, Paraclemcnsia acerijoliella. The larva infests the leaves of 
maple, and occasionally is so abundant 
that it does serious injury. The larva is at 
first a leaf-miner, but later it is a case-bearer. 
The leaves of an infested tree present a 
strange appearance (Fig. 335). They are 
perforated with numerous elliptical holes, 
and marked by many, more or less perfect, 
ring-like patches in which the green sub- 
stance of the leaf has been destroyed but 
each of which incloses an uninjured spot. 
These injuries are produced as follows: 
the larva, after living for a time as a leaf- 
miner, cuts an oval piece out of a leaf, 
places it over its back, and fastens it down 
with silk around the edges. This serves 
as a house beneath which it lives. As it 
grows, this house becomes too small for it. 
It then cuts out a larger piece which it 
fastens to the outer edges of the smaller 
one, the larva being between the two. 
Then it crawls halfway out upon the leaf, and by a dexterous lifting of the 
rear end of its body turns the case over so that the larger piece is over its back. 
When it wishes to change its location it thrusts out its head and fore legs 
from the case and walks off, looking like a tiny turtle. When it wishes to eat, 
it fastens the case to the leaf and, thrusting its head out, eats the fleshy part 
of the leaf as far as it can reach. This explains the circular form of the 
patches, the round spot in the center indicating the position of the case. 
The insect passes the winter in the pupa state within its case, which falls to the 
ground with the infested leaf. The moth is of a brilliant steel-blue or bluish- 
green color, without spots but 
with an orange-colored head; 
it appears in early summer. 

The yucca moth, Tegeticula 
alba, is another interesting 
member of this family. This 
species infests Yucca filamen- 
tosa, a plant not fitted for self- 
pollination or for pollination by 
insects in the ordinary ways ; in 
fact, it is pollinized only by 
moths of the genus Tegeticula, 
the larvae of which feed on its 
seeds. This is one of the few 
cases in which a particular plant 
and a particular insect are so 
specialized that each is dependent upon the other for the perpetuation of the 
species. In the female moth, the maxillae are each furnished with a long, 
curled, and spinose appendage, the maxillary tentacle (Fig. 336), fitted for the 


Fig. 336. — Tezeticula alba: a, side view of head and neck 
of fern ile denuded; i, load of pollen; 2, maxillary tentacle; 
.?, maxillae; 4, maxillary palpi; 5, antennae; b, maxillary ten- 
tacle and palpus. All enlarged. (From Riley.) 


i 9 6 THE STUDY OF INSECTS 

collection of pollen. After collecting a large load of pollen, often thrice as 
large as the head (Fig. 336), the female moth places her eggs, by means 
of her long, extensile ovipositor, into an ovary, usually of another flower 
than that from which the pollen was collected. After oviposition, the 
moth runs up to the tip of the pistil and thrusts the pollen into the 
stigmatic opening. Thus is insured the development of seeds, upon which 
the larvae hatched from the eggs placed in the ovary are to feed. As 
many more seeds are developed than are needed by the larvae, the per- 
petuation of the yuccas is assured. 

The full-grown larva leaves the yucca pod and makes its way to the 
ground, where it spins a dense cocoon several inches below the surface. 
The adult moth has a wing-expanse of about 1 inch. The wings are silvery- 
white above. 

Family Cossid^e 

The Carp enter -moths 

This family includes moths with spindle-shaped bodies, and narrow, 
strong wings, some of the species resembling hawk-moths quite closely 
in this respect. The larvae are borers; many of them live in the solid 
wood of the trunks of trees. The wood-boring habits of the larvae suggest 
the popular name carpenter-moths for the insects of this family. 

These moths fly by night and lay their eggs on the bark of trees, 
or within tunnels in trees from which adult carpenter-moths have 
emerged. The caterpillars are nearly naked, and, although furnished with 
prolegs as well as true legs, are grub-like in form. The pupa state is 
passed within the burrow made by the larva. When ready to change 
to an adult, the pupa works its way partially out from its burrow. This 
is accomplished by means of backward-projecting saw-like teeth, there 
being one or two rows of these on each abdominal segment. After the 
moths have emerged, the empty pupa-skins can be found projecting from 

the deserted burrows. 

The carpenter-moths 
are of medium or large size. 
The antennae of the males 
are mostly bipectinate ; 
those of the females are 
either very slightly bipect- 
inate or ciliate. In a few 
species the antennae are 
lamellate. The ocelli are 
wanting, and the maxillae 
are vestigial. See Figure 
334 for type of venation. 
The locust-tree car- 

Fig 337. — Prtonoxvstus rohmur, female. , . „ 

penter-moth , Frionoxystus 
roblnice. — Figure 337 represents the female, natural size. The male is 
but little more than half as large as the female. It is much darker than 
the female, from which it differs also in having a large yellow spot, which 
nearly covers the outer half of the hind wings. The moths fly in June 
and July; the larvae bore in the trunks of locust, oak, poplar, willow, 


LEPIDOPTERA 197 

and other trees. It is supposed that the species requires three years to 
complete its transformations. It is found from the Atlantic Coast to 
California. 

The lesser oak carpenter-worm, Prionoxystus macmurtrei. — This is 
a slightly smaller species than the preceding. The larva bores in the 
trunks of oak in the East. The moth has thin, slightly transparent 
wings, which are crossed by numerous black lines. The male is much 
smaller than that of P. robinice, and lacks the yellow spot on the hind 
wings. 

The leopard-moth, Zeuzera pyrina. — This species is white, spotted 
with numerous small, black spots, which suggested its common name. 
The adult has a wing-expanse of from i| to 2 inches. It is a European 
species, which was first observed in the vicinity of New York City in 
1882; since that time it has spread to other parts of the East. The 
larva is a very injurious borer in many species of trees and shrubs. The 
young larvae bore in the small twigs; later they migrate to larger limbs 
or to the trunk. 

Family Pyromorphid^e 
The Smoky-moths 

There are but few insects in our country pertaining to this family; 
only fifteen species are now recognized, but these represent six genera. 
These are small moths, which are chiefly of a smoky-black color; some 
are marked with brighter colors; the wings are thinly scaled; and the 
maxillae are well developed. The larvae are clothed with tufted hair; 
they have five pairs of prolegs, which are provided with normal hooks. 

The grape-leaf skeletonizer, Harrtstna americdna, is a well-known 
member of this family which is widely distributed throughout the eastern 
United States from New England to Florida and 
westward to Missouri and Arizona. 

The wings of this moth are long and narrow 
(Fig. 338) ; the abdomen- is long, and widened 
towards the caudal end. It is greenish -black in 
color, with the prothorax reddish-orange. The 
larva feeds on the leaves of grape and of the Vir- . fig. 338. — Harrisina amer- 
ginia creeper. An entire brood of these larvae will 

feed side by side on a single leaf while young. This species rarely be- 
comes of economic importance. 

Family Megalopygid^; 

The Flannel-moths 

In this family the wings are heavily and loosely scaled, and mixed 
with the scales are long, curly hairs; these give the wings the appear- 
ance of bits of flannel. It is this that suggested the common name of 
these moths. The body is stout and clothed with long hairs. In these 
moths the maxillae are vestigial. The larvae are remarkable for the pos- 
session of seven pairs of prolegs ; these are borne by abdominal segments 
2 to 7 and 10; but those of segments 2 and 7 are without hooks. The 


ig8 


THE STUDY OF INSECTS 


Fig. 339. — Lagoa crispala, male. 


setiferous tubercles bear large numbers of fine setae; so that the body is 
densely hairy; and interspersed among the fine setae are venomous setae. 

The crinkled flannel-moth, Lagoa cris- 
pata, is cream-colored, with the fore wings 
marked with wavy lines of crinkled black 
and br< iwnish hairs. The male is represented 
in Figure 339; the female is larger, expand- 
ing i\ inches. In the female the antennae 
are very narrowly pectinate. 

The larvae feed on many trees and shrubs, 
including oak, elm, apple, and raspberry. 
They are short, thick, and fleshy, and are 
covered with a dense coat of long, silky, brown hairs, which project up- 
ward and meet to form a ridge or crest along the middle of the back; 
interspersed among these fine hairs are venomous setae. 

The cocoons are of a firm, parchment-like texture, covered with a 
thin web of rather coarse threads. Mixed with the silk of the cocoon are 
hairs of the larva. The cocoon is similar to that of the next species. 

The puss-caterpillar moth, Megalopyge opercular is, is somewhat 
smaller than the preceding one; the male has a wing-expanse of about 
1 inch and the female of about \\ inches. The 
fore wings are umber-brown at base, fading to 
pale yellow outwardly; they are marked with 
wavy lines of white and blackish hairs, and the 
fore margins are nearly black. The larvae are sim- 
ilar to those of the preceding species. The cocoon 
is provided with a hinged lid (Fig. 340). 

This species is found from North Carolina 
to Texas. The larva is a very general feeder; 
it is often found on oak. It is a seriously nettling ° penu ans ' 
caterpillar often causing distinct irritation when it comes in contact with 
one's skin. 


Fig. 340. — ■ Old cocoon of Megalo- 


Family Eucleid^ * 
The Slug-caterpillar Moths 

One often finds on the leaves of shrubs or trees, elliptical or oval 
larvae that resemble slugs in the form of the body and in their gliding 
motion. As these are the larvae of moths they have been termed slug- 
caterpillars; but they present very little similarity in form to other 
caterpillars. The resemblance to slugs is greatly increased by the fact 
that the lower surface of the body is closely applied to the object upon 
which the larva is creeping, the thoracic legs being small and the prolegs 
wanting. There is, however, on the ventral side of the abdomen a series 
of sucking-disks, which serve the purpose of prolegs. The head of the 
larva is small and retractile. In some species the body is naked; in 
others it is clothed with tufts of hair; and in others there is an armature 
of branching spines. Several species bear venomous setae. 

The larwe when full-grown spin very dense cocoons of brown silk; 

* This family is termed the Cochlidiidac by some writers, and by others the 
Limacodidae. 


LEPIDOPTERA 


IQQ 


Fig. 341. 

species 


these are egg-shaped or nearly spherical, and are furnished at one end 
with a cap which can be pushed aside by the adult when it emerges 
341). The cocoons are usually spun between leaves. 

The moths are of medium or small size; the 
body is stout, and the wings are heavily and loosely 
scaled. The maxillae are vestigial. These moths 
vary greatly in appearance, and many of them are 
very prettily colored. 

The following are some of the better known 
of this family. 

The saddle-back caterpillar, Siblne stimulea. — This larva 
can be recognized by Figure 342. Its most characteristic 
feature is a large green patch on the back, resembling a saddle- 
cloth, while the saddle is represented by an oval purplish-brown spot. 
The moth is dark, velvety, reddish-brown, with two white dots near the 
apex of the fore wings. The larva feeds on oaks and other forest trees. 
This is one of the species that are armed with venomous setae. 

The spiny oak-slug, Euclea delphinii. — This larva (Fig. 343) is one of 
the most common of our slug-caterpillars and one of those that are armed 
with venomous setae. It feeds on the leaves of oak, pear, willow, and 
other trees. The moth (Fig. 344) is cinnamon-brown, with a variable 
number of bright green spots on the fore wings. 


Fig. 342.— .S7- 
bine stimulea, 
larva. 


Flo. 343. — Euclea del- 
phinii, 1 rva. 


Fig. 344. — Euclea del- 
phinii. 


Fig. 345. — Phnbelrnn pithe- 
cium, larva. (After Dyar.) 


The hag-moth, Phobetron pithecium. — The common name hag-moth 
is applied to the larva of this species on account of its remarkable ap- 
pearance (Fig. 345). It bears nine pairs of fleshy appendages which are 
covered with brown hairs. In the full-grown larva the third, fifth, and 
seventh appendages are longest; these are twisted up and back, and 
suggest the disheveled locks of a hag. This larva feeds on various low 
shrubs and the lower branches of trees. At the time of spinning, the 
larva sheds the fleshy processes, and they remain on the outside of the 
cocoon. 


Family Tineid.-e 

The head is usually clothed with erect hair-like scales. The antennae 
are shorter than the front wings. The maxillae are usually small or 
vestigial. The maxillary palpi are usually large and folded. The labial 
palpi are short and clothed with bristles. In the typical genera the 


200 


THE STUDY OF INSECTS 


venation of the wings is quite generalized (Fig. 346), the base of media 
being preserved in both fore and hind wings and all of the veins charac- 
teristic of the Frenatac being 
present ; but in other genera 
the venation is somewhat re- 
duced. 

Many of the larvae are 
case-bearers ; many are scav- 
engers or feed on fungi ; some 
feed on fabrics, especially 
those that contain much 
wool; few if any feed on 
leaves. 

This is a large family. 
More than one hundred 
twenty-five North American 
species are already known; 
fifty of these belong to the 


Fig. 346. — Wings of Tinea parasilella. (After Spuler.) 


genus Tinea. To this family belong the well-known clothes-moths. 

The naked clothes-moth, Tineola biselliclla. — This is our most com- 
mon clothes-moth. Although the larva spins some silk wherever it goes, it 
does not make a portable case; it is, therefore, named the naked clothes- 
moth. But when the larva is full-grown it makes a cocoon, which is 
composed of fragments of its food-material fastened together with silk. 
The adult is a tiny moth with a wing-expanse of from ^ to § inches; it 
is of a delicate straw-color, without dark spots on its wings. 

The case-bearing clothes-moth, Tinea pellionella. — The larva of this 
species is a true case-bearer, making a case out of bits of its food-material 
fastened together with silk. The case is a nearly cylindrical tube open 
at both ends. The pupa state is passed within the case. The adult is a 
small, silky, brown moth, with three dark spots on each fore wing. It 
expands about \ of an inch. 

The tube-building clothes-moth or the tapestry-moth, Trichophaga 
tapetiella. — The larva of this species makes a gallery composed of silk 
mixed with fragments of cloth. This gallery is long and 
winding and can be easily distinguished from the case of 
the preceding species. The pupa state is passed within 
the gallery. The moth differs greatly in appearance from ^M 

the other two species, the fore wings being black from 
the base to near the middle, and white beyond. It 
expands from \ an inch to one inch. 

Family Psychid^e 

The Bag-worm Moths 

The bag-worm moths are so called on account of the 
silken sacs made by the larvae, in which they live and in 
which they change to pupae. In our more conspicuous 
and best-known species the sac is covered either with 
little twigs (Fig. 347) or, in the case of a species that 
feeds on cedar or arbor-vitae, with bits of leaves of these plants. When the 
larva is full-grown it fastens its sac to a twig and transforms within it. 


Fig. 347. — Bag of 
Oiketicus abboti. 


LEPIDOPTERA 


Fig. 348. — Wings of Tkyridopleryx ep/iemertrformis. 


In the adult state the two sexes differ greatly. The female is wingless, 
and in some genera the eyes, antennae, mouth-parts, and legs are vestigial 
or wanting, the body being quite maggot-like. At the caudal end of the 
body there is a tuft of hair-like scales which are mixed with the eggs. 
In most species the female does 
not leave the sac before oviposition 
but deposits her eggs within it. 

The male moths are winged; 
they are small or of moderate size. 
The wings are thinly scaled and 
in some species nearly naked ; when 
clothed with scales they are usually 
of a smoky color without mark- 
ings. The venation of the wings 
varies greatly within the family. 
Figure 3 48 represents the venation 
of our most common species. 

Only about twenty species are 
known from our fauna, of which 
the following are most likely to be 
observed. 

Abbot's bag- worm, Oiketicus 
abboti. — This species occurs in the 
more southern part of our country. 
The larva makes a bag with sticks 
attached to it crosswise (Fig. 347). The adult male is sable brown, with a 
vitreous bar at the extremity of the discal cell of the fore wings; the 
narrow external edging of the wings is pale; the expanse of the wings is 
1 1 inches. 

The evergreen bag- worm, Thyridopteryx ephemera for mis . — This 
species prefers red cedar and arbor-vita?, and for this reason has been 
named the evergreen bag-worm; but it also feeds on many other kinds 
of trees, and as it is the species that is most likely to attract attention, 
and is sometimes a serious pest, it is often called the bag-worm. It is 
our best-known species, and its life-history will serve as an illustration of 
the habits of the members of the family Psychidae. 

The bag of this species is about the same size as that of Abbot's 
bag-worm (Fig. 347) ; but differs in being covered with sprays of leaves 
when it feeds on cedar or arbor-vitse, or with twigs attached lengthwise 
when it feeds on other trees. When full-grown the larva fastens the bag 
to a twig with a band of silk, and then changes to 
a pupa. When the male is ready to emerge, the pupa 
works its way to the lower end of the bag and half- 
way out of the opening at the extremity. Then its 
skin bursts and the adult emerges. The male moth 
has a black, hairy body and nearly naked wings (Fig. 
349). The adult female only partly emerges from the 
pupa skin and awaits the approach of the male. She 
is entirely destitute of wings and legs. The abdomen of the male can be 
greatly extended, making possible the pairing while the female is still in the 
bag. After pairing, the female works her way back into the pupa skin, where 
she deposits her eggs mixed with the hair-like scales from the end of her 


Fig. 340- 
leryx ephemerajormis. 


202 


THE STUDY OF INSECTS 


body. She then works her shrunken body out of the bag, drops to the 
ground, and perishes. The eggs remain in the pupa skin in the sac till 
the following spring. 

Family Tischeriid^e 

Nearly all of our species belong to the genus, Tischeria. The end of 
each narrow front wing is prolonged into a point; the hind wings are 
long and narrow with few veins. The larvae lack thoracic legs and most 
of them make blotch mines in the leaves of oak; but some infest the 
apple, blackberry, and raspberry. 

The trumpet-leaf miner of apple, Tischeria malifoliella. — This species 
infests the leaves of apple over the eastern half of the United States and 
Canada, and sometimes does serious injury. The larva makes a trumpet- 
shaped mine just beneath the epidermis on the upper side of the leaf; the 
first half of the mine is usually crossed by crescent-shaped stripes of 
white. There are two generations annually in the North, and several in 
the South. The larvae pupate in their mines. The larvae of the last 
generation line their mines with silk and pass the winter in them. They 
transform to pupae in the spring and emerge as adults eight or ten davs 
later. The adult moth expands about \ of an inch; it has shining dark 
brown front wings, tinged with purplish and dusted with pale yellowish 
scales. 


Family Lyonetiid^; 

These are small moths with very narrow wings, the hind wings often 
linear. The larvae are leaf-miners at first and then 
usually feed on the surface of the foliage. 

The morning-glory leaf-miner, Bedellia somnulentclla. 
— The young larva makes a serpentine mine with a 
central line of frass ; later it leaves this mine and makes 
a blotch mine. The pupa is naked, and fixed by the 
caudal end to some cross-threads on the underside of 
the leaf. The adult is yellow and expands about § of 
an inch. 

The apple bucculatrix, Bucculdirix pomifoliella. — 
The larva of this species infests the leaves of apple, 
and when full-grown it makes a small white cocoon 
which is attached to the lower surface of a twig. 
These cocoons sometimes occur in great numbers, side 
by side, on the twigs of an infested tree (Fig. 350). 
They are easily recognized by their shape, being slender 
and ribbed lengthwise. It is these cocoons that usually 
first reveal the presence of the pest in an orchard. They 
arc very conspicuous during the winter, when the 
leaves are off the trees. At this time each cocoon 
contains a pupa. The adult moth emerges in early 
spring. The eggs are laid on the lower surface of the 
leaves. The tiny caterpillar burrows into the leaf and 

mines in it for about eight days. It then comes out and feeds openly on 

the leaf for the rest of its life. 


1 i'. (so < '"> oons 
of Bucculatrix pomifo- 
liella. 


LEPIDOPTERA 


203 


Family Gracilariid.« 

The vestiture of the head varies greatly; the vertex is clothed with 
prominent scales in some 
forms, in others it is 
smooth. The antennas 
are long. The fore wings 
are lanceolate, normal 
or with somewhat re- 
duced venation (Fig. 
351). The hind wings 
are lanceolate or linear. 

The adult moths when 
at rest elevate the front 
part of the body, the 
fore legs being held r „ , , 

vertically so that the *"• "*• ~ Wings of Qndkrm - (After Spuler - ) 
tips of the wings touch the surface on which the insect rests. 

The larvae are extraordinary; when young they are very much 
flattened and have thin, blade-like mandibles and vestigial maxillae and 
labium; they merely slash open the cells of the leaf and suck up the 
cell-sap; later they usually have normal mouth-parts and eat the 
parenchyma. The young larvae always make a flat blotch mine; later 
many make a blotch mine in which the epidermis of one side of the leaf is 
thrown into a fold by the growth of the leaf, i.e., a tentiform mine, or they 
roll a leaf. The larvae have only fourteen legs or none, never any on the 
sixth segment of the abdomen. 


Fig. 352. — Phyllonorycter hamadryadella: a, mine; b, young larva; c, full-grown, flat-form larva; d, head 
of same, enlarged; e, antenna of same, enlarged; /, round-form larva from above; g, same from below; h, 
head of same, enlarged; i, antenna of same, enlarged; k, maxilla and palpus of same, enlarged; /, labium, 
labial palpi, and spinnerets of same; m, pupa; ». side view of pupal crest; 0, front view of same; q, cocoon; 
Q, moth. 


204 


THE STUDY OF INSECTS 


This is a large family; about two hundred North American species 
have been described. 

The white-blotch oak-leaf miner, Phyllonorycter hamadryadella. — 
This little miner infests the leaves of many different species of oaks, and 
is very common throughout the Atlantic States. The mine is a whitish 
blotch mine in the upper side of the leaf, and contains a single larva ; but 
often a single leaf contains many of these mines (Fig. 352). The young 
larva is remarkable in resembling more the larva of a beetle than the 
ordinary type of lepidopterous larvae (Fig. 352, 6). It is nearly flat; the 
first thoracic segment is much larger than any of the others; the body 
tapers towards the hind end; and there are only the faintest rudiments 
of legs discernible. The larvae molt seven times. At the seventh molt 
the form of the body undergoes a striking change. It now becomes 
cylindrical in form, and the fourteen feet are well developed. It spins a 
cocoon, which is simply a delicate, semi transparent, circular sheet of 
white silk, stretched over a part of the floor of the mine. The pupa is 
dark brown in color, and bears a toothed crest upon its head (Fig. 352, n, 
o). The moth is a delicate little creature, whose wings expand a little 
more than \ of an inch. 


Family Coleophorid^; 

Moths with a smooth head, without ocelli, and without maxillary 
palpi. The labial palpi are of moderate size. The antennae are held 
extended forward in repose. The wings are very narrow. 

The larvae are usually 
leaf-miners when young 
or feed within seeds; 
later, with few excep- 
tions, they are case- 
bearers. 

All of our species be- 
long to the genus Cole- 
ophora, of which about 
ninety species have been 
found in this country. 
The two following spe- 
cies are those that have 
attracted most attention 
on account of their 
economic importance. 

Fig. 353. — Cohophora malivorella: a, apple twig showing larval cases Ine piStOl Case- 

and work, on leaves; b, larva; c, pupa; d, moth; b, c, d, enlarged. (After bearer, ColeOphOYQ, tUdll- 

vorella. — The larva of 
this species infests apple especially but is also found on quince, plum, and 
cherry. The larvae hatch in mid-summer from eggs laid on the leaves 
and eat little holes in the leaves. They soon construct little pistol-shaped 
cases composed of silk, the pubescence of leaves, and excrement (Fig. 353). 
The larva projects itself out from the case far enough to get a foothold 
and eats irregular holes in the leaf, holding the case at a considerable 
angle with the leaf. About September first the larvae migrate to the 
twigs where they fasten the cases to the bark and hibernate till April. 


LEPIDOPTERA 


205 


The cigar case-bearer, Colebphora fletcherella. — This species, like the 
preceding one, is a pest of apple and other fruit trees, and resembles that 
species to a considerable extent in habits. In this species the young 
larvae are miners in the leaves for two or 
three weeks before making their cases. 
The case (Fig. 354) is composed of frag- 
ments of leaves fastened together by silk. 

Family (Ecophoridve 

The wings of these moths are fairly 
broad, sometimes amply so. The labial 
palpi are well-developed and generally 
curved upward. 

The larvae have sixteen legs ; they are 
often prettily marked with dark tubercles on whitish or yellowish ground. 
The different species vary in their habits; the majority of them either 
live in webbed-together leaves or blossoms or feed in decayed wood ; one 
species, Endrosis lacteella, is a stored-food pest in California and in Europe. 

The parsnip webworm, Depressdria heraclidna, is a common pest on 
parsnip. The larvae of this species web together and devour the unfolding 
blossom-heads of parsnip, celery, and wild carrot. After the larvae have 
consumed the flowers and unripe seeds and become nearly full-grown, 
they burrow into the hollow stems and feed upon the soft lining of the 
interior. Here inside the hollow stem they change to pupae. The moths 
appear in late July and early August, and soon go into hibernation in 
sheltered places. 


Fig. 354. ■ — Cases of cigar case-bearer. 
(After Hammar.) 


Family Gelechiid^; 

This is a very large family of small moths. 

The larvae vary greatly in habits; some are leaf -miners; but more 
feed in rolled or spun together leaves or in stems or seed heads; and one 
is a serious pest of stored grain. 

The Angoumois grain-moth, Sitotroga cerealella. — The larva of this 
moth feeds upon seeds, and especially upon stored grain. It occurs 
throughout our country; but it is especially destructive in the Southern 
States. In that part of the country it is extremely difficult to keep grain 
long on account of this pest and certain beetles that also feed on stored 
grain. The adult moth is of a very light grayish-brown color, more or 
less spotted with black; it expands about \ inch. The common name is 
derived from the fact that it has been very destructive in the province of 
Angoumois, France. 

The peach twig-borer, Andrsia lineatella. — ■ This pest is generally 
distributed throughout the United States and Canada, and sometimes it 
destroys a large part of the crop in some localities. The young larva? 
hibernate in small cavities which they excavate in the bark of young 
twigs. In the spring the larvae burrow into the tender shoots; the leaves 
of the buds unfold and then wither. There are several generations an- 
nually. The summer generations attack both twigs and fruit. 

The potato-tuber moth, Phthorim&a opercntfllQ, — This is a cosmo- 


206 


THE STUDY OF INSECTS 


politan insed injurious to the tomato, potato, egg-plant and tobacco. 
( )n the latter plant the larva is known as the tobacco splitworm. 

'I'lic adult is a small moth with the front wings mottled with black 
and ochre and expanding a little over one-half an inch. The larva is 
white often with a pinkish cast on the back and about § of an inch long. 
There are several generations a year. 

The solidago gall-moth, (j'uorimoschema gallcesolidaginis . — There are 
two kinds of conspicuous galls which are enlargements of the stems of 
goldenrod; one of these is a ball-like enlargement of the stem and is 
caused by the larva of a fly, Eurosta solidaginis , described in the next 

chapter; the other is spindle-shaped and is 
caused by the moth named above. The eggs 
are laid on the old plants in the fall and hatch 
in spring. The young larva crawls to a new 
shoot and boring down into it causes the 
growth of the gall (Fig. 355). 


Sc /?, 


a ° Cu 2 

Fig. 355- — Gall of the solidago 
gall-moth. (After Riley.) FlG. 356. — Wings of Peclinophora gossypiella. (After Busck.) 


The pink bollworm, Pectinophora gossypiella. — This species is re- 
garded as one of the most destructive cotton insects known and ranks 
among the half-dozen most important insect pests of the world. It 
often reduces the yield of lint fifty per cent, or more and materially 
lessens the amount of oil obtained from the seeds. 

The adult is a small dark-brown moth, with a wing-expanse of from -§ 
to I of an inch. Figure 356 represents the shape and the venation of the 
wings. The larva eats the seeds and tunnels and soils the lint, causing 
the arrest of growth and the rotting or premature and imperfect opening 
of the boll (Busck). 

The burdock moth, Metzneria lappella. — The stout white legless 
caterpillar of this moth is common in the burs of burdock into which it 
mines and eats out the seeds. It winters in the burs and transforms to 
the moth in June and July. The moth is of a dull olive brown with 
paler yellowish shades and streaks on the front wings. It expands from 
I to f of an inch. 


LEPIDOPTERA 207 

Family Yponomeutid.-e 

This is not a large family but it contains several species of economic 
importance among which is the cedar tineid, Argyresthia thuiella, the 
larvae of which feed on the leaves of cedar, the apple-fruit miner Argy- 
resthia conjugella, the larvae of which burrow in all directions in the fruit 
causing it to decay, the ermine moths and the ailanthus webworm. 

The ailanthus webworm, Atteva punctella. — The larvae live in communi- 
ties in a slight silken web on the Ailanthus; they feed on the leaves 
and also gnaw the leaf-stalks in two. When the larva is full-grown it 
suspends itself in the middle of a loose web and transforms there. The 
adults appear in September and October and pass the winter in this state. 
The adult is very striking in appearance. The fore wings are bright 
marigold-yellow with four bands of round pale sulphur-yellow spots upon 
a brilliant steel-blue ground. The hind wings are transparent, with a 
dusky margin and blackish veins. The wing-expanse is about 1 inch. 

The ermine-moths, Yponomeuta. — There are several species of the 
typical genus of this family that have received the common name ermine- 
moths, because of the color of their fore wings, which are snowy white 
dotted with black. One of these, Yponomeuta padella, is an introduced 
species which is an apple and cherry pest. The larvae live in a common 
web, and in this they spin their cocoons. 

The name ermine-moths is applied also, especially in England, to 
some of the Arctiidae that are white spotted with black. 

Family AZgerudje 

The Clear-winged Moths 

The clear-winged moths constitute a very remarkable family, many 
of them resembling bees or wasps in appearance more than they do 
ordinary moths, a resemblance due to their clear wings and in some cases 
to their bright colors (Fig. 357). There are a few moths 
in other families, that have a greater or less part of the 
wings devoid of scales; but they are exceptions. Here 
it is the rule that the greater part of one or both pairs 
of wings are free from scales. In a small number of 
members of this family the wings are scaled throughout 

■ Fig ^^7 

and the wings are held together by hamuli. 

These insects are of moderate size; as a rule they have spindle- 
shaped antennae, which are terminated by a small silky tuft; sometimes 
the antennae are pectinate; the margins of the wings and the veins of 
even the clear- winged species are clothed with scales; and at the end of 
the abdomen there is a fan-like tuft of scales. 

The fore wings are remarkable for their extreme narrowness and the 
great reduction of the anal area (Fig. 358); while the hind wings have a 
widely expanded anal area. The number of anal veins in the hind wings 
varies greatly within the family, the number ranging from two to four. 

Another remarkable feature of the wings of these insects is that in the 
female the bristles composing the frenulum are consolidated as in the 
male; this condition exists in the females of a few members of other 
families. The females of the ^geriidae possess a frenulum hook; but this 
is not so highly specialized as that of the male. 


208 


THE STUDY OF INSECTS 


The adults fly very swiftly and during the hotter part of the day. They 
frequent flowers thus increasing their resemblance to bees or to wasps. 
The larva' are borers, living within the more solid parts of plants. Some 
species cause serious injury to cultivated plants. More than one hundred 


Fig. 358. — Wings of Synanlhedon exitiosa. 


Among the better 


species have been found in America north of Mexico. 
known species are the following. 

The blackberry-crown borer or the raspberry-root borer, Bembecia 
marginata. — The larva of this species burrows in the roots and lower 
part of the canes of blackberries and raspberries, sometimes completely 
girdling the cane at the crown. 

The peach-tree borer, Synanthedon exitiosa. — This is one of the most 
important enemies of the peach-tree. The eggs are laid on the bark of 
the tree near the ground. The larvas burrow in the inner bark and sap- 
wood just below the surface of the ground. Their injuries cause the 
tree to exude large masses of gum which collect around the base of the 
trunk. The insect passes the winter as a larva and in the spring makes a 
long cocoon at the surface of the ground. The moths appear from May 
to October. 

The steel-blue female moth has (Fig. 359) the 
fore wings covered with scales, and there is a bright 
orange-colored band on the abdomen. In the male 
both pairs of wings are nearly free from scales. 

The Pacific 'peach-tree borer, Synanthedon opa- 
lescens. — On the Pacific Coast there is a peach-tree 
borer that is distinct from the above, and appears 
to be an even more serious pest. The larva is more 
difficult to remove from the tree, as it bores into the solid wood. The 
female of this species lacks the orange-colored band on the abdomen. 


TT 


Fig. 359. — Synanthedon 
exitiosa, female. 


LEPIDOPTERA 


209 


The lesser peach-tree borer, Synanthedon pictipes. — The larvae of 
this species infest peach, plum, cherry, june-berry, beach-plum, and 
chestnut. They do not confine their attacks to the crown but more 
often occur on the trunk and larger branches. Both sexes of the adult 
resemble the male of the peach-tree borer, having both fore and hind 
wings transparent. 

The imported currant borer, Chamcesphecia tipuliformis . — This is a 
small species, the adult having a wing-expanse of only about T \ of an 
inch. There are but few scales on either pair of wings except on the tip 
and discal vein of the fore wings and the outer margin of the hind wings. 
The eggs are laid on the twigs of currant. The larvae penetrate the stem, 
and make a burrow in which they live and undergo their transformations. 


Fig. 360. — Melittia satyriniformis, larva in squash-vine. 

The squash-vine borer, Melittia satyriniformis. — The larva of this 
species (Fig. 360) does great damage by eating the interior of squash- 
vines; it also sometimes infests pumpkin- vines and those of cucumber 
and melon. It is most destructive to late squashes. When full-grown the 
larvae leave the vines and enter the ground, where they make tough silken 
cocoons, a short distance below the surface, in which the winter is passed. 
The adults appear soon after their food -plants start growth. The fore 
wings of the adult are covered with scales and the hind legs are fringed 
with long, orange-colored scales. 

The pine clear-wing moth, Parharmonia pint. — Frequently there 
may be seen on the trunks of pine-trees large masses of resinous gum 
mingled with sawdust-like matter. These are the results of the work of 
the larvae of this insect, which bore under the bark and into the super- 
ficial layers of the wood. The adult resembles the female of the peach- 
tree borer, but the abdomen is more extensively marked with orange 
beneath. 


Family Tortricid^: 
The Tortricids 

The so-called tortricid moths in the wider sense, include three families 
of mostly small moths of which about 800 species from North America 
have been described. They have broad front wings which usually end 
squarely (Fig. 361). The costal margin of each front wing curves for- 
ward strongly near the base of the wing. When the moths are at rest 
the front wings fold above the body like a roof. 

The larvae vary greatly in habits. Many of them are leaf-rollers. 


2io THE STUDY OF INSECTS 

It was this habit that suggested the name Tortrix for the typical genus, 
from which the name of this family is derived. A large portion of the 


gjJtsR, 


Fig. 362. — Nest of At- 
chips cerasivorana. 


Usl id A id A 

Fig. 361. — Wings of Archips cerasivorana. 

rolled leaves found upon shrubs and trees 
are homes of tortricid larvae; but it should 
be remembered that the leaf-rolling habit is 
not confined to this family. While many 
are leaf-rollers probably a larger number are 
borers in stems, buds, or fruits. 

Several of our better-known members 
of this family belong to the genus Archips. 
This is the genus Caccecia of many authors. 
These insects have been named "the ugly- 
nest tortricids; ugly dwelling being the meaning of Caccecia, and also 
descriptive of the nests of the larvae of these insects. The four fol- 
lowing species are common. 

The oblique-banded leaf-roller, Archips rosacedna. — The larva of 
this moth feeds within the rolled and webbed-together leaves of apple, 
pear, cherry, plum, and other fruits. The larva is light yellowish-brown 
to apple-green in color and about § of an inch in 'length. The moth 
expands about one inch. It is cinnamon-brown in color and each front 
wing is crossed by three oblique bands. 

The cherry-tree ugly-nest tortricid, Archips cerasivorana. — This 
species lives upon the choke-cherry and sometimes upon the cultivated 
cherry. The larvae, which are yellow, active creatures, fasten together 
all the leaves and twigs of a branch and feed upon them (Fig. 362), an 
entire brood occupying a single nest. The larvae change to pupae within 
the nest; and the pupae, when about to transform, work their way out 
and hang suspended from the outer portion of the nest. Here they 
transform, leaving the empty pupa skins projecting from the nest. The 


LEPIDOPTERA 211 

wings of the moths are bright ochre-yellow; the front pair marked with 
irregular brownish spots and numerous transverse bands of leaden blue 
(Fig. 363, female). 

The fruit-tree leaf -roller, ,4 rc/z//?s argyrospila. — This 
is one of the most destructive of the leaf -rollers infesting 
fruit-trees. It is a very general feeder attacking both 
fruit and forest-trees. The eggs are laid on the bark of 
the twigs in Tune. The larvae hatch about May 1st of fig. 363. — ArMpscera- 

,, ri1 . j ,1 • -u j 1 sivorana, female. 

the following year and enter the opening buds, where 
they roll and fasten the leaves loosely together with silken threads. After 
the fruits set, they are often ruined by the caterpillars eating large irreg- 
ular holes in them. 

The pine-leaf tube-builder, Eulia pinatubdna. — One of the most in- 
teresting of tortricid nests occurs commonly on white pine. Each nest 
consists of from six to fifteen leaves drawn together so as to form a tube, 
and is lined with silk. This tube serves as a protection to the larva, 
which comes out from it to feed upon the ends of the leaves of which 
the tube is composed; in this way the tube is shortened. The moth 
expands | inch. Its head, thorax, and fore wings are of a dull rust-red 
color, with two oblique paler bands crossing the fore wings, one a little 
before the middle, the other a little beyond and parallel with it. 

The codling-moth, Carpocdpsa pomonella. — This is 
the best known and probably the most important insect 
enemy of the apple. The larva is the worm found feed- 
ing near the core of wormy apples. The adult (Fig. 364) 
fig. 36^ — Car- is a beautiful little creature with finely mottled pale gray 
pocapsa pomoneiia. f ore w i n g S . There is a large brownish spot near the end of 
the fore wing, and upon this spot irregular, golden bands. The moth issues 
from the pupa state in late spring and lays its eggs singly on the surface 
of the fruit or on adjacent leaves. As soon as the larva hatches it burrows 
into the apple and eats its way to the core, usually causing the fruit to 
fall prematurely. When full-grown the larva burrows out through the side 
of the fruit, and undergoes its transformations within a cocoon, under the 
rough bark of the tree, or in some other protected place. The larvae 
winter in their cocoons transforming to pupae during early spring. 

The bud-moth, Tmetocera ocelldna. — The larva of this insect is a pest 
infesting apple-trees. It works in opening fruit-buds and leaf -buds, often 
eating into them, especially the terminal ones, so that all new growth is 
stopped. It also ties the young leaves at the end of a shoot together and 
lives within the cluster thus formed, adding other leaves when more food 
is needed. Sometimes so large a proportion of the fruit-buds are de- 
stroyed as to seriously reduce the amount of the crop. The pupa state 
is passed within the cluster of tied leaves or within a tube formed by 
rolling up one side of a leaf, and lasts about ten days. The moth expands 
about j of an inch; it is of a dark ashen gray, with a large, irregular, 
whitish band on the fore wing. 

The grape-berry moth, Polychrosis vitedna. — The larva of this moth 
causes wormy grapes. The moth emerges in the spring from its cocoon 
on a fallen leaf where it passed the winter. The first generation larvae 
feed upon the embryo grapes. When full-grown, the larva passes to a 
leaf and makes a very peculiar cocoon. It cuts a semicircular incision in 
the leaf, bends over the flap thus made, fastens its free edge to the leaf, 


2i2 THE STUDY OF INSECTS 

and lines the cavity thus enclosed with silk; here it transforms to a 
pupa. The moths of the second and later generations lay their eggs on 
the berries, and the larvae bore into them and feed upon the pulp and 
seeds. 

The oriental fruit-moth, Laspeyresia molesta. — This insect was dis- 
covered here in 1916. It has now spread over most of the eastern half 
of the United Stales. It attacks plum, cherry, peach, quince and apple. 
The pinkish-white larva? which are slightly over one-half inch in length, 
bore into the tender shoots in spring and kill them. Later, they burrow 
into the fruits causing the latter to decay. 

The moth is dark grayish-brown with a wing-expanse of about one- 
half an inch. The winter is passed as a full-grown larva and as a pupa 
beneath flakes of bark on the tree and under objects on the ground. There 
are several generations during a season. 

The European pine-shoot moth, Evetria buoliana. — It was discovered 
here in 191 4. The dark brown larva, about f of an inch long, eats into 
the terminal buds and burrows in the new shoots of pines. The moth is 
brightly colored with reddish-orange front wings suffused with dark red 
and crossed by several irregular silvery lines. It expands about f of an 
inch. 


Family Pyralidiele 

The Pyralids 

The members of this family found in our fauna are mostly small 
moths, but a few are of moderate size. So large a portion of the species 
are small that the family has been commonly classed with the preceding 
families as Microlepidoptera. The members of this family differ so greatly 
in appearance that it is not possible to give a general description that will 
serve to distinguish it; a very large portion of the species have a special 
look, due to their thin and ample hind wings with large anal areas (Fig. 

365). 

The body is slender; the head is 
prominent; the ocelli are usually 
present; the antenna? are almost 
always simple; and the palpi are 
usually moderate in size or long; but 
very often they project beak-like; 
for this reason the name snout-moths 
is often applied to this family. 

This is one of the larger families 
of the Lepidoptera ; nearly one thou- 
sand species have been described 
from America north of Mexico alone. 
The family is divided into many sub- 
families, representatives of fifteen of 
which are found in our fauna. The 

Fio. 365. -Wings of NomophilancctueUa. ^ j^^ spedeS| those that have 

attracted attention on account of their economic importance because 
they attack fruits, vegetables, cereals, stored foods, certain forest-trees 
and even other insects, are the following: 


LEPIDOPTERA 


213 


The Pyraustids 

This group of the pyralids is a large one and although it contains 
many small moths, it also contains a majority of the larger species of 
this family. 

The grape leaf-folder, Desmia funerdlis. — This is a common species 
throughout the United States, the larva of which feeds on the leaves of 
grape. The larva folds the leaf by fastening two portions together by 
silken threads. When full-grown it changes to a pupa 
within the folded leaf. The moth is black with shining 
white spots. The male (Fig. 366) differs from the female 
in having a knot-like enlargement near the middle of each 
antenna. There is some variation in the size and shape 
of the white spots on the wings. In some specimens the fig. 366. — Desmia 
white spot of the hind wings is separated into two or three 
spots. There are two generations of this species in the North and three 
or more in the South. 

The basswood leaf -rol- 
ler, Pantographa limata. — • 
Our basswood trees often 
present a strange appear- 
ance in late summer from 
the fact that nearly every leaf is 
cut more than half way across 
the middle, and the end rolled 
into a tube (Fig. 367). Within 
this tube there lives a bright 
green larva, with the head and 
thoracic shield black. When full 
grown the larva leaves this nest 
and makes a smaller and more 
simple nest, which is 
merely a fold of one 
edge of the leaf, or 
sometimes an incision 
is made in the leaf 
extending around 
about two-thirds of a 
circle and the free 
part bent over and 

fastened; in each case the nest is lined with 
silk, thus forming a delicate cocoon. Here 
the larvae pass the winter in fallen leaves. 
The adult moth expands about i| inches; 
it is straw-colored with many elaborate 
markings of olive with a purplish irridescence 
(Fig. 368). 

The melon-worm, Diaphama hyahnata. 


Fig. 368. — Pantographa limata. 


Fig. 367. — Nest of larva of Pantographa limata. 


This beautiful moth (Fig. 369) 


is often a serious pest in our 
Southern States, where the larva is very destructive to melons and other 
allied plants. The young larvae feed on the foliage; the older ones mine 


2i 4 THE STUDY OF INSECTS 

into the stems and fruit. The insect passes the winter as a pupa in 
loose silken cocoons in dead leaves or under rubbish. The moth is 


Fig. 369. — Diaphania hyalinata: larvae, cocoon, and adults. 

a superb creature, with glistening white wings bordered with black, and 
with a spreading brush of long scales at the end of the abdomen. 

The pickle-worm, Diaphania nitidalis. — This species is closely allied 
to the preceding one. The wings of the moth are yellowish-brown with 
a purplish metallic reflection; a large irregular spot on the front wings 
and the basal two-thirds of the hind wings are semitransparent yellow. 
The tip of the abdomen is ornamented with a brush of long scales, as in 
the preceding species. The range and habits of this species are quite 
similar to those of the melon-worm. 

The cabbage webworm, Hellula undalis. — This species infests various 
cruciferas in the Gulf and South Atlantic States. The larva is about | of 
an inch in length, of a grayish-yellow color, striped with five brownish- 
purple bands. 

The garden webworm, Loxostege similalis. — This species is _ most 
injurious in the Southern States and in the Mississippi Valley. It infests 
various garden crops and corn and cotton. The larva varies in color 
from pale and greenish-yellow to dark yellow and is marked with numer- 
ous black tubercles. 

The European corn-borer, Pyrausta nubilalis. — This is a greatly 
feared pest which has recently appeared in this country. It is a borer in 
the stems of plants, in which it winters as a partly grown larva. Its 
favorite food appears to be corn and especially sweet corn; but it infests 
other cultivated plants, as dahlias and gladiolus, and many large-stemmed 
weeds. The full-grown larva measures about £ of an inch in length ; the 
adult moth has a wing-expanse of from 1 to ij inches. 


LEPIDOPTERA 


215 


The Typical Pyralids 

There are only about twenty-four species in this group and the two 
following are the best known. 

The meal snout-moth, Pyralis farinalis. — The larva of this species 
feeds on meal, flour, stored grain, and old clover hay. It makes little 
tubes composed partly of silk and partly of the fragments of its food. 
It rarely occurs in sufficient numbers to do serious injury; and its 
ravages can be checked by a thorough cleaning of the infested places, 
or when practicable by the use of carbon bisulphide. The moth is com- 
monly found near the food of the larva, but is often seen on ceilings of 
rooms sitting with its tail curved over its back. It expands about 1 inch; 
the fore wings are light-brown, crossed by two curved white lines, and 
with a dark chocolate-brown spot on the base and tip of each. 

The clover-hay worm, Hypsopygia costdlis. — The larva of this species 
sometimes abounds in old stacks of clover hay, and especially near the 
bottom of such stacks. As the infested hay becomes 
covered with a silken web spun by the larva, and by 
its gunpowder-like excrement, much more is spoiled than 
is eaten by the insect. Such hay is useless and should be 
burned, in order to destroy the insects. The moth ex- 
pands about f of an inch. It is a beautiful lilac color, 
with golden bands and fringes (Fig. 370). 


Fig. 370. — Hyp- 
sopygia costalis. 


The Close-wings or Crambids 

This is not a large group but the members of it are more often seen than 
any other pyralids. The larvae of most of the species feed on grass ; and the 
adults fly up before us whenever we walk through meadows or pastures. 
When at rest, the moths wrap their wings closely about the 
body ; this has suggested the name close-wings for the insects 
of this group. When one of these moths alights on a stalk of 
grass it quickly places its body parallel with the stalk, which 
renders it less conspicuous (Fig. 371). Many of the species 
are silvery-white or are marked with stripes of that color. 
About seventy of our species belong to the genus 
Crambus. The moths of this genus are often seen; but the 
larva? usually escape observation. They occur chiefly at or 
a little below the surface of the ground, where they live in 
tubular nests, constructed of bits of earth or vegetable mat- 
ter fastened together with silk. Thus Crambus caliginosellus 
is known as the corn-root webworm on account of its injury 
to young corn plants which it bores into and destroys; it 
is also known as the tobacco stalk-worm, on account of 
similar injury to young tobacco plants. 

Another species, Crambus hortuellus, is known as the 

cranberry girdler. It does considerable injury to cranberry 

vines by destroying the bark of the prostrate stems. 

To this subfamily belong the larger corn-stalk borer, Diatrasa zeacolelta, 

which sometimes bores into the stalks of young corn in the Southern 

States, and the sugar-cane borer, Diatraa saccharalis, which bores into 

the stalks of sugar-cane. 


Fig. 37I- — 
Crambus. 


2l6 


THE STUDY OF INSECTS 


Thk Bee-moth Group 

This is a small subfamily of which only seven species have been found 
in our fauna. The best known of these is the bee-moth, Gallctia mello- 
nella. The larva of this species is a well-known pest in apiaries. It 
feeds upon wax; and makes silk-lined galleries in the honey-comb, thus 
destroying it. When-full grown the larva is about i inch in length. It 
lies hidden in its gallery during the day, and feeds only at night, when 
the tired-out bees are sleeping the sleep of the 
just. When ready to pupate the caterpillar 
spins a tough cocoon against the side of the 
hive. 

The moth has purplish-brown front wings, and 
1 >r< >wn or faded yellow hind wings. The fore wings 
of the male are deeply notched at the end, while 
those of the female (Fig. 372) are but slightly 
so. The female moth creeps into the hive at night to lay her eggs. 

This pest is found most often in weak colonies of bees, which it 
frequently destroys. The best preventive of its injuries is to keep the 
colonies of bees strong. Of course the moths and larvae should be de- 
stroyed whenever found. 


Fg. 372. — Galleria mcUonella. 


Some live 


The Phycitids 

Our most common members of this subfamily are small moths with 
rather narrow but long fore w r ings, which are banded or mottled with 
shades of gray or brown. This is a very large subfamily; more than 
three hundred species have been described from our fauna, and there are 
doubtless many undescribed species in this country. 

The larvae of the different species vary greatly in habits, 
in flowers, some fold or roll leaves within which they live 
and feed; some are borers; others feed upon dried fruits, 
or flour and meal; and one, at least, is predacious, feed- 
ing on coccids. Usually the larva lives in a silken tube 
or case, lying concealed by day and feeding by night. 
The case made by certain of the leaf-eating species is 
very characteristic in form (Fig. 373), being strongly 
tapering and much curved; in this instance the case is 
composed largely of the excrement of the larva. 

The following species are those that have attracted most 
attention on account of their economic importance. 

The Indian-meal moth, Plodia inter pun ctella. — This is the best- 
known of the species that infest stored provisions. The larva is the 
small whitish worm, with a brownish-yellow head, that spins thin silken 
tubes through meal or among yeast -cakes or in bags or boxes of dried 
fruits. The moth expands about | of an inch. The basal two-fifths of 
the fore wing is dull white or cream-colored; the outer part reddish- 
brown, with irregular bands of blackish scales. 

The Mediterranean flour-moth, Ephestia kithnicUa, is an even more 
serious pest than the preceding species, which it resembles in habits. It 
has become very troublesome in recent years in flour-mills. The moth 
expands about 1 inch and is grayish in color. 


LEPIDOPTERA 


217 


Zimmermann's pine-pest, Pinipestis zimmermanni, is a common 
species, the larva of which is a borer. It infests the trunks of pine, 
causing large masses of gum to exude. The moths appear in mid-sum- 
mer. 

The coccid-eating pyralid, LcBtUia coccidivora, differs from the other 
members of this family in being predacious. It feeds on the eggs and 
young of various scale-insects 
(Pulvinaria, Dactylopius, and 
Lecanium). Figure 374 
represents the different stages 
of this insect enlarged, and 
the moths natural size resting 
on egg-sacs of Pulvinaria. 
Like other members of this 
family the larva spins a silken 
tube, within which it lives. 
On a thickly-infested branch 
these tubes may be found 
extending from the remains 
of one coccid to another. 

To this subfamily belong 
also the gooseberry fruit 
worm, Zophodia grossuldrics, 
which feeds within the fruit 
of the gooseberry and cur- 
rant, and the cranberry fruit 
worm, Mineola vaccinii, 
which bores into cranberry 
fruit. 

Family Pterophorid^ 

The Plume-moths 

The plume-moths are so 
called on account of the re- 
markable form of the wings 
in most species; the wings 
being split by longitudinal fis- 
sures into more or less plume-like divisions. In most species each fore 
wing is separated into two parts, by a fissure extending about one-half 
the length of the wing; while each hind wing is divided 
into three parts by fissures extending farther towards the 
base of the wing. 

One of our most common species is the gartered 
plume, Oxyptilus periscelidactylus. This is a small moth, 
expanding about f of an inch. It is of a yellowish-brown 
color marked with dull whitish streaks and spots (Fig. 
375). The larvae hatch early in the spring and feed upon the 
newly-expanded leaves of the grape. They fasten together several of them, 
usually those at the end of a shoot, with fine white silk; between the 
leaves thus folded the caterpillars live either singly or two or three 


Fig. 374. — Lcetilia coccidivora: a, egg; b, larva; c, pypa; d, adult; 
e, e, moths natural size, resting on egg sacs of Pulvinaria. 


Fig. 375. — Oxy- 
ptilus periscelidacty- 
lus. 


2l8 


THE STUDY OF INSECTS 


together. They become full-grown and change to pupae early in June. 
The pupa is not enclosed in a cocoon, but is fastened to the lower side 
of a leaf by its tail by means of a few silken threads, in nearly the same 
way as the chrysalids of certain butterflies are suspended. The pupa 
state lasts about eight days. 

Family Sphingid^e 

The Hawk-moths or Sphinxes 

Hawk-moths are easily recognized by the form of the body, wings 
and antenna?. The body is very stout and spindle-shaped; the wings 
are long, narrow and very strong; the antennae are more or less thickened 
in the middle or towards the tip. which is frequently curved back in the 
form of a hook; rarely the antennae are pectinated. The sucking-tube 
(maxillae) is usually very long, being in some instances twice as long as 


Fig. 376. — Wings of Protoparce quinquemaculata. 

the body; but in one subfamily it is short and membranous. When not 
in use it is closely coiled like a watch-spring beneath the head. None of 
the species has ocelli. 

The venation of the wings (Fig. 376) is quite characteristic; the most 
distinctive feature is the prominence of the basal part of vein Ri of the 
hind wing, the part that extends from the stem of radius to the subcosta. 
This free part of vein Ri has the appearance of a cross-vein and is as 
stout as the other veins. 


LEPIDOPTERA 


219 


Some of the hawk-moths are small or of medium size; but most of 
them are large. They have the most powerful wings of all Lepidoptera 
in our fauna. As a rule they fly in the twilight, and have the habit of 
remaining poised over a flower while extracting the nectar, holding them- 
selves in this position by a rapid motion of the wings. This attitude 
and the whir of the vibrating wings give them a strong resemblance to 
humming-birds, hence they are sometimes called humming-bird moths; but 
they are more often called hawk-moths, on account of their long, nar- 
row wings and strong flight. 

Of all the beautifully arrayed Lepidoptera some of the hawk-moths 
are the most truly elegant. There is a high-bred tailor-made air about 
their clear-cut wings, their closely fitted scales and their quiet but ex- 
quisite colors. The harmony of the combined hues of olive and tan, 
ochre and brown, black and yellow, and grays of every conceivable shade, 
with touches here and there of rose color, is a perpetual joy to the artistic 
eye. 

The larv£e of the Sphingidse feed upon leaves of various plants and 


Fig. 377. — Sphinx chersis, larva. 

trees and are often large and quite remarkable in appearance (Fig. 377). 
The body is cylindrical and naked and usually has a horn on the eighth 
abdominal segment. Sometimes instead of the horn there is a shiny 
tubercle or knob. We cannot even guess the use of this horn, unless it is 
ornamental, for it is never provided with a sting. These caterpillars 
when resting rear the front end of the body up in the air, curl the head 
down in the most majestic manner, and remain thus rigid and motionless 
for hours. When in this attitude they are supposed to resemble the 
Egyptian Sphinx, and so the typical genus was named Sphinx and the 
family the Sphingidas. 

Most species pass the pupa state in the ground in simple cells made in 
the earth; some, however, transform on the surface of the ground in 


220 


THE STUDY OF INSECTS 


imperfect cocoons composed of leaves fastened together with silk. One 
hundred species of hawk-moths occur in this country. The following are 
some of the more common ones. 

The twin-spotted sphinx, Smerinthus geminatus. — This exquisitely- 
colored moth expands about 
2 1 inches. The thorax is gray 
with a velvety dark brown spot 
in the middle. The fore wings 
are gray, with a faint rosy tint 
in some specimens, and tipped 
and banded with brown as 
shown in Figure 378. The 
hind wings are deep carmine 
fig. 378. - Smerinthus geminatus. at t k e middle, and are bordered 

with pale tan or gray. Near the anal angle there is a large black spot 
in which there is a pair of blue spots, which suggested the name gem- 
inatus. The larva feeds upon the leaves of apple, plum, elm, ash, and 
willow. 

The pen-marked sphinx, Sphinx chersis. — This moth is of an almost 
evenly distributed ashy-gray color. This sombre color is relieved some- 
what by a black band on each side of the abdomen, marked with four or 
five white transverse bars; by two dark brown, smoky bands which cross 
the hind wings; and by a series of black dashes on the fore wings, one in 
each cell between the apex of the wing and the anal vein. These dashes 
appear as if drawn casually with a pen. The larva is not uncommon 
upon ash and lilac; it is greenish or bluish-white above, and darker 
below; there are seven oblique yellow bands on the sides of the body, 
each edged above with dark green. When disturbed it assumes the 
threatening attitude shown in Figure 377. 

The tomato-worm, Protoparce quinquemaculata. — This larva is the 
best known of all our sphinxes, as it may be found feeding on the leaves 
of tomato, tobacco, or potato wherever these plants are grown in our 
country. It resembles in its general appearance the larva of Sphinx 
chersis (Fig. 377); but is stouter and has a series of pale longitudinal 
stripes low down on each side, in addition to the oblique stripes; and 
its favorite attitude is with the fore end of the body slightly raised. It 
is usuallv green, but individuals are often found that are brown, or even 
black. There appear at frequent intervals in the newspapers accounts of 
people being injured by a poison 
excreted by the caudal horn of this 
larva; but there is absolutely no 
foundation whatever for such stories. 
The pupa (Fig. 379) is often ploughed 
up in gardens, and attracts at- 
tention on account of its curious 
tongue-case a part of which is free 
resembling the handle of a pitcher. The moth is a superb creature, ex- 
panding four or five inches. It is of many delicate shades of ash-gray, 
marked with black or very dark gray; there arc a few short black dashes 
on the fore part of the thorax, and some irregular black spots edged 
with white on the posterior part; the abdomen is gray with a black 
middle line, and five yellow, almost square spots along each side. Each 


Fir,. 379. — Protoparce quinquemaculata, pupa. 


LEPIDOPTERA 


of these spots is bordered with black, and has a white spot above and 
below, on the edge of the segment. The hind wings are crossed by four 
blackish lines, of which the two intermediate are zigzag. 

The tobacco-worm, Protopdrce sexta. — This species closely resem- 
bles the preceding and the two are often mistaken the one for the other. 
The larvae have similar habits, feeding on the same plants; but in this 
species the larva lacks the series of longitudinal stripes characteristic 
of the tomato-worm. The moths are easily distinguished; this species 
is brownish-gray instead of ashy-gray; at the end of the discal cell of 
the fore wings there is a distinct white spot; and the two dark bands 
crossing the middle of the hind wings are not zigzag, and are less dis- 
tinctly separate; often they are united into a single broad band. 

The hog-caterpillar of the vine, Ampelceca myron. — There is a group 
of hawk-moths the larvae of which have the head and first two thoracic 
segments small, while the two following segments are greatly swollen. 
These larvae from a fancied resemblance to fat swine have been termed 
hog-caterpillars; and the present species, which is common on grape, has 
been named the hog-caterpillar of the vine. It is a comparatively small 
species, the full-grown larva being but little more than 2 inches long. 
There is a row of seven spots varying in color from red to pale lilac, each 
set in a patch of pale yellow, along the middle of the back. A white 
stripe with dark green margins extends along the side from the head to 
the caudal horn, and below this are seven ob- 
lique stripes. This larva is often infested by 
braconid parasites; and it is a common oc- 
currence to find one of them with the cocoons 
of the parasites attached to it (Fig. 380). 
The pupa state is passed on the surface of the 
ground within a rude cocoon made by fasten- 
ing leaves together with loose silken threads. The adult expands about 
2^ inches. The fore wings are olive-gray, with a curved, olive-green, ob- 


Fig. .380. — Ampelcsca myron, larva with 
cocoons of parasites. 


Fig. 381. — Pholus pandorus. 


lique band crossing the basal third, a discal point of the same color, and 
beyond this a large triangular spot with its apex on the costa and its base 
on the inner margin. 

The pandorus sphinx, Pholus pandorus. — This magnificent moth 


222 


THE STUDY OF INSECTS 


expands from 4 to 43 inches. The ground color of its wings is pale olive, 
verging in some places into gray; the markings consist of patches and 
stripes of dark, rich velvety olive, sometimes almost black (Fig. 381). 
Near the inner margins of both pairs of wings the lighter color shades 
out into pale yellow, which is tinged in places with delicate rose-color. 
These markings show a harmony of contrasting shades rarely equalled 
elsewhere by nature or art. The larva is one of the hog-caterpillars. It 
feeds upon the leaves of Virginia-creeper. When young it is pinkish in 
color, and has a long caudal horn; as it matures it changes to a reddish- 
brown, and the horn shortens and curls up like a dog's tail and finally 
disappears, leaving an eye-like tubercle. The caterpillar has on each side 
five or six cream-colored oval spots, enveloping the spiracles. 


Fig. 382. — Celerio lineala. 


The white-lined sphinx, Celerio lineata. — This moth can be easily 
recognized by Figure 382. Its body and fore wings are olive-brown; 
there are three parallel white stripes along each side of the thorax; the 
outer one of these extends forward over the eyes to the base of the palpi ; 
on the fore wings there is a buff stripe extending from near the base of 
the inner margin to the apex, and veins R 5 and 2d A are lined with white; 
the hind wings are black with a central reddish band. The larva is ex- 
tremely variable in color and markings. It feeds on many plants, among 
which are apple, grape, plum, and currant. 

The thysbe clear-wing, Hcemorrhagia thysbe. — There is a group of 
hawk-moths that have the middle portion of the wings transparent, re- 
sembling in this respect the ^Egeriida? ; but 
they are easily recognized as hawk-moths 
by the form of the body, wings, and an- 
tenna?. One of the more common of these 
is the thysbe clear- wing (Fig. 383). The 
scaled portions of the wings are of a dark 
reddish -brown ; but this species is most 
easily distinguished from all our other 
species by a line of scales dividing the 
discal cell lengthwise and representing the 
position of the base of vein M. The larva of this species feeds on the 
different species of Viburnum, the snow-berry, and hawthorn. 


Fig. 383. — Hcrmorrhazia thysbe. 


LEP1D0PTERA 


223 


Fig. 384. — A measuring-worm. 


Family Geometrid^ 

The Geometrids or the Measuring-worms 

The family Geometridae is composed of those moths the larvae of 
which are known as measuring-worms, span-worms, or loopers. They 
progress by a series of looping movements. 
They first cling to the supporting twig or leaf 
by their thoracic legs; then arch up the back 
while they bring forward the hinder part of the 
body and seize the support, at a point near the 
thoracic legs, by the prolegs at the caudal end 
of the body; then, letting loose the thoracic 
legs (Fig. 384), they stretch the body forward, 
thus making a step; this process is then re- 
peated. 

The larvae of geometrids have as a rule only the last two pairs of pro- 
legs well developed; and hence, as the middle part of the body is not 
supported, they are unable to walk in the way that other caterpillars 
walk. It is probable, however, that the loss of the first three pairs of 
prolegs is the result of the looping gait rather than the cause of it. 

Frequently measuring-worms when resting cling by their prolegs and 
hold the body out straight, stiff, and motionless, appearing like a twig; 
this is doubtless a protective resemblance. 

The geometrid larvae are leaf-feeders, and some species occur in such 

large numbers as to be serious pests. 

The pupae are slender, and some 
species are green or mottled in this 
state. The pupa state is passed in a 
very flimsy cocoon or in a cell in the 
ground. 

The moths are of medium size, 
sometimes small, but only rarely very 
large. Usually the body is slender, 
and the wings broad and delicate in 
appearance. These moths occur on 
the borders of woods and in forests, 
rarely in meadows and pastures. 
Their flight is neither strong nor long 
sustained. Many species when at 
rest hold the wings horizontally and 
scarcely overlapping ; but other spe- 
cies assume other positions, some 
similar to butterflies. The type 
of venation is shown in Figure 

385- . e 

There are many species of geom- 
eters but the following are best 
known. 

The fall canker-worm, Alsbphila 
pometaria. — The canker-worms are 


Fig. 38;. — Wings of Caripela angusliorata. 


well-known pests, which are often very destructive to the foliage of fruit- 


224 THE STUDY OF INSECTS 

trees and shade-trees. Although they attack many kinds of trees, the 
apple and the elm are their favorite food-plants. 

There are two species of canker-worms which resemble each other to 
such an extent that they were long confounded; but they differ struc- 
turally, and they differ also in habits. The two species agree in being 
loopers or measuring-worms in the larval state, in the possession of ample 
wings by the adult male, and in the adult female being wingless. They 
are easily distinguished however, in all stages, the eggs, larvae, and adults 
differing markedly. 

The fall canker-worm is so called because the greater number of the 
moths mature in the autumn and emerge from the ground at this season; 
but a considerable number come out of the ground in the winter during 
warm weather, and in the spring. As the females are wingless they are 
forced to climb up the trunks of trees in order to lay their eggs in a 
place from which the larvae can easily find their food. The eggs appear 
as if cut off at the top, and have a central puncture and a brown circle 
near the border of the disk. They are laid side by side in regular rows 
and compact batches, and are generally exposed. 
They hatch in the spring at the time the leaves 
appear; and the larvae mature in about three 
weeks. In this species there is a pair of ves- 
tigial prolegs on the fifth abdominal segment. 
The pupa state is passed beneath the ground in 
a perfect cccoon of fine densely spun silk. The 
adult male is represented by Figure 3S6. There 
is a distinct whitish spot near the apex of the 
fore wings. The moths of both sexes lack 
the abdominal spines characteristic of the spring canker-worm. 

The spring canker-worm, Paleacrita vernata. — The eggs are ovoid 
in shape, and are secreted in irregular masses, usually under loose scales 
of bark or between the leaflets of the expanding buds. The larvae hatch 
about the time the leaves expand, and become full-grown in from three 
to four weeks. They vary greatly in color, and are marked on the back 
with eight narrow, pale, longitudinal lines which are barely discernible; 
the two lateral lines of each side are much farther apart than the others; 
and there are no prolegs on the fifth abdominal segment as in the fall 
canker-worm. The pupa state is passed below the surface of the ground 
in a simple earthen cell, which is lined with very few silken threads. The 
adult moths usually emerge early in the spring before the leaves expand; 
but they sometimes appear late in the fall, or on warm days during the 
winter when the ground is thawed. In both sexes the adult of this species 
is distinguished by the presence of two transverse rows of stiff reddish 
spines, pointing backwards, on each of the first seven abdominal seg- 
ments. 

The raspberry geometer, Synchlora tzrdta. — The larva of this species 
feeds on the fruit and foliage of raspberry, but chiefly on the fruit. It, 
like some other members of this subfamily, has the curious habit of 
covering its body by attaching to it bits of vegetable matter, so that it is 
masked beneath a tiny heap of rubbish. The wings of the adult are of a 
delicate pale green color crossed by two lines of a lighter shade; the face 
is green; and the abdomen is not marked with pink and white ocellate 
spots, as is the case in certain allied species. 


FlG. 386. — Ahopliila pometaria. 


LEPIDOPTERA 


225 


Fig. 387. — Dyspteris abortivaria. 


Calocalpe undu- 


The bad-wing, Dyspteris abortivaria. — It is easy to recognize this 
moth (Fig. 387) by the peculiar shape of its wings, the hind wings being 
greatly reduced in 
size. It is of a 
beautiful pea -green 
color, with two 
white bands on the 
fore wings and one 
on the hind wings 
The larva feeds on 
the leaves of grape, 
which it rolls. 
The scallop-shell moth, Calocalpe itndu- 
lata. — This is a pretty moth, with its yel- 
low wings crossed by 
so many fine, zigzag, 
dark brown lines that 
it is hard to tell which 
of the two is the 
ground-color (Fig. 
388). It lays its eggs 
in a cluster on a leaf 
near the tip of a twig 
of cherry, usually wild cherry. The larvae 
make a snug nest by fastening together the 

leaves at the end 
of the twig ; and 
within this nest 
(Fig. 389) they 
live, adding new 
leaves to the out- 
side as more food 
is needed. The 

Fig. 3 go.-Lygrisgracilineaia. leaveg die &nd 

become brown, and thus render the nest con- 
spicuous. There are two generations in the year. The larvae of the fall 
brood are black above, with four white or green stripes, and flesh-colored 
below; the larvae of the summer brood are black only on the sides. 
When full-grown they descend to the ground to transform, and pass 

the winter in the pupa state. 

The many-lined moth, Lygris gracilineata. — 
This moth has pale ochre-yellow wings, with a 
brownish shade near the outer margin, and 
crossed by many diverging brown lines (Fig. 
390) . It varies from 1^ inches to 2 inches in ex- 
panse. We have often found this moth on the 
side of our room, resting on the wall, head down- 
ward, and with its abdomen hanging down over 
its head in a curious manner. The larva feeds on the leaves of grape. 

The beggar, Eudule mendlca. — One of the most delicate winged moths 
that we have in the northern Atlantic States is this species (Fig. 391). Al- 
though the wings are yellowish- white in color they are almost transparent. 


Fig. 389. — Eggs and nest of Calocalpe 
undulata. 


9i- — Eudule mendica. 


226 


THE STUDY OF INSECTS 


( )n the fore wings there are two transverse rows of pale gray spots, and a 
single spot near the outer margin between veins M 3 and Cm. (This spot 
was indistinct in the specimen figured.) The moth is common in mid- 
summer. The larva feeds on violet. 

The chain-dotted geometer, CingUia catenaria. — This moth has 
snow-white wings marked with zigzag lines and with dots of black as 
sh< >wn in Figure 392. The head is ochreous-yellow in front; and the thorax 
is yellowish at the base of the patagia. The moth flies during September 
and October. The larva feeds on various shrubs and trees. The pupa state 
is passed in a slight but well-formed web of yellow threads, which is made 
between twigs or leaves, and through which the pupa can be seen. 


Fig. 392. — CingUia catenaria. 


Fig. 393. — Nepytia semidusaria. 


The evergreen nepytia, Nepytia semidusaria. — This beautiful moth 
(Fig. 393) is common in the vicinity of pines, spruce, fir, and hemlock 
during August and September. It varies from a smoky-ash color to 

almost snow- 
white; the wings 
are marked with 
black. The larva 
feeds on the 
leaves of conifers . 
It is reddish-yel- 
low above, with 
lateral yellow 
bands below, 
while on each side 
are two pairs of 
black hair-lines. 
There are black 
spots above on 
the segments. 
When full-grown 
it is a little more 
than 1 inch long 
and spins a loose 
cocoon among 
the leaves. The 
chrysalid is green 
with whit e 
stripes and is 

Fig. 394. — Erannis liliaria. Verv OrettV 

The lime-tree winter-moth, Erannis tiliaria. — This species (Fig. 394) 


LEPIDOPTERA 


227 


resembles the canker-worms in many particulars. The larva is a looper 
which infests both fruit and forest-trees; and in the adult state the male 
has well-developed wings, while the female is wingless. 

The eggs are oval, of a pale yellow color, and covered with a network 
of raised lines. They are thrust by the female under loose bark and in 
crevices on the trunk and large limbs. They hatch in May, and the 
larva? attain their full growth in the latter part of June. The larva is 
yellow, marked with ten crinkled black lines along the top of the back; 
the head is rust-colored, and the venter yellowish-white. There is a 
second form of the larva which is brown above with slate color towards 
the sides. When full-grown the larva measures about i-J inches in length. 
The pupa state is passed in the ground. The moths issue in October or 
November; and then the wingless females ascend the trees to oviposit as 
do the females of the canker-worms. The female is represented in the 
lower left-hand part of the figure. She is grayish in color, with two black 
spots on the back of each segment except the last, which has only one. 
The male has pale yellow and brown or buff fore wings, with a central 
spot and a band beyond the middle, while the hind wings are much 
lighter. ^ 

The notched- wing geometer, Ennomos magnarius. — This is one of 
the larger of our geometrids. The larva is a common looper upon maple, 
chestnut, and birch trees, and measures about 2 \ inches in length when 
full-grown. It spins a rather dense, spindle-shaped cocoon within a 
cluster of leaves. The moth (Fig. 395) is ochre-yellow with reddish 
tinge. The wings are shaded towards the outer margin with brown, and 
are thickly spotted with small brown dots. The polished greenish-brown 
to bronze colored eggs are laid side by side in a long linear row on the 
branches of apple, pear, lilac, and chestnut. 


Fig. 395. — Ennomos magnarius. 


Fig. 396. — Amphidasis cognataria. 


The pepper-and-salt currant-moth, Amphidasis cognataria. — This 
moth (Fig. 396) differs remarkably in appearance from most geometrids, 
the body being stouter, and the wings appearing heavier. It can be 
easily recognized by its evenly distributed pepper-and-salt markings. 
The larva feeds on various plants, but is found most often on currant. 


Family Notodontid^; 

The Prominents 

This family includes moths of moderate size, only a few of the larger 
ones expanding more than 2 inches. The body is rather stout and 
densely clothed with hair, and the legs, especially the femora, are clothed 
with long hairs. The wings are strong, and not very broad, the anal 


228 


THE STUDY OF INSECTS 


angle of the hind wings rarely reaching the end of the abdomen. In 
their general appearance many of these mollis bear a strong resemblance 
to noctuids. The venation of the wings is illustrated in Figure 397. 


id A 

■ Wings of Hyperaschra slragula. 

In some species the front wings have a prominence or backward 
projecting lobe on the inner margin, which suggested the common name 
of prominents for these insects (Fig. 398). The name is more generally 
appropriate, however, for the larvae, as a much larger proportion of them 
than of the adults bear striking prominences. 

The larvas feed upon the leaves of shrubs and trees. Our most com- 
mon species live exposed; but some species live in folded leaves. They 
are either naked or clothed with hairs. Many species have only four 
well-developed pairs of prolegs, the anal pair being rudimentary, or trans- 
formed into elongated spikes. Some species are hump-backed; and 
spines or fleshy tubercles are often present. The transformations occur in 
cocoons or in the ground. 


Fig. 398. — Pheosia rimosa. 


The family Notodontida: is represented in this country by about one 
hundred species. 


LEPIDOPTERA 


229 


The handmaid moths, Datana. ■ — Among the more common repre- 
sentatives of the Notodontida? are certain brown moths that have the 
fore wings crossed with bars of a different 
shade (Fig. 399) and that bear on the fore 
part of the thorax a conspicuous patch of 
darker color. In most of our species the fore 
wings are also marked with a dot near the 
center of the discal cell and a bar on the dis- 
cal vein. These moths belong to the genus 
Datana. The common name, handmaid, is a 
translation of the specific name of our 
most common species, D. ministra. But as 
this species is now generally known as the yellow-necked apple-tree worm, 
and as all of our species are dressed in sober attire as becomes modest 
servants, we have applied the term handmaid moths to the entire genus. 

The larva? of the handmaid moths are easily recognized by their 
peculiar habits. They are common on various fruit and forest-trees, but 
especially on apple, oak, and hickory. 

They feed in colonies; and have the habit of assuming the curious 
attitude shown in Figure 400. The body is black or reddish, marked 
with lines or stripes of yellow or white. Owing to the gregarious habits 
of these larva? they can be easily collected from the trees they infest. 


Fig. 3gg. — Datana ministra. 


Fig. 400. — Datana, larva. 

All the species that we have studied agree in being single-brooded, 
the moths appearing in midsummer; the eggs are laid in a cluster on a 
leaf; the larva? are conspicuous in August and September. In some of 

the species the larva? have the curious habit 

of leaving the branch upon which they are 

feeding when the time to molt arrives, the 

whole colony gathering in a large mass on 

the trunk of the tree, where the molt takes 

place. The pupa state is passed in the 

ground, in a very light cocoon or in none at 

all, and lasts about nine months in the 

species that we have bred. 

The white-tipped moth, Symmerista albifrons. — This beautiful moth, 

which is quite common, can be easily recognized by the accompanying 

figure (Fig. 401); the white patch, which extends along the costa of the 


Fig. 401. — Symmerista albifrons. 


230 


THE STUDY OF INSECTS 


fore wing for half the length from the tip, being very characteristic. 
The larva is quite common in the autumn on leaves of oak. It is known 
as the red-humped oak-caterpillar; it is smooth and shining, with no 
hairs; along each side of the back there is a yellow stripe, and between 
these, on the back, fine black lines on a pale lilac ground; on each side 
below the yellow stripes there are three black lines, the lowest one just 
above the spiracles. The head is orange-red; and there is an orange-red 
hump on the eighth abdominal segment. 

The two-lined prominent, Heterocampa bili- 
neata. - — The larva of this species (Fig. 402) is 
much more apt to be observed than the adult. 
— iickrocampa biiineata, It is common in the latter part of the summer 
and in early autumn, feeding on the leaves of 
elm, beech, and basswood. It measures when full-grown about if 
inches in length. Its ground-color is usually green, but sometimes 
claret-red. There is a pale yellow stripe along the middle of the 
back, and on each side a stripe of the same color. The course of these 
side stripes is very characteristic; passing back from the head, they con- 
verge on the prothorax; on the mesothorax and metathorax they are 
separated from the dorsal line only by a narrow band of red or purple; 
on the first abdominal segment they diverge to the lateral margin of the 
back, but converge again on the seventh and eighth abdominal segments. 
This yellow subdorsal line is bordered without by a milk-white stripe; 
and extending from this stripe over the side of the body there is a whitish 
shade which fades out below. The moth is ash-colored, with the fore-wings 
crossed by two wavy lines between which the wing is darker; between the 
outer wavy line and the outer margin of the wing there is a faint band. 


IS 


Fig. 403. — Schizura concinna, larva. 

The red-humped apple-worm, Schizura concinna. — The larva of this 
species (Fig. 403) is common on apple and allied plants. The head 
coral-red, and there is a hump of the same color on the 
back of the first abdominal segment ; the body is striped 
with slender black, yellow, and white lines, and has two 
rows of black spines along the back, and other shorter 
ones upon the sides. When not eating, the larvae re- 
main close together, sometimes completely covering the 
branch upon which they rest. This species passes the 
winter in the pupa state. The adults appear in June 
and July. 

The poplar mocha-stone moth, Mclalopha inclusa 


- The adult 


404) is a brownish-gray moth with the fore wings crossed by three irregu- 


LEPIDOPTERA 


231 


lar whitish lines. The basal line is broken near the middle of the wing; 
and the intermediate one forms an inverted Y, the main stem of which 
joins the third line near the inner margin of the wing, making with it a 
prominent V. These lines are bordered without by rust-red; there is a 
chocolate-colored spot near the apex of the fore wings, and an irregular 
row of blackish dots near the outer margin. The hairs of the thorax 
form a prominent crest, the fore side of which is a rich dark brown. The 
hind wings are crossed by a wavy band, which is light without and dark 
within. 


Fig. 405. — Eggs, larva, and nest of Melalopha inclusa. 


The eggs are nearly spherical and smooth; they are deposited in a 
cluster a single layer deep on a leaf (Fig. 405). When the larvae hatch 
they make a nest either by fastening several leaves together or, as is the 
case when they infest poplar, by folding the two halves of a single leaf 
together; frequently in the latter case the tip of the leaf is folded in as 
shown in the figure. Within this nest the entire colony lives, feeding on 
the parenchyma, and causing the leaf to turn brown. Later other leaves 
are added to this nest or additional nests are made among adjoining 
leaves. All of these infested leaves are securely fastened to the twig by 
bands of silk. When the larvae become large they leave their nests at 
night to feed upon other leaves. These they entirely consume excepting 
the petioles, midribs, and larger veins. 

The full-grown larva measures if inches in length. It is striped with 
pale yellow and brownish-black, and bears a pair of black tubercles close 
together on the first abdominal segment, and a similar pair on the eighth 
abdominal segment. The cocoon is an irregular thin web; it is made 
under leaves or other rubbish on the ground. The insect remains in the 
pupa state during the winter, and emerges as a moth in the latter part 
of June or later. In the South 
this species infests willow as 
well as poplar, and is double- 
brooded. 

Among the more gro- 
tesque larva? belonging to this 
family are those of the genus 
Schizura, of which we have several species. Figure 406 represents the 
larva of Schizura ipomeaz. At the left in the figure is shown a front view 
of the longest tubercule. This species feeds on oak, maple, and many 
other plants. In the Gulf States it feeds on Ipomea coccinea, which fact sug- 
gested its specific name. 


Fig. 406. 
at left. 


■ Schizura ipomea', larva; tubercle enlarged 


232 


THE STUDY OF INSECTS 


Family LymantriidjE 

The family Liparidas of some writers 

The Tussock-moths 

The larvae of these moths are among the most beautiful of our cater- 
pillars, being clothed with brightly-colored tufts of hairs; and it is to 
this characteristic clothing of the larva? that the popular name tussock- 
moths refers. 

The adult moths are much plainer in appearance than the larvae; 
and in the genera, to which our most common species belong, the females 
are practically wingless, the wings being at most short pads, of no use as 
organs of flight. 

The tussock-moths are of medium size, with the antennae of both 
sexes when winged pectinated, those of the males very broadly so; the 
wingless females have serrate or narrowly pectinate antennae. 

The larvae of our native species are very characteristic in appearance. 
The body is hairy; there are several conspicuous tufts of hairs on the 
dorsal aspect of the abdomen, and at each end of the body there are 
long pencils of hairs; on the sixth and seventh abdominal segments there 
is on the middle of the back of each an eversible gland supposed to be a 
scent-organ similar to the osmateria in the larvae of Papilio, and it is 
stated that a fine spray of liquid is sometimes thrown from them. 

The white-marked tussock-moth, Hemerocampa 
leucostigma. — This is our most common represent- 
ative of the family. It frequently occurs in such 
great numbers that it seriously injures the foliage of 
shade-trees and orchards. The male (Fig. 407) is of 
an ashy-gray color; the fore wings are crossed by 
Hemerocampa undulated bands of darker shade and bear a conspicu- 
ous white spot near the anal angle. The female is 
white and resembles a hairy grub more than a moth. She emerges from her 
cocoon and after pairing lays her eggs upon it, covering them with a frothy 
mass. The larva (Fig. 408) is one of the most beautiful of our caterpillars. 


Fig. 407. 
leucostigma. 


Fig. 408. — Hemerocampa leucostigma, larva. 

The head and the glands on the sixth and seventh abdominal segments are 
bright vermilion-red. There is a velvety black dorsal band, bordered with 
yellow subdorsal stripes; and there is another yellow band on each side 
just below the spiracles. The prothorax bears on each side a pencil of 


LEPIDOPTERA 233 

long black hairs with plume-like tips; a similar brush is borne on the 
back of the eighth abdominal segment, and the first four abdominal 
segments bear dense brush-like tufts of cream-colored or white hairs. 

The California tussock-moth, Hemerocampa vetusta. — The white- 
marked tussock-moth described above is found only in the East; this 
species is found in California, where it is common on live oak and yellow 
lupin trees, and has injuriously infested apple and cherry orchards. The 
larvae have black heads, crimson hair-bearing warts and prolegs, and the 
four tussocks or brush-like tufts of hairs on the back are often dark gray 
with brownish crests. In general the life-history of this species is similar 
to that of the eastern species. 

The old tussock-moth, Notolophus antlqua. — The male is of a rust- 
brown color; the fore wings are crossed by two deeper brown bands and 
have a conspicuous white spot near the anal angle. The body of the 
grub-like female is black, clothed with yellowish-white hairs; she lays 
her eggs on her cocoon, but, unlike the two preceding species, does not 
cover them with anything. The larva differs from either of the preceding 
in having an extra pair of pencils of plume-like hairs arising from the 
sides of the second abdominal segment; the head is jet-black; the glands 
on the sixth and seventh abdominal segments are vermilion-red or some- 
times bright orange; and the tubercles on the sides of the back of the 
second and third thoracic and the sixth and seventh abdominal segments 
are orange-red or yellow margined with pale yellow. 

The gypsy moth, Porthetria dispar. — This is a European species 
which was introduced in Massachusetts in 1866 by a French naturalist 
who was conducting experiments with silk-worms. Some of the insects 
escaped from him into a neighboring woodland and became established 
there; but they did not attract particular attention till about twenty 
years later. It was then realized that this species is a serious pest. Since 
then millions of dollars have been expended by the State of Massachu- 
setts and the Federal Government in an unsuccessful effort to extermin- 
ate it. It has spread over a large part of New England, and isolated 

colonies have been found in New York. 
The larva has a wide range of food- 
plants, feeding on the foliage of most 
forest and fruit-trees. The male moth 
is brown; -the female white (Fig. 409). 
In each the fore wings are crossed by 
many dark lines and bear a black 
lunule on the discal vein. The speci- 
men figured is unusually small. The 

FK.W.- Porthetria dispa,. eggg ^ ^ ^ & magg Qn Rny CQn _ 

venient object and are covered with hair from the abdomen of the 
female. The larva differs greatly in appearance from those of the pre- 
ceding genera, lacking the peculiar pencils and tufts of hair; but the 
characteristic glands of the sixth and seventh abdominal segments are 
present and are red. The body is dark brown or black, finely reticulated 
with pale yellow, and with narrow yellow dorsal and subdorsal lines. On 
the dorsal aspect of each segment there is a pair of prominent, rounded 
tubercles bearing spiny black hairs. The first five pairs of these tubercles 
are bluish, the others dark crimson-red. There are also two rows of 
tubercles on each side of the body which bear longer hairs. 


2 34 THE STUDY OF INSECTS 

The brown-tail moth, Euproctis chrysorrhcea. — The brown-tail moth 
is another European pest, which was introduced into Massachusetts. It 
first attracted attention by its ravages in 1897, and since then has spread 
over a considerable part of New England and has extended into New 
Brunswick and Nova Scotia. The wings of the female moth are white; 
and the tip of the abdomen bears a tuft of yellowish-brown hairs, hence 
the popular name of the insect. The female expands about 1^ inches. 
The male is a little smaller than the female; and the brownish tuft at 
the end of the abdomen is not so conspicuous as in the female. The larva 
feeds on the foliage of fruit-trees and of almost all kinds of shade-trees ex- 
cept conifers. The eggs are laid in an elongate mass on the underside of 
a leaf, during July. The egg-mass is covered with brownish hairs from 
the tip of the abdomen of the female. The eggs hatch in two or three 
weeks. The larvae hatching from an egg-mass feed together on adjoining 
leaves at the tip of a branch. These they web together with silk, making 
a nest within which they pass the winter in a partially grown condition. 
In early spring the larvae leave their winter quarters and feed on the 
expanding foliage. They become full-grown in five or six weeks; and 
then spin thin cocoons of white silk in curled leaves, crevices in bark of 
trees, or under any convenient shelter. About three weeks later the 
moths emerge. 

The full-grown larva of the brown-tail moth measures about i| inches 
in length. It is nearly black in ground color, clothed with tufts of brown- 
ish barbed hairs, and has a row of nearly white tufts on each side of the 
body. In the center of the sixth and seventh abdominal segments are 
small, red, retractile tubercles. The barbed hairs borne by the subdorsal 
and lateral tubercles are venomous and produce an inflammation of the 
skin of man much like that caused by poison ivy. As the cast skins of 
the larvae are blown about by the wind, people are frequently badly 
poisoned where this pest is common. 

Family Noctuid^; 
The Noctuids or the Owlet-moths 

If only our fauna be considered, this is the largest of all of the families 
of the Lepidoptera; more than 2500 species of noctuids are now know to 
exist in America north of Mexico. The great majority of the moths that 
fly into our houses at night, attracted by lights, are members of this 
family. The nocturnal habits of these insects, and the fact that often 
when they are in obscurity their eyes shine brightly suggested the name 
of the typical genus, Noctua, from the Latin for owl, as well as the pop- 
ular name owlet-moths, by which they are known. Similar popular 
names have been given them in several other languages. 

Although there exist within the limits of the family great differences 
in size, form, and coloring, most of the species are dull-colored moths of 
medium size. 

In the typical noctuids, the body is large in proportion to the size of 
the wings; the front wings are strong, somewhat narrow, and elongated, 
the outer margin being shorter than the inner margin; and when at rest, 
the wings are folded upon the abdomen, giving the insect a triangular 
outline. The antennae are thread-like, fringed with hairs, or brush-like, 


LEPIDOPTERA 


235 


or frequently pectinate in the males. Two ocelli are almost always pres- 
ent. The labial palpi are well developed, and in some species quite prom- 
inent. The maxillas are quite long and stout in most species. The thorax 
is heavy and stout. In the majority of the species the scales on the dorsal 
surface of the thorax are turned 
up more or less, forming tufts. 
The abdomen is conical and ex- 
tends beyond the anal angle of 
the hind wings when these are 
spread. Figure 410 shows the 
type of venation. 

The majority of the larvae 
are naked, of dull colors, and 
provided with five pairs of 
prolegs. As a rule they feed 
on the leaves of plants, but 
some are borers and some gnaw 
into fruits. Among them are 
some of the more important in- 
sects injurious to agriculture. 

The family Noctuidas has 
been divided into many sub- 
families. In the following 
pages the more important 

r ,1 1 • Fig. 410. — Wings of a noctuid, Agrolis ypstlon. 

of those represented m our 

fauna are briefly discussed, in order to show, as well as possible in a 
limited space, the variations in form included in this family, and to indi- 
cate the position of our more important species. 


The Deltoids 

There is a group of moths, the deltoids, which are placed at the foot 
of this family on account of their apparent relationship to the geometrids 
and to the pyralids. These. moths are usually of dull colors and of medium 
size. The name deltoids was suggested by the triangular outline of the 
wings when at rest, which is well represented by the Greek letter delta. 
When in this position the wings slope much less than with other noctuids, 
the attitude being more like that assumed by the geometrids. Two 
species of this group will serve as examples. 

The green clover-worm, Plathypena scabra. — This is a common del- 
toid. The usual food-plant of the larva is clover, but it occasionally 
defoliates peas, beans and lima beans. It is a slender green worm meas- 
uring when full-grown f of an inch in length and only about -^ of an inch 
in width in its widest part; it has a narrow subdorsal whitish line and a 
lateral one of the same color. When ready to 
transform it webs together several leaves and passes 
the pupa state in the nest thus made. The 
adult (Fig. 411) is a blackish -brown moth, with 
an irregular grayish shade on the outer half of the 
fore wings, and with very broad hind wings. The 
palpi, which are not well shown in the figure, are 
long, wide, and flattened; they project horizontally like a snout. 


bra. 


Fig. 411. — Plathypena sea- 


23 6 THE STUDY OF INSECTS 

The hop-vine deltoid, Hypena hiimuli. — This species is closely allied 
to the preceding and has often been confounded with it. The larva feeds 
on the leaves of hop, and is sometimes a serious pest. 

Thk Dark Noctuids 

There is a large group of noctuid moths many of which are decidedly 
dark in color and of which the black witch is the most striking example. 
The three following species are of this group. 


Fig. 412. — Erebus odora. 

The black witch, Erebus odora. — This is the most magnificent in 
size of all of the noctuids found in this country (Fig. 412). There is 
much variation in the depth of coloring. The individual figured is a 
female; in the male the fore wings are more pointed at the apex and the 
medium band is indistinct. It is a native of the West Indies; but it is 
believed that it breeds in the extreme southern portion of the United 
States. Isolated individuals are found in the North in late summer or 
autumn. These arc found as far north as Canada and west to Colorado, 

and even in California. These have doul >t- 
less flown north from their southern breed- 
ing places, possibly from Cuba or Mexico. 
The larva feeds on certain tropical le- 
guminous trees. 

The scalloped owlet,Scolidpteryx libatrix. 
— This moth is easily recognized by the 

Fig. 413. — Scohopleryx libatrix. ... i • r 

shape of its wings, the outer margins 01 
whichare deeply cut and scalloped (Pig. 413). The color of the fore wings is 
soft brownish-gray, slightly powdered with rust -red, and frosted with white 
along the costa. There is an irregular patch of rust-red reaching from 
the base to the middle of the wing, a single, while, transverse line before 
the middle, and a double one beyond the middle. The larva feeds on wil- 
low. This species is found in all parts of the United States and in Europe. 


LEPIDOPTERA 


237 


is an important insect 
insect (Fig. 414) is a 


The cotton-worm Alabama argillacea. — This 
pest in the cotton-growing states. The adult 
brownish moth with its fore wings crossed with 
wavy lines of darker color and marked with a 
bluish discal spot and two white dots as shown 
in the figure. This moth is found in the northern 
states and even in Canada in the latter part of 
the summer and in the autumn. But this oc- 
currence in the North is due to migrations from 
the South, as the insect can not survive the 
winter north of the tropics. The larva feeds on 
the foliage of cotton ; and as there are five or six generations in a year, the 
multiplication of individuals is very rapid, and the injury to the cotton great. 


Fig. 414. — Alabama argillacea. 


The Plusias 

There are nearly seventy species of moths in this group of which most 
of the typical members were formerly placed in the genus Plusia. 

In a large number of these the fore wings are marked with metallic- 
colored scales. The most common form of this marking is a silvery spot, 
shaped something like a 

comma, near the center o 

of the wing (Fig. 415). 
In some of the species 
the metallic markings 
cover a large portion of 
the fore wings, in others 
they are wanting. 

a 


Fig. 415. — Aulographa falcifera. 

The larvse have only 
three pairs of prolegs, 
the first two pairs being 
wanting; due to this 
fact they walk with a 
looping motion (Fig. 
416) resembling some- 
what that of the geometrids. 

The two following species have attracted attention by their injuries 
to cultivated plants; the celery looper, Autographa falcifera, and the 
cabbage looper, Autographa brassier. 


FlG. 416. — The cabbage-looper, Autographa brassica: a, 
male moth; b, egg; c, full-grown larva; d, pupa in cocoon. 
(After Howard and Chittenden.) 


The Catocalas 

There are many species in North America of these handsome moths 
but as a rule their caterpillars are not of much economic importance. m 


Lj I L I ■ R A R Y 


2 3 8 


THE STUDY OF INSECTS 


The most striking in appearance of the noctuids, if we except the 
black witch and one or two allied species, are the moths belonging to the 
genus Catocala. These moths are of large size, often expanding 3 inches 
or more. The fore wings are visually brown or gray, marked with wavy 
or zigzag lines. The ground-color of the hind wings is black; but in 
many species these wings are conspicuously banded with red, yellow, or 
white. This peculiarity has suggested the name underwings by which 
these insects are commonly known in England. The genus is a very 
large one; more than 100 species are now known from this country; 
and many of these are extremely variable, so that nearly twice that 


Fig. 417. — Catocala ilia. 

number of named forms are now recognized. The ilia underwing, Cat- 
ocala ilia, will serve as an example (Fig. 417). The larvae of the under- 
wings feed on the leaves of various forest trees. Many species infest 
oak and hickory. By careful search both the adults and larvae can be 
found resting on the trunks of these trees; but it needs sharp eyes to do 
it, as the colors of these insects are usually protective, the bright-colored 
hind wings of the moths being covered by the fore wings when the in- 
sect is at rest. 

In the same group with the underwings are the clover-looping owlets. — 
Among the more common noctuids that occur in our meadows and pas- 
tures, and that fly up before us as we walk through them, are two species 

belonging to the genus Ccenurgia. These 
may be called the clover-looping owlets; for 
the larvae feed on clover, and, as they have 
only three pairs of prolegs they walk in a 
looping manner. One of these species is 
Ccenurgia erechtea. This moth (Fig. 418) 
has dark or light drab-gray fore wings, 
which are marked by two large dark 
bands, as shown in the figure. These bands 
are always separate, distinct, and well de- 
fined towards the inner margin in the male; in the female the markings 
are much less distinct, the bands usually invisible. 

The other common species of this genus is Ccenurgia crassiiiscula. In 
this species the fore wings have either a distinct violaceous brown or a 
red or buffy shade, with the two large dark bands very variable, often 
shading into the ground-color on the outer edge or coalescing near the 
inner margin; all the markings are equally distinct in both sexes. 


Fig. 418. — Canur^ia erechtea. 


LEPIDOPTERA 


239 


Fig. 419. — Apalela morula. 


The Daggers 

Nearly one hundred species of this group belong to the typical genus 
Apatela, which is named Acronycta, by some authors. There are also 
many other forms in this group with the daggers. 

The fore wings of these moths are gen- 
erally light gray with dark spots, and in 
many species have a dagger-like mark 
near the anal angle. On this account 
they have received the name of daggers. 
The larvas exhibit much diversity in ap- 
pearance; those of some species are hairy 
like the larvae of arctiids, while others are 
nearly naked. 

The ochre dagger, Apatela morula. — 
This moth (Fig. 419) is pale gray with a yellowish tinge. Besides the black 
line forming part of the dagger near the anal angle of the fore wing, there 
is a similar black line near the base of the wing, and a third near the 
outer margin between veins Mi and M 2 . The larva feeds on elm and 
basswood. When full-grown it is mottled brown and greenish like bark; 
it is clothed with but few scattered hairs, and has a hump on the first, 

fourth, and eighth abdominal segments. 

The American dagger, Apatela americana. 
— This is a gray moth resembling in its 
general appearance the preceding, but with 
the black lines on the fore wings much less 
distinct. Its larva, however, is very different 
(Fig. 420). This larva looks like an arctiid, 
being densely clothed with yellow hairs. 
But these hairs are scattered over the sur- 
face of the body instead of growing from 
tubercles as with the larva? of arctiids. 
Along the sides of the body and at each 
end are a few scattered hairs that are 
longer than the general clothing, and there 
are two pairs of long black pencils borne 
by first and third abdominal segments, and 
a single pencil on the eighth abdominal seg- 
ment. When at rest the larva remains 
curled sidewise on a leaf, as shown in the 
figure. It feeds on maple, elm, and other 
forest trees. 

The stalk-borer, Papaipema nebris. — The larva is a borer in the 
stalks of potato, tomato, corn, dahlia, aster, and other plants. It is 
about 1 1 inches long and has five white stripes, one along the back and 
two along each side of the body. The side stripes fade out on the first 
segment of the abdomen. The moth has olive front wings expanding 
about 1 1 inches with three white spots on the inner third of each and a 
yellow crescent with three to five dots near the white crossline. The 
other common form, nitcla, has darker olive wings without any white 
dots and is slightly smaller. 

The brown-tailed diver, Bellura diffusa. — One of the most remark- 


Fig. 420. — Apatela americana, larva. 


240 


THE STUDY OF INSECTS 


able exceptions to what are usually the habits of members of this order is 
presented by the larva of this species. This larva is able to descend into 
water and remain there for a long time. 

The young larvae of this species have not been observed; doubtless 
they are leaf-miners. The older larvae live in the leaf-stalks of the pond- 
lily, a single larva in a leaf -stalk. The larva bores a hole from the upper 
side of the leaf into the petiole, which it tunnels in some instances to the 
depth of two feet or more below the surface of the water. This necessi- 
tates its remaining below the surface of the water while feeding. The 
tracheae of these larvae are unusually large, and we believe that they 
serve as reservoirs of air for the use of the insect while under water. 
The form of the hind end of the larva has also been modified, so as to fit 
it for the peculiar life of the insect. The last segment appears as if the 
dorsal half had been cut away; and in the dorsal part of the hind end of 
the next to the last segment, which, on account of the peculiar shape of 
the last segment, is free, there open a pair of spiracles much larger than 
those on the other segments. When not feeding the larva rests at the 
upper end of its burrow, with the segment bearing these large spiracles 
projecting from the water. 


The Armyworms 

Not all of the moths in this group have caterpillars that are gregarious 
and march over the ground in great numbers. Some are simply cut- 
worms with the habits of ordinary cutworms although most of these pests 
are found in the next group. 

The armyworm, Cirpkis unipuncta. — The armyworm is so called 
because it frequently appears in great numbers, and, after destroying the 

vegetation in the field where the eggs are 
laid, marches like an army to other fields. 
It is, however, a simple cutworm in most 
years. This insect occurs throughout the 
United States east of the Rocky Moun- 
tains and is present every year; but it 
attracts attention only when it appears 
in great numbers. The larva is from if 
to 2 inches long when full-grown and is 
striped with black, yellow, and green. 
The adult is of a dull brown color, 
marked in the center of each fore wing 
with a distinct white spot (Fig. 421). In 
seasons of serious outbreak of this pest 
it usually appears first in limited areas, 
in meadows or pastures. 

The green fruit-worms. — There are three species, Xyllna antennaria, 
X. laiicineria, and X. grotei, the larvae of which attack the fruit of the 
apple, pear, peach and plum. The caterpillars are yellowish-green or 
apple-green in color, about if inches long and much alike in appearance. 
They eat cavities in the sides of the fruit, which scar and deform the 
apples and pears especially. 

The moths of the three species are gray in color, very similar in ap- 
pearance and with a wing-expanse of about if inches. 


Fig. 421. — Cirphis unipuncta. 


LEPIDOPTERA 241 

The Cutworms 

This last group of the noctuids is a very large one containing more 
than 500 species. The larger number of our common cutworms belong 
to this group but there are other members of the group which have very 
different habits. 

Few pests are more annoying than the rascally little cutworms that 
nightly, in the spring, cut off our corn and other plants before they are 
fairly started. There are many species of these cutworms, but they are 
all the larvae of owlet-moths. In general their habits are as follows : the 
moths lay their eggs during midsummer. The larvae soon hatch, and feed 
upon the roots and tender shoots of herbaceous plants. At this time, as 
the larvae are small and their food is abundant, they are rarely observed. 
On the approach of cold weather they bury themselves in the ground and 
here pass the winter. In the spring they renew their attacks on vegeta- 
tion; but now, as they are larger and in cultivated fields the plants are 
smaller, their ravages quickly attract attention. It would not be so bad 
if they merely destroyed what they eat; but they have the unfortunate 
habit of cutting off the young plants at the surface of the ground, and 
thus destroy much more than they consume. They do their work at 
night, remaining concealed in the ground during the daytime. When 
full-grown they form oval chambers in the ground in which they pass the 
pupa state. The moths appear from the month of June to September. 

There are some exceptions to these generalizations: some species of 
cutworms ascend trees during the night and destroy the young buds; 
many pass through two generations in the course of a year; and a few 
pass the winter in the pupa state. 

The corn earworm or the cotton-boll worm, Heliothis obsoleta. — This 
is a widely distributed pest, the larva of which infests many different 
plants. It is often found feeding on the tips of ears of growing corn, 
especially of sugar-corn. And it is also one of the more important of the 
pests of cotton, ranking next to the boll-weevil and the cotton-worm; 
the larva bores into the pods or bolls of the cotton, destroying them. It 
frequently infests tomatoes, eating both the ripe and the green fruit. 
Occasionally it is found within the pods of peas and of beans, eating the 
immature seeds. It also bores into the buds, seed-pods, and flower-stalks 
of tobacco. The full-grown larva measures from 1 J to if inches in length. 
It varies greatly in color and markings. The pupa state is passed in the 
ground. The number of generations annually varies according to lati- 
tude; there is probably only one in Canada, but in the Gulf States there 
are from four to six. Like the larva, the moth is extremely variable in 
color and markings. 

Family Agaristid^e 
The Foresters 

This family seems to be growing smaller for some of the familiar 
genera formerly included in it have been removed to the Noctuidae. 
There are only sixteen species left in the family and but one of these is 
commonly known. 

The eight-spotted forester, Alypia octomaadata. — This species is of a 


2\2 


THE STUDY OF INSECTS 


deep velvety-black color. The front wings have two large sulphur- 
yellow spots; and the hind wings, two white spots. The tegulae are 

sulphur-yellow. 

The larva (Fig. 422) feeds 

''"| KP y^\^ X upon the leaves of grape and 

>v"' Av "* r ^P" Virginia-creeper, and some- 

J *" times occurs in such large 

numbers as to do serious 

FIG. 422. - Alypia oclomaculala, larva. injury. The gTOUnd-COlor of 

the larva is white, with eight black stripes on each segment, and a broader 
orange band, bounded by the two middle stripes; the orange bands are 
marked by black, conical, elevated spots. There are usually two broods 
each year, the moths appearing on the wing in May and August, the cat- 
erpillars in June and July, and in September. The pupa state is passed 
in an earthen cell in the ground. 

This species is found in the Atlantic States from Massachusetts to 
Texas. 


Family Arctiid^; 
The Tiger-moths and Footman-moths or Arctiids 

The Arctiidae includes stout-bodied moths, with moderately broad 
wings, which in the majority of cases are conspicuously striped _ or 
spotted, suggesting the popular name tiger-moths; some of the species, 
however, are unspotted. A large proportion of the species are exceedingly 
beautiful; this renders the family a favorite one with collectors. As a 
rule, when at rest, the wings are folded, roof -like upon the body. Most 
of the moths fly at night, and are attracted to lights. Those moths of 
this family which are white with black spots are known in this country 
as ermine moths. 

The larva? of the tiger-moths, except that of Utetheisa, are clothed 
with dense clusters of hairs. In fact a large proportion of our common 
hairv caterpillars are members of this family. In some species, certain 
of the clusters of hairs are much larger than the others, resembling in 
this respect the clothing of the tussock-moths. Most larvas of the arctiids 
feed upon herbaceous plants, and many species seem to have but little 
choice of food-plant; but certain common species feed upon leaves of 
forest trees. 

Haploa contigna. — This species 
(Fig. 423), is one of a number of very 
handsome moths belonging to the 
genus, Haploa. Some are snow- 
white or light yellow with the fore 
wings banded with brown. They 
vary greatly in their markings. 

The harlequin milkweed cater- . 
pillar, Euchatias cgle. — This larva is FlG - «■ - Ea *^ «•"*-■ 

the most common caterpillar found on milkweed. It is clothed with 
tufts of orange, black, and white; those at each end of the body are 
longer than the others and are arranged radiately (Fig. 424). When full 
grown the larva makes a felt-like cocoon composed largely of its hairs. 


LEPIDOPTERA 


243 


The adult has mouse-gray wings; the abdomen is yellow, with a row of 
black spots along the middle of the back. 

The tiger-moth, A panics is virgo. — This moth is probably one of the 


Fig. 424. — Euchcetias egle, larva. 


most typical and striking in appearance of all the tiger-moths. The front 
wings are velvety-black marked with cream-colored bands. The hind 
wings are reddish with black spots and the stout abdomen is also red with 
a row of black spots down the middle of the back and a similar row along 
each side (Fig. 425). There are other members of this genus similarly 
marked in striking and attractive patterns. 


Fig. 423. — Apantesis virgo. 


Fig. 426. — Estigmene acraa. 


The salt-marsh caterpillar, Estigmene acrcea. — The popular name 
of this insect was given to it nearly a century ago, and was suggested by 
the fact that the salt-marsh meadows near Boston, were overrun and laid 
waste by swarms of the larvae. But the name is misleading, as the species 
is widely distributed throughout the United States, and infests a great 
variety of grasses and garden crops. The moth (Fig. 426) is white, marked 
with yellow and black. There are many black dots on the wings, a row 
of black spots on the back of the abdomen, another row on the venter, 
and two rows on each side. The sexes differ greatly in the ground-color 
of the wings; in the female, this is white throughout; in the male, only 
the upper surface of the fore wings is white, the lower surface of the fore 
wings and the hind wings above and below being yellow. The number 


244 THE STUDY OF INSECTS 

and size of the black spots on the wings vary greatly. There are usually 
more sub-marginal spots on the hind wings than represented in our 
figure. 

The fall webworms, Hyphdntria cunea and Hyphdntria tcxtor. — A 
very common sight in autumn in the North and in midsummer in the 
South is large ugly webs enclosing branches of fruit or forest trees. These 
webs are especially common on apple and on ash; but the insects that 
make them infest more than one hundred kinds of trees. These webs 
differ from those made by the apple-tree tent-caterpillar in being much 
lighter in texture and in being extended over all of the leaves fed upon 
by the colony; and they are also made later in the year. Each web is 
the residence of a colony of larvae which have hatched from a cluster of 
eggs laid on a leaf by the parent moth. 

In the North the adults are all snow-white in color and there is only a 
single generation annually. This form is the Hyphantria textor of those 
who believe that there are two species. 

In the South, some of the moths have the fore wings thickly studded 
with dark brown points, some are pure white, and every gradation exists 
between these two types. Of this southern form there are two generations 
annually. This form is known as Hyphantria cunea. 

Both forms winter in the pupa state. 

The Isabella tiger-moth, Isia Isabella. — " Hurrying along like a 
caterpillar in the fall " is a common saying among country people in New 
England, and probably had its origin in observations made upon the 
larva of the Isabella tiger-moth. This is the evenly clipped, furry cater- 
pillar reddish-brown in the middle and black at either end, which is seen 

so commonly in the autumn and early 
spring (Fig. 427). The extent of the 
black color varies in different individ- 
, uals; rarely, the body is all brown. 
In the spring after feeding for a time 

Fig. 427- -IsiaisabeUa, larva. thg lafya makeg & b lackish-brown CO- 

coon composed largely of its hair. The adult is of a dull grayish tawny- 
yellow, with a few black dots on the wings, and frequently with the hinder 
pair tinged with orange-red. On the middle of the back of the abdomen 
there is a row of about six black dots, and on each side of the body a simi- 
lar row of dots. 

The yellow-bear, Diacrisia virglnica. — The larva of this species is 
one of the most common hairy caterpillars found feeding on herbaceous 
plants. The long yellow hairs with which the body is clothed are uneven 
in length, some scattered ones being twice as long as the others. The 
long hairs are nowhere gathered into pencils as with the tussock-cater- 
pillars. This larva varies greatly in color. The body is most often of a 
pale yellow or straw color, with a black, more or less interrupted, longi- 
tudinal line along each side, and a more or less distinct transverse line of 
the same color between each of the segments. Sometimes the hairs are 
foxy-red or light brown, and the body brownish or even dark brown. 
The head and the ends of the feet and fore legs are yellowish, and the 
venter is dusky. The larva feeds on almost any plant especially on the 
silk of corn. The cocoon is light, and is composed almost entirely of the 
hairs of the caterpillar. This insect passes the winter in the pupa state: 
and it is probable that there are usually two or more broods each year; 


LEPIDOPTERA 


245 


but these are not well marked. The moth (Fig. 428) is snowy-white, 
with the wings marked by a few black dots; these vary in number, but 
there are rarelymore than three on eitherwing. 
There is a row of black spots on the back of I 
the abdomen, and another on each side, and be- j 
tween these a longitudinal deep yellow stripe. 
The hickory tiger-moth, Halysidota cdrycs. 
— One of the most abundant of caterpillars in 
the Atlantic States and westward during the 
months of August and September is one clothed 
with dense tufts of finely barbed white hairs (Fig. 429) ; there is a ridge or 
crest of black hairs on the middle of the back of the abdominal segments, a 
few long white hairs projecting over the head from the thorax, and others 
projecting back from the last segment ; there are also two pairs of pencils of 
black hairs, one on the first and one on the seventh abdominal segment, 
and a similar pair of pencils of white hairs on the eighth abdominal seg- 


Fig. 428. — Diacrisia virginica. 


Fig. 42g. — Halysidota caryw, larva. 


ment. This larva feeds oh hickory, butternut, and other forest-trees. 
Its grayish cocoons, composed almost entirely of the hair of the larva, are 
often found under stones, fences, and other similar places. The fore 
wings of the adult (Fig. 430) are dark brown spotted with white. 


Fig. 430. — Halysidota caryce. 


Fig. 431. — Hypoprepia miniata. 


The striped footman, Hypoprepia miniata. -■ — This beautiful moth is 
of a deep scarlet color, with three broad lead-colored stripes on the front 
wings. Two of the stripes extend the entire length of the wings; while 
the third is between these and extends from the end of the discal cell to 
the outer margin (Fig. 431). The outer half of the hind wings is also 
slate-colored. Vein M 2 of the fore wings is present; but Vein M 2 of the 


246 THE STUDY OF INSECTS 

hind wings is wanting. The larva feeds upon lichens, and may be found 
under loose stones or on the trunks of trees. It is dusky, and thinly 
covered with stiff, sharp, and barbed black bristles, which grow singly 
from small warts. The cocoon is thin and silky. 

The banded footman, Illice unifascidta. — This little beauty occurs in 
the Atlantic States from New York to Texas. The fore wings are lead- 
colored, and crossed by a yellow band, which extends also along the inner 
margin to the base of "the wings. The hind wings are pink except the apex, 
which is lead-colored. There is much variation in the width of the yellow 
band. 

There. are several closely allied species which are difficult to distin- 
guish from this one. 

Family Citheroniid^; 
The Royal-moths 

The royal-moths are stout-bodied and hairy, with sunken heads and 
strong wings. The species are of medium or large size, some of them 
being nearly as large as the largest of our moths. In these moths the 
frenulum is lost and its place is taken by a greatly expanded humeral angle 
of the hind wing (Fig. 432, p. 285), which, projecting under the fore wing, 
insures the acting together of the two in flight without the aid of a 
frenulum. The antenna; of the males are broadly pectinated, but for only 
little more than half their length. The palpi and the maxilla? are very 
small. 

The larvae are armed with horns or spines, of which those on the sec- 
ond thoracic segment, and sometimes also those on the third, are long 
and curved. These caterpillars eat the leaves of forest trees, and go into 
the ground to transform, which they do without making cocoons. The 
rings of the pupa bear little notched" ridges, the teeth of which, together 
with some strong prickles at the hinder end of the body, assist it in forc- 
ing itsway upwards out of the earth. 

This is a small family; it is not represented in Europe, and less than 
twenty species are known to occur in this country. The more common 
ones are the following. 

The regal-moth Citheronia regdlis. — This is the largest and most mag- 
nificent of the royal-moths (Fig. 433). The fore wings are olive-colored, 
spotted with yellow, and with the veins heavily bordered with red scales. 
The hind wings are orange-red, spotted with yellow, and with a more or less 
distinctly marked olive band outside the middle. The wings expand from 
4 to 6 inches. 

When fully grown the larva measures from 4 to 5 inches in length. 
It is our largest caterpillar, and can be readily recognized by the very 
long spiny bonis with which it is armed. Those of the mesothorax and 
metathorax are much longer than the others. Of these there are four on 
each segment; the intermediate ones measure about f of an inch in 
length. This larva feeds on various trees and shrubs. It is known in some 
regions as the hickory homed devil. 

The imperial -moth, Basilona iuipcridlis. — This moth rivals the 
preceding species in size, expanding from 4 to $] inches. It is sulphur- 
yellow, banded and speckled with purplish-brown. The full-grown larva 


LEPIDOPTERA 


247 


248 


THE STUDY OF INSECTS 


(Fig. 434) measures from 3 to 4 inches in length. It is thinly clothed 
with long hairs, and bears prominent spiny horns on the second and third 
thoracic segments. Jn the early larval stages these thoracic horns are 
very long and spiny, resembling those of the larva of the regal-moth. 


Fig. 434. — Basilona imperialis, larva 

The larva feeds on hickory, pine, oak, butternut, and other forest trees. 

The two-colored royal -moth, Adeloccphala blcolor. — In this species 
the upper side of the fore wings and the underside of the hind wings are 
yellowish-brown, speckled with black. The underside of the fore wings 
and the upper side of the hind wings are to a considerable extent pink. 
There is usually a dark discal spot on the fore wings, upon which, es- 
pecially in the males, there may be two white dots. This species is more 
common in the South than in the North. The expanse of wings in the 
male is 2 inches; in the female, 2§ inches. The larva feeds on the leaves 
of the honey-locust and of the Kentucky coffee-tree. 

The rosy-striped oak-worm, Anisota virginiensis. ■ — The wings of the 
female are purplish-red, blended with ochre-yellow; they are very thinly 


Fig. 435. — Anisota virginiensis, female 


Fig. 436. — Anisota virginiensis, 
male. 


scaled, and consequently almost transparent; and are not speckled with 
small dark spots (Fig. 435). The wings of the male are purplish-brown, 
with a large transparent space on the middle (Fig. 436). The larva is of 
an obscure gray or greenish color, with dull brownish-yellow or rosy 
stripes, and with its skin rough with small white warts. There is a row of 
short spines on each segment, and two long spines on the mesothorax. 

The orange-striped oak-worm, Anisota senatoria. — The wings of the 
female are more thickly scaled than in the preceding species and are 
sprinkled with numerous blackish dots; in other respects the two are 
quite similar in coloring. The male differs from that of A. virginiensis in 


LEPIDOPTERA 249 

lacking the large transparent space on the middle of the wings. The 
larva is black, with four orange-yellow stripes on the back and two along 
each side; its spines are similar to those of the preceding species. 

The spiny oak-worm, Anisota stigma. — The female closely resembles 
that of A. senatorial and as both species are variable it is sometimes 
difficult to determine to which a given specimen belongs. In A. stigma 
the wings are rather darker and have a greater number of blackish spots, 
and the hind wings are furnished with a middle band which is heavier 
and more distinct than in A. senatoria. The male differs from that of 
the other two species in quite closely resembling the female in coloring, 
and in having the wings speckled. The larva differs from the other 
species of Anisota in having long spines on the dorsal aspect of the third 
thoracic and each abdominal segment in addition to the much longer 
spines on the mesothorax. It is of a bright tawny or orange color, with a 
dusky stripe along its back and dusky bands along its sides. 

The rosy Anisota, Anisota rubicunda. — The wings of this moth 
(Fig. 437) are pale yellow, banded with 
rose-color. The distribution of the color 
varies greatly in different specimens. 
In some the pink of the fore wings pre- 
dominates, the yellow being reduced to 
a broad discal band, while in one variety 
the ground-color is yellowish-white 
and the pink is reduced to a shade at 
the base and a narrow stripe outside 
the middle. The hind wings may be 
entirely yellow, or may have a pink 
band outside the middle. The expanse of wings in the male is about 1^ 
inches; in the female about 2 inches. 

The larva of this species is known as the green-striped maple-worm, 
and is sometimes a serious pest on soft-maple shade-trees. It measures 
when full grown about i\ inches. It is pale yellowish-green, striped 
above with eight very light, yellowish-green lines, alternating with seven 
of a darker green, inclining' to black. There are two prominent horns on 
the second thoracic segment, and two rows of spines on each side of the 
body, one above and one below the spiracles. And on the eighth and 
ninth abdominal segments there are four prominent dorsal spines. The 
species is one- or two-brooded, and winters in the pupa state. 


Family Saturniid^e 

The Giant Silk-worms 

The large size' of members of this family and the ease with which 
cocoons of some of the species can be collected render them well known 
to every beginner in the study of entomology. They are stout-bodied, 
hairy moths with more or less sunken heads and strong wide wings. The 
palpi are small, and the maxillse but little developed, often vestigial. 
The sexes of these moths can be distinguished by the fact that the an- 
tennas of the males are more broadly pectinated than are those of the 
females. 


Fig. 437. — Anisota rubicunda. 


250 


THE STUDY OF INSECTS 


The family includes our largest lepidopterous insects and all of our 
species are above medium size. 

The wings are often furnished with transparent, window-like spots. 
The frenulum is completely lost. The humeral angle of the hind wings is 
largely developed, and is usually strengthened by a deep furrow. 

The larvae of most of our species live exposed on the leaves of trees 
and shrubs; but some of them, as the New Mexico range-caterpillar, feed 
on grass. They are more or less armed with tubercles and spines and are 
very conspicuous on account of their large size. Most of them transform 
within silken cocoons, which are usually very dense, and in some cases 
have been utilized by man. These cocoons are often attached to trees 
and shrubs, and are sometimes inclosed in a leaf. They can be easily 
collected during the winter months, and the adults bred from them. The 
larvae of some members of the family as Hemileuca maia enter the ground 
to transform. 

The maia-moth, Hemileuca maia. — 

The genus Hemileuca is represented in 

our fauna by eleven species, but only 

two of these are found in the East. In 

maia (Fig. 438) the wings are thinly 

scaled, sometimes semi-transparent ; 

they are black with a common white 

band near their middle; and the discal 

veins are usually white and broadly 

bordered with black. There are great 

variations in the width of the white 

ig. 438.— cmiewa band on the wings. The larva feeds on 

the leaves of oak; it is brownish-black, with a lateral yellow stripe; and 

is armed on each segment with large, branching, venomous spines. The 

larva almost always enters the ground to transform. 

The New Mexico range-caterpillar, Hemileuca olivice. — Of the ten 
western species of Hemileuca this is doubtless of the greatest economic 
importance It is a grass-feeding species, which has been very destruc- 
tive in certain sections of the cattle-range in northeastern New Mexico. 
It was estimated that in 1809 the total infested area was at least 15,000 
square miles, and that there were an average of 10 caterpillars to the 
square rod over this region. For a full account see U. S. Dept. Agr. 
Bull. No. 85, Part V. 

The io-moth, Au- 
tomeris io. — This is a 
common species in the 
East. The female is 
represented by Figure 
439. In this sex the 
ground-color of the fore 
wings is purplish-red. 
The male differs from 
the female in being 
somewhat smaller and 
of a deeper yellow color, 
but otherwise it resem- 
bles the female. fig. 439.— Automerk io. 


LEPIDOPTERA 


251 


Fig. 440. — Automeris io, larva. 


The larva is one that the student should learn to recognize in order 
that he may avoid handling it; for it is armed with spines the prick of 
which is venomous (Fig. 440). The same is true of the larva of the maia- 
moth, but that is much less common. 
The larva of the io-moth is green, 
with a broad brown or reddish stripe, 
edged below with white, on each 
side of the abdomen. The spines are 
tipped with black. This larva feeds 
on various trees and shrubs. 

The polyphemus-moth, Telea polyphemus. — This is a yellowish or 
brownish moth with a window-like spot in each wing. There is a gray 
band on the costal margin of the fore wings; and near the outer margin 
of both pairs of wings there is a dusky band, edged without with pink; 
the fore wings are crossed by a broken dusky or reddish line near the 
base, edged within with white or pink. The transparent spot on each 
wing is divided by the discal vein, and encircled by yellow and black 
rings. On the hind wings the black surrounding the transparent spot is 
much widened, especially toward the base of the wing, and is sprinkled 
with blue scales. The wings expand from 5 to 6 inches. 


Fig. 441. — Telea polyphemus, larva. 


The larva (Fig. 441) feeds on oak, butternut, basswood, elm, maple, 
apple, plum, and other trees. When full-grown it measures 3 inches or 
more in length. It is of a light green color with an oblique yellow line on 
each side of each abdominal segment except the first and last; the last 
segment is bordered by a purplish-brown V-shaped mark. The tubercles 


252 


THE STUDY OF INSECTS 


. 


on the body are small, of a reddish color with metallic reflections. The 

cocoon (Fig. 442) is dense and usually 
enclosed in a leaf; it can be uti- 
lized for the manufacture of silk. 
When the adult is ready to emerge, 
it excretes a fluid which softens the 
cocoon at one end, and breaking 
the threads by means of a pair of 
stout spines, one on each side of the 
thorax at the base of the fore wings, 
it makes its exit through a large 
round hole. 
The Luna-moth, Tropcea luna. — This magnificent moth (Fig. 443) is 

a great favorite with amateur collectors. Its wings are of a delicate light 

green color, with a purple-brown band on the costa of the fore wings; 

there is an eye-like spot with a transparent center on the discal vein of 


Fig. 442. — Cocoon of Telea polyphemus. 


Fig. 443. — Tropcra luna. 


each wing; and the anal angle of the hind wings is greatly prolonged. 
The larva feeds on the leaves of walnut, hickory, and other forest-trees. 
It measures when full-grown about 3 inches in length. It is pale bluish 
green with a pearl-colored head. It has a pale yellow stripe along each 


LEPIDOPTERA 253 

side of the body, and a transverse yellow line on the back between each 
two abdominal segments. The cocoon resembles that of the preceding 
species in form, but is very thin, containing but little silk. 

The promethea-moth, Callosamia promethea. — This is the most 


Fig. 444. — Callosamia promethea, female. 

common of the giant silk- worms. The wings of the female (Fig. 444) are 
light reddish-brown; the transverse line crossing the middle of the wings 
is whitish, bordered within with black; the outer margin of the wings is 
clay-colored, and each wing bears an angular discal spot. The discal 
spots vary in size and distinctness in different specimens. The male 
differs so greatly from the female that it is liable to be mistaken for a 
distinct species. It is blackish, with the transverse lines very faint, and 
with the discal spots wanting or very faintly indicated. The fore wings 
also differ markedly in shape from those of the female, the apex being 
much more distinctly sickle-shaped. The males fly by day. The larva 
when full-grown measures 2 inches or more in length. It is of a clear 
pale bluish-green color; the legs and anal shield are yellowish; and the 
body is armed with longitudinal rows of tubercles. The tubercles are 
black, polished, wart-like elevations, excepting two each on the second 
and third thoracic segments, which are larger and rich coral-red, and one 
similar in size to these but of a yellow color on the eighth abdominal seg- 
ment. This larva feeds on the leaves of a large proportion of our com- 
mon fruit and forest- trees; but we have found it more frequently on 
wild cherry, lilac, tulip-tree, ash, and sassafras than on others. The co- 
coons can be easily collected during the winter from these trees. This is 
the best way to obtain fresh specimens of the moths, which will emerge 
from the cocoons in the spring or early summer. The cocoon (Fig. 445) 
is interesting in structure. It is greatly elongated and is enclosed in a 
leaf, the petiole of which is securely fastened to the branch by a band of 
silk extending from the cocoon; thus the leaf and enclosed cocoon hang 
upon the tree throughout the winter. At the upper end of the cocoon 
there is a conical valve-like arrangement which allows the adult to emerge 
without the necessity of making a hole through the cocoon. This structure 
is characteristic of the cocoons of the moths of this and the following genus. 


254 


THE STUDY OF INSECTS 


The angulif era-moth, Callosamia angullfera. — This is a somewhat 
rare insect which closely resembles the promethea-moth. Specimens of 

it are usually a little larger than those of C. 
promethea, and the transverse line and discal 
spots are more angular. The most import- 
ant differences, however, are presented by 
the male, which quite closely resembles the 
female of the promethea-moth in color and 
markings, and thus differs decidedly from 
the male of that species. The male of this 
species is nocturnal, differing in this respect 
from C. promethea. 

The larva feeds on the leaves of the tulip- 
tree and of magnolia. It makes its cocoon 
within a leaf or it crawls down the trunk of 
the tree and spins its cocoon in the grass or 
fastens it to some object on the ground. 
The cocoon usually has no stem and when 
made in a leaf falls to the ground in it 
when the leaf falls. 

The cecropia-moth, Samia cecropia. — 
This is the largest of our giant silk-worms, 
the wings of the adult expanding from 5 to 
6f inches. The ground color of the wings is 
a grizzled dusky brown, especially on the 
central area. The wings are crossed beyond 
the middle by a white band, which is broadly 
margined without with red, and there is a red 
spot near the apex of the fore wing just 
outside of a zigzag line. Each wing bears near 
its center a crescent-shaped white spot 
bordered with red. The outer margin of 
the wings is clay-colored. The larva is known 
to feed on at least fifty species of plants, 
fig. 445- — Callosamia promethea, co- including apple, plum, and the more com- 
mon forest-trees. When full-grown it meas- 
ures from 3 to 4 inches in length and is dull bluish-green in color. The body is 
armed with six rows of tubercles, extending nearly its entire length, and there 


Fig. 446. — Samia cecropia, cocoon. 

is an additional short row on each side of the ventral aspect of the first 
five segments following the head. The tubercles on the second and third 


LEPIDOPTERA 


255 


thoracic segments are larger than the others, and are coral-red. The 
other dorsal tubercles are yellow, excepting those of the first thoracic and 
last abdominal segments, which with the lateral tubercles are blue; all 
are armed with black bristles. The cocoon is represented by Figure 446. 
The ailanthus-worm, Philosamia walkeri. — This is an Asiatic species 
which has been introduced into this country. It has become a pest in 
the vicinity of New York City, where it infests the Ailanthus shade-trees. 
The moth differs from all our native species of this family in having rows 
of tufts of white hairs on the abdomen. Its cocoon resembles that of the 
promethea-moth. The specific identity of this species is in doubt. 


Family Bombycid^e 

The Silk-worm 

The family Bombycidse is not represented in our fauna; but a single 
species, the silk-worm, is frequently bred in this country, and is usually 
present in collections of Lepidoptera. 

The silk-worm, Bombyx 
won. — The moth (Fig. 447) 
is of a cream-color with 
two or three more or less 
distinct brownish lines 
across the fore wings and 
sometimes a faint double 
bar at the end of the discal 
cell. The head is small; 
the antennas are pectinated 
broadly in both sexes; and 
the ocelli, palpi, and 
maxillae are wanting. A 
striking feature of the 
venation of the wings (Fig. 
448) is the obvious pres- 
ence of the base of vein Ri 
in the hind wings. 


2dA 

Fig. 448. — Wings of Bombyx mori. Fig. 447. — Bombyx mori. 

The usual food of the silk-worms is the leaf of the mulberry. Our 


2s6 


THE STUDY OF INSECTS 


native species, however, are not suitable. The species that are most 
used are the white mulberry (Morus alba) of which there are several 
varieties, and the black mulberry (Morus nigra); the former is the 
better. The leaves of osage orange (Madura aurantiaca) have also been 
used as silk-worm food to a considerable extent. In case silk-worms 
hatch in the spring before cither mulberry or osage-orange leaves can be 
obtained, they may be quite successfully fed, for a few days, upon let- 
tuce-leaves. 

The newly-hatched larva is black or dark-gray, and is covered with 
long stiff hairs, which spring from pale-colored tubercles. The hairs and 
tubercles arc not noticeable after the first molt, and the worm becomes 
lighter and lighter, until in the last larval period it is of a cream-white 
color. There is a prominent tubercle on the back of the eighth abdomi- 
nal segment, resembling those borne by certain larvae of the Sphingidae. 

There are many special treatises on this insect, some of which should 
be consulted by any one intending to raise silk-worms. 


Family Lasiocampid^e 

The Lasiocampids 

The best-known representatives of this family are the tent-caterpillars 
and the lappet-caterpillars. The adults are stout-bodied, hairy moths of 


Fig. 449. — Malacosoma amerkana, cg?s, tent, larva, cocoons, and adult. 

medium size. The antennae are pectinated in both sexes, and from one- 
fourth to one-half as long as the front wings; the teeth of the antennae 
of the male are usually much longer than those of the female. The ocelli 


LEPIDOPTERA 257 

and the maxillae are wanting; and the palpi are usually short and woolly. 
But the most distinct characteristic is found in the wings. The frenulum 
is wanting, there being instead, as in the giant silkworm moths a largely 
expanded humeral angle of the hind wings. 

The larvae of the Lasiocampidae feed upon the foliage of trees, and are 
frequently very destructive. 

Less than thirty North American species are known. 

The apple-tree tent-caterpillar, Malacosoma americdna. — Th'is insect 
builds large webs in apple and wild cherry trees in early spring. Figure 
349 represents its transformations. The moth is dull reddish-brown, 
with two transverse whitish or pale yellowish lines on the fore wing. The 
figure represents a male; the female is somewhat larger. These moths 
appear early in the summer. The eggs are soon laid, each female laying 
all her eggs in a single ring-like cluster about a twig; and here they re- 
main unhatched for about nine months. This cluster is covered with a 
substance which protects it during the winter. The eggs hatch in early 
spring, at the time or just before the leaves appear. The larvae that 
hatch early feed upon the unopened buds till the leaves expand. The 
larvae are social, the entire brood that hatch from a cluster of eggs keep- 
ing together and building a tent in which they live when not feeding. 
The larvae leave the nest daily in order to feed ; and spin a silken 
thread wherever they go. The larvae become full-grown early in June; 
one of them is represented on a partially-eaten leaf in the figure. When 
ready to transform they leave the trees and make their cocoons in some 
sheltered place. These cocoons are quite peculiar in appearance, having a 
yellowish-white powder mixed with the silk. The pupa state lasts about 
three weeks. 

Another species of the genus Malacosoma found in the East is the 
so-called forest tent-caterpillar, Malacosoma dis stria. The range of this 
species extends throughout the United States and Canada. It differs 
from the preceding species in that the larvae do not construct a true tent. 
It feeds on the leaves of many forest and fruit-trees, but maple is its 
favorite food-plant. In other respects its life history is quite similar to 
that of the apple-tree tent-caterpillar. The moth differs from M. amer- 
icana in having the oblique lines on the wings dark instead of light; the 
larva differs in having a row of spots along the back instead of a con- 
tinuous narrow line; the egg-masses differ in ending squarely instead of 
being rounded at each end; and the cocoon is more fragile, with less 
powder, and distinctly double. 

The Great Basin tent-caterpillar, Malacosoma fragilis. — This species 
is found throughout the northern portions of the Great Basin, extending 
from the Rocky Mountains to the Cascades and Sierra Nevadas, and has 
been found in California. It feeds on Ccanothus 
and many other wild shrubs. 

The California tent-caterpillar, Malacosoma 
californica, feeds normally on oak but also at- 
tacks fruit-trees. The caterpillars are orange- 
colored and about 1 inch long. 

The velleda lappet, Tolype velleda. — The 
bodv of the moth is milk-white, with a large 
blackish spot on the middle of its back (Fig. 450) . FlG ' 4S °- _ Tolype velleda - 

That part of this spot which is on the thorax is composed of erect scales, 


258 THE STUDY OF INSECTS 

the caudal part of recumbent hairs. The wings are dusky gray, crossed 
by white lines as shown in the figure. The figure represents the male; 
the female is much larger. The moths are found in August and Sep- 
tember. The larva feeds upon the leaves of apple, poplar, and syringa. 
lis body is bluish-gray, with many faint longitudinal lines; and across 
the back of the last thoracic segment there is a narrow velvety-black 
band. The larva reaches maturity during July. The cocoon is brownish- 
gray, and is usually attached to one of the 
branches of the tree on which the larva has fed. 

The American lappet, Epicnaptera americajta. 
— This species is found from the Atlantic to the 
Pacific. It is somewhat variable, and the different 
varieties were formerly regarded as distinct spe- 
Fig. 451. — Epicnaptera ameri- cies. The moth (Fig. 45 1 ) is reddish-brow T n, 
with the inner angle of the front wings and the 
costal margin of the hind wings deeply notched. Beyond the middle 
of each wing there is a pale band edged with zigzag, dark brown lines. 
The larva lives upon apple, cherry, oak, birch, maple, and ash. When 
full-grown it measures 2§ inches in length and | inch in breadth. The 
upper side is slate-gray, mottled with black, with two transverse scarlet 
bands, one on the second and one on the third thoracic segments. There 
is a black spot on each end and in the middle of each of these bands. 
The larva is found during July and August. It is said that the cocoons 
are attached to limbs like those of Tolype; but the larvae of this species 
that we have bred made their cocoons between leaves, or in the folds of 
the muslin bag enclosing the limb upon which they were feeding. The 
species passes the winter in the pupa state; and the moth appears in 
June, when it lays its eggs upon the leaves of the trees it infests. 

THE SKIPPERS 

The skippers are so-called on account of their peculiar mode of flight. 
They fly in the daytime and dart suddenly from place to place. When 
at rest most species hold the wings erect in a vertical position like butter- 
flies; in many the fore wings are thus held while the hind wings are 
extended horizontally ; and a few extend both pairs of wings horizontally. 
The head is wide; the antennae are widely separated; they are thread- 
like, and enlarged toward the tip; and in most cases the extreme tip is 
pointed and recurved, forming a hook. The abdomen is usually stout, 
resembling that of a moth rather than that of a butterfly. 

Family Megathymid^e 

The Giant Skippers 

This family includes a small number of large skippers, which are 
found in the South and far West. In the adult insect the head is of 
moderate size, the width, including the eyes, being much less than that 
of the metathorax. The club of the -antenna? is large; and, although the 
tip is turned slightly to one side, it is neither drawn out to a point nor 
recurved. The body is very robust. These insects fly in the daytime 
and with a rapid, darting, flight. When at rest they fold their wings in a 
vertical position. 


LEPIDOPTERA 259 

So far as is known the larvae in the later stages of their growth are 
borers in the stems and roots of various species of Yucca and Agave and 
the larvae spin silken tubes between the young and tender shoots of these 
plants. 

Megathymus streckeri (Fig. 452) will serve as an example of the giant 
skippers. The specimen figured is a female of the variety known as 
texana. 


Fig. 452. — Megathymus streckeri. 

A much better known species is the yucca-borer, Megathymus yuccas. — 
The female of this species differs from that of the preceding in having 
much darker wings, all of the spots being smaller, and in having only 
one or two white spots on the lower surface of the hind wings. The male 
lacks the erect hairs on the hind wings. The larva bores in the stem and 
root of the Yucca or Spanish bayonet. It differs greatly in appearance 
from the larvae of the Hesperiidae, having a small head. This species is 
widely distributed through the southern part of our country. 

Family Hesperiid,e 
The Common Skippers 

This family includes all of our skippers except the very small number 
that belong to the preceding family, the giant skippers. 

The larvae of the common skippers present a very characteristic ap- 
pearance, having large heads and strongly constricted necks (Fig. 453). 
They usually live concealed in a folded leaf or in a nest made of several 
leaves fastened together. The pupae are rounded, not angular, resembling 
those of moths more than those of butterflies. The pupa state is passed 
in a slight cocoon, which is generally composed of leaves fastened to- 
gether with silk, and thinly lined with the same substance. 

One group in this family is known as the skippers with a costal fold. 
The males of many of these forms have a fold in the fore wing near the 
costal margin which forms a long slit-like pocket containing a sort of 
silky down. This structure forms a scent-organ, and the pocket is known 
as the costal fold. It is not present in all of the species. 

These skippers are of both moderate and rather large size. Most are 
dark brown marked with white or translucent angular spots. The an- 
tennae usually have a long club which is bent at a considerable distance 
from the tip. 


>6o 


THE STUDY OF INSECTS 


The silver-spotted skipper, Epargyreus tttyrus. — This is one of the 
largest of our common skippers, having a wing-expanse of nearly or quite 2 
inches. It is dark chocolate-brown, 
with a row of yellowish spots ex- 
tending across the fore wing and 
with a large silvery-white spot on 
the lower si< le of the hind wing (Fig. 
454). It is found in nearly the whole 


Fig. 453. — Epargyreus tityrus, larva. 


Fig. 454. — Epargyreus tityrus; under surface at 
left. (From Scudder.) 


United States and in southern Canada. The larva (Fig. 453) feeds upon 
various papilionaceous plants. It is common on locust. It makes a nest, 
within which it remains concealed, by fastening together, with silk, the 


Fig. 455. — Nest of larva of Epargyreus tityrus. 


leaflets of a compound leaf (Fig. 455). This is one of the very few skip- 
pers that winter in the pupa state; most species winter as larvae, either 
partly grown or in their cocoons. 

The bean leaf-roller, Goniilrus prdteus. — This skipper by the shape 
of its wings reminds one of a swallow-tail butterfly, the hind wings being 
furnished with long tails. It expands about if inches and the greatest 
length of the hind wings is about \\ inches. The wings are very dark 
chocolate-brown. The front wings contain several silvery-white spots; 
and the body and base of the wings bear metallic-green hairs. The larvae 
feed upon both Leguminosae and Cruciferae. In the South it is sometimes 
a pest in gardens, cutting and rolling the leaves of beans, turnips, and 
cabbage, and feeding within the rolls thus formed. It is found on the 
Atlantic border from New York southward into Mexico. 

The northern cloudy- wing, Thorybes pylades. — This is a common 
skipper with dark brown wings. The fore wings are flecked with tiny 
white spots while the hind wings are crossed beneath by two rather 
narrow, parallel, inconspicuous, dark bands. The species is found in nearly 
all parts of the United States. The larva commonly feeds on clover. 

The genus Hesperia includes a considerable number of small skippers, 
which are easily recognized by their checkered markings of white upon a 
dark brown ground. In this genus the white spots are unusually large, so 


LEPIDOPTERA 261 

large in some cases that they occupy the greater part of the wing. One 
of the more common species is the variegated tessellate, Hesperia tessel- 
lata. This is distributed from the Atlantic to the Pacific and is the only 
one common in the Eastern United States. In this species more than 
one-half of the outer two-thirds of both fore and hind wings is white. 

A second group of skippers in this family is known as the skippers 
with a brand. It includes the greater number of our small skippers as 
well as some which are of fairly large size. All of our tawny skippers 
together with some black and dark brown species belong here. The anten- 
nae usually have a stout club with a short recurved 
tip, the latter sometimes wanting. 

In the majority of our species the males can be rec- 
ognized at a glance by a conspicuous patch crossing 
the disk of the fore wings, which usually appears to the 
naked eye like a scorched, oblique streak, and which 
on this account is termed the brand (Fig. 456). The 
brand is a complicated organ, composed of tubular ? IG - 456. — Atrytone con- 
scales, the androconia, that are the outlets of scent- s - lcua " 
glands, and of other scales of various shapes; in some species the 
brand is wanting. 

This subfamily is an exceedingly difficult one to study. One hundred 
and twenty-five species have been described from America north of 
Mexico; and in many cases the differences between allied species are not 
well marked. The following two are named merely as examples. The 
first one is easily recognized. 

The least skipper, Ancyloxyipha niimitor. — ■ This skipper is the smallest 
of our common species, and is also remarkable for lacking the recurved 
hook at the tip of the antennae. The wings are tawny, broadly mar- 
gined with dark brown. In some specimens the fore wings are almost 
entirely brown. The larger individuals expand about 1 inch. The larva 
feeds upon grass in damp places. 

The black-dash, Atrytone conspicua. — The male of this species is rep- 
resented by Figure 456. It is blackish-brown with considerable yellow on 
the basal half of the fore -wings. The brand is velvety black. This spe- 
cies is distributed from Massachusetts to Nebraska. 

THE BUTTERFLIES 

The butterflies differ from moths in that they have clubbed antennae, 
fly only in the daytime (except some species in the tropics), hold the 
wings erect above the back when at rest, and have no frenulum. Some 
moths present one or more of these characteristics, but no moth presents 
all of them. Butterflies can be distinguished from skippers by the vena- 
tion of the front wings. 

Among the many works treating of American butterflies the two 
following are especially useful for the classification of our species, each 
of these works is illustrated by many full-page plates representing the 
insects in their natural colors: " How to Know the Butterflies, A Manual 
of the Butterflies of the Eastern United States " by J. H. and A. B. Corn- 
stock, and " The Butterfly Book, A Popular Guide to a Knowledge of 
the Butterflies of North America " by W. J. Holland. 

The butterflies found in America north of Mexico represent five families. 


262 


THE STUDY OF INSECTS 


Family Papilionid^e 

The Swallow-tails and the Parnassians 

This family includes the swallow-tail butterflies, which are common 
throughout our country, and the parnassians, which are found only on 
high mountains or far north. These insects are distinguished from all 
other butterflies found in our fauna by the fact that vein M 2 of the fore 
wings appears to be a branch of cubitus, making this vein appear to be 
four-branched, and by the fact that the anal area of the hind wings is 
more reduced than the anal area of the fore wings, the former containing 
only a single anal vein, the latter two in the parnassians and three in 

the swallow-tails. 

The caterpillars are never 
clothed with spines but are either 
naked or clothed with a few fine 
hairs. In at least one species in 
our fauna, the body bears fleshy 
filaments. 

A striking peculiarity of the 
larvae of this family is the pres- 
ence of a bright-colored, forked, 
horn-like process which can be 
projected from a slit in the dorsal 
wall of the prothorax. This is 
the osmeterium which is an organ 
of defense; for it exhales when pushed out an 
cdor which in some species is exceedingly dis- 
agreeable. 

The black swallow-tail, PapUio polyxenes. — 
The larva of this swallow-tail (Fig. 457) is well- 
known to most country children. It is the green 
worm, ringed with black and spotted with yellow, 
that eats the leaves of caraway in the back yards 
of country houses. It feeds also on parsnips 
and other umbelliferous plants. The young larva 
is black, banded about the middle and caudal 
end with white. There are two generations 
annually in the North and at least three in the 
South. 

In the adult the wings are black, crossed 
with two rows of yellow spots, and with marginal 
lunules of the same color. The two rows of 
spots are much more distinct in the male than in 
Papiih polyxenes, the female, the inner row on the hind wing forming a 
continuous band crossed with black lines on the 
veins. Between the two rows of spots on the hind wings there are many 
blue scales; these are more abundant in the female. Near the anal angle 
of the hind wing there is an orange spot with a black center. On the 
lower surface of the wings the yellow markings become mostly orange 
and are heavier. 

This species is found throughout the United States and in the south-- 


LEPIDOPTERA 


263 


ern parts of Canada. In California the black swallow-tail is replaced as a 
celery and parsley pest by a related species, Papilio zolicaon. 

The tiger swallow-tail, Papilio glaucus. — The larva of this butter- 
fly (Fig. 458) is even more striking in appearance than 
that of the preceding species. When full-grown it is 
dark green, and bears on each side of the third thoracic 
segment a large greenish-yellow spot, edged with black, 
and enclosing a small black figure 10. This caterpillar 
has the curious habit of weaving upon a leaf a carpet 
of silk, upon which it rests when not feeding; when 
nearly full-grown, instead of spinning a simple carpet 
as before, it stretches a web across the hollow of a leaf 
and thus makes a spring bed upon which it sleeps 
(Fig. 458). 

The larva of this species feeds on birch, poplar, 
ash, wild cherry, fruit-trees, and many other trees and 
shrubs. 

In the adult state two distinct forms of this 
insect occur. These differ so greatly in appearance 
that they were long considered distinct species. They 
may be distinguished as follows. 

(1) The turnus form, Papilio glaucus turnus. — 
The wings are bright straw-yellow above, and pale, 
faded straw-yellow beneath, with a very broad 
black outer margin, in which there is a row of yel- 
low spots. On the fore wings there are four 
black bars, extending back from the costa; the inner 
one of these crosses the hind wings also. This form is represented by 
both sexes, and is found in nearly all parts of the United States and Canada. 

(2) The glaucus form, Papilio 
glaucus glaucus. — In this form the 
disk of the wings is entirely black, 
but the black bands of the' turnus 
form are faintly indicated, espe- 
cially on the lower surface, by a 
darker shade. The marginal row of 
yellow spots is present, and also the 
orange spots and blue scales of the 
hind wings. This form is repre- 
sented only by the female sex, and 
occurs only in the more southern 
part of the range of the species, i.e., 
from Long Island to Montana and 
southward. It was the first of the 
two forms to be described, hence 
the species bears the name glau- 
cus. 

The zebra swallow-tail, Iphiclides marcellus. — This butterfly (Fig. 
459) differs from all other swallow-tails found in the eastern half of the 
United States in having the wings crossed by several bands of greenish- 
white. This is one of the most interesting of our butterflies, as it occurs 
under three distinct forms, two of which were considered for a long time 


Fig. 458. — Papilio glau- 
cus, larva upon its bed. 


Fig. 459. — Iphiclides marcellus. 


264 


THE STUDY OF INSECTS 


distinct species. Without taking into account the more minute difference^ 
these forms can be separated as follows. 

(1) The early-spring form, Tphiclides marcellus marcellus. — This is 
the f«»rni figured here. It expands from c| to 2^ inches; and the tails of 
the hind wings are about f of an inch in length and tipped with white. 

(2) The late-spring form, Iphiclldes marcellus telamonides. — This 
form is a little larger than the early spring form and has tails nearly one- 
third longer; these tails are bordered with white on each side of the distal 
half or two-thirds of their length. 

(3) The summer form, Iphiclldes marcellus lecontei.- — -The summer 
form is still larger expanding from 3I to 3^ inches, and has tails nearly 
two thirds longer than the early spring form. 

The life history of this species has been carefully worked out by Mr. 
W. H. Edwards. He has shown that there are several generations each 
year, and that the winter is passed in the chrysalis state. But the early- 
spring form and the late-spring form are not successive broods; these are 
both composed of individuals that have wintered as chrysalids, those that 
emerge early developing into marcellus marcellus, and those that emerge 
later developing into marcellus telamonides. All of the butterflies pro- 
duced from eggs of the same season, and there are several successive 
broods, are of the summer form, marcellus lecontei. 

The larva feeds upon papaw 
(Asimina). This insect is found 
through out the eastern half of the 
United States except in the extreme 
north. 

The pamassians. — They are 
butterflies of medium size in which 
the ground color of the wings is 
white shaded with black, and 
marked with round red or yellow 
spots margined with black. 

In structure the pamassians are 
closely allied to the swallow-tails; 
but in their general appearance 
they show little resemblance to 
them, differing in the ground color 
of the wings, and in lacking the 
tail-like prolongations of the hind 
wings in all of our species. 

In the venation of the wings 
(Fig. 460) they differ from the swal- 
low-tails in that radius of the fore 
wings is only four-branched and 
the first anal vein is wanting. They 
agree with the swallow-tails and differ from all other butterflies in that 
the cubitus of the fore wings is apparently four-branched. 

The larva? possess osmeteria similar to "those of the larvae of swallow- 
tails. When about to pupate the larva either draws a leaf or leaves 
about its body by a few threads or it merely hides under some object on 
the ground. The pupa is cylindrical and rounded, not angulate like 
those of swallow-tails. 


FlG. 460. — Wings of Parnassius. 


LEPIDOPTERA 


265 


Only four species have been found in North America; they all belong 
to the genus Parnassius. Of the four species, two are Alaskan ; the others 
occur in the mountains of the Pacific States, in Wyoming, and in the 
Rocky Mountains. Of each of the two latter there are several named 
varieties. 

Family Pierid^e 

The Pier ids 

These butterflies are usually of medium size, but some of them are 
small; they are nearly always white, yellow, or orange, and are usually 
marked with black. They are the most abundant of all our butterflies, 
being common everywhere in fields and roads. Some species are so abun- 
dant as to be serious pests, the larvas feeding on cultivated plants. 

In this family the fore legs are well developed in both sexes, there being 
no tendency to their reduction in size, as in the three following families. 

The larvas are usually slender green worms clothed with short, fine 
hairs; the well-known cabbage-worms are typical illustrations (Fig. 461). 
The chrysalids are supported by the tail and by a girth around the 


Fig. 461. — Pieris rapr, larva and pupa. 

middle. They may be distinguished at a glance by the presence of a 
single pointed projection in front (Fig. 461). 

Our genera of this family can be separated into three groups, which 
seem hardly distinct enough to be ranked as subfamilies. These are the 
whites, the yellows and the orange-tips. 


THE WHITES 


The more common representatives of this group are the well-known 
cabbage-butterflies. They are white butterflies more or less marked 
with black. Occasionally the white is tinged with yellow; and sometimes 
yellow varieties of our white species occur. About a dozen North Amer- 
ican species of this group are known. 


266 


THE STUDY OF INSECTS 


Fig. 462. — Pieris rapcr. 


The cabbage-butterfly, Pieris rapes. — The wings of this butterfly 

are dull white above, occasionally tinged 
with yellowish, especially in the female; 
below, the apex of the fore wings, and 
the entire surface of the hind wings are 
pale lemon yellow. In the female there 
are two spots on the outer part of the 
fore wing besides the black tip, in the 
male only one (Fig. 462). 

There is considerable variation' in the 
intensity of the black markings, and in 
the extent of the yellow tinge of the wings. 
The larva of this species (Fig. 
461) feeds principally on cabbage, but 
it also attacks many other cruciferous plants. Its color is the green of 
the cabbage-leaf, with a narrow, greenish, lemon-yellow dorsal band, and 
a narrow, interrupted stigmatal band of the same color. The body is 
clothed with very fine short hairs. 

Pieris rapes is without doubt the most injurious to agriculture of all 
our species of butterflies. It is an introduced species, but has spread over 
the greater part of this country. As it is three-brooded in the North and 
more in the South, it is present nearly the entire season, so that it needs 
to be fought constantly. 

The checkered white, Pieris protodice. — The two sexes of this species 
differ greatly in appearance, the female being much more darkly marked 
than the male. The wings are white, marked above with grayish-brown. 
There is a bar of this color at the end of the discal cell ; beyond this there 
is in the male a row of three more or less distinct spots, and in the fe- 
male an almost continuous band of spots. Besides these there is in the 
female a row of triangular spots on the outer margin of both fore and 
hind wings, and on the hind wings a submarginal zigzag bar. 

The larva of this species is colored with alternating stripes of bright 
golden yellow and dark greenish-purple, upon which are numerous black 
spots. It feeds upon cabbage and other cruciferous plants, and occurs in 
nearly the whole of the United States. 


THE ORANGE-TIPS 


These, like the butterflies comprising the preceding group, are white, 
marked with black. Their most characteristic feature is the presence on 
the lower surface of the hind wings of a 
greenish network, or a marbled green mot- 
tling. This usually shows through the wing so 
as to appear as a dark shade when the wings 
are seen from above (Fig. 463) . Many species 
have a conspicuous orange spot on the apical 
portion of the front wings. This has sug- 
gested the common name orange-tips for the 
group. But it should be remembered that 
some species lack this mark, and that in 
some others it is confined to the males. 
Most of our species are western. The two following occur in the East. 


Fig. 463. — Eucklte ausonide 


LEPIDOPTERA 267 

The falcate orange-tip, Anthocharis genutia. — In this species the apex 
of the fore wings is hooked, reminding one of the hook-tip moths. In 
the males there is a large apical patch. This butterfly is found through- 
out the southeastern part of the United States, not including Florida. 
It occurs as far north as New Haven, Conn. It is nowhere abundant. 
The larva feeds on rock-cress, bitter cress, shepherd's purse, Sisymbrium, 
and other Cruciferas that are slender in form. 

The olympia orange-tip, Synchlce olympia. — In this species the 
orange patch is wanting in both sexes. There is a conspicuous black bar 
at the end of the discal cell of the fore wings, and the apical portion of 
these wings is gray including a large irregular white band. 

The larva is striped lengthwise with pale slate color and bright yellow; 
the feet, legs, and head are grayish-green. It feeds on hedge-mustard 
and other Cruciferse. 

THE YELLOWS 

The yellows are easily recognized by their bright yellow colors, al- 
though in some species whitish forms occur. They abound almost every- 
where in open fields, and are common about wet places in roads. To this 
group belong the larger number of our 
pierids. 

The roadside butterfly or the clouded 
sulphur, Eurymus philodice. — The wings 
above are rather pale greenish-yellow, with 
the outer borders blackish -brown. Figure 
464 represents the male; in the female the 
border on the fore wings is broader, and 
contains a sub-marginal row of yellow 
spots. The discal dot of the fore wings is 

, , « , , r 11 1-1 • • Fig. 464. — Eurymus plnloaue. 

black, that of the hmd wings is orange. 
The under surface is sulphur-yellow. 

This species is dimorphic. The second form is represented only by 
the female sex, and differs, in having the ground-color of the wings white 
instead of yellow. 

This butterfly often occurs in large numbers in muddy places in 
country roads, for this reason it may be known as the roadside butterfly. 
It is also known as the clouded sulphur. Its range extends from the 
mouth of the St. Lawrence to South Carolina and westward to the Rocky 
Mountains. Its larva feeds upon clover and other Leguminosae. 

The orange sulphur, Eurymus eurytheme. — This species closely re- 
sembles the preceding one in size, shape and markings. The typical form 
differs from E. philodice in being of an orange color above instead of 
yellow. This butterfly is found chiefly in the Mississippi Valley and west 
to the Pacific Ocean; it is also found in the Southwestern States, and 
occurs very rarely north to Maine. It is one of the most polymorphic 
of all butterflies; the forms differ so much in appearance that four or 
five of them have been described as distinct species. The larva feeds on 
clover and allied plants, and is sometimes a pest in alfalfa fields. 

The dog's head, Zerene ccesonia. — The wings are lemon-yellow above 
bordered on the outer margin with black. On the hind wings the border 
is narrow, but on the fore wings it is broad. The outline of the yellow of 


268 THE STUDY OF INSECTS 

the fore wings suggests a head of a dog or of a duck, a prominent black 
spot on the discal vein serving as the eye. This is an abundant species 
in the southeastern and southwestern states, extending from the Atlantic 
to the Pacific. The larva feeds on clover. 

The little sulphur, Eurema euterpe. — Although this species is con- 
siderably below the average size of our yellows, the larger individuals 
expand about f of an inch. The wings are canary-yellow above, with the 
apex of the fore wings and the outer margin of both fore and hind wings 
blackish-brown. The border of the hind wings is narrow and sometimes 
wanting. There is a red-brown splash on the apex of the hind wings 
below. 

The distribution of this species is from New England to Florida and 
westward to Lower California. The larva feeds on Cassia. 

The cloudless sulphur, Catopsilia eubule. — This large butterfly differs 
greatly in appearance from those described above. It expands 2\ inches. 
The wings above are of uniform bright canary-yellow. In the male they 
are without spots, except frequently an inconspicuous brown dot at the 
tip of each vein, and a lilac-brown edging of the costal border. In the 
female there is a discal dot on the fore wings and a marginal row of 
brown spots at the ends of the veins. 

This is a southern species which occasionally extends as far north on 
the coast as New York City, and in the Mississippi Valley as far as 
southern Wisconsin. The larva feeds on Cassia. 

Family Nymphalid^e 
The Four-footed Butterflies 

The family Nymphalidae, includes chiefly butterflies of medium or 
large size, but a few of the species are small. With a single exception, 
Hypatus, these butterflies differ from all others in our fauna in having 
the fore legs very greatly reduced in size in both sexes. So great is the 
reduction that these legs cannot be used for walking, but are folded on 
the breast like a tippet. 

This is the largest of the families of butterflies. It not only surpasses 
the other families in number of species, but it contains a greater number 
and variety of striking forms, and also a larger proportion of the species 
of butterflies familiar to every observer of insects. There may be in any 
locality one or two species of yellows or of whites more abundant, but 
the larger number of species commonly observed are four-footed butter- 
flies. 

THE FRITILLARIES 

The fritillaries are butterflies varying from a little below to somewhat 
above medium size. The color of the wings is fulvous, bordered and 
checkered with black, but not so heavily bordered as in the next sub- 
family. The lower surface of the wings is often marked with curving 
rows of silvery spots. The common name fritillary was suggested by the 
spotted coloration of these butterflies. 

In the larvae there is an even number of rows of spines on the abdo- 
men, due to the fact that there are none on the middle of the back. The 
larvae feed upon the leaves of violets. 


LEPIDOPTERA 


269 


Fig. 465. — Argynnis cybele. 


There are many species of fritillaries, about fifty occur in America 

north of Mexico, and it is difficult to separate the closely allied species. 
The great spangled fritil- 

lary, A rgynnis cybele. — This 

species (Fig. 465) will serve 

to illustrate the appearance 

of the larger members of 

this group, those belonging 

to the genus Argynnis. In 

this genus vein RVof the fore 

wings arises before the apex 

of the discal cell. 

There are a number of 

common fritillaries which 

resemble the preceding in 

color and markings but 

which are much smaller, the 

wings expanding considerable less than 2 inches. These belong to the genus 

Brenthis. In this genus vein R2 of the fore wings arises beyond the apex 

of the discal cell. 

The variegated fritillary, Euptoieta claudia. — This butterfly agrees 

with the smaller fritillaries {Brenthis) in the origin of vein R 2 of the fore 

wing beyond the apex of the discal 
cell, but differs from them in the 
shape of the fore wing, the apex of 
which is much more produced (Fig. 
466) and the outer margin, except 
at the apex, concave; it is also con- 
siderably larger. 

This species occurs throughout 
the United States east of the Rocky 
Mountains; but is very rare in the 
fig. 4 oo. -Euptoieta daudia. northern half of this region. The 

larva feeds on the passion-flowers. 


THE CRESCENT-SPOTS ■ 

This group includes some of the smaller members of the Nymph- 
alidas. The color of the wings is sometimes black, with red and yellow 
spots; but it is usually fulvous, with the fore wings broadly margined, 
especially at the apex, with black, and crossed by many irregular lines 
of black. 

In the larva there is an odd number of rows of spines on the abdomen, 
due to the presence of spines on the middle of the back of some of the 
abdominal segments. 

Sixty-three species of crescent-spots have been described from Amer- 
ica north of Mexico; but nearly all of these are restricted to the far 
West. 

The baltimore, Euphydryas phaeton. — The wings are black above, 
with an outer marginal row of dark reddish-orange spots, and two 
parallel rows of very pale yellow spots ; on the fore wings a third row is 
more or less represented. The wings expand 2 inches or more. 


270 


THE STUDY OF INSECTS 


The larvae feed on a species of snakehead, Chelone glabra; they are 
gregarious in the fall and build a common nest in which they pass the 
winter; but separate after hibernation. They are very striking in ap- 
pearance. The head and first two thoracic segments are shining black 
and the last three abdominal segments are black with two orange bands 
around each. All the other segments have a ground color of orange with 
various narrow transverse lines of black. This species occurs in Ontario 
and the northern half of the United States east of the Rocky Mountains. 
It is very local, the butterflies remaining near the bogs or moist meadows 
where the food -plant of the larva is found. 


Fig. 467. — Vanessa alalania. 


THE ANGLE-WINGS 

To this group belong many of our best-known butterflies; there are 
twenty-five species in our fauna. With these the outer margin of the 
fore wings is usually decidedly angular or notched as if a part had been 
cut away. A large proportion of the species hibernate in the adult state, 
and some of them are the first butterflies to appear in the spring. Some 

of the hibernating species, how- 
ever, remain in concealment till 
quite late in the season. 

The red admiral, Vanessa at- 
aldnta. — The wings are purplish- 
black above. On the fore wing 
there is a bright orange-colored 
band beginning near the middle of 
the costa, and extending nearly to 
the inner angle ; between this and 
the apex of the wing are several 
white spots as shown in Figure 
467 ; on the hind wing there is an 
orange band on the outer margin inclosing a row of black spots. 

The larva feeds chiefly on elm, nettle, and hop. When first hatched it 
folds together a half-opened leaf at the summit of the plant; when larger 
it makes its nest of a lower expanded leaf. There are two broods; both 
butterflies and chrysalids hibernate. This butterfly occurs over nearly 
the whole of the European and North American continents. 

The painted beauty, Vanessa vir- 
giniensis. — Figure 468 represents the 
upper side of- this butterfly. The 
darker parts of the wings are very dark 
brownish black, the lighter parts a 
golden orange, sometimes with a 
pinkish tinge. In the apical portion 
of the fore wings there are several 
white spots as shown in the figure; 
the largest of these, the proximal one, 
is salmon or flesh-colored in the fe- 
male. A characteristic feature of this Fia 468 " ~ Vanessa ™«»""™- 
species is the presence of two submarginal eye-like spots on the lower side 
of the hind wings. The larva feeds on everlasting {Antennaria) and 
allied plants. This species occurs from Canada to South America. 


LEPIDOPTERA 


271 


The painted beauty has been commonly known in this country as 
Vanessa huntera; but Vanessa virginiensis is the older name. 

The cosmopolite, Vanessa cdrdui. — The butterfly resembles the pre- 
ceding very closely in color and markings. There is however, a smaller 
proportion of orange markings; and on the lower surface of the hind 
wings there is a submarginal row of four or five eye-like spots. 

The larva feeds upon Compositae, especially thistles. This species is 
very remarkable for its wide distribution. Mr. Scudder states " with 
the exception of the arctic regions 
and South America it is distributed 
over the entire extent of every conti- 
nent." 

The American tortoise-shell, Aglais 
milberti. — The wings above are brown- 
ish-black, with a broad orange-fulvous 
band between the middle and the 
outer margin. There are two fulvous 
spots in the discal cell of the front 
wings (Fig. 469). The larvae feed on nettle (Urtica) and are gregarious 
in habits. This species occurs in the northern portions of the United 
States and in Canada. 

The mourning-cloak, Euvanessa antlopa. — The wings above are 
purplish-brown, with a broad yellow border on the outer margin sprinkled 


Fig. 469. — Aglais milberti. 


Fig. 470. — Euvanessa antiopa. 


with brown, and a submarginal row of blue spots. The upper surface is 
represented by Figure 470, the lower by Figure 471, 5. 

The larvas live on willow, elm, poplar and Celtis; they are gregarious, 
and often strip large branches of their leaves. The species is usually 
two-brooded. " This butterfly is apparently distributed over the entire 
breadth of the Northern Hemisphere below the Arctic Circle as far as the 
thirtieth parallel of latitude." {Scudder.) 

The compton tortoise, Eugdnia j-album. — This butterfly (Fig. 472) 
resembles in its general appearance those of the genus Polygonia, but it is 
sharply distinguished from them by the inner margin of the fore wings 
being nearly straight, by the heavier markings of the fore wings, and by 


272 


THE STUDY OF INSECTS 


Fig. 471. — t, Lycana argiolus: 2, Poly gonia founts; 
3, Polygonia comma; 4, Incisalia niphon; 5, Euva- 
nessa anttopa; 6, Mitoura damon; 7, Lycana, 
argiolus; 8, Polygonia inlerrogalionis. 


LEPIDOPTERA 


273 


the presence of a whitish spot on both fore and hind wings, near the 
apex, and between two larger black patches. On the lower surface of the 
hind wings there is a small re- 
shaped silvery bar. This species 
occurs throughout Canada and 
the northern portion of the 
United States east of the Rocky 
Mountains. It is double- 
brooded. 

Polygdnia. — The butterflies 
of this genus resemble the pre- 
ceding species in having a me- 
tallic spot on the lower surface 
of the hind wings, but differ in 
having the inner margin of the 
fore wings roundly notched 
beyond the middle. f IG - 472 ' ~ **"**»»««■• 

Ten species occur in this country. These differ principally in the 
coloring and markings of the under surface of the hind wings. The fol- 
lowing are some of the more common ones. 

The green comma, Polygdnia faunus. — The silvery mark of the hind 
wings is usually in the form of a C or a G, the ends being more or less 
expanded (Fig. 471, 2) but sometimes it is reduced to the form of an L. 
The lower surface of the wings is more greatly variegated than in any 
other species of this genus; and there is a larger amount of green on this 
surface than in any other of the eastern species, there being two nearly 
complete rows of green spots on the outer third of each wing. 

The larva feeds upon black birch, willow, currant, and wild goose- 
berry. This is a Canadian species; but it is also found in the mountains 
of New England and of New York, and in the northern portions of the 
western states, extending as far south as Iowa. It is single-brooded. 

The hop-merchant, Polygdnia comma. — As in the preceding species, 
the silvery mark of the hind wings is in the form of a C or a G (Fig. 
471, 3) but the general color of the lower surface of the hind wings is 
very different, being marbled with light and dark brown; and the green 
spots so characteristic of faunus are represented here by a few lilaceous 
scales on a submarginal row of black spots. 

Two forms of this species occur. In one P. comma dryas, the hind 
wings above are suffused with black on the outer half, so that the sub- 
marginal row of fulvous spots is obscured, and on the lower side the 
wings are more yellowish than in the other form. The latter is the 
typical form of P. comma comma. 

The larva feeds upon hop, elm, nettle, and false-nettle. It is often 
abundant in hop-yards, and the chrysalids are commonly known as hop- 
merchants, from a saying that the golden or silvery color of the metallic 
spots on the back of the chrysalis indicates whether the price of hops is 
to be high or low. This species is found in Canada and the northern 
part of the eastern half of the United States; its range extends south to 
North Carolina, Tennessee, Arkansas, and Oklahoma. It is double-brooded 
in the North, and at least three-brooded in the South. 

The violet tip, Polygdnia interrogations. — This butterfly (Fig. 471, 
8) is somewhat larger than the preceding species of Polygonia and differs 


274 


THE STUDY OF INSECTS 


in the form of the silvery mark, which consists of a dot and a crescent 
resembling a semicolon. It received its scientific name from the Greek 
note of interrogation, which is identical with our semicolon. On the 
upper side, the outer margins of the wings and the tails of the hind wings 
are tinged with violet, which fact suggested its common name. 

This species is dimorphic ; and the two forms differ so constantly and 
in such marked manner that they were described as distinct species. In 
P. interrogationis interrogationis the upper surface of the hind wings is 
not much darker than that of the fore wings, and there is a submarginal 
row of fulvous spots in the broad ferruginous brown border. In P. 
interrogationis umbrosa the outer two-thirds of the upper surface of the 

hind wings is blackish, and the 
submarginal fulvous spots are ob- 
literated, except sometimes faint 
traces near the costal margin. 

This species is found in Canada 
and throughout the United States 
east of the Rocky Mountains. 


THE SOVEREIGNS 


Fig. 473. — Wings of Basilarchia aslyanax. 

known species. 

The banded purple, Basil- 
archia arthemis. — ■ The upper 
surface of the wings is velvety 
chocolate-black, marked with a 
conspicuous white bow (Fig. 
474)- 

This is a Canadian species 
which extends a short distance 
into the United States ; the larva 
feeds on birch, willow, poplar, 
and many other plants. 


The members of this group differ 
from other Nymphalidae in that the 
first three veins of the hind wings 
separate at the same point (Fig. 
473) ; in the other nymphs the hu- 
meral vein arises beyond this point. 
The club of the antennae is very 
long, and increases in size so grad- 
ually that it is difficult to determine 
where it begins. In its thickest 
parts it is hardly more than twice 
as broad as the stalk. The palpi are 
slender, and the wings are rounded. 

The larvae present a very gro- 
tesque appearance, being very ir- 
regular in form, and strongly 
mottled or spotted in color. 

The following are our best- 


Fig. 474. — Basilarchia arthemis. 


LEPIDOPTERA 


275 


The red spotted purple, Basilarchia astyanax. — The upper surface of 
the wings is velvety indigo-black, tinged with blue or green. There are 
three rows of blue or green spots on the outer third of the hind wings; 
the spots of the inner row vary greatly in width in different individuals. 
On the lower surface there is a reddish-orange spot on the discal cell of 
the fore wings, and one on the discal vein; on the hind wings there are 
two orange spots similarly situated, a third at the base of cell Ri and a 
row of seven spots just within a double row of submarginal blue or green 
spots. 

This species occurs throughout nearly the whole of the Eastern United 
States south of the 43rd parallel of latitude. The larva feeds on many 
plants; among them are plum, apple, pear, and gooseberry. 

The viceroy, Basil- 
archia archippus. — The 
wings vary in color from 
a dull yellow orange tinged 
slightly with brown to 
a dark cinnamon color; 
they are bordered with 
black, and all the veins 
are edged with the same 
color (Fig. 475). The fringe 
of the wings is spotted 
with white, and the black 
border on the outer mar- 
gin contains a row of white 
spots. 

This species is remarkable for its resemblance to the monarch, Danaus 
archippus (Fig. 480). But aside from the structural characters separating 
the two subfamilies which these butterflies represent, the viceroy can be 
easily distinguished from the species it mimics by its smaller size, and by 
the presence of a transverse black band on the hind wings. As Danaus 

archippus has been termed 
the monarch, this species is 
aptly called the viceroy. 

The larva (Fig. 476, a) 
when full-grown is about 1-^ 
inches in length. The body 
is humped and naked, with 
many tubercles. In color 
it is dark brownish-yellow 
or olive-green, with a pale 
buff or whitish saddle on 
the middle segment of the 
abdomen. The tubercles 
on the second thoracic 
segment are club-shaped 
and spiny. 

The larva of the viceroy feeds upon willow, poplar, balm of gilead, 
aspen, and cottonwood. The species is two- or three-brooded and 
hibernates as a partially grown larva in a nest made of a rolled leaf 
(Fig. 476, c). This nest is lined with silk, and the leaf is fastened to the 


Fig 475. — Basilarchia archippus. 


Fig. 476. — Basilarchia archippus: a, larva, b, pupa, c, nest; 
d, partly eaten leaf before rolled to form nest. (From Riley.) 


2 7 6 


THE STUDY OF INSECTS 


twig with silk so that it cannot fall during the winter. So far as is 
known all of the species of the sovereigns hibernate as larvae in nests of 
this kind, it is worthy of note that only the autumn brood of cater- 
pillars make these nests; so that the nest -building instinct appears only 
in alternate generations, or even less frequently when the species is more 
than two-brooded. B. archippus is found over nearly the whole of the 
United States as far west as the Sierra Nevada Mountains, and has been 
found sparingly even to the Pacific coast near our northern boundaries. 

THE EMPERORS 

This group is poorly represented in our fauna; our best-known species 
are the two following, which occur in the South. 


Fig. 477. — Chlorippe clylon: a, eggs; b, larva; c, pupa; d, upper 
surface of male butterfly; the dotted line at left indicates the contour 
of the wings of the female. (From Riley.) 

The tawny emperor, Chlorippe clyton. — In this species the apex of 
the front wings and the anal angle of the hind wings are considerably 
produced in the males, but more rounded in the females. The male is rep- 
resented in Figure 477 and the dotted line at the left indicates the con- 
tour of the wings of the female. This excellent figure is from the sixth 
Missouri report by C. V. Riley, where a detailed account of the life- 
history of the species is given. The wings of this butterfly are more or 
less obscure tawny, marked with blackish-brown, and with pale spots. 
There is a submarginal row of six eye-like spots on the hind wings. 

The species is dimorphic; the dimorphism affects both sexes and is 
independent, so far as is known, of season, as there is only one brood each 
year. It is the typical form Chlorippe clyton clyton that is figured here. 
The second form, Chlorippe clyton proserpina, differs in having the hind 
wings darker and the submarginal row of eye-like spots wanting. 

The larva (Fig. 477, b) feeds on hackberry. 


THE AN^AS 

The butterflies of the genus Ancea are quite distinct from any of the 
preceding divisions of the Nymphalina?, although they have been classed 
with the emperors. There are three species found in the United States, 
A. portia from Florida, A. morrisonii from Arizona, and the following 
one. 


LEPIDOPTERA 


277 


The goat-weed butterfly, Anaza andria. — The female of this species 
can be easily recognized by Figure 478. The male is smaller, with wings 
of a rich dark orange, margined with brown, and without the light- 


Fig. 478. — Anna andria. 

colored band characteristic of the female. This species is found in the 
Mississippi Valley from Illinois to Texas. The caterpillar has a large 
head, small neck and folds a leaf thus closely resembling the larva of a 
skipper. 

THE MEADOW-BROWNS 

This subfamily includes chiefly brown butterflies whose markings 
consist almost entirely of eye-like spots. Some western species, however, 
are bright-colored. In our species some of the veins of the fore wings are 
greatly swollen at the base. This character is not quite distinctive; for 
in some species of the preceding groups of the Nymphalidas that are found 
in southern Florida and in Texas near the Mexican border some of the 
veins of the fore wings are swollen at the base. 

The larva? are cylindrical, tapering more or less towards each end. 
The caudal segment is bifurcated, a character that distinguishes them 
from all other American butterfly larvae excepting those of the emperors, 
Chlorippe. 

The eyed brown, Satyrodes canthus. — 
The upper surface of the wings is soft 
mouse-brown on the basal half and paler 
beyond, considerably so in the female; each 
wing bears a row of four or five small black 
eye-like spots (Fig. 479). This species is 
found in Ontario, and throughout the east- 
ern half of the United States in wet places. 
The larva feeds on swamp grasses ; its head 
and caudal segment are each adorned with a 
pair of red cone-shaped tubercles. 

The grayling, Cercyonis alope. - — This species is found from the At- 
lantic to the Pacific; it occurs under several forms, some of which have 
been described as distinct species. The most common forms found East 
of the Rocky Mountains are the first two described below and intergrades 
between these. The expanse of the wings is from 2 to 2\ inches. The 
larva feeds on grass. 


Fig. 47g. — Satyrodes canthus. 


27 S THE STUDY OF INSECTS 

(i) The blue-eyed grayling, Cercyonis alope alope. — The upper sur- 
face of the wings is dark brown ; on the outer half of the fore wings there 
is a distinct yellow band, which extends from vein R5 to the anal vein; 
in this band there are two dark spots with a white or bluish center. The 
hind wings usually bear a small spot in cell Cui, which is narrowly 
rimmed with yellow and has a minute white pupil. The lower surface 
of the hind wings is either with or without eye-like spots, usually with 
six of them. 

(2) The dull-eyed grayling, Cercyonis alope nepkele. — In this form 
the yellow band of the fore wings is either absent or represented by a faint 
pallid cloud. In other respects it closely resembles the blue-eyed grayling. 

This is a northern form; the southern limits of its range overlap the 
northern limits of the range of the blue-eyed grayling as given above. 

The White Mountain butterfly, QLneis semidea. — The genus CEneis 
is composed of cold-loving arctic species whose natural habitat is the 
far North; but some members of this genus are found within the limits 
of the United States. Their presence here and their distribution are 
extremely interesting. The best-known of these forms is the White 
Mountain butterfly. 

This butterfly is found only on the higher parts (above 5,000 feet) 
of the White Mountains in New Hampshire, and on the highest peaks 
of the Rocky Mountains of Colorado, above 12,000 feet. 

These two widely separated colonies of this butterfly are believed to 
be the remnants of an arctic fauna which was forced southward during 
the Ice Age. At the close of this period, as the arctic animals followed 
the retreating ice northward, the tops of these mountains became colo- 
nized by the cold-loving forms. Here they found a congenial resting place, 
while the main body of their congeners, which occupied the intervening 
region, was driven northward by the increasing heat of the lower land. 
Here they remain, clinging to these islands of cold projecting above the 
fatal sea of warmth that fills the valleys below. 

The White Mountain butterfly is a delicate-winged species. The 
upper surface of the wings is grayish-brown, without spots, except some- 
times a minute one in cell Mi of the fore wings; the fringe of the wings is 
brownish-white interrupted with blackish-brown at the ends of the veins. 
On the hind wings the marbling of the lower surface shows through some- 
what. On the lower surface, the tip of the fore wings and the greater 
part of the hind wings are beautifully marbled with blackish-brown and 
grayish -white. The expanse of the wings is about 1 \ inches. 

THE HELICONIANS 

This subfamily consists chiefly of tropical butterflies. They are of 
medium or rather large size, and are easily recognized by their narrow 
and elongated fore wings, which are usually more than twice as long as 
broad. Most of the species are striking in appearance, being black 
banded with yellow or crimson, and sometimes with blue. The discal 
cell of the hind wings is closed by a well-preserved vein. The following 
species is the only one found in our fauna that unquestionably belongs to 
this subfamily. 

The zebra, Heliconius charitonius. — This is a black butterfly with its 
wings banded with lemon yellow. There are three bands on the fore 


LEPIDOPTERA 279 

wings; on the hind wings there is a broad band parallel with the front 
wings when they are spread, a submarginal row of about fifteen spots, 
and a row of dots on the outer margin near the anal angle. The wings 
expand from 2$ to 4 inches. The larva feeds upon the passion-flower. 
This species is found in the hotter portions of the Gulf States. 

The gulf fritillary, Dione vanillce. — In this species the front wings 
are about twice as long as broad, but the markings of the wings resemble 
those of a fritillary more than those of an heliconian. The wings are 
reddish fulvous above; the veins of the front wings are black on the 
outer two-thirds of the wing; the black expands into spots at the ends 
of veins M 3 to anal; there are two white spots in the discal cell and one 
at the apex of it, each of these spots is surrounded with black; cells M 3 , 
Cui, and Q12 each contains a round black spot. The outer margin of the 
hind wings has a broad black border, which contains a fulvous spot in 
each cell. The wings expand from 2 to 3 inches. 

The larva feeds on the passion-flower. In addition to the six rows of 
thorny spines, which characterize the caterpillars of many other fritillaries 
this one has on the head a pair of backward bending spines branched like 
the others. 

This species occurs from New Jersey and Pennsylvania southward, 
also in Arizona and California. 

THE MILKWEED BUTTERFLIES 

These butterflies are of large size, with rounded and somewhat elon- 
gate wings, the apical portion of the fore wings being much produced. 
The discal cells of the wings are closed; the third anal vein of the fore 
wings is preserved; and the antennas are apparently without scales. 
Only a very few species of this family occur in our fauna. The two 
following are the best-known. 


Fig. 480. — Danaus archippus. 


The monarch, Danaus archippus. — The upper surface of the wings 
is light ruddy brown, with the borders and veins black, and with two 
rows of white spots on the costal and outer borders as shown in Figure 
480. The figure represents a female; in the male the veins of the wings 


280 


THE STUDY OF INSECTS 


are more narrowly margined with black, and there is a black pouch next 
to vein C112 of the hind wings, containing scent-scales or androconia. 

The larva feeds upon different species of milk-weed, Asclepias. When 
full-grown it is lemon or greenish-yellow, broadly banded with shining 
black. It is remarkable for bearing a pair of long fleshy filaments on the 
second thoracic segment, and a similar pair on the seventh abdominal 
segment (Fig. 481). The chrysalis is a beautiful object; it is bright 


>^ 


Fig. 481. — Danaus archippus, larva. (From Riley.) 


Fig. 482. — Danaus archippus, 
chrysalis. (From Riley.) 


green dotted with golden spots, and about 1 ijich in length (Fig. 482). 

This species occurs throughout the greater part of the United States, 
and is distributed far beyond our borders. It is believed, however, that 
the species dies otit each year in a large part of the Northern States, 
and that those butterflies which appear first in this region, in June or 
July, have flown hither from the South, where they hibernate in the adult 
state. In the extreme South they fly all winter. Great swarms, including 
many thousands of individuals of this species, are sometimes seen, late 
in the year; and these swarms appear to be migrating southward. 

The queen, Danaus berenice. — This species is found in the Southern 
States. The upper surface of the wings is reddish chocolate-brown with 
the costal margin of the front wings and the outer margins of both pairs 
bordered with black. There are two partial rows of white dots near the 
costal and outer margins of the front wings; and there is a larger white 
spot in each of the cells R5 to Cu. The male possesses a black pouch 
containing androconia next to vein Cu of the hind wings as in the pre- 
ceding species. The wings expand from 2f to 3 inches. 

There is a well-marked variety, Danaus Berenice strigosa, in which on 
the upper surface of the hind wings the veins are narrowly edged with 
grayish-white. 

The larva of this species feeds on milkweed. This larva bears three 
pairs of long, brown, whiplash filaments; these are on the second thoracic 
and the second and eighth abdominal segments. 


Fig. 483. — Ilypatus bachmanni. 


THE LONG-BEAKS 

The long-beaks can be easily recognized by 
their excessively long, beak-like palpi, which 
are from one-fourth to one-half as long as the 
body and project straight forward (Fig. 483). 
The outer margin of the fore wings is deeply 
notched ; the males have only four well-devel- 
oped legs, while the females have six. 


LEPIDOPTERA 


281 


/?«■«* 


Only two species are listed from the United States, one from Texas 
and one from the East ; and these may be merely varieties of one species. 

The snout butterfly, Hypatus bachmanni. — The wings are blackish- 
brown above, marked with orange and white spots. This species occurs 
throughout the eastern United States, excepting the northern part of 
New England and the southern part of Florida. The larva feeds on 
hackberry, and in the West where hackberry does not occur, it feeds on 
wolfberry. 

Family Lyc&nid^e 
The Gossamer-winged Butterflies 

The family Lycasnidae includes butterflies which are of small size 
and delicate structure. In size they resemble the smaller Hesperiidae 
but they can be distinguished at a glance 
from the skippers, as they present an en- 
tirely different appearance. The body is 
slender, the wings delicate and often 
brightly colored, and the club of the an- 
tenna straight. The antennae are nearly 
always ringed with white ; each is situated 
very closely to the edge of an eye, often 
flattening it; they are not in pits; and 
a conspicuous rim of white scales en- 
circles the eyes. 

A characteristic of this family is 
that while in the female the front legs 
are like the other legs, in the male they 
are shorter, without tarsal claws, and 
with the tarsi more or less aborted. The 
venation is shown in Figure 484. 

The caterpillars of the Lycaenidae pre- 
sent a very unusual form being more or 
less slug-like, reminding one of the larvae 
of the Eucleidae. The body is short and 
broad ; the legs and prolegs are short and 
small, allowing the body to be closely 
pressed to the object upon which the insect 
is moving — in fact some of the species glide rather than creep ; and the 
head is small, and can be retracted more or less within the prothorax. 
The body is armed with no conspicuous appendages; but some of the 
species are remarkable for having osmeteria which can be pushed out 
from the seventh and eighth abdominal segments, and through which 
honey-dew is excreted for the use of ants. Certain other species are re- 
markable in being carnivorous; one American species feeds exclusively 
upon plant-lice. 

The chrysalids are short, broad, ovate, and without angulations. 
They are attached by the caudal extremity, and by a loop passing over 
the body near its middle. The ventral aspect of the body is straight and 
often closely pressed to the object to which the chrysalis is attached. 

The family Lycaenidae is represented in our fauna by three well- 
marked groups of genera, which are hardly distinct enough to be ranked 


ad A 

Fig. 484. — Wings of Ileodes thcc. 


282 THE STUDY OF INSECTS 

as subfamilies; these are known as the hair-streaks, the coppers, and the 
blues respectively. In addition to these there is a single species, the 
wanderer, the relationship of which is uncertain. 

THE HAIR-STREAKS 

The hair-streaks are usually dark brown, with delicate striped mark- 
ings, which suggested their common name; but some species are bril- 
liantly marked with metallic blue, green, or purple. The hind wings are 
commonly furnished with delicate tail-like prolonga- 
tions (Fig. 485), and the eyes are hairy. The fore 
wings of the male often bear a small, dull, oval spot 
near the middle of the costal part of the wings, the 
discal stigma, which is filled with the peculiar scent- 
scales known as androconia. The males are also dis- 
tinguished by having a tuft of hair-like scales, the 
beard, on the front; this is wanting or very thin in 
the females. More than sixty species occur in 
America north of Mexico; of these nearly twenty 
occur in the eastern half of the United States. 
fig. 4 s 5 . -Thedacaianus. The banded hair-streak, Thecla calanus. — In the 

northeastern United States the most common of the hair-streaks is this spe- 
cies (Fig. 485). The upper surface of the wings is dark brown or black- 
ish-brown. The under surface is blackish slate-brown nearly as dark as 
the upper surface, and marked as shown in the figure. 

The larva feeds on oak and hickory. Excepting the southern portion 
of the Gulf States, the species is found throughout our territory east of 
the Rocky Mountains, and in the southern part of Canada. 

The olive hair-streak, Mitoura damon. — The upper surface of the 
wings is dark brown, with the disk more or less deeply suffused with 
brassy yellow in the male or tawny in the female; the hind wing has two 
tails, one much longer than the other, both black tipped with white. 
The lower surface of the hind wings is deep green; both fore and hind 
wings are marked with white bars bordered with brown. (Fig. 471, 6.) 
Southern individuals have much longer tails than the one shown in 
the figure; and there is a variety, pater soma, in which the upper surface 
of the wings is all dark brown. 

The larva feeds on red cedar and smilax. This species occurs from 
Massachusetts to Florida and westward to Dakota and Texas. 

The great purple hair-streak, Atlides halesus. — This is the largest of 
our eastern hair-streaks, the larger individuals expanding 2 inches. In the 
male the greater part of the upper surface of the wings is bright blue; 
the discal stigma, the outer fourth of the fore wings, the apex of the 
inner margin of the hind wings, and the tails are black. In the female 
the outer half of the wings is black. 

This species occurs in the southern half of the United States and 
southward. It has been found as far north as Illinois. The larva is 
said to feed on oak. 

The white-m hair-streak, Thecla m-album. — This is a smaller species, 
expanding about i\ inches. The upper surface of the disk of the wings 
is a rich, glossy dark blue, with green reflections; a broad outer border 
and costal margin are black. The hind wing has two tails, and a bright 


LEPIDOPTERA 283 

dark orange spot preceded by white at the anal angle. The under surface 
is brownish-gray, and on this surface both wings are crossed by a com- 
mon, narrow white stripe which forms a large W or reversed M on the 
hind wings. 

This species occurs in the southern half of the United States. The 
larva feeds on oak and on milk- vetch. 

THE COPPERS 

The coppers, as a rule, are easily distinguished from other gossamer- 
winged butterflies by their orange-red and brown colors, each with a 
coppery tinge, and conspicuous black markings. They are the stoutest 
of the Lycasnidag. Among the exceptions to the more common coloring 
of these insects are the following: In the male of Heodes epixanthe, a 
small species which frequents cranberry bogs, the wings have a purple 
tinge; and in Heodes heteronea, a species found from California to Colo- 
rado, the male is blue. 

Eighteen species of the group are now listed in our fauna; the two 
following will serve as examples: 

The American copper, Heodes hypophlceas. — This is the most common 
of our coppers in the Northeastern States and in Canada. Its range 
extends also along the boundary between the United States and Canada 
to the Pacific Ocean, and southward into California; and in the east 
along the Alleghany Mountains south to Georgia. The fore wings are 
orange-red above, spotted with black, and with a blackish-brown outer 
border; the hind wings are coppery -brown, with a broad orange-red 
band on the outer margin; this band is indented by four black spots. 

The larva feeds on the common sorrel (Rumex acetosella). 

The bronze copper, Heodes thee. — ■ This is larger than the preceding 
species, the wings expanding i| inches or more. In the male the wings 
are coppery-brown above, spotted with black, and with a broad orange- 
red band on the outer margin of the hind wings. The female differs in 
having the fore wings orange-red above, with prominent black spots. 

This species occurs in the Middle and Western States from the Con- 
necticut Valley to Nebraska. The larva feeds on curled dock (Rumex 
crispus) . 

THE BLUES 

The blues can be distinguished from the other gossamer-winged 
butterflies by the slender form of the body, and the blue color of the 
upper surface of the wings of the males at least; in many species the 
upper surface of the wings of the female is much darker than that of 
the male. Thirty-eight North American species have been described; 
but most of these occur only in the far West. This is a rather difficult 
group to study owing to the fact that in several cases a single species 
exists under two or more distinct forms, and also that the two sexes of 
the same species may differ greatly. It often happens that two individ- 
uals of the same sex but of different species resemble each other more 
closely in the coloring of the upper surface than do the two sexes of 
either of the species. 

The spring azure, Lyccena argiohts. — In this species the hind wings 


284 THE STUDY OF INSECTS 

are without tails, the eyes are hairy, and the lower surface of the wings 
is pale ash-gray. This combination of characters will distinguish it from 
all other blues occurring in the eastern United States. But the species 
is not confined to this region, as it occurs in nearly all parts of the United 
States, in a large part of Canada, and most of the Old World. 

This butterfly exhibits polymorphism to the greatest degree of any 
known species. In this country alone there are thirteen or more named 
forms. Some of these are geographical races; some are seasonal forms; 
and some are distinct forms that exist at the same time and place as the 
more typical form. In the Old World many other forms of this species 
have been described. Two forms are represented in Figure 471, 1 and 7. 

The larva feeds on the buds and flowers of various plants, especially 
those of Cornus, Cimicifuga, and Actinomeris. They are frequently 
attended by ants for the sake of the honey-dew which they excrete from 
osmeteria which they push out from the seventh and eighth abdominal 
segments. 

The tailed blue, Everes comyntas. - — The butterflies of the genus 
Everes can be distinguished from our other blues by the presence of a 
small tail-like prolongation of the hind wing. This is borne at the end 
of vein Cu. Our common species (E. comyntas) is distributed over nearly 
all parts of North America. The male is dark purplish-violet above, 
bordered with brown; the female is dark brown, sometimes flecked with 
bluish scales. In the Eastern United States this is the only species of 
the genus. 

The larva feeds upon clover and other leguminous plants. 

THE GENUS, FENISECA 

The wanderer, Ferns eca tarquinius. — This is the only known member 
of the genus Feniseca. It does not seem to belong to either of the three 
groups of genera mentioned above. A distinctive feature of this genus is 
the fact that vein Mi of the fore wings coalesces 
with a branch of radius for a considerable distance 
beyond the apex of the discal cell; in this respect 
it differs from all other members of the Lycsenidse 
found in our fauna. 

The upper surface of the wings of this butterfly 
■Feniseca tar- (Fig. 486) is dark brown, with a large irregular, 
orange-yellow patch on the disk of the fore wing, 
and one of the same color next the anal angle of the hind wing. 

This species is of unusual interest, as the larva is carnivorous in its 
habits. It feeds on plant-lice; and, so far as observed, it feeds only on 
the woolly aphids. It is found more often in colonies of the alder blight 
(Schizoncura tessellata) than in those of the allied species. It is found 
from Maine to northern Florida and westward to Kansas. It is a very 
local insect, being found only in the neighborhood of water where alder 
grows. 

I do not know why the name the " wanderer " was applied to this butter- 
fly, it may have been on account of its local appearance in widely sepa- 
rated places, or because in habits the larva deviates far from the more 
usual habits of caterpillars. The name is also appropriate as its nearest 
relatives are found in Africa and in Asia. 


LEPIDOPTERA 


285 


The chrysalis of Feniseca presents a remarkable appearance (Fig. 
487); the anterior half when viewed from above 
bears a curious resemblance to a monkey's face; 
and it differs from all other lycsenid pupae in our 
fauna in having on each side a row of small rounded 
tubercles. 

FAMILIES OF LEPIDOPTERA NOT DISCUSSED 

The order Lepidoptera contains a large number of 
families the members of which are not commonly 
collected by the general student. The following list 

includes the families 
not discussed in this 
Manual but of which 
the student can find an account in " An 
Introduction to Entomology " by J. H. 
Comstock. 


Fig. 487. — Chrysa- 
lis of Feniseca. En- 
larged. 


2d A 


Fig. 432. — Wings of Anisota virgimensis. 
See pages 246 and 248. 


Nepticulidae 

Dalceridee 

Epipyropidae 

Acrolophidae 

Tischeriidae 

Oinophilidae 

Elachistidae 

Heliozelidae 

Douglasiidae 

Ethmiidae 

Stenomidae 

Blastobasidae 

Cosmopterygidae 

Scythrididae 

Glyphipterygidae 

Heliodinidae 


Phaloniidae 

Carposinidae 

Orneodidae 

Thyrididae 

Hyblaeidae 

Manidiidae 

Dioptidae 

Pericopidae 

Euchromiidae 

Eupterotidae 

Epiplemidae 

Thyatiridae 

Drepanidae 

Lacosomidae 

Riodinidae 


CHAPTER XXV 
ORDER DIPTERA* 

The Flies 

The winged members of this order have only two wings; these are borne 
by the mesothorax. The second pair of wings is represented by a pair of 
knobbed, thread-like organs, the halteres; these are present in nearly all flies, 
even when the mesothoracic wings are wanting. The mouth-parts are formed 
for sucking. The metamorphosis is complete. 

To the order Diptera belong all insects that are properly termed flies, 
and only these. The word fly forms a part of many compound names of 
insects of other orders, as butterfly, mayfly, and chalcis-fly; but when 
used alone, it is correctly applied only to dipterous insects. To some flies 
other common names have been applied as mosquito, gnat, and midge. 
The presence of a single pair of wings and of a pair of halteres is 
sufficient to distinguish most members of this order from those of all 
other orders, except in the case of male coccids. 

The wings of flies are thin, membranous, and usually either naked or 

clothed with microscopic hairs; but 
with mosquitoes the wings bear scales, 
and with the moth-like flies (Psycho- 
didse) and some others the clothing of 
hairs is very conspicuous. The hind 
wings are represented by a pair of 
knobbed organs, the halteres; these can 
be easily seen in a crane-fly (Fig. 488). 
They are present in nearly all flies, even 
when the front wings are wanting. 

The mouth-parts of flies are formed 

for sucking, and sometimes also for 

piercing. Their structure differs greatly 

in different families; and in some cases 

fig. 4*88. -A crane-fly, showing wingTand hai- it is exceedingly difficult to determine 

teres - the correspondence of the different parts. 

In the more typical forms the mouth-parts consist of six bristle-like 

or lance-like organs enclosed in a sheath, and a pair of jointed palpi. 

According to the most generally accepted view the six bristles rep- 
resent the upper lip (labrum), the tongue (hypopharynx) , the two man- 
dibles, and the two maxillae, and the sheath enclosing these bristles is 
the lower lip (labium). The palpi which are not enclosed in the sheath 
are the maxillary palpi. At the tip of the lower lip there is, on each 
side, a lobe-like appendage; these are the labial palpi. The labial palpi 
of certain flies are quite large; in the housefly, for example, they are ex- 
panded into broad plates, which are fitted for a slight rasping function. 
In their transformations flies pass through a complete metamorphosis. 
The larvae are commonly called maggots. These are usually cylindrical 
* Diptera: dis (Sis), two; pteron {wrepbv), a wing. 
286 


DIPT ERA 


287 


and are footless; some possess a distinct head, others do not; and there are 
remarkable variations in the form of the respiratory organs, especially as 
to the number and position of the spiracles. The pupa? are usually 
either naked or enclosed in the last larval skin. A few are enclosed in 
cocoons. When the pupa state is passed within the last larval skin the 
body of the pupa separates from the larval skin more or less completely ; 
but the larval skin is not broken till the adult fly is ready to emerge. In 
this case the larval skin, which serves as a cocoon, is termed a puparium. 
In some families the puparium retains the form of the larva; in others 
the body of the larva shortens, assuming a more or less barrel-shaped 
form (Fig. 553), before the change to a pupa takes place. 

This is a large order, both in number of species and individuals. The 
species differ much in habits. Some are very annoying to man. Famil- 
iar examples are the mosquito, which attacks his person; the flesh-flies 
which infest his food ; the bot-flies and gad-flies that torment his cattle ; 
and the gall-gnats that destroy his crops. Other species are very benefi- 
cial. Many of the Syrphidas, and Tachinidse destroy certain noxious 
insects; and other species, while in the larval state, feed upon decaying 
animal and vegetable matter, thus acting as scavengers. 

Although the habits of some of these creatures, which revel in all 
kinds of filth, are very disgusting, we cannot help admiring that arrange- 
ment by which a mass of filth, instead of being left to poison the atmos- 
phere, is transformed into myriads of living beings, whose swift flight and 
delicate forms lend life and beauty to the landscape. 


CLASSIFICATION OF THE DIPTERA 

In the following table for determining the families of the Diptera, use 
is made chiefly of characters based on the form of the head, antennae, 
and wings. 

The more important of the charac- 
ters presented by the head are the pres- 
ence or absence of the frontal lunule, and 
the presence or absence of. the frontal 
suture when the lunule is present. 

The frontal lunule is a small crescent- 
shaped piece immediately above the an- 
tennae, which is characteristic of the 
second suborder, the Cyclorrhapha. In 
most of the members of this suborder 
there is a suture separating the lunule 
from that part of the head above it, the 
frontal suture; and frequently this suture 
extends down on each side to near the 
mouth (Fig. 489). But as the suture is 
wanting in several families of the Cyclor- 
rhapha, it is often difficult to determine 
whether the lunule is present or not. 

In those families that possess the 
frontal suture there exists a large blad- 
der-like organ, the ptilinuni which is 
pushed out through this suture when the adult is about to emerge from 


Fig. 489. — Head of a fly: A, antennae; ar, 
arista; E, eye; /. /., frontal lunule; f.s., frontal 
suture. 


288 


THE STUDY OF INSECTS 


the puparium. In this way the head end of the puparium is forced off, 
making a large opening through which the adult escapes; afterwards the 
ptilinum is withdrawn into the head. If a specimen is captured soon 
after its emergence from the puparium, there may be seen instead of 
the frontal suture the bladder-like ptilinum projecting from the head, 
immediately above the antennae. 

The form of the antennae is of prime importance in determining to 
what family a fly belongs. In the more generalized families the antenna 
consists of many segments, which, except the basal two, are similar in 


Fig. 490. 


Fig. 491. 


Fig. 492. 


Fig. 403. 


Fig. 494, 


Fig. 495. 


form (Fig. 490). Frequently such antennae bear whorls of long hairs 
(Fig. 491). In the more specialized families there is a reduction in the 
number of segments of the antenna. This is brought about either by a 
more or less complete consolidation of the segments beyond the second 
into a single segment (Figs. 492 and 493), or by a dwindling of the terminal 
segments, so that they form merely a slender style (Fig. 494) or bristle (Fig. 
495). Such a bristle is termed by many writers the arista. In most cases 
where a style or arista exists it is borne by the third segment, and this 
segment is then usually greatly enlarged. When the enlargement of this 
segment has taken place evenly the style or arista is terminal; but fre- 
quently one part of the third segment is expanded so that it projects 
beyond the insertion of the arista (Fig. 496) ; then the arista is said to be 
dorsal. 

The legs vary greatly in length and in 
stoutness. The coxae are usually long, and 
in most of the fungus-gnats (Mycetophilidae) 
they are very long. When pulvilli are de- 
veloped they are membranous pads, one 
beneath each tarsal claw. A third append- 
age, the empodium, often exists between the 
two pulvilli of each tarsus. The empodia 
may be bristle-like, or tapering (Fig. 497), 
or membranous, resembling the pulvilli in 
form (Fig. 498) ; in the last case they are 
described as pulvilliform. 

Variations in the form and venation 
of the wings afford characters that are much used in the classification of 
flies. In many families there is a notch in the inner margin of the wing 
near its base (Fig. 499, a e) ; this is the axillary excision; that part of the 
wing lying between the axillary excision and the base of the wing is the pos- 


FiG. 496. 


DIPTERA _ 289 

terior lobe (Fig. 499, 1). In certain families there is a membrane beneath the 
base of the wing and above the halter or rudimentary hind wing ; this is the 
alula or alulet. The alulae are well developed in the common housefly. Each 
alula, in those species where the alulae are well developed, consists of two 
lobes which fold over each other when the wings are closed. The alulae are 


R< /?j+i 


2d A+Cu, 


O* 


Fig. 499. — Wing of Conops. 


called the tegulce by many writers on Diptera; but the term tegula was 
first used in insect anatomy for the cup-like scale which covers the base 
of the wing in certain insects, as most Hymenoptera, and should be re- 
stricted to that use. The terms alula and alulet are also often misap- 
plied, being used to designate the posterior lobe of the wing. 


R> R,+> 


id A 

FlG. 500. — Wing of Anisopus. 

The plan of the venation of the wings can be easily learned by a 
study of the wing of Anisopus (Fig. 500), which is very generalized in 
structure, except that vein R is only three-branched, which in certain 
still more generalized forms is five-branched (e.g., the primite wing of 
Psychoda, Fig. 506). In the figures of wings in this chapter both the 
veins and the cells are lettered. The letters outside of the margin of the 
wing refer to the veins; those within, to the cells, except when otherwise 
indicated by a dotted line or by an arrow. It should be remembered 
that each cell bears the same letter as the vein that forms its front mar- 
gin when the wings are spread. When a cell is divided by a cross-vein 
the two parts are numbered 1st and 2d. Thus in Anisopus, cell M 2 is 
divided, and the parts are designated as the 1st cell M 2 and the 2d cell 
M 2 (Fig. 500, 1st M 2 , 2d M 2 ). A cross-vein is marked by an arrow. 


2 9 o THE STUDY OF INSECTS 

The Costa extends along the costal margin of the wing; it usually 
ends somewhere near the apex of the wing; in Anisopus it ends at the 
tip of win K 4 i„ (Fig. 500). In some families it extends entirely around 
the wing; it is then called the ambient vein. Vein Sc is simple. Vein R is 
typically five-branched ; but the number of branches is usually reduced to 
four or to three. Vein M is three-branched in the more generalized 
forms. Vein Cu is two-branched. The first anal vein is usually merely a 
concave fold jusl behind vein Cu and parallel with that vein; it is repre- 
sented in most of the figures of wings by a dotted line. The second anal 
vein is usually present; and sometimes the third anal vein also exists. 

One of the most marked features in the specialization of the wings 
of Diptera is a tendency of the veins to coalesce from the margin of the 
wing towards the base. This is illustrated by the wing of Conops (Fig. 
499). In this genus veins R 4+5 and Mi +2 coalesce at the margin of the 
wing; veins M 3 and Cui coalesce for nearly their entire length. The re- 
sult of this coalescence is to cause the free part of vein M 3 to appear 
like a cross- vein between cells M and the 1st cell M 2 . Veins Cu 2 and 
2d A also coalesce at the margin of the wing. 

In a few genera of flies certain longitudinal veins are bent so as to 
form a sharp angle, and from this angle a spur is developed. Thus in 
the primitive crane-flies there is a sharp angle near the base of vein R 2+5 
which bears a spur; in Mydas a similar spur is formed on vein R 4 (Fig. 
549); and in Pantarbes this spur on vein R 4 is prolonged so as to form 
a complete cross-vein dividing cell R 3 into two parts. 


TABLE OF FAMILIES OF DIPTERA 

A. Flies in which the abdomen is distinctly segmented, and the two legs of each 

thoracic segment are not widely separated. Habits various, but the adults do 

not live parasitically upon either birds or mammals. 

B. Antennae consisting of at least six distinct segments, the palpi in most cases 

of four or five segments (Nemocera). 

C. Small moth-like flies, with the body and wings densely clothed with hair 

and scales. Wing with from nine to eleven longitudinal veins but with no 

cross- veins except sometimes near the base of the wing (Fig. 506). p. 295. 

PSYCHODID^E 

CC. Flies that do not resemble small moths in appearance. 

D. Mesonotum with a more or less distinct V-shaped suture (including Tany- 

derinae, Ptychopterinas and Pipulinae). p. 293 Tipulid^e 

DO. Mesonotum without a distinct V-shaped suture. 

E. Media three-branched; ocelli present, p. 295. (In part) Anisopid^e 
EE. Media simple, two-branched or wanting; cell M 2 not divided by a 
cross-vein. 

F. Wing with network of fine lines, p. 304 Blepharocerid^e 

FF. Wing without network of fine lines. 

G. Margin of wings and wing-veins fringed with scales or scale-like 

hairs. (Fig. 512). p. 297 CuLlCIDiE 

GG. Wing veins with or without hairs but without fringe of scales. 
H. Anal vein entirely wanting; vein M wanting or represented by a 

single unbranched fold. p. 301 Cecidomyid,*: 

HH. Anal vein usually present or represented by folds; vein M 
present or represented at least by a fold which is usually 
branched. 
I. Ocelli present. 

J. Antennae shorter than the thorax; coxae not usually long; 

cross- vein m-cu absent or present, p. 302 Bibionid^e 

JJ. Antennae usually longer than the thorax and in many cases 
with much elongated coxae. 


DIPT ERA 


291 


K. With tibial spurs, p. 300 Mycetophilidje 

KK. Without tibial spurs, p. 301 Cecidomyid^e 

II. Ocelli absent. 

J. Antennae short, segments wider than long; wings very broad. 

P- 303 9 SlMULIID^E 

JJ. Antenna? either with narrow segments or bushy with dense 
coat of hairs; wings narrow or moderately broad. 
K. Media forked and cross-vein m-cu present, p. 295. 

Dixid.e 

KK. Media not forked when m-cu cross-vein is present. 

(Inclusive of Thaumalea) p. 296 Chironomid,e 

BB. Antennas consisting of not more than four segments, in some cases the last 
segment is again divided into several closely fused subsegments; palpi with 
not more than two segments; if the antenna; have numerous segments in 
exceptional cases, the empodium is developed pulvilliform (Fig. 498). 
C. Empodium developed pulvilliform, that is, three rounded pads under the 
tarsal claws. 
D. Third antennal segment consisting of several subsegments or antennae 
consisting of more than three segments. 
E. Branches of the radius crowded together near the costal margin in most 
cases (Fig. 536), tibiae without spurs, costal vein discontinued at or 

before the apex of the wing. p. 307 Stratiomyid^e 

EE. Venation not of this type. 

F. Alulets large; venation as in figure 532 Tabanid^e 

FF. Alulets small or vestigial. Coenomyid<e, Xylomyhxe, and Xylopha- 

GID/E. 

DD. Third antennal segment simple. 

E. Alulets very large; head very small, p. 308. . . . (Cyrtid^e) Acrocerid/E 
EE. Alulets small. 

F. Costa extends around the apex of the wing. p. 307 .... Rhagionid^e 
FF. Costa ends at the apex of the wing; venation intricate. 

Nemestrinidce 

CC. Empodium absent or in the form of a thread, that is, only two pads under 
the tarsal claws. 
D. Antennae consisting apparently of a single globular segment with arista; 
anterior veins of the wing stout, posterior veins weak. (Fig. 554). p. 313. 

Phorid^e 

DD. Antennas with but few exceptions with three easily distinguished seg- 
ments. 
E. Cells M and 1st M 2 not separated (Fig. 550). 

F. Frontal suture absent; vein R with a knot-shaped swelling near the 
forking of the radial sector; the r-m cross- vein near this swelling 
when present; flies in most cases metallic in coloring, p. 310. 

Dolichopodim: 

FF. Frontal suture present; vein R with or without this swelling; the 
cross vein more remote from the base of the wing in most cases. 
Acalyptratas such as some Drosophilid^e, p. 318, Agromyzid^e, p. 318, 

EPHYDRIDvE, p. 317, CHLOROPID.E, p. 317, BORBORID/E. 

EE. Cells M (or 2d M) and 1st M 2 separate. 
F. Radial sector three branched. 

G. Vertex of the head distinctly hollowed out between the eyes; eyes 
never contiguous. Large species in most cases. 
H. Proboscis with fleshy labella at tip; venation complicated (Fig. 

549)- P- 310 Mydaid^e 

HH. Proboscis horny and rigid, without labella at tip. p. 309. 

ASILID.E 

GG. Vertex not hollowed out between the eyes. 
H. Cell M 3 present. 

I. Vein R 5 ending before the apex of the wing Apiocerida 

II. Vein R 5 not ending before the apex of the wing. p. 309. 

■ • • Therevid^e 

H. Cell M 3 obliterated by the coalescence of veins M 3 and Cui. 
I. Third segment of the antennas without a style or an arista; 
vein Mi ending at or before the tip of the wing. p. 309. 
Scenopinid^e 


29 2 THE STUDY OF INSECTS 

II. Third segment usually with style or arista; Mi ending beyond 
the apex of the wing. 
J. First branch of the cubitus extending free to the margin of 
the wing or coalesced with the vein 2d A for a short dis- 

tance a1 the margin of the wing. p. 308 Bombyliid^ 

JJ. First branch of the cubitus joining 2d A far from the margin 
of the wing, often extending to the base of the wing. p. 311. 

Empidid,e 

FF. Radial sector with not more than two branches. 

G. Wings lanceolate (Fig. 552). p. 312 Lonchopterid,e 

GG. Wings not of this type. 

H. Vein Cu 2 not coalesced with 2nd A to such an extent as to cause 
the free part to appear like a cross- vein. 

I. Antennae with terminal arista, hind tarsi often broad and flat. 

( Fig. 495) Platypezida 

II. Antennae with dorsal arista; or in some cases, a terminal style. 
J. Head extremely large; entire surface nearly occupied by eyes. 

(Fig- 555)- P- 313 Pipuncuud^e 

JJ. Head not of the type represented by figure 555. 

K. Wing with a vein-like thickening, the spurious vein, 
between veins R and M; if wanting then front convex 

beneath antennae (Fig. 556). p. 314 Syrphid^e 

KK. Wing without spurious vein; front with grooves or a 

depression beneath the antennae Conopidce 

HH. Vein Cu 2 appearing as a cross- vein or curved back toward the 
base of the wing (Figs. 550, 551). 

I. Frontal suture absent; antennae in most cases with a terminal 

style or arista, p. 31 1 EmpididjE 

II. Frontal suture present; antennae with dorsal arista. 

J. Alulae or calypteres small or rudimentary; subcostal vein 
often indistinct or vestigial but often well preserved; vein 
Ri rather short; thorax without complete transverse suture; 
abdominal spiracles in most cases in the conjunctiva. Aca- 
lyptratae including Agromyzid^e, p. 318, Piophilid,e, p. 316, 
DiopsidcE, Psilid^e, p. 317, ChloropiDjE, p. 317, Ortalieme, 
p. 315, Trypetid^e, p. 315, Sapromyzida, etc. 
JJ. At least the lower lobe of the calypteres or alulae well de- 
veloped; subcostal vein distinct for its whole course; trans- 
verse suture complete; abdominal spiracles in most cases in 
the lower margin of the tergites. 
K. Proboscis much reduced or vestigial, not functional; 
mouth-opening small (bot-flies). 
L. Cell R 5 wide open in the margin (horse bots), p. 319. 

Gasterophilid.e 

LL. Cell R 5 nearly closed in the wing margin, p. 320. 

CEstriDjE 

KK. Mouth-opening normal; mouth-parts functional. 

L. Hypopleura (sclerite below the posterior spiracle and 
above hind coxae) bare or with only some fine hairs. 
M. Cell R 5 very slightly or not at all narrowed in the 
wing margin. 
N. Alulets rather small, lower one not projecting notice- 
ably beyond the upper; under surface of the 
scutellum without short, fine hairs; anal vein not 
suddenly flexed up toward the end. (Scatophagidas). 

p. 318 CORDYLURID^E 

NN. Alulets larger, the lower one projecting beyond the 
upper, or if small, either there are short hairs on 
the lower surface of the scutellum or the second 
anal vein is short and suddenly flexed up toward 

the end. p. 319 Anthomyid;E 

MM. Cell R 6 much narrowed in the wing-margin; arista 

plumose in most cases, p. 323 Muscid>e 

LL. Hypopleura with one or more vertical series of strong 
setae. 


DIPT ERA 293 

M. Postscutellum very distinct, i.e., metanotum with a double 
convexity, (including Dexiinae, Phasiinae, and Megapro- 

sopina3).p. 323 Tachinid^e 

MM. Postscutellum not distinct, metanotum with single con- 
vexity. 
N. Notopleural setae* (i.e., those just above the dorso-pleural 
suture in front of the base of the wing) two in number; 
hind coxae bare behind, above base of hind femur; in 
most cases metallic greenish or bluish species, p. 321 

Calliphorid^e 

NN. Notopleural setas three or four in number, if with 
but two, then arista either pubescent or bare; 
species in most cases grayish with a more or less 

tessellated abdomen, p. 322 Sarcophagid;e 

AA. Parasitic flies in which the abdomen is indistinctly segmented (except in Braula) 
and the two legs of each thoracic segment are widely separated by the broad ster- 
num. Parasitic upon bees, Braulidae; upon bats, Streblidae and Nycteribiidae; 
upon other mammals and birds, Hippoboscidae. p. 324 Pupipara 

Suborder ORTHORRHAPHA f 

The Straight-seamed Flies 

This suborder includes those flies in which the pupa escapes from the 
larval skin through a T-shaped opening, which is formed by a lengthwise 
split on the back near the head and a crosswise split at the front end of 
this (Fig. 501), or rarely through a crosswise 
split between the seventh and eighth abdominal 
segments. The adults do not have a frontal lunule. 

The families included in this suborder are 
commonly grouped in two series: the Nemocera and the Brachycera. 

SERIES I. STRAIGHT-SEAMED FLIES WITH LONG ANTENNA 

{Nemocera J) 

Family Tipulid^e 

The Typical Crane-flies 

The crane-flies are mosquito-like in form; but they are usually very 
much larger than mosquitoes. The body is long and slender, the wings 
narrow, and the legs very long (Fig. 502). This family includes the 
larger members of the Nemocera but it also includes some species that 
are not larger than certain mosquitoes. The most distinctive feature of 
crane-flies is the presence of a transverse V-shaped suture on the dorsal 
side of the mesothorax (Fig. 503). 

Crane-flies are seen most often in damp localities, especially where 
there is a rank growth of vegetation; but sometimes they occur in great 
numbers flying over meadows and pastures. In most cases their power of 
flight does not seem to be well developed for they fly slowly, and only a 
short distance at a time. Some species, however, sustain themselves in 

* See "An Introduction to Entomology" by J. H. Comstock, p. 784. 
f Orthorrhapha; orthos (6p6s), straight; rhaphe (pa<f>r)), a seam. 
| Nemocera: nema (vrj/jta), thread; (k«p<xs), horn. 


294 THE STUDY OF INSECTS 

the air for long periods. This is especially true of some of the smaller 
species, which often collect in swarms at twilight, forming a small cloud, 


Fig. 503. — Tho- 
rax of a crane-fly 
showing the V- 
Fig. 502. — A crane-fly. shaped suture. 

and dancing up and down like some of the midges. Their ability to walk 
is also poor; for they use their long legs awkwardly, as if they were in 
the way. This has suggested the rhyme : — 

"My six long legs, all here and there, 
Oppress my bosom with despair." 

The larvae of crane-flies vary greatly in habits both as to the situa- 
tions in which they live and as to the nature of their food. Some are 
aquatic; some live in or beneath damp cushions of moss. Many live in 
mud or sand along the margins of streams, in swamps, or in shaded 
woods, while others are strictly terrestrial, burrowing in the soil of 
meadows and pastures. 

The larvae of most species are scavengers feeding on decaying vege- 
table matter, but some feed on living vegetable tissue, and still others are 
carnivorous. 

The Tipulidae is a large family; nearly 3,000 species are known and 
about 500 species have been described from North America alone. 

The larvae of some species of crane-flies, most of which belong to the 
genus Tipula, often do considerable damage in meadows, pastures, and 
grain fields by devouring the roots of the plants. The full-grown larvae 
are about one inch long and of a dirty-grayish color. As the body-wall 
is of a tough leathery texture these larvae are commonly known as 
leatherjackets. Serious outbreaks of these pests have occurred at various 
times in Ohio, Indiana, Illinois, and California. In the case of the 
species infesting ranges, pastures, and grain and alfalfa fields in Cali- 
fornia it was found that the larvae usually come out upon the surface of 
the ground during the night and could be destroyed by the use of poi- 
soned-bran bait, made by mixing one pound of Paris green, twenty-five 
pounds of bran, and sufficient water to make a flaky mash. The bait is 
applied with a broadcast grain seeder. 

There are three other families of closely related crane-flies, namely: 
the primitive crane-flies, Tanyderidce, which are of interest because they 
are the most generalized of living crane-flies; the phantom crane-flies, 
Ptychopterida, of which one species, Bittacomorpka cldvipes, is the most 


DIPTERA 


295 


common and interesting. Its legs, which are banded with black and 
white are held outspread as it flies and make it a very conspicuous object 
as it drifts phantom-like through the air; and the false crane-flies 
Anisopidce, some of which are mosquito-like with spotted wings and often 
enter houses where they are found on window panes. Others of the genus 
Trichocera, appear in swarms in autumn and early spring and sometimes 
on warm sunny days in winter. 

Family Dixid^e 
The Dixa-midges 

These midges closely resemble mosquitoes 
in size and form; but the wing-veins do not 
bear scales. The family includes only a single 
genus, Dixa. 

The adult midges occur in the vicinity of 
streams and in swampy places. 

The larvae are aquatic, living in ponds or 
slowly running water ; they resemble somewhat 
those of Anopheles but the body is almost always 
bent so that the head and tail come close to- 
gether. They progress by alternate thrusts of 
the two ends of the body, the bent portion 
traveling foremost (Fig. 504). 

Family Psychodid^ 

The Moth-like Flies 

There may be found frequently upon windows and on the lower sur- 
face of the foliage of trees small flies which have the body and wings 
densely clothed with hair and which resemble tiny moths in 
appearance. The wings are broad, and when at rest slope at the 
sides in a roof-like manner or are held horizontally in such away 
as to give the insect a triangular outline (Fig. 505). The vena- 
tion is peculiar; cross-veins are almost wanting (Fig. 506). 

The moth-like appearance of these insects is sufficient to 
distinguish them from all other flies. 


Fig. 504. — Larva of Dixa. (After 
Needham and Lloyd.) 


^TN 


Fig. 505. — A 
moth-like fly. 


Fig. 506. — Wing of a moth-like fly. 


296 


THE STUDY OF INSECTS 


The antenna? are long and slender, and 
hairs (Fig. 507). 


are clothed with whorls of 


The moth-like flies are often very minute 
and rarely exceed I of an inch in length. Most 
of the species, so far as is known, feed on nectar 
or other fluid matter other than blood; but the 
species of the genus Phlcbotomus are blood-suckers, 
feeding upon the blood of various reptiles, 
amphibians and mammals, including man; and 
it has been found that some exotic species trans- 
mit certain diseases of man, as the European 
pappatici fever, or three day fever, and the Peru- 
vian verruga. One or two species of the genus, 

Phlebotomus, have been found in the United States. 

The larvae of members of this family are found in various situations; 

in decaying vegetable matter, in sewage, in cow dung, in exuding sap on 

tree-trunks, and in streams. 


Fig. 507. — Antenna? of Psy- 
choda. m, antenna of male and the 
second segment of the same more 
enlarged; /, antenna of female and 
the tip enlarged. 


Family Chironomid^e 
The Midges 

The members of this family are more or less mosquito-like in form, 
but are usually more delicate than mosquitoes. The 
abdomen is usually long and slender; the wings nar- 
row; the legs long and delicate; and the antennae, 
especially in the males, strongly plumose (Fig. 508). 
In fact many of these insects are commonly mistaken 
for mosquitoes; but only a few of them can bite, the 
greater number being harmless. 

The midges are most easily distinguished from 
mosquitoes by the structure of the wings (Fig. 509). 
These are furnished with fewer and usually less dis- 
tinct veins; and the veins, although sometimes hairy, are not fringed 
with scale-like hairs. 


Fig. 508. — Antennas of 
Chironomus. f, female; m, 
male. 


/?, /?, + 3 


Ra, + i 


-JM 


Fig. 509. — Wing of Chironomus. 

The name midge has been used in an indefinite way, some writers 
applying it to any minute fly. It is much better, however, to restrict it 
to members of this family except where it has become firmly established 
as a part of a specific name. 

Midges often appear in large swarms, dancing in the air, especially 
towards the close of day. Professor Williston states that, over meadows 


DIPTERA 


297 


in the Rocky Mountains, he has seen them rise at nightfall in most 
incredible numbers, producing a buzzing or humming noise like that of a 
distant waterfall. 

Most larva? of midges are aquatic; but some live either in manure, 
in decaying vegetable matter, under bark, or in the ground. Some of the 
pupse are free and active, others are quiescent. The larvae and pupae of 
the aquatic species are of much importance as fish-food. 

Many of the aquatic larvae live in tubes which they build of bits of 
dead leaves and particles of sand fastened together with viscid threads. 
These tubes are frequently seen upon the surface of dead leaves, stones, 
and sticks; and they are often made in the mud of the bottom of a pool, 
in which case they open at the surface of the mud. Many of the species 
are blood-red in color, and hence are frequently known as blood-worms. 

The aquatic larvae feed on algae, decaying vegetable matter, diatoms, 
and small Crustacea; the terrestrial species, on manure or decaying 
vegetable matter. There are a few cases 
reported of the larvae infesting the roots of 
plants in greenhouses and mining in the 
leaves of plants. 

To the genus Culicoides belong the small 
midges commonly known as sandflies or 
punkies. Certain minute species are some- 
times very abundant, and extremely an- 
noying on account of their bites. They are 
exceedingly troublesome in the Adirondack 
Mountains, in the White Mountains, and 
along mountain streams generally; they 
are also abundant in some places at the 
are sometimes called " no-see-um,' 


Fig. 510. — A punkie, Culicoides gultipennis. 


seashore. These tiny midges 
an Indian name for them (Fig. 510). 


Family Culicid^e 
The Mosquitoes 


The mosquitoes are small flies, with the abdomen 
fig. 511. — Antenna l° n & an( A slender, the wings narrow, the antennae 
of mosquitoes, m, male; plumose in the males, (Fig. 511), and usually with 
a long, slender, but firm proboscis. The most dis- 
tinctive feature of mosquitoes is the fringe of scale-like setae on the margin 
of the wings and also in most cases on each of the wing- veins (Fig. 512). 
The mouth-parts of most mosquitoes are constructed for piercing and 


id A 

Fig. 512. — Wing of a mosquito. 


2g8 


THE STUDY OF INSECTS 


sucking. They consist of six bristles or stylets enclosed in a sheath 
formed by the" labium. In those members of the subfamily, Corethrincs, 

the mouth-parts are short and not 
adapted to sucking. 

The different species of mosqui- 
toes differ greatly in their manner of 
oviposition. Those most often ob- 
served about water-barrels, Culex, 
lay their long, slender eggs side by 
side in a boat-shaped mass, on the 
surface of the water (Fig. 513); 
species of Anopheles deposit their 
eggs separately upon the surface of 
the water ; and many Aedes lay their 
eggs on the ground after the pools in 
which they were developed have 
dried out. In this case the eggs re- 
main unhatched until later rains or 
melting snows refill the pools. The 
eggs of some mosquitoes hatch very 
soon after they are laid; but with 
Fio. 513. — a glass of water containing eggs, iarvs, the majority of species the winter 

and pupa, of mosquitoes. fe passed in ' the egg state _ 

The larvae of mosquitoes are all aquatic. They are well known and 
are commonly called " wigglers," a name suggested by their wriggling 
motion as they swim through the water. They vary in details of struc- 
ture but the larva of Culex will serve to illustrate the general form of the 
body (Fig. 514, a). The head and 
thorax are large and the abdomen 
is slender. The next to the last ab- 
dominal segment, the eighth, bears 
a breathing-tube; and when the 
larva is at rest it hangs head down- 
ward in the water, with the opening 
of this tube at the surface (Fig. 
513). At the end of this tube 
there is a rosette of plate-like 
lobes (Fig. 515, a) which resting 
on the surface film, keeps the larva in position. 

The food of most mosquito larvae consists of organic matter which 
they find in the water in which they live. Some larvae are predacious 
on small aquatic animals. 

The pupae of mosquitoes like the larvae are aquatic, but they differ 
greatly in form from the larvae (Fig. 514. &)■ The head and thorax are 
greatly enlarged and are not distinctly separated, while the abdomen is 
slender and flexible. With the change to the pupa state a remarkable 
change takes place in the respiratory system. There are now two breath- 
ing tubes, and these are borne on the thorax. 

Only female mosquitoes suck blood and many of these attack birds 
and mammals rather than man. Some species are said not to suck blood 
at all. Male mosquitoes feed on nectar, the juices of ripe fruits and 
other sweet substances. 


Fig. 514. — Mosquitoes. 
a, larva; b, pupa. 


end 
of 
larva; b, breathing 
tube of pupa. 


Fig. 5i5- 
breathing-tube 


DIPT ERA 


299 


The small group of mosquitoes of the subfamily, Corethrinoe, have 
short probosces unfitted for sucking blood. The larvae of these forms 
are predacious and live on infusoria, small crustaceans and small larvae of 
other mosquitoes. All of our common mosquitoes belong to the sub- 
family, Culicince, the more important ones to the genera, Culex, Anopheles 
and Aides. 

Culex. — To this genus belong our common house mosquitoes that 
have unspotted wings and short palpi in the females. These are very 
annoying pests; but although many of the species of this genus transmit 
blood diseases of birds and animals they do not play an important role 
in human diseases except one species which conveys the organism causing 
elephantiasis. 

Aides. — This is a very large genus of world-wide distribution. The 
species vary greatly in habits; but with most of them the larvae develop 
from over-wintering eggs in early spring pools. Some species, however, 
breed in water-barrels, and other artificial containers; one of these is the 
carrier of yellow fever. 

The yellow-fever mosquito, Aides cegypti, is distributed throughout 
all tropical regions of the world and is often carried by commerce into 
temperate regions. But as it is destroyed by frost it can not become 
established when frosts occur. Hence outbreaks of yellow fever in the 
North are checked naturally as winter approaches, and with our present 
knowledge of the method of control of this disease it is not probable that 
it will be permitted to become epidemic again in the "United States. 

The yellow-fever mosquito breeds in cisterns, water-barrels, flower- 
vases, and in the various water receptacles about houses. The life-cycle 
under favorable conditions is completed in from twelve to fifteen days. 
This is essentially a domesticated species. It is rarely found far from the 
habitations of man. 

Anopheles. — To this genus belong those mosquitoes that have been 
found to be the carriers of malaria. At least four species of Anopheles 
in the United States, are known to be carriers of this disease. In this 
genus the palpi of both sexes are nearly or quite as long as the proboscis 
and the wings are frequently spotted. When at rest on a vertical wall 
the body is usually held at an angle with the vertical. Some species often 
enter houses. They hibernate in the adult state and can be found during 
the winter in cellars. 

The larva when at rest floats in a 
horizontal position beneath the sur- 
face film (Fig. 5r6). There is no res- 
piratory tube but instead a flattened 
area on the eighth abdominal segment 
into which the two spiracles open. FlG _ Sl6 __ Normal posit!on of the larviE of Cuhx 

Other mOSquitO-bome diseases Of an .d Anopheles when at rest. Culex, left, Anopheles, 
T \ . , • , 1 middle; Culex pupa, right hand figure. 

man. — In tropical countries there are, 

in addition to malaria and yellow fever, two other diseases of man that 
have been found to be transmitted by mosquitoes; these are dengue and 
filariasis. The latter disease is accompanied by extraordinary deformities 
and enlargements of different parts of the human body known as ele- 
phantiasis. Filariasis is due to the presence in the blood, the lymphatics, 
and certain tissues of the body, of nematode (round) worms of the family, 
Filariidae. These worms pass a part of their life-cycle in the bodies of 
certain mosquitoes. 


300 


THE STUDY OF INSECTS 


Family Mycetophilid-iE 

The Fungus-gnats 

These flies are of medium or small size, and more or less mosquito- 
like in form. They are most easily recognized by the great length of 
the coxae (Fig. 517), and the fact that all the tibiae are furnished with 


Fig. 517. — A fungus-gnat. (After Johannsen.) 


Fig. 518. — An 
antenna of a male 
fungus-gnat. 


spurs. They also differ from the closely-allied families in lacking whorls 
of hairs on the antennae of the males (Fig. 518), and in possessing ocelli. 

The fungus-gnats are exceedingly numerous both in number of in- 
dividuals and in number of species. They are often found in great num- 
bers on fungi and in damp places where there is decaying vegetable 
matter. They are active and leap as well as fly. 

The larvae of most species live upon and destroy mushrooms, usually 
I lie wild plants, but sometimes they are pests in mushroom cellars; other 
species are found in decaying wood. 

The larvae of the fungus-gnats are more or less cylindrical, smooth, 
soft, whitish in color, and with small strongly chitinized heads which are 
usually brown or black, and are provided with mandibles and maxillae. 
There are usually eight pairs of spiracles. 

The pupa is not enclosed in the skin of the larva; but in some genera 
the transformations are undergone in a delicate cocoon. 

The larvae of some species of the genus Sciara often attract attention 
on account of a strange habit they have of sticking together in dense 
patches. Such assemblages of larvae are frequently found under the bark 
of trees. But what is more remarkable is the fact that when the larvae 
are about to change to pupae an assemblage of this kind will march over 
the surface of the ground, presenting the appearance of a serpent-like 
animal. Such a congregation is commonly spoken of as a Sciara-army- 
worm. Examples have been described that were four or five inches wide 


DIPTERA 


301 


and ten or twelve feet long, and in which the larvas were piled up from 
four to six deep. The larvas crawl over each other so that the column 
advances about an inch a minute. 

Some species of Sciara are sometimes injurious to house plants and to 
plants in greenhouses for their larvas live in the soil and eat off the roots 
of the plants. 

Family Cecidomyid^e 

The Gall-gnats 

The gall-gnats are minute flies which are extremely delicate in struc- 
ture. The body and wings are clothed with long hairs, which are easily 
rubbed off. The antennas are usually long and clothed with whorls of 
hairs (Fig. 519); but they vary greatly in length and in the number of 
their segments. The legs are slender and quite long, but the coxae are 
not greatly elongated and the tibiae are without spurs. 

In most, the wing-veins are greatly reduced in number, 
the anal veins being entirely wanting. 

To this family belong the smallest of the midge-like 
flies. The larvae of many species cause the growth of 
galls on plants. Other species arrest the growth of the 
plants they infest, and cause very serious injury. 

The larvae are small maggots, with nine pairs of 
spiracles. The head is small, poorly developed, and with- 
out mandibles. Many species are brightly colored, be- 
ing red, pink, yellow, or orange, and many species 
possess in the last larval instar a peculiar chitinous organ 

on the ventral aspect of the prothorax; 

this organ is known as the breast-bone or 

sternal spatula, or anchor process (Fig. 

520). It varies in form in different species ; different views 

are held regarding 

its function, none of 

which seems well 

established. 
The larval mouth-parts are fitted 
only for taking liquid food; but the 
nature of this food differs greatly in 
different members of the family. 
Some suck the juices from the bodies 
of living aphids, coccids, mites, and 
larvae and pupae of other flies; but 
most live on the juices of plants. 

The different species vary as to the 
method of undergoing their trans- 
formation ; in some the pupa is naked ; 
in others the pupa is enclosed in the 
dried skin of the larva; and in still 
others it is enclosed in a delicate co- 


519. — An- 
tennae of gall-gnats; 
m, male; /, female, 
enlarged more than 
that of the male. 


Fig. 520. — Head- 
end of larva showing 
the breast-bone. 


coon. 


Fig. 521. — The pine-cone willow-gall. 


One of the most conspicuous of the galls made by gall-gnats is the 
pine-cone willow-gall (Fig. 521). This often occurs in abundance on the 


3 o2 THE STUDY OE INSECTS 

tips of twigs of the heart-leaved willow, Salix cordata. The gnat that 
causes the growth of this gall is Rhabdophaga strobiloides. The larva 
remains in the heart of the gall throughout the summer and winter, 
changing to a pupa early in the spring. The adult emerges soon after- 
ward, and lays its eggs in the newly-started buds of the willow. 

The clover-flower midge. Dasyneura legumimcola, is a very serious 
pest. The larvae live in the heads of clover and destroy the immature 
seed. Different kinds of clover are infested by this pest; but red clover 
is its chief food plant. 

The larva of the clover-flower midge passes the winter on or slightly 
below the surface of the ground, usually but not always, in a cocoon; 
it changes to a pupa early in the spring, and emerges an adult in late 
April or early May. The eggs are laid in the small green clover heads, 
many eggs in a single head, as each larva infests a single floret. The 
larvae mature in about four weeks, and then drop to the ground to trans- 
form. Two or three weeks later a second generation of midges appear 
and lay their eggs. 

The Hessian-fly, Phytophaga destructor, is the most serious pest in- 
festing wheat in this country. The larvae live at the base of a leaf be- 
tween it and the main stalk, where they draw their nourishment from 
the plant. There are two or three broods of this insect in the course of 
the year. The larva? of the fall brood infest the young wheat plants near 
the surface of the ground. When full-grown each changes to a pupa 
within a brown puparium, which resembles a flaxseed. Here they re- 
main throughout the winter. In the spring the adult gnats emerge and 
lay their eggs in the sheaths of leaves some distance above the ground. 
The infested plants are so weakened by the larvae that they produce but 
little if any seed, and often bend or even break off at the weakened spot. 

The wheat-midge, Thecodiplosis mosellana, is also a very serious 
enemy of wheat. It deposits its eggs in the opening flowers of wheat. 
The larvae feed on the pollen and the milky juice of the immature seeds, 
causing them to shrivel up and become comparatively worthless. When 
full-grown the larvae drop to the ground, where the transformations are 
undergone near the surface. The adults appear in May or June. 

The pear-midge, Contartnia pyrivora, deposits its eggs by means of a 
long ovipositor, in the interior of the unopened blossoms of pear. The 
young fruit is destroyed by the larvae. There is a single annual genera- 
tion. The winter is passed in the ground, usually as pupae but sometimes 
as larvae. 

The chrysanthemum gall-midge, Diarthronomyia hypogcea, causes the 
growth of galls on the leaf, stem, and flower-head of the chrysanthemum 
plant, and is sometimes a serious pest in greenhouses. 

There are a few species of gall-gnats that are remarkable for their 
mode of reproduction. The larvae of these gnats which live beneath the 
bark of decaying trees give birth to living larvae. Such a type of repro- 
duction is known as pedogenesis. 

Family Bibionid^e 

The March-flies 

In this family the abdomen is often comparatively robust, and the 
legs shorter and stouter than in most of the families with thread-like 


DIPTERA 


303 


antennas (Fig. 522). The antennas are rarely longer than the head and 
thorax, and composed of short, broad, and closely-pressed-together seg- 
ments (Fig. 523). 

The adult flies are generally black 
and red, sometimes yellow or wholly 
black. They are most common in early 
spring; which has suggested the name 
March-flies ; but some occur later in the 
season, and even in the autumn. 

The larvae vary in habits; some species feed on 
decaying matter, while others attack the roots of growing plants, especially 
of grass. They have ten pairs of spiracles, which is a rather large number, 
although there are other insects that have as many. The pupae are usually 
free. 

The subfamily, Scatopsince, includes a few species of minute black 
flies which are from -^ to -^s oi an inch in length. Most of the known 
larvae live in excrement. 


Fig. 523. — Antenna 
of Bibio. 


Fig. 522. — Bibio. 


Family Simuliid^e 

The Black-flies 

The common name, black-flies, given to the members of this family is 
not distinctive, for there are many species of other families that are of 
this color. It is like the word blackberry; some blackberries are white, 
and not all berries that are black are blackberries. 

In this family the body is short and stout ; the thorax is much arched, 
giving the fly a humpbacked appearance (Fig. 524); and the legs are 
comparatively short. The antennae are scarcely longer than the head and 
are eleven- jointed ; the segments are short and closely pressed together 
(Fig. 525); they are clothed with fine hairs. The ocelli are absent. In 
the male the eyes are very large and contiguous, and divided; the upper 
half of each has the facets very much larger than the lower, from which 

they are distinctly divided by a 
horizontal line. In the female, the 
eye facets are of almost uniform 
size ; and the two eyes are widely 
separated. 

The larvae are aquatic; and 
usually live in swiftly-flowing 
streams, clinging to the surface of 
rocks in rapids or on the brinks of 
falls. They sometimes occur in 
such large numbers as to form a moss-like coating over the rocks. 
There is a disk-like sucker fringed with little hooks at the caudal end 
of the body by means of which the larva clings to the rocks; and 
just back of the head there is a fleshy proleg which ends in a similar 
sucker fringed with hooks (Fig. 526). Respiration is accomplished 
by means of blood-gills. The head bears two large fan-shaped organs, 
which aid in procuring food. The food consists chiefly of algae and dia- 
toms. 

When full-grown the larva spins a cocoon within which the pupal 


Fig. 324. — Sitnu- 
lium. 


Fig. 525. 


Fig. 526. — Head 
of larva. 


3 04 THE STUDY OF INSECTS 

slate is passed (Fig. 527). This cocoon is firmly fastened to the rock 
upon which the larva has lived or to other cocoons, for they occur in 
dense masses, forming a carpet-like covering on the 
rocks. The pupa breathes by tracheal gills which are 
borne on the prothorax. 

The adult fly, on emerging from the pupa-skin, 
rises to the surface of the water and takes flight at 
once. Soon after this the eggs are laid. Sometimes 
the eggs are laid under water attached to rocks and 
sometimes on blades of grass, twigs or leaves which 
are dipping in the water. 
527- — cocoon and flie females of many species suck blood and are 
well-known pests. Unlike mosquitoes and midges, the 
black-flies like heat and strong light. They are often seen in large num- 
bers disporting themselves in the brightest sunshine. 

The species that have attracted most attention in the United States 
are the following. 

The Adirondack black-fly, Prosimulium hirtipes, is a widely distributed 
species but it has attracted most attention in the mountains of the 
Northeastern States, where fishermen find it to be a scourge in May and 
June. In this species the radial sector is distinctly forked. 

The southern buffalo-gnat, Eusimulium pecudrum, is the " Buffalo- 
gnat " of the Mississippi Valley, which in the past has been a terrible 
pest of mules and other domestic animals, sometimes causing their death ; 
but it seems to be much less common now than in former years. In 
this species the radial sector is very indistinctly forked at the apex. The 
popular name of this insect refers to a fancied resemblance in the shape 
of the insect when viewed from one side to that of a buffalo. 

The turkey-gnat, Simulium meridiondle, closely resembles the pre- 
ceding in habits, infesting all kinds of domestic animals, especially in the 
Mississippi Valley. As it appears at the time that turkeys are setting 
and causes great injury to this fowl, it is commonly known as the 
turkey-gnat. In this species the radial sector is not forked. 

The white-stockinged black-fly, Simulium veniistum, is widely dis- 
tributed and is one of the more common species of the genus. It can be 
distinguished from the other species mentioned here by the fact that the 
tibiae are silvery white above. In the Adirondacks it appears later than 
Prosimulium hirtipes and is not so serious a pest. Professor Needham 
writes: " Guides have a saying, that, when the black-flies put on their 
white stockings in June, the trouble is about over. This species has the 
white stockings." 

The innoxious black-fly, Simulium pictipes, is very widely distributed 
and at Ithaca it is our most common species. 

Family Blepharocerid^ 
The Net-winged Midges 

The net-winged midges are extremely remarkable insects; for in 
certain respects the structure of the adults is very peculiar, and the larvae 
appear much more like crustaceans than like insects. 

The adults are mosquito-like in form; but they differ from all other 


DIPT ERA 


305 


insects in having the wings marked by a network of fine lines which 
extend in various directions and are not influenced at all by the veins of 


R*+t 


2d A Cu, 

Fig. 528. — Wing of Blepharocera tenuipes. 

the wing (Fig. 528). They are, however, quite constant in their position 
in the species studied. 

When a wing is examined with a microscope, the fine lines are seen 
to be slender thickenings extending along the courses of slight folds in 
the wing. The wing in the pupal sheath is plaited like a fan and folded 
along these fine lines so that all the insect has to do when it issues from 
swiftly flowing water is to unfold the wing quickly and take flight at 
once. Most insects have to wait for a time to allow the wings to expand 
and dry before they can fly. 

The immature forms of these insects are even more wonderful than 
are the adults. The larvae live in water, in swiftly-flowing streams, where 
the water flows swiftest. They are readily seen on account of their black 
color. 

The body consists of seven large segments alternating with five 
smaller ones. Most of the larger segments bear a pair of conical, leg-like 
appendages, a sucker on the ventral side for clinging to the rocks, and 
tufts of tracheal gills. 

The pupae occur in the same place as the larvae closely attached by 
suckers to the rocks. They are black and conspicuous and often clustered 

close together. On the dorsal side of the pupa 
the skin is hard, forming a convex scale over 
the body (Fig. 529); and the thorax bears 
a pair of breathing organs. 

Since the larvae of the net-winged midges 
live only in swift-flowing streams, they are 
found only in mountainous or at least hilly 
regions. It is believed that they feed chiefly 
on algae and diatoms. It does not seem 
probable that these delicate midges can de- 

F1G.S29.- Blepharocera. a, larva, dor- P 0sit . theil " e gg S ° n the r0cks in . the Swi % 

sai view; b, larva, ventral view; c, pupa- running water where the larvae live. It is 

more likely that the eggs are deposited on the 
wet rocks at the margins of the stream and that the larvae migrate to the 
center of the stream. There are not many species of these midges but they 
are found around the world, from the Americas to Europe, Australia, and 
New Zealand. 


306 


THE STUDY OF INSECTS 


SERIES II. STRAIGHT-SEAMED FLIES WITH SHORT ANTENNA. 

(Brachycera) * 

Family Tabanid^e 

The Horse-flies 

The horse-flies are well-known pests of stock, and are often extremely 
annoying to man. They appear in summer, are common in woods, and 
are most abundant in the hottest weather. 

In this family the flagellum of the antenna; is 
composed of from four to eight, more or less closely 
consolidated segments and is never furnished with a 
distinct style or arista (Figs. 530, 531). The vena- 
tion is shown in Figure 532. 

The flight of these flies is very powerful, they are 
able to outstrip the swiftest horse. The males feed 
on the nectar of flowers and on sweet sap. The 
_ mouth-parts of the female are fitted for piercing the 
Antenna oiTab- skin and sucking the blood of men and quad- FlG __ 
rupeds; the females, however, also feed on sweets Antenna 'of 
of plants when they cannot obtain blood. 

The larger species, as well as some of moderate size, belong to the 


Fig. 530. 


Fig. 532. — Wing of Tabanus. 

genus Tabanus of which nearly two hundred species are listed from North 
America. One of the most common of these is the 
mourning horse-fly, Tabanus atratus. This insect is of 
uniform black color throughout, except that the body 
may have a bluish tinge (Fig. 533). The species of this 
genus attack cattle and other farm animals 
almost exclusively. 

To the genus Chrysops belong the smaller 
and more common horse-flies with banded 
wings (Fig. 534). The species of this genus 
attack man as well as other animals. To this 
Tabanus genus belong the well-known deer-flies familiar 
to fishermen and hunters. The eggs are de- 
posited in masses on plants or on exposed stones in the bed of a stream. 
* Brachycera: brachy, short; ceras (nepas), a horn. 


DIPTERA 


307 


The larvas are aquatic or semi-aquatic. As far as known, they are 
predacious, feeding on various small animals, some upon snails, others 
upon the larva? of insects. 

Family Stratiomyid^e ,. 

The Soldier-flies 

The soldier-flies are so called on account of the bright-colored 
stripes with which some of the species are marked. In the 
more typical members of this family the abdomen is broad and myta - 
greatly flattened (Fig. 535), and the wings when at rest lie parallel 
upon each other over the abdomen (Fig. 536). 

The antennas vary greatly in form, in some genera the flagellum is 
long and consists of several quite distinct segments (Fig. 537), in others 
it is short with but few indistinctly separated seg- 
ments and with an arista (Fig. 538). 

The larvas are spindle-form or elliptical and flat- 
tened. Some are aquatic, some live in cow-manure 
and some under the loosened bark of trees. 

There are three small families of flies, the Xylo- 
myidce, Xylophagidce , and Ccenomyidce which occur in 
the series here and which the student will find dis- 
cussed in detail in "An Introduction to Entomology" 
Fig. 537. b y J- H. Comstock pp., 832, 833, and 834. fig. 538. 

Sc /?! /?;+: 


Fig. 536. — Wing of Stratiomyia. 


Family Rhagionid^ 

The Snipe-flies 

These trim-appearing flies have rather long 
legs, a cone-shaped abdomen tapering towards the 
hind end (Fig. 539) and sometimes a downward- 
projecting proboscis, which with the form of the 
body and legs has suggested the name snipe-flies. 
The body is naked or hairy, but it is not clothed 
with strong bristles. Frequently the hairy cover- 
ing, though short, is very dense and is of strongly- tenna' of Chryso- 
contrasting colors. Three ocelli are present. The antennas are pila - 
only three-jointed and the third segment bears a style or an arista (Fig. 540). 


Fig. 539- — 
Chrysopila tho- 
racica. 


3 o8 


THE STUDY OF INSECTS 


■CL> 


Fig. 541. 


The proboscis is usually short, only a few members of the family having 
it long like the bill of a snipe. The wings are broad, and when at rest are 
held half open. The empodia are pulvilliform (Fig. 541). 

The flies are usually of moderate size. They may be found 
about low bushes and on tall grass. They are sometimes slug- 
gish and, therefore, easily caught. 

Large masses of these flies have been observed in various 
parts of this country ; and formerly, in the far West, they 
were collected by the Indians and used for food after being 
cooked. It is said that as many as a hundred bushels of flies 
could be collected in a single day. 

The larvae of this family are found in various situations; 
some live in water, but a larger number live in earth, in decaying wood, 
or in sand. 

Family Acrocerid^; 

The Small-headed Flies 

These flies are easily recognized by the unusually small head, the 
large humpbacked thorax, the inflated abdomen, and the very large 
alulets (Fig. 542). The body is devoid of bristles and the empodia are 
pulvilliform. 

The head is composed almost entirely of eyes, and in 
some genera is minute. The eyes are contiguous in both 
sexes or nearly so. The antennae are three-jointed, and 
are furnished with a style or an arista in some genera, in 
other genera the style and arista are absent. 

The flies are generally slow and feeble in their movements. In some 
species that feed upon flowers the proboscis is very long, sometimes ex- 
ceeding the body in length. Other species take no nourishment in the 
adult state, and have no proboscis. 

The larvae of only a few members of this family have been observed; 
these are parasitic in the egg-sacs or in the bodies of spiders. 


Fig. 542. — Plero- 
dontia misella. 


Family Bombyliid^; 

The Bee-flies 

These flies are mostly of medium size, some are small, others are 
rather large. In some the body is short and broad and densely clothed 
with long, delicate hair (Fig. 543). Other species resem- 
ble the horse-flies somewhat in appearance, especially 
in the dark color or markings of the wings; but these 
can be distinguished from the horse-flies by the form of 
the antennae and the venation of the wings. 

The antennae are usually short; they are three- 
jointed and with or without a style. The ocelli are 
present. The proboscis is sometimes very long and 
slender, and sometimes short and furnished with fleshy lips at the extremity. 
The adult flies feed on pollen and nectar, and are found hovering 
over blossoms, or resting on sunny paths, sticks or stones; they rarely 
alight on leaves. The larvae are parasitic infesting hymenopterous and 
lepidopterous larvae and pupae and the egg-sacs of Orthoptera. 


Fig. 543. — Bombylius. 


DIPT ERA 


3°9 


Family Therevid^e 
The Stiletto-flies 

With the flies of this family the head is transverse, being nearly as 
wide as the thorax; and the abdomen is long and tapering, suggesting 
the name stiletto-flies. These flies are small or of medium size; they are 
hairy or bristly. The antennas are three-jointed; the third segment is 
simple, and usually bears a terminal style. The legs are slender and 
bristly; the empodia are wanting. It is a small family. 

The adult flies are predacious; they conceal themselves among the 
leaves of low bushes or settle on the ground in sandy spots, waiting for 
other insects, chiefly Diptera, upon which they prey. 

The larvas are long and slender, and the body is apparently composed 
of nineteen segments. They are found in earth, fungi, and decaying 
wood. 

Family Scenopinid^e 

The Window-flies 

The window-flies are so-called because the best-known species are 
found almost exclusively on windows; but the conclusion that these are 
the most common flies found on windows should not be drawn from this 
name; for such is not the case. 

These flies are of medium size, our most common species measuring 
\ of an inch in length. They are usually black, and are not clothed with 
bristles. The thorax is prominent, and the abdomen is flattened and 
somewhat bent down, so that the body when viewed from the side 
presents a humpbacked appearance (Fig. 544). When 
^jm^ at rest, the wings lie parallel, one over the other, on the 

(^^ abdomen. The antennas are three- jointed; the first and 

" second segments are short, the third is long and bears 

Fig S44-— neither a style nor an arista (Fig. 54O. 

Scenopwus. J . . r 1 • 1 n ■ Fig de 

1 he larvas, which are sometimes round in dwellings ' i4> ' 
under carpets or in furniture, are very slender, and are remarkable for the 
apparently large number of the segments of the body, each of the abdominal 
segments except the last being divided by a strong constriction. They 
are also found in decaying wood, and are supposed to be carnivorous. 


547)- 


Family Asilid^e 
The Robber-flies 

These are mostly large flies, and 
some of them are very large. The 
body is usually elongate, with a 
very long, slender abdomen (Fig. 
546) ; but some species are quite 
stout, resembling bumblebees in 
form and coloring. 

The vertex of the head is hol- 
lowed out between the eyes (Fig. 
In this family the proboscis is pointed and does 


Fig. 546. — Erax apica- 
lis destroying a cotton- 
worm. (From the Author's 
Report for 1879.) 


Fig. 547 
robber-fly. 


— Head of 


3 io THE STUDY OF INSECTS 

not bear fleshy lips at the tip. The antennas are three-jointed, and with 
or without a terminal style. 

The robber-flies are extremely predacious. They not only destroy 
other flies, but powerful insects, as bumblebees, tiger-beetles, and dragon- 
flies, fall prey to them; they will also feed upon larvae. They are com- 
mon in open fields and are as apt to alight on the ground as on elevated 
objects. 

The larvae live chiefly in the ground or in decaying wood, where they 
prey upon the larvae of other insects; some, however, are supposed to 
feed upon the roots of plants. The pupae are free. 

More than five hundred North American species of this family, repre- 
senting seventy-five genera, have been described. 

Family Mydaid^e 

The Mydas-flies 

The mydas-flies rival the robber-flies in size, and quite closely re- 
semble them in appearance. As in that family, the vertex of the 
head is hollowed out between the eyes; but these flies can be dis- 
tinguished by the form of the proboscis, which bears a pair of fleshy 
lobes at the tip, by the form of the antennae, which are four- 
jointed, long and more or less clubbed at the tip (Fig. 548) and 
by the peculiar venation of the wings (Fig. 549). 

The adults are said to be predacious. The larvae of some spe- 
cies, at least, live in decaying wood, and some are known to prey 
upon the larvae of beetles. 
fig^548. The family is a small one; but it includes the largest flies 
in the Diptera. 


M+. 


M^Cut 


Cut+zd A 

Fig. 549- — Wing of Mydas. 


Family Dolichopodid^e 
The Long-legged Flies 

These flies are of small or medium size and usually bright metallic 
green or blue in color. The legs are much longer than is usual in the 
related families but not as long of course as in the crane-flies. The family 
is a very large one. 

The members of this family are easily distinguished as such by the 
peculiar venation of the wings (Fig. 550). 


DIPTERA 


3" 


The members of this family have three ocelli; the antennas are three- 
jointed; the second segment of the antenna? is sometimes vestigial and the 
third segment bears an arista; the palpi are one-jointed; and the em- 
podia are not pulvilliform. 

The adults are predacious and hunt for smaller flies and other soft- 
bodied insects. They are usually found in damp places, covered with 
rank vegetation. Some species occur chiefly on the leaves of aquatic 
plants, and about dams and waterfalls; and some are able to run over 
the surface of water. Others occur in dry places. 

The larva? live in a variety of situations, some in earth or decom- 
posing vegetable matter, some in the burrows of wood-boring larvae and 
also under bark; some in the stems of plants; and a few are aquatic. 
But little is known regarding the habits of the larvae; it is said that 
some species feed on decaying vegetation, while others are believed to be 
predacious. 


Fig. 55°. — Wing of Psilopodius sipho. 


Family Empidid^e 

The Dance-flies 

The dance-flies are of medium or small size; they are often seen in 
swarms flying with an up and down movement under trees or near shrubs 
and over the surface of water. These flies are predacious, like the 
robber-flies, but they also frequent flowers. The family is a rather 
difficult one to characterize owing to great variations in the form of the 
antennae and in the venation of the wings (Fig. 551). 


Fig. 551. — Wing of Rhamphomyia. 


312 


THE STUDY OF IXSECTS 


The larva? live in various situations, some in the ground or in decay- 
ing wood, and some species are aquatic; they are believed to be either 
predacious or scavengers. The pupae are free. 

This family is a large one. 

Family Lonchopterid^e 
The Spear-winged Flies 

These are minute flies, which measure from -^ to -J of an inch in 
length, and are usually brownish or yellowish but never green nor metallic 
in color. When at rest the wings are folded flat, one over the other, on 
the abdomen. The apex of the wing is pointed, and the wing as a whole 
is shaped somewhat like the head of a spear (Fig. 552). This suggested 
the family name. 

The venation of the wings is very characteristic, and is sufficient to 
distinguish these flies from all others. 

These flies are common from spring till autumn, in damp grassy 
places. They frequent the shores of shady brooks, where the atmosphere 
is moist. The males are very rare in this country. 

" The larvae live under leaves and decomposed vegetable matter." 

The family includes a single genus, Lonchbptera. 


Fig. 552. — Wing of Lonchoptera, female. 


Suborder CYCLORRHAPHA* 

The Circular-seamed Flies 

To this suborder belong those families of flies in which the pupa 
is always enclosed in a puparium from which the adult escapes 
through a round opening made by pushing off the head-end of it. 
(Fig. 553); the cap thus pushed off is often split lengthwise, as 
shown in the figure. The adult flies possess a frontal lunule and 
except in the first three families a frontal suture, through which the 
ptilinum is pushed out, when the adult is about to emerge from the 
puparium. The antennae are usually three-jointed and nearly all have a 
terminal or dorsal arista, — rarely with a terminal style. 

* CyclSrrhapha: cyclos, (kvkXos), a circle; rhaphe, (pa<pij), a seam. 


DIPTERA 


313 


SERIES I. CIRCULAR-SEAMED FLIES WITHOUT A FRONTAL SUTURE. 

(Aschiza) 

Family Phorid^: 
The Humpbacked Flies 

These are minute, dark-colored, usually black flies, which can be 
easily recognized by their humpbacked form, their peculiar antennae, and 
the peculiar venation of the wings. Certain species are often found run- 
ning about rapidly on windows, others on fallen leaves. Sometimes they 
are seen in swarms dancing up and down in the air. 

The head is small; the thorax large and humped; and the abdomen 
rather short. The antennae are three- jointed; but the first segment is 
exceedingly small, and the second is enclosed in the third, so that they 
appear as single- jointed. The third segment bears an arista. The legs 
are large and strong and well adapted to jumping. The wings (Fig. 554) 
are large, and are furnished with a series of strong veins near the costal 
border, which extend but a short distance beyond the middle of the 
wing. 

In the females of some species that live in the nests of ants and 
termites the wings are absent or very much reduced in size. 

The larvae of the different species differ greatly in habits, some feed 
on decaying vegetable matter, dead insects, snails, etc.; some are com- 
mon in mushrooms, and are sometimes a pest in mushroom cellars; 
some are internal parasites of other insects, as bees, wasps, ants, saw- 
flies, etc. ; several species are known to live in the nests of ants. 


/?:+; R++; 


Fig. 554. — Wing of Phora. 

Family Pipunculid^e 
The Big-eyed Flies 

The members of this family are small flies with very 

large heads composed almost entirely of eyes (Fig. 555). 

Fio y 555. — Pi- The head is nearly spherical and broader than the thorax. 

The antennas are small, short, three-jointed, with a 

dorsal arista. The ocelli are present. The abdomen is somewhat elongate 

with the sides nearly parallel. The body is thinly clothed with hair or 


3 i 4 THE STUDY OF INSECTS 

nearly naked. The wings are much longer than the abdomen, and when 
at rest they lie parallel to each other upon it. 

The flics hover in shady places. They are sometimes found on 
flowers, and may be swept from low plants; our most common species 
measure about \ of an inch in length, not including the wings. The 
larva? so far as known are parasitic upon leafhoppers. 

This small family is represented in North America by about thirty 
species, nearly all of which belong to the genus Pipunculus. 

Family Syrphid^e 
The Syrphus-flies 

The family Syrphidae includes many of our common flies; but the 
different species vary so much in form that no general description of their 
appearance can be given. Many of them mimic hymenopterous insects, 
thus some species resemble bumblebees, others the honeybee, and still 
others wasps; while some present but little resemblance to any of 
these. 

The most distinctive characteristic of the family is the presence of a 
thickening of the membrane of the wing, which appears like a longitudi- 
nal vein between veins R and M. This is termed the spurious vein, and 


R, /?* + J /? 4 + 5 


Fig. 556. — Wing of Erislalis. 

is lacking in only a few members of the family; it is represented in Fig- 
ure 556 by a band of stippling. 

The adults frequent flowers and feed upon nectar and pollen. Some 
fly with a loud humming sound like that of a bee, others hover motion- 
less except as to their wings for a time, and then dart away suddenly for 
a short distance, and then resume their hovering. 

The larvae vary greatly in form and habits. Some prey upon plant 
lice, and are often found in the midst of colonies of these insects; some 
feed in the stems of plants and in bulbs; others feed on decaying vege- 
table matter, and live in rotten wood, in mud and in water; and others 
live in ordure or in decomposing animal remains. Some are found in 
the nests of ants; and some in the nests of bumblebees and wasps. 

The larvae of the genus Volucclla live as scavengers in the nests of 
bumblebees and of wasps (Vespa). Some of the species in the adult state 
very closely resemble bumblebees. 

The larvae of the genus Microdot! are hemispherical, slug-like crea- 


DIPTERA 


3i5 


tures (Fig. 557), which resemble mollusks more than ordinary maggots; 

they are common in ants' nests. 

The larvae of several species that live in water as well as some that 

live in rotten wood are known as rat-tailed mag- 
gots on account of the long, tail-like, air-tube with 

which the hind end of the body is furnished. This 

tube enables the insect to obtain air when its body 

is submerged beneath several inches of water or Fl ^. ss7-—Microdon, adult 

decaying matter. This tube being telescopic can 

be lengthened or shortened as the insect may need it; and at its tip 

there is a rosette of hairs, which, floating on the surface of the water, 

keeps the tip from being submerged. 

One of these " rat-tailed " maggots is the larva of the drone-fly, 
Eristalis tendx. The maggot lives in foul water but obtains 
good air through its air-tube which projects up to the sur- 
face. The adult fly resembles a male honey-bee. 

Among the more common members of this family are the 

yellow-banded species belonging to the genus Syrphus (Fig. 

fig. 558. — 55&)- The larvae of these live in colonies of aphids and do 

Syrphus. good by destroying these pests. 

SERIES II. CIRCULAR-SEAMED FLIES WITH A FRONTAL SUTURE. 

(Schizophora) 

The flies of the next eight of these families with a frontal suture have 
very small or rudimentary alula or calypteres. They are therefore known 
as acalyptrate flies or muscids. 

Family Ortalid^ 

This family like the Trypetidae is a large one and contains many com- 
mon species which have the wings beautifully marked with dark spots or 
bands. 

Comparatively few species of the Ortalidae have been bred and these 
differ greatly in habits. The larvae of some have been found under bark 
of dead trees, others in excrement, some are parasitic on lepidopterous 
larvae, and several infest growing plants. Among the latter are Chaztopsis 
(Bnea and Tritoxa flexa which sometimes infest onions. 

Family Trypetidae 

This is a very large family including many common species with 
pictured wings, in which it resembles the preceding family, the Ortalidae. 

The larvae of the species that have been bred infest living plants. 
Some are leaf-miners, some live in the stems of plants, some make galls, 
and some are pests that infest fruit. Among the better-known species 
are the following so-called fruit-flies. 

The apple-maggot, Rhagoletis pomonella. — The adult is blackish with 
the head and legs yellowish; the abdomen is crossed by three or four 
white bands (Fig. 559) and the wings are crossed by four dark confluent 
bands. The female punctures the skin of the apple with her ovipositor 
and lays her eggs in the pulp. The larvae bore tunnels in all directions 


316 


THE STUDY OF INSECTS 


through the fruit. Early maturing varieties of apples are especially 
attacked. When full-grown the larva goes into the ground to transform 
where it hibernates in a brownish puparium. 

The cherry-fruit flies, Rhagoletis 
cingulata and Rhagoletis fausta. — 
These two species, which are closely 
allied to the apple-maggot, infest 
cherries. 

The currant-fruit fly, Epbckra can- 
adensis. — The larva of this species 
is a small white maggot which feeds 
within currants and gooseberries. The 
infested fruit colors prematurely and 
usually falls to the ground. 

The Mediterranean fruit-fly, Ceratitis 
capitata, a cosmopolitan pest, has lately 
been discovered over a wide area in 
Florida. It is about the size of a 
housefly, yellowish in general color, and 
infests a multitude of fruits especially 
the citrus and stone fruits. The fly 
is a most serious pest in tropical and 
subtropical countries but will probably 
not prove of great economic importance 
in the northern portions of the United 
States. 

The melon-fly, Bactrocera cucurbitce, 
is another fruit-fly of Asiatic origin and 

Fig. 550. — The applc-maceot: i, larva; 2, • tt tj. j. 1 

puparium; ,, adult; la, head of larva from side, nOW present in Hawaii. It attacks 

feMi^ftKebwj^'SdrS^ melons - squashes, and other cucurbits in 
larva. a very destruc- 

tive manner. 
The round goldenrod gall. — One of the 
most familiar of abnormal growths on plants 
is a ball-like enlargement of the stem of gold- 
enrod (Fig. 560). This is caused by a maggot, 
which lives within it, and which develops into a 
pretty fly with banded wings; this is Eurosta 
soliddginis. The larva hibernates in the gall ; the 
adult emerges in May. 


The round gold- 


Family PlOPHILID^E 

This family includes only a few species of small flies, rarely exceeding 
£ of an inch in length. They are usually glistening black or slightly 
bluish-metallic in luster. They are found about either decaying organic 
matter, preserved meats, or cheese. The best-known species is the follow- 
ing. 

The cheese-maggot, Piophila casei. — This fly lays its eggs on cheese, 
ham, and bacon. The larvae live in these substances and are often serious 
pests. They are commonly known as " skippers " on account of the re- 
markable leaps they can make. This is accomplished by first bringing 


DIPTERA 317 

the head and tail ends together and then suddenly straightening the 
body; in this way they can leap several inches. 

Family Psilid^e 

The flies of this family are of moderate size and slender. In many of 
the species the antennas are very long and decumbent, but in others they 
are of moderate length. The following is our best-known species. 

The carrot rust-fly, Psila yoscb. — The larva of this species infests 
carrots, celery, parsnips, and parsley. In the case of carrots and parsnips 
the larva? perforate the roots in all directions; their burrows are of a 
rusty color, hence the common name of the insect. When celery is at- 
tacked the fibrous roots are eaten off and destroyed. 

Family Ephydrid^e 

These are small or very small, black or dark-colored flies, that live 
in wet places. 

Most of the species live about fresh water; but to this family belong 
the " brine-flies " the larvse of which live in salt or strongly alkaline 
waters. These are common in pools about salt-works; and in the far 
West and in Mexico these larvas occur in the alkaline lakes in countless 
numbers. The best-known " brine-flies " belong to the genus Ephydra. 

Still more remarkable are the habits of the larva of the petroleum-fly, 
Psildpa petrolei, which lives, feeds, and swims about in the pools of crude 
petroleum, which are numerous in the various oil-fields of California. 

Family Chloropid^e 

This family includes a considerable number of species that are com- 
mon in meadows and other places where there is rank growing grass. In 
such situations they can be collected in large numbers by a sweep-net. 

The members of this family are small bare species; with moderately 
short or very short wings. - 

The larvae of the different species differ in their habits ; many species 
infest the stems of wheat, oats, rye, and grasses; some live in burrows in 
plants made by other insects; some live in excrement, while a few develop 
in the egg-sacs of spiders. 

Among the more important members of this family is the following 
species. _ 

The European frit-fly, Oscinis frit. — This is a minute black species, 
measuring from -^ to -^ of an inch in length. It was first described 
by Linnaeus in Sweden, where it was a very serious pest of barley, the 
larvae feeding upon the immature kernels. The light and worthless 
kernels resulting from this the Swedes called " frits," hence the common 
name of the species. There are several generations annually. The larvae 
of the late fall generation winter as stem miners in winter grain; and 
spring grain is attacked in the same way by the spring generation. In 
this country the commonest form of injury is to the stems of wheat 
close to the ground. The larva of this species can be easily distinguished 
from the larva of the hessian fly by the fact that it works in the center of 
the stem and crawls actively when removed. 


3i8 


THE STUDY OF INSECTS 


Family Drosophilid^ 

The Pomace-flies and their Allies 

There are certain small yellowish flies from | to i of an inch in length 
which are very common about the refuse of cidermills, decaying fruit, 

and fermenting vats of grape pomace; 
these are the pomace-flies (Fig. 561). 

The larvae of most species of this fam- 
ily, so far as is known, live in decaying 
fruit or in fungi; a few are leaf-miners. 

One of the pomace-flies, Drosbphila 
melanogdster, which is easily bred and which 
has a short life-cycle, is widely used in 
laboratories in the study of heredity. 
This species has been commonly known 


Fig. 561. — A pomace-fly. 


as Drosoph ila ampeloph ila; but melano- 
gaster is the older specific name. 

Family Agromyzid^e 

This family includes small or minute 
flies, most of which infest living plants. 
The larva? form galls on the stems or 
mine in various parts of the plants, 
but principally in the leaves. A com- 
mon species, Phytomyza aquilegice, 
makes serpentine mines in the leaves 
of wild columbine (Fig. 562). Other 
species mine in the leaves of oats, 
wheat, strawberries, asters, goldenrod, 
and blackberries, while one species, 
Agromyza maura var simplex, is a 
pest to asparagus for the larvae mine under the epidermis of the 
stems. 


Fig. 562 — Mine of Phytomyza aquilegice. 


The following eight families of those flies which have a frontal suture 
possess well developed alula or calypteres. They are therefore known as 
the calyptrate flies or muscids. To this group belong some of the most 
familiar flies, for example, the housefly and the flesh-flies. 


Family Cordylurid.^ 
The Dung-flies 

The members of this family are often of considerable size. 

Although members of several families of flies frequent excrement, 
certain species of this family and of the Borboridae are so commonly 
observed about dung and refuse that they have received the common 
names of dung-flies. Among these are those of the genus_ Scatophaga; 
these are rather slender flies, which have the body clothed with yellowish 


DIPTERA 319 

hair, and which are often abundant especially about fresh cow-dung. 
Other members of this family are found in meadows and in moist places ; 
some feed on other insects which they capture. 

The larvae of some species have been bred from excrement; some live 
in the stems of plants; and some are said to be parasitic in caterpillars. 

This family is named the Scatophagidae by some writers. 

Family Anthomyid^e 
The Anthomyids 

The anthomyids are very common flies of which about five hundred 
species have been described from North America. They are somewhat 
similar to the housefly in appearance but structurally distinct. 

The larval habits are variable. Most species live in decaying vege- 
table matter; many live in excrement. A few species are parasitic within 
living insects and some attack growing plants. Among the latter are 
certain well-known pests of garden crops. The more important of these 
are the following. 

The cabbage-root maggot, Hylemyia brassicce. — This insect in its 
larval state feeds on the roots of cabbage, radish, turnip, and cauli- 
flower; it also attacks the roots of various weeds belonging to the same 
family of plants. There are two or more generations of this pest each 
year. The first generation infests the young plants; the eggs of the sec- 
ond generation are laid late in June or in July. The maggots are espe- 
cially injurious to cabbage plants in the seedbed and to early cabbage 
plants in the field. 

The onion maggot, Hylemyia antlqua. — The larva of this species is 
often exceedingly destructive to onions, destroying young plants in the 
spring, and when the plants are older, burrowing into the bulb and 
causing decay. 

The beet or spinach leaf -miner, Pegomyia hyoscyami. — This leaf- 
miner infests the leaves of beets, sugar-beets, spinach, orach, mangels, 
and chard. The mine at first is thread-like but is soon enlarged to form 
a blotch. Several larvae usually occupy the same leaf and their mines 
usually coalesce. There are several generations each year, and the winter 
is passed in the pupal state under fallen leaves in the soil. 

The kelp-flies, Fucellia. — The larvae of these flies live in brown sea- 
weeds, cast up by waves along ocean beaches. The adults can be found 
all summer on the masses of these weeds often in immense numbers. 

Family Gasterophilid^; 
The Bot-flies of Horses 

This family includes the well-known pests the larvae of which infest 
the alimentary canal of horses and which are commonly known as 
bots. Three species are now well established in the United States and 
Canada. In the adult flies the oral opening is small and the proboscis 
vestigial. 

The common bot-fly or the stomach bot, Gasterophilus intestinalis . — 
The adult fly closely resembles the honey-bee in form except that the 


3 2o THE STUDY OF INSECTS 

female (Fig. 563) has the end of the abdomen elongate and bent forward 
under the body. The wings are transparent with dark spots, those near 
the center form an irregular, transverse band. This fly is 
most often seen flying about horses, which have an instinc- 
tive fear of it. The eggs are laid on different parts of the host, 
but preferably on the long hairs investing the inside of the 
fore legs. The eggs rarely hatch when left untouched; but 
the horse by scratching the fore legs with the teeth removes 
fig. 563. t j ie sma u ca p f th e egg-shell and inadvertently takes the larva 
into its mouth. The larvae thus taken into the mouth are carried with 
the food or water to the stomach. When the larvae reach the stomach 
they fasten themselves to the inner coat of it, and remain there until 
full-grown. Then they pass from the animal with the dung, and crawl 
into some protected place, where they transform within a puparium. 

The chin-fly or the throat-bot, Gasterophilus veterinus, is smaller than 
the common bot-fly and the wings are not marked with dark spots as in 
that species. The female usually deposits its eggs upon hairs under the 
jaws, and for this reason is commonly known as the chin-fly; but some- 
times the eggs are laid upon the flanks or fore legs of the host. 

The red-tailed bot-fly or the nose-fly, Gasterophilus hcemorrhoidalis , is 
easily distinguished by the bright orange-red tip of the abdomen. The 
wings are unspotted as in the chin-fly but differ from those of both of 
the preceding species in that the cross-vein m-cu is much farther from 
the base of the wing than is cross-vein r-m. The female oviposits on the 
lips of the horse; the flight of the fly about the nose of the horse when 
attempting to oviposit on its lips, suggested the common name, the nose- 

fly. 

Family CEstrid^; 
Bot-flies (except Gasterophilus) and Warble-flies 

This family includes flies that are large or of medium size; most of 
the species resemble bees in appearance; some, the honey-bee, others, 
bumblebees. The mouth-opening is small, and the mouth-parts are 
usually vestigial. 

The larvae are parasitic upon mammals; some develop in tumors 
under the skin and others, in the pharyngeal and nasal cavities of their 
hosts. As a rule each species infests a single species of mammal. In 
addition to the species that infest our domestic animals, other species 
infest rabbits, squirrels, deer, and reindeer. One that lives beneath the 
skin of the neck of rabbits is common. 

The sheep bot-fly, CEstrus ovis.- — This species is viviparous; the 
female fly deposits larvae, which have hatched within her body, in the 
nostrils of sheep. The larvae pass up into the frontal sinuses and into the 
horns when they are present. Here they feed upon the mucus. They 
are very injurious to sheep, causing vertigo or the condition known as 
"staggers." When full-grown they pass out through the nostrils and 
undergo their transformations beneath the surface of the ground. 

The heel-fly, Hypod&rma lineatutn. — The adult fly is \ of an inch in 
length; the anterior part of the thorax is black and shining; the alulae 
are uniformly white; and the tail end of the abdomen is reddish-orange 


DIPTERA 321 

(Fig. 564). The eggs are laid mostly when the cattle are recumbent and 
on all parts which the fly can reach when it is resting on the ground. 


Fig. 564. — Hypoderma lineatum. 

Even when the cows are standing the fly is able to lay eggs on those hairs 
which are close to the ground, namely on the heels. 

The eggs hatch and the larvae penetrate the skin at once and burrow 
their way, probably under the hide, to the neck. Here they enter the 
walls of the oesophagus and work down its tissues to the diaphragm 
and thence up the ribs to their resting places along each side of the back- 
bone beneath the skin. Here each one forms a swelling or " warble." 
In the spring, each maggot works out through the hole in the hide, drops 
to the ground, pupates and in about 40 days emerges as a fly. This fly 
is especially troublesome to milch cows. 

The bomb-fly, Hypoderma bovis. — The adult fly measures a little 
over \ an inch in length; there is yellow hair on the anterior part of 
the thorax; the alulae are bordered with reddish-brown; and the tail end 
of the abdomen is orange-yellow. As a rule the flies lay their eggs while 
the cattle are running; the eggs are laid singly at the roots of the hairs; 
the flies are clumsy insects and strike at the animals blunderingly. The 
presence of one of these flies in a herd of cattle causes them to scatter 
and stampede. This species is prevalent in the North and is also annoy- 
ing to milch cows. 

Family Calliphorid^e 
The Blow-fly Family 

Certain members of this family are very familiar objects and are 
commonly known as blow-flies, bluebottle-flies, or greenbottle-flies. With 
these, and with most other members of the family as well, the body, 
especially the abdomen, is metallic-blue or green in color. 

The larvae of the different species vary in habits; some have been 
bred from cow-dung; some feed on fresh or decaying meat and on the 
bodies of dead animals; one frequently infests wounds on animals, and 


322 THE STUDY OF INSECTS 

two are blood-sucking parasites of nestling birds. The following are our 
best-known species. 

The blow-fly, Colli phora vomitoria, is larger than the housefly, and 
black in color, with a steel-blue abdomen. It flies with a loud buzzing 
noise, and lays its eggs upon meat, cheese, and other provisions. The 
eggs hatch in about twenty-four hours, and the larvae become full-grown 
in a few days. 

The greenbottle-fly, Lucilia ccesar, is a common species which re- 
sembles the blow-flies in habits but it is smaller. The abdomen is some- 
times bluish but more often greenish. 

The screw-worm fly, Chrysomyia macellaria, is a bright metallic-green 
fly, with three black stripes on the thorax; it measures about one third of 
an inch in length. This pest resembles the flesh-flies in habits, and it 
deposits its eggs in wounds, sores, and the nostrils and ears of men and 
cattle. The larva? living in these situations often cause serious sickness, 
and sometimes even death. 

The cluster-fly, Pollenia rudis, is so-called because of its habit of 
entering houses in the autumn and hiding away in protected nooks in 
large groups or clusters. It is a dark colored fly slightly larger than the 
housefly. The thorax bears many short golden hairs. Its larvae are 
parasitic on earthworms. 

Family Sarcophagid^ 
The Sarcophagids 

This family has been commonly known as the flesh-flies because some 
of them lay their eggs in bodies of dead animals, resembling in habits the 
blow-fly, which belongs to the family Calliphoridse ; but a wider knowl- 
edge of the habits of various members of this family shows that this 
name is misleading. 

The Sarcophagidae includes all of the Muscoid flies that agree in 
having the following characteristics: The coloration is gray or silvery, 
tessellated or changeable pollinose; vein M'i +2 has an almost angular 
bend and ends considerably before the apex of the wing; the sides of the 
face are hairy; and the arista of the antennae is plumose above and below 
for nearly half its length or a little more. None of the species has discal 
machrochaetae on the abdominal segments, hairy eyes, long proboscis, 
rudimentary palpi, or more than a single pair of discal scutellar bristles. 

So far as is known all species of this family are larviparous. The 
different species show a wide range in larval habits; but by far the 
greater number of the species that have been bred are parasitic in other 
arthropods. They have been bred from various insects, from scorpions, 
and from the egg-sacs of spiders. Several species have been bred from 
dead fish; and a considerable number from the excrement of mammals. 
Five or six species live only in the tubular cups of pitcher-plants (Sarra- 
cenia), feeding on the dead insects found there. It has been found that 
Sarcophaga hcemorrhoidalis is sometimes the source of intestinal myiasis 
in man, and several cases of cutaneous myiasis caused by larvae of Wohl- 
fahrtia vigil have been described. 

If one wishes to determine the species of this family he should obtain 
the monograph, "Sarcophaga and allies in North America" by J. M. Al- 
drich, published in 191 6. 


DIPTERA 


3 2 3 


Family Tachinid^e 
The Tachina-flies 

The tachina-flies are often found about flowers and rank vegetation. 
They are usually short, stout, and bristly (Fig. 565). 

This is a very large family, more than fourteen hundred species are 
listed from North America alone; and from 
the standpoint of the agriculturist it is the 
most beneficial family of the Diptera. 

This family includes four subfamilies; the 
Dexiinas, Phasiinae, Megaprosopinae, and the 
Tachininas, each of which is regarded as a sep- 
arate family by some writers. 

The larvae are parasitic, chiefly within cater- 
pillars, but they have been bred from members 
of several other orders of insects. 

The manner in which the larva finds its 
way into the body of its host differs greatly 
in different species of tachinids. In many species the female fastens her 
eggs to the skin of the caterpillar (Fig. 565); when the larvae hatch they 
bore their way into their host and live there till they are full-grown. 
In some of the viviparous species the female punctures the skin of the 
caterpillar with the sheath of her ovipositor and deposits the larva 
within the body of the host. Some species deposit their eggs on the 
leaves of the food-plant of their host; these eggs are swallowed when 
the leaves are eaten. 


Ftg. 565. — A tachina-fly. Larva, 
adult, puparium, and eggs upon the 
fore part of an army-worm. 


Family Muscid^e 
The Typical Muscids 

With these flies the bristle of the antenna is pubescent or plumose to 
the tip; but the abdomen is not bristly except near the tip. Here belong 
many of the best-known members of the Diptera. Among the more 
important ones are the following : — 

The housefly, Musca domestica. — This is the most familiar repre- 
sentative of the order Diptera, as it abounds in our dwellings. It lays its 
eggs in horse-manure and in other decaying organic matter, a single 
female laying from one hundred and twenty to one hundred and sixty 


Fig. 566. — Wing of the housefly. 


3 2 4 THE STUDY OF INSECTS 

the larvae become full-grown in from five to seven days, having 
molted twice; the pupa state lasts from five to seven days. There may 
be in the warm season a generation each month. Since the fly picks up 
the germs of typhoid fever in the filthy places where it breeds and carries 
them to our kitchens and dining rooms, it is a dangerous fly and should 
be destroyed wherever possible. The fifth longitudinal vein (Mi +2 ) turns 
abruptly upward at the end (Fig. 566). 

The stable-fly, Stombxys calcitrans. — This species resembles the 
housefly in appearance, but it is a trifle larger and has its mouth-parts 
fitted for piercing and for sucking blood. It annoys cattle greatly; and 
before storms and in the autumn it enters our dwellings and attacks us. 
The popular belief that the housefly bites more viciously just before a 
rain is due to invasions of this species at such times. The mouth-parts 
of the true housefly are not fitted for piercing. 

The horn-fly, Hcematobia irriians. — This is an exceedingly annoying 
pest of horned cattle. It resembles the housefly in appearance, but is 
less than half as large. These flies cluster in great numbers around the 
base of the horns; they also settle upon the back. The larvae live in 
fresh cow-manure. 

The tsetse-fly, Glosslna morsitans. - — This species, which is closely 
allied to the stable-fly, is widely distributed in Africa and is the carrier of 
the blood parasite that causes the disease of cattle known as " nagana." 
The closely related species, Glosslna palpalis, carries the blood parasite 
which causes the sleeping sickness of man. 

THE PUPIPARA 

There are several families of related flies in some of which, at least, 
the larva? attain their full growth within the body of the female fly and 
within a few hours after the larvae are born they change to pupa?. It was 
formerly supposed that the young were born as pupae hence the name, 
Pupipara. 

The adult flies are parasitic and live like lice on the bodies of birds 
and mammals. Two species are parasites of the honey-bee. The wings 
are well developed in some forms while in others they are vestigial or 
wanting. 

Family Hippoboscid^; 

The Louse-flies 

The louse-flies are very abnormal flies that, in the adult state, live 
like lice, parasitically, upon the bodies of birds and mammals. Some 
species are winged, others are wingless, and still others are winged for a 
time and then lose their wings. 

The sheep-tick, Meldphagus ovinus. — This well-known 
pest of sheep is the most common member of the Hippo- 
boscidae found in this country. It is wingless and its halteres 
are vestigial (Fig. 567). It is about \ of an inch in length, 
of a reddish or gray-brown color, and with the entire body 
fig. 567. covered with long bristly hairs. This pest is often very in- 
jurious, especially to lambs after shearing time, as it tends to migrate 
from the old sheep to the lambs at this period. 


DIPTERA 


325 


There is a yellowish winged species, Lynchia americana, which is rather 
common on owls, and on the ruffed grouse. 

Family Braulid^e 

The Bee-lice 

This family includes only a single genus, Braula, of which there is 
only one well-known species, Braula cceca. This is a minute insect, T V of 
an inch in length, which is parasitic upon the honey-bee (Fig. 568). 


Fig. 568. — Braula caeca. (From Sharp after Meinert.) 

It is found clinging to the thorax of queens and drones. It is wingless 
and also lacks halteres; the head is large; the ocelli are wanting; the 
eyes are vestigial; the legs are comparatively short; and the last seg- 
ment of the tarsi is furnished with a pair of comb-like appendages. 

The bee-louse lays eggs and therefore does not seem to be a member 
of the Pupipara. 


FAMILIES OF DIPTERA NOT DISCUSSED 

The order, Diptera, contains a large number of families the mem- 
bers of which are not likely to come within the field of the general stu- 
dent of entomology. The following list includes those families of flies 
which have not been discussed in this work but of which the student can 
find an account in " An Introduction to Entomology " by J. H. Corn- 
stock. 

Thaumaleidae Helomyzidas Sepsidas 

Xylomyidas Borboridae Diopsidae 

Xylophagidae Phycodromidae Canaceidae 

Coenomyidas Sciomyzidas Asteiidae 

Nemestrinidas Sapromyzidas Geomyzidas 

Apioceridse Lonchaeidae Milichiidae 

Conopidae Tanypezidae Ochthiphilidae 

Clusiidae Micropezidae St.reblidae 


CHAPTER XXVI 
ORDER SIPHONAPTERA * 


The Fleas 

The members of this order are small, wingless insects, in which the body 
is laterally compressed, so that the transverse diameter is small, the vertical 
one great. The month-parts are formed for piercing and sucking. The 
metamorphosis is complete. 

These tiny tormentors are best known to us in the adult state; for 
it is only the adults that annoy us and our household pets. The larvas 
and pupae are rarely observed except by students who search for them. 

The body of the adult is oval and 
greatly compressed, which allows the 
insect to glide through the narrow 
spaces between the hairs of its host. 
The integument is smooth, quite hard, 
and armed with bristles, which are 
arranged with great regularity (Fig. 
569) and thus afford good characters 
for distinguishing the different species. 
The smoothness and firmness of the ^^ *** 


The dog-flea and its 


Fig. 570. — Head of a flea, Ceralophyllus 
multispinosus: f, falax; mx, maxilla; mx.p, 
maxillary palpi; p, proboscis. (After Baker.) 


body make it easy for the insect to escape when caught between the 
fingers of man or the teeth of lower animals. When once out of the 
clutch of an enemy it quickly leaps away. 

The head is broadly joined to the thorax. There are no compound 
eyes; but on each side of the head there is usually an unfaceted eye; 
these, however, are sometimes wanting. Each antenna lies in a groove 
somewhat behind and above the eye (Fig. 570). The antennas are three- 
segmented; the third segment, which is called the flagellum, may also 
be divided into several divisions or false-segments. The legs of fleas are 
long, strong, and fitted for leaping. 

* Siphonaptera: siphon (trL^uv) a tube; apteros (airrcpos) without wings. 

326 


SIPHON APTERA 327 

The mouth-parts are formed for piercing and sucking. When seen 
without dissection, the following parts are apparent; the maxillae, which 
are triangular plates; the maxillary palpi, which are long and four- 
jointed; and the proboscis (Fig. 570). 

The eggs of fleas are scattered about the floors of dwellings and 
in the sleeping-places of infested animals. The larvae are slender, worm- 
like creatures, with a distinct head and without legs. (Fig. 569.) They 
have biting mouth-parts, and feed upon the decaying particles of animal 
and vegetable matter always to be found in the dirt in which they live. 
When full-grown the larva spins a cocoon within which the pupa state is 
passed. 

Fleas are parasitic only in the adult state. Some species infest birds, 
but by far the larger number prey upon mammals, and most mammals 
are subject to the attacks of these parasites. Although the different 
species of fleas infest different hosts they are not so restricted in their 
host relations as are many parasites, and may pass from their normal 
host to another species; for example, both the dog-flea and the cat-flea 
frequently attack man. 

Formerly fleas were regarded as merely annoying pests of man and his 
pets; but it has been found that fleas are the carriers of bubonic plague; 
this fact has greatly increased the interest in these insects. 

Except where bubonic plague is present the bites of fleas are not likely 
to cause serious results, although they may be very annoying. The irri- 
tation caused by them can be relieved by the use of some cooling applica- 
tion as menthol, camphor, or carbolated vaseline. Scratching the bites 
should be avoided as that aggravates the inflammation. 

There are hundreds of species of fleas in the world but the following 
forms are among those best known because they are most intimately 
associated with man: 

The cat-flea, Ctenocephalns Jelis. — This is the species that is most 
often found in our dwellings in the East and in the South, and the one 
that most often attacks man in these regions. This species infests dogs 
as well as cats. Its head and thorax bear rows of short, stout, dark 
spines known as ctenidia. 

The dog-flea, Ctcnocephalus cams. — This species is closely allied to 
the cat-flea. It infests dog, cat, and man. The head and thorax bear 
ctenidia. 

The human flea, Pulex irritans. ■ — On the Pacific Coast this is the 
species that is most often found in houses attacking man. It is easily 
distinguished from the two preceding species by the fact that its head and 
thorax lack ctenidia. Man is its natural host; but it will infest various 
other animals temporarily. 

The Indian rat-flea, Xenopsylla cheopis. — Among the various species 
that are supposed to transmit the bubonic plague, this cosmopolitan 
species is regarded as one of the more important. It resembles the human 
flea in lacking ctenidia. 

The sticktight flea, Echidnophaga gallinacea. — This is a very serious 
pest of poultry especially in the southern and southwestern portions of 
the United States. It is a small, dark brown species, which is often found 
in dense masses attached to its host; heads of chickens are often covered 
with dark patches of these fleas. While this species is chiefly a pest of 
poultry, it is often found in dense masses on the ears of dogs and cats. 


i2 S THE STUDY OF INSECTS 

The chigoe (chig'o) or jigger, Tiiiiga penetrans. - - This is a small flea 
found in the West Indies, Mexico, Central and South America, and in 
tropical Africa. It lias been reported from Florida but it is not known 
to be established in the United States. The males and the unimpreg- 
nated females live in dry, sandy soil; they are only about one millimeter 
in length, and behave in the ordinary manner of fleas, feeding on the 
Mood of man and many other animals, domestic and wild, and even 
birds. When impregnated, the female burrows into the skin of her host. 
Soon after this the abdomen becomes distended with eggs and acquires 
the size of a small pea. This species often causes serious injury to man 
by burrowing beneath the skin of the foot, causing the formation of a 
sore, which may become infected with bacteria, and cause the loss of a 
toe or a leg. 

In the southern United States the names chigoe and jigger are im- 
properly applied to the harvest-mites, which are the immature six-legged 
forms of various mites that attach themselves like ticks to the skin and 
become gorged with blood. 


CHAPTER XXVII 
ORDER HYMENOPTERA* 


Bees, Wasps, Ants, and others 

The winged members of this order have four wings; these are membranous 
and have the wing-venation more or less reduced. The hind wings are smaller 
than the fore wings. The mouth-parts are formed for chmving or for both 
chewing and sucking. The abdomen in the females is usually furnished with 
a sting, piercer, or saw. The metamorphosis is complete. 

The Hymenoptera is a very large order, including a vast number of 
species. The bees, wasps, and ants are among the better-known members 
of it ; but in addition to these it includes a large number of less familiar 
forms. Many of these are minute parasites of other insects; others 
cause the growth of galls on plants; and still others, in their larval state, 
feed on the foliage of plants or are borers in the stems of bushy or her- 
baceous plants or in the limbs and trunks of trees. 

The members of this order are chiefly of small or moderate size, and 
many of them abound wherever flowers bloom. From very early times 
some of them have been favorites with students of the habits of animals, 
for among them we find wonderful developments of instinctive powers. 
Many volumes have been written regarding their ways, and much re- 
mains to be discovered, even concerning our most common species. 

The membranous nature of the wings, which suggested the name of 
the order, is not a distinctive characteristic, for it is possessed by the 
wings of many other insects. 

The two pairs of wings are similar in texture. The wings of each side 
are held together by a row of hooks, the hamuli, on the front margin of 


Fig. 571. — Wings of bee showins hamuli, h. 

the hind wing (Fig. 571) ; these hooks fasten to a fold in the hind margin 
of the front wing, so that the two wings present a continuous surface. 
The hind wings are smaller than the fore wings and have a more reduced 
venation. Some forms are apterous. 

* Hymenoptera: Hymen (iW), membrane; pteron {irrepov), wing. 

329 


330 


THE STUDY OF INSECTS 


This is one of the orders in which in the specialization of the wings 
the wing-venation is reduced. In the more generalized members of the 
order this reduction of the wing- venation is slight, but in the more spe- 
cialized forms it is extreme. 

Figures 572 and 573 represent what may be regarded as a typical 


*d A A/ A 

Fig. 572. — The veins of a typical hymenopterous wing. 


hymenopterous wing; in the former the veins are lettered, in the latter, 
the cells. 

The cells marked m, m, m, in Figure 573 are termed the marginal cells; 


Fig. 573- — The cells of a typical hymenopterous wing. 

and those marked sm, sm, sm, sm, the submarginal cells; the three cells, 
M 4 , 1 st M 2 , and M 3 are termed the discal cells. 

The working out of the various ways in which the wing-venation has 
been reduced in the more specialized families is an exceedingly difficult 
problem, one that is beyond the scope of this book. 

The mouth-parts are formed for chewing in all Hvmenoptera, and in 
the more specialized members of the order they are fitted for both chew- 
ing and for sucking or lapping liquid food. In the sawflies, for example, 
the mouth-parts resemble quite closely the orthopterous type, while in 
the bees they differ markedly from this type; and intermediate forms 
exhibit intermediate degrees of modification of the mouth-parts. 

In the long-tongued bees the labrum and mandibles retain the form 
characteristic of chewing insects and the mandibles function as organs for 
crushing or cutting; but the labium and maxillae are elongated; the 
maxillae form a sheath to the labium; the three organs thus constituting 
a suctorial apparatus (Fig. 574). In this figure the maxillae are repre- 
sented separated from the labium. 


HYMENOPTERA 


33i 


The legs of the Hymenoptera present characters that are much used 
in the classification of these insects. Among the more striking of these 


Fig. 574- — Head 
of a honey-bee: a, 
antenna; c, clypeus; 
u, labrum; m, man- 
dible; mx, maxilla; 
p, labial palpus; /, 
labium. 


Fig. 575. — Leg of an ant, and strigilis enlarged. 
(From A. B. Comstock, Handbook of Nature Study.) 


are the following; the trochanter may consist of two segments (Fig. 
64, B) or of only one; the metatarsus of the hind legs is greatly en- 
larged in bees (Fig. 64, C); and in several families the fore legs are 
fitted with an organ which is used in cleaning the antennas, the antenna 
cleaner or strigilis. This consists of a curved, comb-like, movable spur 
on the distal end of the fore tibia (Fig. 575) and opposite this, on the 
base of the metatarsus, a concavity fringed with hairs. In cleaning an 
antenna it is drawn through the space between these two parts of the 
strigilis. 

In the Hymenoptera the metamorphosis is complete. The larvae of 
the first suborder are caterpillar-like in form and are furnished with 
thoracic legs and usually with abdominal prolegs; but in some, mostly 
borers or internal feeders, the prolegs are wanting. In all the forms of 
the third suborder the larvae are maggot-like in form and have no legs. 
The pupae are of the exarate type, that is, the legs and wings are free, as 
in the Coleoptera. With many species the larva, before changing to 
a pupa, spins a cocoon about its body. With some this cocoon is com- 
posed of comparatively loose silk, and resembles somewhat the cocoon 
of a moth. In others the cocoon is of a dense parchment-like texture, 
and in still others it resembles a very delicate foil. 

Parthenogenesis. — The production of young by females that have not 
mated is known to occur in members of several families of this order. 
In some species the young thus produced are all males; in others they 
are all females; and in still others both males and females are developed 
from unfertilized eggs. 

Polyembryony. — In several genera of minute parasitic Hymenoptera 
the number of young produced is not dependent upon the number of 
eggs laid, for with these insects many embryos are developed from a 
single egg. This type of development is termed polyembryony. 

THE CLASSIFICATION OF THE HYMENOPTERA 

The sequence of the families and arrangement of the groups adopted 
in this chapter are after Messrs. J. C. Bradley, S. A. Rohwer, and J. 


332 THE STUDY OF INSECTS 

Bequaert. Since there is lack of agreement regarding the names of 
genera and families we have preferred to retain the older forms. 

In order for the student to use the keys to advantage certain terms 
need to be defined. 

The propodcuni. — The first abdominal segment when it forms a 
part of the alitrunk or wing-bearing region of the body. 

The posterior lobes of the pronotum. — A distinctly differentiated 
rounded lobe, on each side covering the spiracle, which forms the lateral 
extension of the pronotum of Sphecoidea. 

The prepectus. — An area along the cephalic margin of the episternum 
of the mesothorax which in some Hymenoptera is separated by a suture- 
like furrow. 

The gaster. — The swollen portion of the abdomen behind the pedicel 
in the suborder Clistogastra. 

The pygtdial area. — In many of the aculeate or stinging Hymen- 
optera there is an area on the pygidium which is bounded on each side 
by a carina, the two carinas meeting posteriorly on the middle line of 
the segment; this area is known as the pygidial area. 

The anal lobe. — The portion of the anal area of the hind wing which 
is cut off by the axillary excision (Fig. 576). 

The axillary excision. — A notch in the inner margin of the hind wing 
near its base (Fig. 576). 


ae Pae 

Fig. 576. — Hind wing of Elis showing anal lobe; axillary excision, a; preaxillary excision, pm. 

The preaxillary excision. — A notch in the inner margin of the hind 
wing distad of the axillary excision (Fig. 576). 

The preanal lobe. — That portion of the anal area of the hind wings 
that lies between the axillary excision and the preaxillary excision con- 
stitutes the preanal lobe. 

The pygidium. — The tergite or dorsal wall of the last segment of the 
abdomen. 

The hypopygium. — The sternite or ventral wall of the last segment 
of the abdomen. 

The legida. — The scale-like plate overlapping the base of each front 
wing. 

The corbicula. — A smooth area on the outer surface of the tibia of 
the hind legs margined on each side by a fringe of long curved hairs. 

KEY TO THE SUBORDERS OF THE HYMENOPTERA 

A. Base of the abdomen not slender but broadly joined to the thorax. 

B. Antenna- inserted between the eyes above the base of the clypeus with the 
bases of the antennae exposed; front wings with the transverse part of vein 
Mj present or if wanting (Hylotoma) then vein R 4 is present in the hind wings 


HYMENOPTERA 333 

which therefore have a closed submarginal cell; ovipositor either saw-like or a 
sturdy borer, never thread-like or capable of being coiled within the body. p. 338 

Chalastogastra 

BB. Antenna; inserted below the eyes immediately above the mandibles under 
a transverse ridge, their bases concealed; front wings with the transverse part 
of vein M 2 wanting; vein R 4 in the hind wings wanting, therefore no closed 
submarginal cells; ovipositor thread-like and coiled within the mesothorax. 

p. 343 Idiogastra 

AA. Base of the abdomen constricted into a narrow pedicel, p. 345. . . .Clistogastra 

TABLE FOR DETERMINING THE FAMILIES OF THE 
CHALASTOGASTRA 

A. Front wings with three marginal cells, both vein R and R 2 being present; the 
basal segments of the flagellum are consolidated, thus forming what appears to 
be a very long third segment, and the remaining segments are small. 

XyelidcB* 

A A. Front wings with the free part of vein R 2 always wanting; antennae with three 
or more segments, third segment never as long as all the following segments 
together; if the third segment be long, antennas, consisting of only three seg- 
ments. 
B. Front wings with subcosta present as a distinct longitudinal vein. p. 339 

Pamphiliid^e 

BB. Front wings with subcosta absent; rarely it is present as a pale, very in- 
distinct line, closely appressed to vein R + M, or vein Sci may be present as a 
transverse vein. 
C. Radial cross-vein (r) of the front wings received by the 2nd submarginal 
cell (R&) or if it is absent or the 2nd and 3rd submarginal cells united 
(R4 united with R 5 ), then the anterior tibiae have a single apical spur. 
D. Front wings with the cross-vein m-cu subequal in length to the first section 
of the free part of media. 
E. Vein Sci absent in the front wings; the last abdominal segment bears a 
more or less horn-like prolongation; maxillary palpi one-segmented; 
labial palpi two- or three-segmented, the last segment enlarged and 
bearing a large sensory cup, the first segment not elongate, p. 339 

SlRICID^E 

EE. Vein Sci present; last abdominal segment without horn-like pro- 
longation; maxillary palpi four-segmented; labial palpi three-seg- 
mented, the last without a sense-cup, the first elongate. Xiphydriida 
DD. Front wings with the cross-vein m-cu joined to vein M at or near its 

separation from vein R. p. 340 Cephid^e 

CC. Radial cross-vein (r) of the front wings received by the 3rd or 4th submargi- 
nal cell (cell R4 or R3) or wanting; anterior tibiae always with two apical 
spurs. 
D. Abdomen with distinct pleural sclerites; bearing the spiracles, antennae 

clavate. p. 341 Cimbicid^e 

DD. Abdomen without separate pleural sclerites; antennae not clavate in 
North American forms, p. 342 TenthrediniDjE 

TABLE OF FAMILIES OF THE CLISTOGASTRA f 

A. With well-developed wings. 

B. Hind wings without an anal lobe.t 

C. No erect scale or node between the gaster and the propodeum. 

* The families in italics are not discussed in the text. 

f This table of families of the North American Clistogastra is compiled from a 
table of the families of the Clistogastra of the world prepared by Professor J. Chester 
Bradley. 

t In the hind wings of the insects belonging under this category neither the second 
anal furrow nor the axillary excision is present, but there is sometimes present a weak 
preaxillary excision, more rarely (some genera of Braconidae) a pronounced notch, but 
never forming a deep slit. See also footnote on page 335. 


334 THE STUDY OF INSECTS 

D. The costal cell of the fore wings eliminated by the coalescence of the 
costal and subcostal veins, except in the case of two or three rare genera. 
The venter is membranous and has in dried specimens a longitudinal 
fold. 
E. The transverse part of vein M 2 of the fore wings wanting, causing the 
union of cells M, and 1st M 2 (Fig. 583). 
F. The abdomen not very long and slender and strongly compressed. 

p. 346 BRACONIDiE 

FF. The abdomen very long, slender, and strongly compressed. (The 

genus Pharsalia) p. 347 Ichneumonid^ 

EE. Cells Mi and 1st M 2 separated by the transverse part of vein M 2 

(Fig. 587). p. 347 Ichneumonid^; 

DD. The costal cell of the fore wings present. The venter chitinized. 

E. Abdomen borne on the dorsal surface of the propodeum far above the 

hind coxae Aulacidce and Gasteruptionida * 

EE. Abdomen borne between the hind coxae, or on the end of the pro- 
podeum slightly above them. 
F. The transverse part of vein M present and situated close to the 
stigma. 
G. Antennae in both sexes of more than fifteen segments; trochanters 

clearly two-segmented Trigonalidce, Stephanidce 

GG. Antennae of thirteen segments in the male and twelve in the fe- 
male; trochanters one-segmented. 
H. Pronotum without posterior lobes its lateral extensions reaching 
the tegulae. 

I. Cell M4 of the fore wings shorter than cell Cu + Cui or absent 

(Mutillinae). p. 356 Mutillid^: 

II. Cell M4 of the fore wings present and longer than cell Cu + 
Cui (Fig. 607). (Vespinas) p. 364 Vespid^e 

HH. Pronotum with posterior lobes terminating at a distance from 
the tegulae. (This distance is short in the Ampulicinae.) Go to 

EE, p. 337 for the bees Ampulicida and Some Bees 

FF. The transverse part of vein M situated about two-thirds of the 
way from the wing base to the end of the costal cell (C + Sci) or 
wanting. 
G. Wings not longitudinally plaited in repose. Ovipositor not carried 
along the mid-dorsal line. 
H. The pronotum laterally reaching the tegulae. No prepectus 
present. 

I. Hind metatarsi one-fourth the length of the following segment. 

Large insects; the abdomen of the female filiform and several 
times the length of the head and thorax together; that of the 
male long and clavate. p. 348 PeleciniDyE 

II. Hind metatarsi at least as long as the following segment. 

J. Mandibles in a reversed position, their apices directed out- 
wardly, away from the mouth-opening Vanhomiidce 

JJ. Mandibles in a normal position. 

K. Cells Cu + Cui and Ms of the fore wings fully enclosed 
and separated from each other by perfect veins. 

HeloridcE and Roproniidce 

KK. Cells Cu + Cui and M 3 partly enclosed by brown lines, 
or altogether wanting. Claws not pectinate. 
L. Abdomen sharply margined by a carina along the sides; 
antennae arising near the clypeus. 

Platygasterida and Scelionidoe 

LL. Abdomen immargined laterally (acute in Telenominae 
but without a carina). 
M. Fore wings with a distinct stigma. 

N. A closed, usually very short, marginal cell (2d 
Ri + R 2 ) present. Antennae of thirteen segments. 
Abdomen with a short cylindrical petiole, the second 
segment much longer and larger than the others, 
p. 348 PrOCTOTRUPIDjE 

* The families in italics are not discussed in the text. 


HYMENOPTERA 335 

NN. No closed marginal cell (2d Ri + R 2 ) but the 
basal part of the marginal vein (vein C) often present 

in the fore wings Ceraphronida and Belytidce 

MM. Fore wings without a distinct stigma. 

N. Costal cell (C + ScO either closed along the margin 
or if open very narrow; the marginal cell (2d R t 
+ R 2 ) if present narrowly triangular, its proximal 
margin a straight line: Abdomen not compressed 
nor dorsally keeled. Hypopygium of the female 
not divided, but closely applied to the pygidium, the 
ovipositor issuing from between them at the tip of 
the abdomen. 

Belytidce, Scelionidce and Ceraphronidce 

NN. Costal cell (C + ScO open along the costal margin 
and abnormally wide. The marginal cell (2d Ri + 
R 2 ) present; often closed; often open along the 
costal margin, sometimes at tip; it is always four- 
sided, acute at apex and at its base. Abdomen 
more or less strongly compressed and with a mid- 
dorsal keel, if rarely but little compressed and 
without a keel, it is more or less swollen dorsally. 
Hypopygium of the female divided, the ovipositor 
issuing from the cleft thus formed, anterior to the 

apex of the abdomen, p. 349 Cynipid^; 

HH. The pronotum not reaching the tegulae, separated therefrom 
by a chitinized sclerite, the prepectus. Antennae elbowed, never 
more than thirteen-segmented. Fore wings with a short narrow 
costal cell open along its anterior margin (Fig. 598); its apex 
remote from the stigmal vein (Fig. 598, d); a more or less elon- 
gate marginal vein (Fig. 598, b); postmarginal and a stigmal 
spur (Fig. 598, d). An occasional trace of the transverse part of 
vein M is the only additional vein present, there being never 

any closed cells, p. 352 Chalcidid^e 

GG. Wings longitudinally plaited in repose, ovipositor carried along 
the mid-dorsal line. Pronotum reaching the tegulae, the prepectus 

not being distinctly set off. {Leucospis.) p. 352 Chalcidid^e 

CC. An erect scale or one or two nodes between the propodeum and the gaster. 

p. 357 Formicid^e 

BB. Hind wings with an anal lobe.* If there are any closed cells in the hind 
wings the antenna? are thirteen-segmented in the male, twelve- in the fe- 
male, except in a few instances where the number is reduced by fusion, but 
then the apical segments always form a club, or are abruptly recurved or 
otherwise strikingly modified, (except that in some species of Crabro both 
sexes have twelve-segmented, otherwise normal antennas). 
C. Hind wings without closed cells. Antennal segments never thirteen in the 
male and twelve in the female, nor are the apical segments in the male 
formed into a distinct club or otherwise peculiarly modified. Venation re- 
duced. 

D. Abdomen attached to the dorsal surface of the propodeum Evaniidce 

DD. Abdomen attached normally, at the apex of the propodeum between 

or slightly above the hind coxas. 

E. Antennae composed of ten segments, or if of thirteen in the female 

(Ampulicomorpha) then the pronotum is elongate and has a median 

longitudinal sulcus. Antennae inserted close to the clypeus. Fore 

tarsi of the female usually chelate, p. 370. .Embolemidce and Dryinid^ 

EE. Antennae usually composed of thirteen segments, more rarely of twelve 

or eleven segments, or multiarticulate. 

F. Abdomen with six exposed segments or less. Fore wings always with 

* If there is a very deep or slit-like incision on the margin of the hind wing, the 
insect is certain to come under this heading. There are some genera of Sphecidae 
in which the axillary excision or both axillary and preaxillary excisions are reduced to 
small and inconspicuous notches, close to one another, and in some cases the axillary 
excision is altogether lacking. But in all such cases the second anal furrow is distinct. 
In all insects falling under grouping B this furrow is wanting. 


336 THE STUDY OF INSECTS 

cells M and Cu + Cui closed. Ovipositor an extensile jointed tube. 
Abdomen with from three to six exposed segments. Brilliantly metal- 
lic. ] i. 356 Cleptida; and Chrysidid^e 

FF. Abdomen with eight exposed segments, the petiolar segment short 

and scarcely perceptible. Ovipositor a sting Bethylidce 

CC. Hind wings with at least a closed median cell (cell M). Males with thir- 
teen, females with twelve antennal segments, except in rare instances, where 
they have been reduced slightly below that number in the males, in which 
case they usually either end in a jointed club or the last segments are re- 
curved or hooked or otherwise modified. Venation usually well preserved. 
D. The pronotum extending laterally directly to the tegulae, where its lateral 
prolongations do not terminate in the form of a rounded "posterior lobe" 
covering the spiracles. 
E. Cell M4 of the fore wings longer than cell Cu + Cuj. Lateral prolonga- 
tions of pronotum forming a posterior angle which lies above the tegulae. 

Wings usually longitudinally plaited, p. 364 VESPlDiE 

EE. Cell M4 of the fore wings shorter than cell Cu + Cui or absent. Lateral 

prolongations of pronotum bluntly rounded, not lying dorsad of the 

tegulae. Wings never longitudinally plaited. 

F. Mesopleura divided by a transverse suture into an upper and lower 

plate. First and second abdominal sternites imbricate. Coxae very 

large and long; the legs long and usually distinctly spinose. p. 355 

Pompilid;e 

FF. Mesopleura not divided by a transverse suture. Coxae and legs not 

unusually long. 

G. First abdominal segment united by a ball and socket joint to the 

second, and itself forming an almost completely separated "scale" 

or "node." Hypopygium of male unciform. Females winged; a 

worker caste present. (Some more primitive genera of ants.) 

p. 357 Formicid^e 

GG. First abdominal sternite attached to the second by a suturiform 
articulation or more or less imbricate, the first segment not forming 
a "scale" or "node" between the propodeum and the gaster.* 
H. Mesosternum not forming with the metasternum a continuous 
plate overlying the bases of the hind and middle coxae. Axillary 
excision of the hind wings in normal position, apex of male ab- 
domen without three retractile spurs between the last tergite and 
its sternite. 
I. Vein M4 + Cui of the fore wings opposite vein m-cu or nearly so. 
Second and third tarsal segments of the female not dilated. 
J. Mesosternum with two laminae which overlie the bases of the 
middle coxae. 
K. Little or no constriction between the first and second 
abdominal sternites, which are almost or somewhat 
imbricate. Hypopygium of male not unciform. Both 

sexes winged Anthoboscida 

KK. First and second abdominal sternites separated by a 

strong and distinct suturiform articulation and either the 

hypopygium of the male is unciform, or the females are 

wingless and carried about by the males in mating. 

L. Hypopygium of the male not unciform; but sometimes it 

is tridentate at apex. Females apterous and carried 

about by the males in mating. First submarginal cell 

usually divided by a weak vein (base of the radial 

sector) Thynnidce 

LL. Hypopygium of male unciform, known American fe- 
males winged. First submarginal cell not divided (base 
of R s wanting). 
M. Diurnal insects with normal eyes and ocelli. Fe- 
males winged. (Tiphiinae). p. 356 Tiphiid/E 

* Some genera of Mutillidae in which the first or first and second abdominal 
segments are more or less nodose may be recognized as falling in this category by 
thr unciform hypopygium of the males, the apterous females, and the absence of a 
neuter caste. 


HYMENOPTERA 337 

MM. Nocturnal insects with enlarged eyes and ocelli. 
The marginal cell (2d Ri + Rj) removed from the 
apex of the wing by several times its length. Fe- 
males unknown but presumably apterous. (Brachy- 

cistinae). p. 356 Mutillid.* 

JJ. Mesosternum simple or with two minute erect teeth be- 
tween the bases of the coxas. 
K. Marginal cell (2d R x + R 2 ) removed by less than its length 
from the wing apex; the fourth submarginal cell (R3) 
not traversed by an adventitious vein. Abdomen never 
petiolate. 
L. No constrictions between the abdominal segments (except 
between the first and the second), all tergites and all 
but the first and second sternites loosely imbricated 
plates. Both sexes winged. Mesosternum unarmed, 

upper surface of hind coxae simple Sapygidce 

LL. Strong constrictions between each of the abdominal 
segments, the tergites and sternites all heavily chitinized 
and not loosely imbricate; the last tergite modified 
and hood-like. Female apterous. Upper surface of 
the hind coxae, at least in the male, with a lamella. 

(Methocinae and Myrmosinas). p. 356 Tiphiid;e 

KK. Marginal cell (2d Ri + R 2 ) removed by two or more 
times its length from the apex of the wing; cell R3 when 
present usually traversed by a longitudinal adventitious 
vein. Often nocturnal insects with large eyes and ocelli. 
Females apterous. (Several subfamilies.) p. 356. 

MUTILLID/E 

II. Vein M 4 + Cui of the fore wings more than two-thirds its length 
apicad of vein m-cu. Second and third tarsal segments of the 
female dilated, deeply excised, and filled with membrane between 
the lobes. Nocturnal insects with very large eyes and ocelli. Pet- 
iole long and slender. Hypopygium unarmed Rhopalosomidce 

HH. Mesosternum and metasternum together forming a continuous 
plate overlying the bases of the hind and middle coxa?, separated 
from each other by a transverse suture. Axillary excision of the 
hind wings almost opposite the apex of cell M3 + Cui + Cu. 

Abdomen of male with three spines, p. 357 Scoliid/E 

DD. Pronotum terminating behind laterally in the form of two clearly differ- 
entiated rounded "posterior lobes, " covering the spiracles. These lobes 
reach the tegulas in North American forms only in the extremely rare 
genus Dolichurus. 
E. Posterior metatarsus 'not dilated. No plumose hairs. Females without 
pollen-collecting apparatus, but often with a comb on the anterior tarsi. 
Maxillae rarely elongate; if so, either the ocelli are distorted, or the 
abdomen has a petiole composed only of the first sternite. 
F. Abdomen of the male with only three or four exposed tergites. Last 

sternite of the female, enclosing the sting Ampidicidce 

FF. Abdomen of the male with seven exposed tergites. Sting not en- 
closed by the hypopygium. p. 370 Sphecid^e 

EE. Posterior metatarsi elongate and dilated. Some of the hairs, especially 
of the thorax, plumose. A pollen-collecting brush or a corbicula present 
in the majority of females. Maxillae usually with either the stipes or 
the lacinia elongate; the latter often very long and covering the tongue; 
the ocelli never distorted; the abdomen rarely petiolate, and never with 
a petiole composed only of the first sternite. 
F. Hind tibiae with apical spurs. If the marginal cell (2d Ri + R 2 ) is long 
and slender, reaching nearly to the wing apex, the anal lobe is short 
and fully separated. Cell M4 usually as large as cell 1st M 2 . 
G. Females without a corbicula. First submarginal cell (R + 1st Ri) 
rarely divided (by the base of R s ) in which case there is a large 
anal lobe present. In case the marginal cell (2d Ri +R 2 ) is longer 
than the three submarginals, taken together, there is usually a well- 
marked anal lobe in the hind wings. 
H. Wings with two submarginal cells (very rarely less). 


338 THE STUDY OF INSECTS 

I. Tongue short and the basal segments of the labial palpi not 

sheath-like; or the labrum is large and free and uncovered. 

Females without a ventral pollen-collecting brush; often with a 

pygidial area. 

J. Tongue short, its apex bifid; labial palpi normal. Female 

only rarely with a pygidial area. Mesepistcrnal suture 

present. Labrum hidden (Prosopinae) Prosopida 

J J. Tongue long or short, but its apex acute; the labial palpi 
normal or their basal segments sheath-like. Mesepistcrnal 
suture wanting. (Many.) p. 375 Andrenid^e 

II. Tongue elongate, the basal segments of the labial palpi sheath- 
like. Labrum not large and free, usually entirely covered by 
the clypeus, or if somewhat visible, then strongly inflexed. 
Females without a pygidial area; those of the non-parasitic 
species with a ventral pollen-collecting brush, p. 377 
Megachilid^e 

HH. Wings with three submarginal cells. Females without a ventral 
pollen-collecting brush; often with a pygidial area. 

I. Tongue short, its apex bifid. Labial palpi normal. Females 

rarely with a pygidial area. Mesepistcrnal furrow present. 
Prosopidce 

II. Tongue long or short, but its apex acute. The labial palpi 
normal, or the basal segments sheath-like. Mesepisternal 
suture rarely present. (Most.) p. 375 Andrenid^e 

GG. Females and workers with corbiculae (except Psithyrus). First 
submarginal cell divided by a transverse, hair-like chitinized streak 
(base of R s ), rarely indistinct. Marginal cell (2d Ri + R 2 ) rather 
long and pointed or appendiculate, usually as long as the three 
submarginal cells taken together, and extending far beyond the 
apex of the third (R4). Malar space large and distinct. Hind 
wings stalked, the anal lobe absent. Tongue very long; the two 
basal segments of the labial palpi and the laciniae elongate, and 
forming a sheath. Social insects with normally a worker caste 

(except in Psithyrus). p. 379 Bombid^e 

FF. Hind tibiae without apical spurs. Social insects with a worker caste. 

Workers with corbiculae; females without functionally developed ones. 

Marginal cell (2d Ri + R>) long and slender reaching nearly to the 

wing apex. Anal lobe of the hind wing long and scarcely separated. 

Cell 1st M 2 much larger than cell M 4 . Eyes hairy, p. 381 Apid^e 

AA. Without wings. 

B. A "scale" or "node" between the propodeum and the gaster. p. 357. Formicid/E 
BB. Without a scale or node between propodeum and gaster. 

C. Females; sting well developed, p. 356 Tiphiid^e and MutilliDjE 

CC. Males, or, if females, the ovipositor does not form a sting. Occasional species 
or genera of several families of the parasitic Hymenoptera. pp. 345 to 355. 

Suborder CHALASTOGASTRA * 

The Saw flies 

This suborder includes the more generalized members of the Hymen- 
optera, those in which the form of the body is less modified and the 
venation of the wings less reduced than is the case with other members of 
the order. 

The basal segments of the abdomen are similar in form and the ab- 
domen is broadly joined to the thorax as in the more generalized orders 
of insects. The first abdominal segment is not closely anchylosed to the 
thorax, forming a propodeum, as is the case in the Clistogastra, and its 
tergum is usually longitudinally divided on its middle line. 

* Chalastogastra; chalastos (xaXaoros), loose; gastros (vaorpos), the belly. 


HYMENOPTERA 339 

The ovipositor of the females is well developed and complicated in 
structure. It is fitted for making incisions in the leaves or stems of 
plants and is more or less saw-like in form. 

The larvae of the Chalastogastra are all plant-feeders. With the ex- 
ception of those that are leaf-miners they are caterpillar-like in form. The 
prolegs, however, are not provided with hooks as are those of caterpillars. 

A striking feature of the larvae of this suborder is the possession of a 
pair of ocelli, one on each side, which in their position and in their struc- 
ture agree with the ocelli of adult insects, that is, they are primary ocelli. 
This characteristic distinguishes these larvae from the larvae of Lepidop- 
tera. 

The members of this suborder are known as sawflies because the 
ovipositor is saw-like and fitted for making slits in leaves and stems in 
which to deposit the eggs. 

Family Pamphiliid^ 
The Web-spinning and the Leaf-rolling Sawflies 

The common names given above were suggested by the fact that the 
larvae of some species build nests by tying the leaves of their food plants 
together with a web of silk, and others build nests by rolling the edge of 
a leaf and live inside the tube so formed. The larvae of some species are 
gregarious. The larvae of members of this family have long, seven- 
jointed antennae, well-developed thoracic legs, but lack abdominal prolegs. 

The body of the adult is robust. The posterior margin of the prono- 
tum is straight or nearly so. The mesonotum is short and never extends 
much beyond the anterior margins of the tegulae. The anterior tibiae are 
armed with two apical spurs. The ovipositor of the female is short. 

More than fifty species have been described from America north of 
Mexico; but the larvae of only a few of these are known; among these 
are the following. 

The plum web-spinning sawfly, Neurotoma inconspicua. — The larvae 
of this species feed on the foliage of plum and cherry; they are gregarious 
and form unsightly nests by spinning webs over the leaves; frequently 
these webs cover an entire tree. The injury is done in early summer. 
When full-grown the larvae find their way to the ground, where they pass 
the remainder of the summer and winter in earthen cells; they transform 
to pupae in the spring, and the adults emerge in May or June. 

The peach sawfly, Pamphilius persicus. — This pest of the peach is 
one of the leaf -rolling species. The adults emerge from the ground late 
in May or early in June and lay their eggs on the leaves; the eggs soon 
hatch ; each larva cuts a slit in a leaf and then rolls over a portion of the 
leaf, making a case within which it stays during the daytime, feeding 
chiefly at night. There is a single generation a year. The larva passes 
the winter in the ground. 

Family Siricid^e 
The Horn-tails 

The common name horn-tails is applied to members of this family 
because the last abdominal segment bears a more or less horn-like pro- 


34Q 


THE STUDY OF INSECTS 


Fig. 577. — Trtmex columba. 


longation. This is short and triangular in the males, and is a prolon- 
gation of the last ventral segment; in the females it is long and often 

spear-shaped, and is a prolongation of the 

last dorsal segmenl . 

The body is cylindrical (Fig. 577); the 

head large ami widened behind the eyes; 


the pronotum is right-angled, so that it 
presents both a strictly dorsal and a ceph- 
alic aspect, the latter concave; vein Sci 
of the front wing is absent; thepropodeum 
is divided longitudinally; the anterior 
tibia? each with only one apical spur; the 
sheath of the ovipositor is very long and 
exserted beyond the end of the abdomen; 
the ovipositor is fitted for boring. 

The Siricida? is a small family; only 
about fifty species representing five genera are known. 

The larvae bore in the trunks of trees; our best-known species is the 
following one. 

The pigeon horn-tail, Trcmex columba. — The larva of this species 
infests maple, elm, apple, pear, beech, oak, and sycamore. The female 
(Fig. 577) in order to oviposit pierces the wood of a tree to the depth of 
about \ of an inch; the eggs are laid singly; sometimes her ovipositor 
gets wedged in the wood and holds her a prisoner until she dies. The 
larva is cylindrical and attains a length of if inches. It transforms 
within its burrow, in a cocoon made of silk and fine chips. 

The adults of this species vary in color and marking; based on these 
variations, three fairly distinct races have been recognized, which to a 
considerable extent are geographical, although their ranges overlap. In 
the typical form, race columba, the abdomen is black, with ochre-yellow 
bands and spots along the sides; this is the common form in Quebec, 
Ontario, and the northeastern United States. In the race aureus, the 
ground color of the abdomen is yellow and the markings black; this is 
the common form in the Rocky Mountains and is found on the Pacific 
Coast. In the race sericeus, the entire body is fulvous, the legs beyond 
the femora yellow, and the wings dark reddish-brown; this race is found 
in the southeastern United States and as far north as Pennsylvania and 
West to Utah. 


Family Cephid^e 
The Stem Saw flies 

The stem sawflies are so-called because the larvae bore into the stems 
of plants or in the tender shoots of trees and shrubs. The adults are 
slender, elongate insects of moderate size. The pronotum is more or less 
quadrate and longer than is usual in the Hymenoptera. The anterior 
tibiae are armed with one terminal spur. 

This family is of moderate size; less than a score of species have been 
found in our fauna; but these represent nine genera. Some of the species 
are of economic importance. Several species bore in the stems of grains 
and grasses. The following species illustrate the habits of these. 


HYMENOPTERA 341 

The wheat-sawfly-borer, Cephus pygmceus. — The larvae of this species 
bore in the stems of wheat, a single larva in a stem, dwarfing and stunt- 
ing the growth of the plant. As the grain becomes ripe the larva works 
its way toward the ground ; and at the time of harvest the greater num- 
ber of them have penetrated the root. Here, in the lowest part of the 
cavity of the straw, they make preparations for passing the winter, and 
even for their escape from the straw, as adults, the following year. This 
is done by cutting the straw circularly on the inside, nearly severing it a 
short distance from the ground, so that a strong wind will cause it to 
break off at this point. After the circular cut has been made, the larva 
fills the cavity of the straw just below it for a short distance with a plug 
of borings. Between this plug and the lower end of the cavity, the wall 
of the cavity is lined with silk forming a cocoon within which the larva 
passes the winter and changes to a pupa in March or April. The adult 
insects emerge early in May. 

The currant-stem girdler, Janus Integer. — The larva of this species 
bores in the upper portion of the canes of currant. Its presence is in- 
dicated by the wilting and drooping, in late spring, of the new growth at 
the tip of the infested cane. This is due to the fact that the parent saw- 
fly after depositing her egg in the cane moves up a short distance above 
where the egg is deposited and with her ovipositor girdles the cane, some- 
times nearly severing it. This killing of the tip, and thus checking the 
growth of the cane, seems to be necessary for the development of the egg 
and larva. The larva bores in the pith of the cane. In the fall it eats a 
hole through the woody wall of the cane to the outer bark, thus making 
provision for the escape of the adult, and then spins a cocoon in which it 
hibernates. The change to the pupa state takes place in April and the 
adult emerges in May. The obvious method of control of this pest is to 
remove and burn the infested portion of the canes while the larva? are in 
them. 

Family Cimbicid^e 
The, Cimbicid Saw flies 

This is a small family, which is represented in our fauna by a few 
genera and a limited number of species. In this family the body is stout 
and often very large; there are dis- 
tinct pleural sclerites in the abdomen 
(Fig. 578) and the antennae are clav- 
ate. The sheath of the ovipositor 
extends but little if at all beyond the 
end of the abdomen. 

The body of the larva is cylin- 
drical, stout, and covered with a 

wflyv hlnom whpn livincr- fhp fhnrarir FlG - 578. — Ctw&ex americana. Abdomen 

waxy Dioom wnen mmg, me tnoracic except first segment . 7> ?> p> p i eur j t es; t, t, t, 

legs are Well-developed and five- tergites; S, S, S, sternites; cr, cercus; sp, spiracle. 

jointed; and the abdomen bears eight ter no grass ' 

pairs of prolegs. The larvae live free upon foliage upon which they feed. 
The American sawfly, Cimbex americana. — This is the largest of our 
common sawflies. The female is about § of an inch in length and has a black 
head and thorax, a steel-blue or purplish abdomen, with four yellowish 
spots on each side, smoky-brown wings, and black legs, while her feet and 


342 


THE STUDY OF IX SECTS 


short, knobbed antennae are pale yellow. The male is longer and slen- 
derer and differs somewhat in color. Several varieties of this species, 
differing in color, have been described. The eggs are laid in June in 
crescent-shaped slits made in leaves. The food plants are elm, birch, 
linden, and willow. The larva is greenish-yellow, with black spiracles 
and a black stripe down its back. When disturbed it spurts forth a 
fluid from glands just above the spiracles. It clings to the upper surface 
of a leaf and feeds on the edge of the leaf. When not feeding it rests on 
one side with the body curled up in a spiral form. There is but one 
generation each year. When the larva is full-grown it burrows in the 
ground, makes an oval, brownish cocoon, and there spends the winter, 
not changing to a pupa until spring. The adults appear in May or June. 

Family Tenthredinid^e 

The Typical Saw/lies 

This is a very large family, including more than seven-eighths of all of 
the members of the suborder Chalastogastra. 


Fig. 579. — The locust sawfly, Pleronidea Irilineala: 
a, egg; b, young larva; c, full-grown larva; d, anal seg- 
ment of full-grown larva; e, cocoon; /, adult. 

The larvae are caterpillar-like; the thoracic legs are always present 
and are usually well developed, but are vestigial in some species. Prolegs 
are usually present; these are borne on abdominal segments 2-7 and 10 
or 2-8 and 10, rarely the prolegs are vestigial. The larvae of the different 
species differ greatly in size varying from f to if inches in length. 

The larvae of the majority of the species live free on the foliage of 


HYMENOPTERA 343 

plants, upon which they feed (Fig. 579). The larvae of some species are 
leaf -miners ; some make galls on stems and leaves of plants. Among 
the species that have attracted attention on account of their economic 
importance are the following. 

The imported currant-worm, Pteromdea ribesi. — This is the com- 
monest and best-known of the garden pests. The adult sawflies appear 
early in the spring and the females lay their eggs in rows along the prin- 
cipal veins on the underside of the leaves of currants and gooseberries. 
They hatch in a week or ten days; and the larvae begin at once to feed 
upon the leaves. The larvae are at first whitish, as they increase in size 
the color changes to green; after the first molt the body becomes covered 
with many black spots and the head is black; at the last molt they lose 
their black spots and assume a uniform green color tinged with yellow 
at the ends. When full-grown the larvae descend to the ground and spin 
their cocoons, either just below the surface of the ground or beneath 
rubbish; sometimes the cocoons are attached to the stems or leaves some 
distance from the ground. A second generation of the sawflies appears 
late in June or early in July; and sometimes a third generation is de- 
veloped. 

The pear-slug, Caliroa cerasi. — This is a well-known pest of pear, 
cherry, and plum. It causes the leaves of the infested tree to turn brown. 
When such leaves are examined it is found that the injury is due to small, 
slimy, slug-like larvae, which have eaten off the upper surface of the 
leaves, leaving the skeleton of veins and the lower epidermis to turn 
brown, wither and fall; sometimes trees are entirely defoliated in this 
way by midsummer. When full-grown the larvae descend and burrow 
into the ground a short distance, where each constructs an earthen cell 
in which it transforms. A second generation of the sawflies appear and 
lay their eggs about three weeks later. 

The rose-slug, Cladius isbmerus. — Often in the summer our rose- 
gardens look as if fire had swept over them, so scorched and brown are 
the leaves. The cause of this apparent conflagration is a transparent 
jelly-like slug, greenish above and yellowish below, which eats the upper 
surface of the leaves, leaving patches of the lower surface and the veins. 
These slugs usually feed by night and remain hidden on the lower surface 
of the leaves by day. When ready to pupate they crawl down or drop to 
the ground and burrow beneath the surface; here each makes a little 
cell and then transforms. The adult fly is shining black with smoky 
wings and with the fore and middle legs grayish or dirty-white. The fe- 
male is about \ of an inch in length. There are two broods a year, one 
in June and one in August. The last brood passes the winter in the 
ground. 

Suborder IDIOGASTRA * 

The Oryssids 

This suborder, includes a single small family of rare insects, the Orys- 
sidae, which formerly was included in the suborder Chalastogastra. 

The suborder Idiogastra stands intermediate between the other two 

* Idiogastra: idio (idios), distinct; gastros (yoarTpos), the belly. 


344 


THE STUDY OF INSECTS 


Fig. 580. — Oryssus sayi; A, female; B, head 
seen from in front, (from Sharp.) 


suborders of the Hymenoptera. In this suborder the adults (Fig. 580) 
resemble the Chalastogastra in the shape of the abdomen; but the form 

and habits of the larva? are those cha- 
racteristic of the Clistogastra. The 
distinctive characteristics of the Idio- 
gastra are those of the single family- 
included in it. 

Family Oryssid^ 

The Oryssids 

In the shape of the body the mem- 
bers of this family strongly resemble 
the Siricidac. They are easily dis- 
tinguished, however, from all of the 
Chalastogastra by the anomalous 
position of the antennae, which are 
inserted far below the eyes, imme- 
diately above the mandibles, under a 
transverse ridge; by the more reduced 
venation of the wings ; and by the re- 
markable form of the ovipositor. 

In the form of the ovipositor and 
in its position when at rest the 
Oryssidse differ from all other Hymenoptera. For a description of the 
ovipositor the student is referred to "An Introduction to 
Entomology " by J. H. Comstock, p. 904. 

The Oryssidse is a widely distributed family, members 
of it having been found in all of the major geographical 
regions of the world. But it is a small family, including 
only a few genera and species. A single genus, Orysstts, 
is found in North America, of which about a dozen species 
have been described from this region. 

The adults are very active and are found running over 
the trunks of trees and" on timber. The larvae were formerly 
supposed to be borers in the trunks of trees; but it has 
been shown that they are parasitic on the larva? of Buprestis 
and probably on other wood-boring larvae. 

The larva of only a single species, Oryssus occidentalis, is 
known. This is white, subcylindrical, about one-third as 
thick as long, and legless; but the positions of the legs 
are indicated by chitinized disks. The mouth-parts are 
very simple, the labrum, labium, and maxillae 
merely fleshy lobes, but the mandibles are hard and horn- Cushman.) 
like; the antennae are tubercle-like and set at the summits of rounded 
elevations. 

In the pupa of the female (Fig. 581) the terminal portion of the ovi- 
positor is external and extends over the back the entire length of the 
body. This long, slender, external form of the ovipositor in the pupa is 
rather remarkable, especially in view of the very different form it assumes 
in the adult female. 


Fig. 581. — Pupa 

of Orvssus, female. 

being (After Rohwer and 


HYMENOPTERA 345 

Suborder CLISTOGASTRA * 
The Parasitic Hymenoptera, and the Ants, Wasps, Bees, and Allies 

The most striking characteristic of this suborder is the fact that what 
appears to be the first abdominal segment, but which is really the second, 
is greatly constricted forming a slender petiole or waist between the 
larger portion of the abdomen and the alitrunk or wing-bearing region of 
the body (Fig. 582). 

In this suborder the intermediate region of the body 
is not merely the thorax but includes also the first ab- 
dominal segment, only the tergum of which is preserved 
in the adult. This is known as the median segment, 
or the propodeum and can be identified by its spiracles, the third pair of 
this region of the body. It should be remembered that the thorax bears 
only two pairs of spiracles. From the above it follows that what appears 
to be the first abdominal segment in the Clistogastra, and which is usually 
so-called, is really the second. 

In some the ovipositor is a boring instrument by means of which 
deep holes are made into trees and eggs placed in these holes ; in others 
it is used for thrusting the eggs into the bodies of other insects; and in 
still others it is modified so as to form a sting with which poison glands 
are connected. 

THE PARASITIC HYMENOPTERA 

When the discouraged farmer sees his crops harvested before due time 
by hordes of hungry insects, he is apt to long for a miracle to remove the 
plague from his fields. Oftener than he dreams the miracle takes place, 
and millions of insect pests never live to lay their eggs for another brood. 
Such miracles are frequently wrought by members of a large group of in- 
sects, which is commonly known as the parasitic Hymenoptera. 

Although some of these insects are external parasites, most of them 
live within the bodies of their hosts, within which they pass their entire 
larval existence. Their presence in this strange situation is due to the 
fact that the parent lays her eggs within or upon the body of the victim. 
When the egg is laid upon the body of the victim the larva as soon as it 
hatches bores its way into the body. So in either case the young parasite 
is in the midst of suitable food. It is probable that the parasite feeds at 
first only on the blood of its host; hence the parasitized insect is not 
destroyed at once, but lives on with the parasite within it, which grad- 
ually attains its growth. Finally, the parasitized insect perishes; and from 
the larva that has been nourished in its body there is developed a winged 
creature, which in turn lays its eggs in other victims. Frequently a para- 
sitic insect lays several eggs within a single victim, so that a number of 
parasites may be developed within the body of a single insect. Each 
species of these parasites infests only certain insects, each insect having, 
to a great extent, its peculiar parasites. 

The parasitic Hymenoptera does not constitute a natural division 
of the order but includes representatives of many families. 

* Clistogastra: clisto (-xXtiaTos) , closed; gastros (yaa-rpos), the belly. 


346 


THE STUDY OF INSECTS 


Family Braconid^; 

The Braconids 

The family Braconida? includes a large number of species, which are 
small or of moderate size. In this and in the following family the costal 
cell of the fore wings has been eliminated by the coalescence of veins 


Fig. 583. — Wings of a braconid. 

(Fig. 583) and the venter is membranous and has in dried specimens a 

longitudinal fold. 

It is nof an uncommon thing, especially in vineyards to find a feeble 

caterpillar with its back covered with lit- 
tle, white, oblong bodies, which the unin- 
formed usually think are eggs (Fig. 584). 
These are the cocoons of braconid parasites. 
The larvae obtain their growth within the 

584. — Caterpillar with cocoons . B , . , - . 

of a braconid. body of the caterpillar, and just before it 

perishes they leave it, and spin their silken cocoons upon 
its back. When these cocoons are examined with a lens 
they are found to be beautiful objects, resembling in mini- 
ature those of the silkworm. The adult parasite in em- 
erging from its cocoon cuts a neat little lid at its upper 
end. These parasites belong to the genus Microgaster. 
Bunches of white or yellow cocoons of Microgaster are often 
found attached to grass or other plants instead of to the 
back of the caterpillar which the larvae have destroved 
(Fig. 585)- 

Perhaps the most interesting of the com- 
mon forms belonging to this family are 
those belonging to the genus Aphidius. The 
members of this genus are minute creatures 
which infest plant-lice. If colonies of 
aphids be examined, the dried bodies of 
dead ones may be found in which the 
abdomen is more or less spherical, being greatly distended. These bodies 
remain clinging to the leaves in the position in which the insects were 
when they died. From each one there emerges in due time an Aphidius. 
The parasite in emerging cuts a very regular circular lid in the dorsal 
wall of the abdomen of its host (Fig. 586). We have watched with much 


Fig. sS6. 


Fig. 58s. 


HYMENOPTERA 


347 


interest these little braconids ovipositing in. the bodies of plant-lice. 
When one has selected a plant-louse in which to oviposit she stands with 
her head toward it, and bending her abdomen under her thorax between 
her legs she darts her ovipositor forward into the body of the aphid. The 
species of this genus do not construct cocoons, but undergo their meta- 
morphosis within the dried skins of plant-lice. 


Family Ichneumonid^; 
The Ichneumon -flies 

This is a large family including a great number of genera and species. 
Although it includes some minute forms the species are mostly of con- 
siderable size, and here belong the larger of the parasitic Hymenoptera. 

In this family, as in the 
preceding one, the costal 
cell of the fore wings has 
been eliminated by the coa- 
lescence of veins and the 
venter is usually membra- 
nous and has in dried speci- 
mens a longitudinal fold 

(Fig. 587)- 

Students collecting Hy- 
menoptera will find many 
species of ichneumon-flies; 
and those attempting to 
rear caterpillars will be dis- FlG ' s87 ' ~ Win?s of an Ichneumon Ay- 

appointed often by the breeding of ichneumon-flies instead of moths or 

butterflies. 

Megarhyssa lunator, which was 
formerly known as Thalcssa lunator, 
is one of the larger of ichneumon- 
flies (Fig. 588). It is a parasite of 
the wood-boring larva of the pigeon 
horn-tail, Tremex columba. When a 
female finds a tree infested by this 
borer she selects a place which she 
judges is opposite a Tremex-burrow, 
and elevating her long ovipositor in 
a loop over her back, with its tip on 
the bark of the tree (Fig. 588), she 
makes a derrick out of her body 
and proceeds with great skill and 
precision to drill a hole into the 
tree. When the Tremex-burrow is 
reached she deposits an egg in it. 
The larva that hatches from this egg 
creeps along this burrow until it 
reaches its victim, and then fastens itself to the horn-tail larva, which it 
destroys by sucking its blood. The larva of Megarhyssa when full-grown 
changes to a pupa within the burrow of its host, and the adult gnaws a 


Fig. 588. — Megarhyssa lunator. 


348 


THE STUDY OF INSECTS 


hole out through the bark if it does not find a hole already made by 
the Tremex. Sometimes the adult Megarhyssa, like the adult Tremex, 
gets her ovipositor wedged in the wood so tightly that it holds her a 
prisoner until she dies. 

Among the more common of our larger Ich- 
neumon-flies are those of the genus Ophion (Fig. 
589); these have yellow bodies. One species 
infests the caterpillars of the Polyphemus moth 
and only a single egg is laid within each victim. 
The caterpillar lives until it spins a cocoon, but 
does not change to a pupa. The Ichneumon larva 
when full-grown spins a dense brownish cocoon 
within the cocoon of the caterpillar. 


Fig. 589. — Ophion. 


Fig. 590. 


Family Proctotrupid^e and Allies 

The Proctolrupoids 

There is a group of nine closely related families of the Hymenoptera 
which together are known as the proctotrupoids. The group, as a whole, 
is of great economic importance because the differ- 
ent species are parasitic upon a great variety of 
insects. 

The members of this group are slender insects 
and mostly of minute size. Their color is almost 
invariably black or brown without metallic luster. 
The venation of the wings is greatly reduced and 
in many foims the wings are veinless; there are 
also many wingless species. Figure 590 represents 
a proctotrupoid greatly enlarged. 

The proctotrupoids are all parasitic wasps; and very many of them 
infest the eggs of other insects. The female proctotrupid bores a hole 
with her ovipositor through the shell of an egg of one of the larger in- 
sects, and deposits one of her eggs inside of it. Here the young parasite 
when it hatches finds itself in the midst of food which is sufficient for it 
till it is full v grown. The transformations are passed within the infested egg, 
from which the parasite comes forth an adult. Other species are internal 
parasites of larvae, and some are secondary parasites, that is, parasites 
upon other parasites. None has been found to be injurious to vegetation. 
Perhaps the most remarkable species of the proctotrupoids is Peleclnus 

polyturdtor, the only rep- 
resentative in our fauna 
of the family, Pelecinidae. 
The females are common 
in the regions in which 
the species occurs and are 
easily recognized by the 
long and slender abdomen 
(Fig. 591). The abdomen 
of the male is club-shaped 
and only about twice as 
long as the head and thorax. This sex is very rare in this country but is 


Fig. 591. 


HYMENOPTERA 349 

common in some parts of South America; it can be recognized by the 
venation of the wings, which is similar to that of the female. This species 
is parasitic on the larva? of May-beetles. 

Family Cynipids 
The Cyuipids 

Most members of this family are small insects and many of them are 
minute; for this reason they are not commonly observed; but the galls 
produced by some species, especially those that are found on oaks and 
roses, are very familiar objects. Not all cynipids, however, produce galls; 
some are parasites and others are inquilines, living in galls produced by 
other species. 

The antennae of the cynipids are not elbowed and only rarely com- 
posed of more than sixteen segments; the 
pronotum is produced on each side so as 
to reach the tegula or is separated from it 
only by a membranous area; the wings 
lack a stigma and have at most five closed 
cells; the wings are rarely wanting; the 
abdomen is strongly compressed. 

In most of the cynipids the dorsal 
sides of the basal segments of the abdo- 
men are very long and appear to project 
over and cover the last segments so that 
only the edges of the latter are visible (Fig. 

p q 2 ) Fig. 592. — A mpliibolips. 

The cynipids are of interest because some of them are parasitic on 
other insects, especially aphids and the larvae of flies, and because some 
cause galls on various plants. 

The work of the gall-producing species is much more conspicuous 
than that of the parasitic forms and more is known about the gall-makers 
which are commonly known as gall-flies. It should be remembered, how- 
ever, that galls on plants are produced by other insects, namely, plant- 
lice, flies, moths and occasionally beetles and also by mites. In the case 
of galls made by the cynipids the gall is closed and a hole must be made 
by the insect in order to emerge. Moreover, there is no reproduction of 
insects within the galls of gall-flies, as there is within the galls of mites 
and plant-lice. 

It is a remarkable fact that each species of gall-insects infests a special 
part of one or more particular species of plants, and the gall produced by 
each species of insect is of a definite form. Hence when an entomologist 
who has studied these insects sees a familiar gall, he knows at once what 
species of insect produced it. 

Naturalists have speculated much as to the way galls are made to 
grow. It has been supposed that at the time the egg is laid there is 
deposited in the tissue of the plant with it a drop of poison, which causes 
the abnormal growth. By this theory the differences between the galls 
of different insects was explained by supposing that the fluid produced 
by each species of insect had peculiar properties. There are certain 
kinds of galls which may be produced in this way. Thus it is said that 


350 THE STUDY OF IXSECTS 

the wound made by a certain sawfly in the leaves of willow causes an 
abundant formation of plant-cells, and the gall thus formed attains its 
full growth at the end of a few days, and before the larva has escaped 
fnun the egg. But with the gall-flies the gall does not begin to grow until 
the larva is hatched; but as soon as the larva begins to feed, the ab- 
normal growth of the plant commences. In this case, therefore, if the 
gall is produced by a poison, this poison must be excreted by the larva. 
Galls produced by the different species of cynipids differ greatly in 
form and are found on all parts of plants. 

There are two terms that are frequently used in the descriptions of 
galls; these are monothalamous , indicating that the gall contains a single 
larval cell, and polythalamous indicating that the gall is compound, con- 
taining more than one larval cell. 

Certain insect-galls have been found valuable for various purposes; 
they have been used in medicine, in the manufacture of ink, for tanning, 
and for dyeing. 

There exists in many species of gall-flies an alternation of generations; 
that is, the individuals of one generation do not resemble their parents, 
but are like their grandparents. In many cases the two succeeding 
generations of a species differ so greatly that they have been considered 
as distinct species until by careful studies of the life-cycle one has been 
found to be the offspring of the other. In those species where an alterna- 
tion of generations exists, one generation consists only of agamic females 
while the other consists of both males and females, which reproduce sex- 
ually. In some cases the galls produced by the two generations are quite 
similar; but in others they are very different and are found on different 
parts of the host-plant. 

The guest gall-flies or inquilines. — Some species of this subfamily do 
not form galls but lay their eggs in the galls made by other species. The 
larvae of these inquilines feed upon the galls produced by their hosts and in 
some cases do not discommode the owners of the galls in the least. But 
some guest gall-flies are parasites as well as guests and their larvae mine 
from cavity to cavity of the gall and feed on the occupant of each in turn. 
Among the more conspicuous of our cynipid galls 
are the following. 

The oak hedgehog gall, Andricus erinacei. — A 

common gall on the leaves of white oak is one known 

as the oak hedgehog gall. This gall is rounded or 

oblong, with the surface finely netted with fissures, and 

more or less densely covered with spines (Fig. 593, 

a). It varies in length from f to f of an inch, and 

occurs on both sides of the leaves. The point of 

attachment is generally on the midrib, though it is 

often found on the lateral veins. When young the gall 

fig so? —The "oak * s yellowish-green, but in autumn it becomes yellowish- 

hedgehog gall: a, gall on brown. This gall is polythalamous, containing from 

two to eight larval cells (Fig. 593, b). 

Within the hedgehog galls is developed one generation, the agamic 

one, of Andricus erinacei. The alternating generation, the sexual one, is 

developed in very different galls made on the terminal growing points of 

buds and bud-scales. These are small, thin-walled, elongate, egg-shaped 

galls from T ^ to f of an inch in length, and are monothalamous. 


HYMENOPTERA 


35i 


The oak-apples. — There are various kinds of galls found on the 
leaves and stems of oaks that are commonly known as oak-apples, a 
name suggested by the spherical form and large size of some of them. 
Several of these are quite similar in external appearance but are markedly 
different in internal structure. In all there is a firm outer wall and a 


Fig. 594. — An oak-apple. 


small, central larval cell (Fig. 594). The part of the gall between the 
larval cell and the outer wall differs in structure in the galls of different 
species of gall-flies; in some it is filled with a spongy mass of tissue, in 
others the larval cell is held in place by a small number of filaments that 
radiate from it to the outer wall. 

The large oak-apple, Amphibolips confluens. — This is the largest 
of our common oak-apples, measuring from 1 to 2 inches in diameter. It 
occurs on several species of oak and is usually attached to a vein or the 
petiole of a leaf. The space between the larval cell 
and the outer wall of the gall is filled with a spongy 
mass of tissue, in which in some of the galls there 
are many radiating fibers, as shown in the figure 
above, but in other galls these fibers are indistinct, 
the space being filled with an amorphous mass of 
tissue. 

In spite of the fact that these galls are com- 
mon and conspicuous the life-cycle of the species 
that produces them has not been fully worked out. 

The large empty oak-apple, Amphibolips 
inanis. — In this gall the space between the 
central larval cell and the outer shell contains 
only a few, very slender, silky filaments, which 
hold the larval cell in place (Fig. 595). The 
gall measures from 1 to if inches in diameter, and is found on the 
leaves of the scarlet oak and red oak. Externally this gall resembles 


Frc. 595. — The large empty 
oak-apple. 


352 


THE STUDY OF INSECTS 


that of the preceding species but is easily distinguished by its internal 
structure. The adult gall-flies emerge in June and early in July; they 
are male and female; an agamic form of this species is not known. 

The giant oak-gall, Andricus calif ornicus. — This is the most com- 
mon oak-gall of the Pacific Coast. It is very abundant on the twigs 
and branches of the California white oaks, and during the winter, when 
the trees are bare, it is a very conspicuous object, on account of its 
abundance and large size. It varies in shape from globose to reniform 
and also varies greatly in size, some of the larger ones measure more 
than 4 inches in their greatest diameter. The outer surface of the gall is 
white and usually smooth; the interior is more or less filled with a com- 
pact soft material, and contains from one to a dozen larval cells. 

The mossy rose-gall, Rhodites roses. — This is a very common poly- 
thalamous gall, which is formed on the stems of rose bushes, especially 


Fig. 596. — The mossy rose-gall. 


of the sweetbrier. The gall consists of a large mass of moss-like filaments 
surrounding a cluster of hard kernels (Fig. 596). In each of these kernels 
a gall-fly is developed. The galls appear early in the summer but the 
adults do not emerge till the following spring. These are male and fe- 
male; there is no alternation of generations in this species. 


Family Chalcidid^e 

The Chalcid-flies 

This family is a very large one for it includes many thousands of 
species. Most of the species are very small insects and some are minute, 
measuring not more than a quarter of a millimeter in length; some spe- 
cies are much larger but these do not exceed the honey-bee in size. Most 
of the species are black, with strong metallic reflections, although some 


HYMENOPTERA 


353 


are yellow and some of the larger species have red markings. The head 
is usually large (Fig. 597); the prothorax does not extend back on each 

side to the tegula; the ovipositor is 
usually hidden, issuing before the apex 
of the abdomen, but in some genera it 
is very long. 


Fig. 597. — A chakid-fly, Aphycus emptor. 


Fig. 598. — Fore wing of a cha!cid-fly 


In most of the chalcids the venation of the wings is reduced to the 
type shown in Figure 598; in a few, however, there are vestiges of other 
veins; but in none are there any closed cells. 

The chalcid-flies constitute an exceedingly important group of insects 
from an economic standpoint; and nearly all of them are beneficial, 
being parasites that do much to keep in check noxious insects. A few 
species, however, are phytophagous; among these are those of the genus 
Isosoma, now known as Harmolita, that infest the stalks of growing grain, 
and species of several genera that infest the seeds of various plants. 
While these are noxious, the fig-insects, although phytophagous, are very 
beneficial to man. 

Insects in all stages of their development suffer from the attacks of 
chalcid-flies, eggs, larvae, pupae, and even adults in a few cases being 
attacked by them. The larvae of chalcid-flies usually feed within the 


Fig. 598a. — A chalcid parasite, Aplielinus jucundus, emerging from the 
geranium aphid. (Figure loaned by Dr. Grate H. Griswold.) 

body of their host, (Fig. 598a) but some species are external parasites of 
other larvae. 

The plant-feeding chalcids are of considerable interest because they 
are destructive to crops. The following are well-known. 


354 THE STUDY OF INSECTS 

The wheat joint-worm, Harmolita tritici. — This is a well-known pest 
which infests the stalks of growing wheat and certain grasses. It causes 
a woody growth which fills up the cavity of the stalk, and sometimes also 
causes a joint to swell and the stalk to bend and lop down. The presence 
of this insect is often indicated by pieces of hardened straw coming from 
the threshing machine with the grain. There is but a single generation 
of this species in a year. The insect remains in the straw and stubble 
during the winter, the adults emerging in the spring. The methods of 
control of this pest are rotation of crops, burning or deep ploughing under 
of stubble when practicable, or harvesting of stubble in spring with a 
horse-rake and burning it before the adults emerge. 

The wheat straw-worm, Harmolita grandis. — This species is often a 
serious pest of wheat west of the Mississippi River; it also occurs in the 
East, but is rarely so injurious in this section as is the wheat joint-worm. 
The adults differ from our other, species of Harmolita in that the meso- 
notum is smooth, polished, and shining. This species also differs in that 
it exhibits a seasonal dimorphism. There is a summer generation, which 
consists only of winged females, and a winter and spring generation which 
consists of both males and females. These are smaller than the summer 
form and are frequently wingless. The adults of the winter and spring 
generations emerge in April and the females deposit their eggs in the 
young wheat plants; the larvae eat out and totally destroy the forming 
heads of wheat. The adults of the second generation deposit their eggs, 
about the time the wheat is heading, just above the youngest and most 
succulent joints which are not so covered by the enfolding leaf-sheaths as 
to be inaccessible to them. The larvae pupate by October and the winter 
is passed in the straw or stubble. 

Another species that is of economic importance is the clover-seed 
chalcid, Bruchophagus Junebris, which infests the seeds of red and crimson 
clovers and alfalfa. This insect usually winters over in the seed as a 
well-developed larva; the pupal stadium is rather short and the adult 
lays her eggs in May and June. 

The fig-insects. — These are remarkable chalcids that live within figs 
and fertilize them. There is but a single species in the United States, 
Blastophaga psenes, which was introduced into California in order to 
make possible the production of the Smyrna fig in that state. 

The fruit of the fig-tree consists of a hollow receptacle on the lining of 
which the flowers are borne. At the apex of the fig there is a more or 
less distinct opening leading into the interior; it is through this opening 
that the female fig-insect leaves the fig in which she was developed and 
enters a young fig in order to oviposit. 

The eggs are laid at the base of a modified form of pistillate flowers, 
known as gall-flowers, that are found in wild figs; and the larvae produce 
little galls in which they develop. The female fig-insect when leaving the 
fig in which she was developed becomes covered with pollen which is 
thus carried into the young fig which she enters to oviposit, and thus the 
flowers in this fig are fertilized. 

The male fig-insect is wingless. It crawls about over the galls in the 
fig in which it was developed and when it finds a gall containing a female 
it gnaws a hole in it and then thrusting the tip of its abdomen through 
the puncture fertilizes the female. 

It is only in the wild figs that the gall-flowers are developed; for this 


HYMEN OPT ERA 355 

reason only the wild figs are suitable for the development of the fig-in- 
sects; but the female fig-insects will enter the cultivated figs seeking a 
place to oviposit and will thus fertilize them. 

Although the numerous varieties of common, cultivated figs do not 
require the stimulus of pollination and the resulting fertilization of the 
ovary to make the fruit set, in the case of the Smyrna fig, which is the 
most desirable variety grown, without this stimulation the young figs 
soon turn yellow and drop. It is the oily kernel of the fertile seed that 
gives the Smyrna figs their superior quality. 

The fertilization of the edible figs is termed caprification ; and it is 
brought about by placing in the fig-trees fruit of the wild figs containing 
the fig-insects. In order, therefore, to produce the Smyrna figs it is 
necessary to grow also the wild figs, or caprifigs as they are termed. 

There are many species of fig-insects living in the wild figs of tropical 
and semi-tropical countries. 

THE COMMON WASPS, ANTS, AND ALLIES 

This is a large group of hymenopterous insects which are closely 
related in certain details of external structure but which vary consid- 
erably in habits and appearance. It includes the well-known wasps and 
hornets, the ants, the velvet-ants, the tiphiid wasps and others, some 
fourteen families in all, of which only a few can be discussed here. 

Family Pompilid^e 
The Spider-wasps 

The members of this family are commonly called spider-wasps, be- 
cause they provision their nests with spiders; this habit, however, is not 
distinctive as certain other wasps use spiders for this purpose. 

The members of this family are slender in form, with long spiny legs. 
The pronotum extends back on each side to the tegula; and the abdomen 
is sessile. Many of the species are of medium size, but some are very 
large; in fact, the largest of our Hymenoptera belong to this family. 

Most of the Pompilidas make their nests in the ground. The wasp 
first finds a spider and stings it until it is paralyzed, and then digs a 
burrow, which is enlarged at the lower end, forming a cell for the recep- 
tion of the spider; the spider is then dragged down into the cell and an 
egg attached to it; then the passage leading to the cell is filled with 
earth. 

Among the giants of this family are the well-known tarantula-hawks 
of the genus Pepsis of the Southwest, which store their burrows with 
tarantulas. Many a hard-fought battle do these spider-wasps have with 
these enormous spiders, and sometimes they are conquered and ignomin- 
iously eaten. 

Not all members of this family are digger-wasps, for some are mason- 
wasps. The species of one genus make thimble-shaped cells, of mud, 
attached to the lower surface of stones, in chinks of walls, under bark and 
in various other situations. The books, "Wasps Social and Solitary," by 
the Peckhams, and "Wasp Studies," by theRaus, contain most interesting 
accounts of these wasps. 


356 


THE STUDY OF INSECTS 


599. — Chrysis nitidula. 


Family Chrysjdid^ 

The Cuckoo-wasps 

The cuckoo-wasps are wonderfully beautiful creatures, being usually 
a brilliant metallic green in color. The species are of moderate size, the 
largest being only about \ of an inch in length. 
They can be distinguished from other Hymenoptera 
by the form of the abdomen, in which there are 
at most five and usually only three or four exposed 
segments (Fig. 599), and which is strongly concave 
below, so that it can be readily turned under the 
thorax and closely applied to it. In this way 
a cuckoo-wasp rolls itself into a ball when attacked 
leaving only its wings exposed. 
The cuckoo-wasps are so-called because they are parasitic in the nests 
of solitary wasps and solitary bees. A cuckoo-wasp seeks until it finds a 
wasp or bee building its nest, and when the owner of the nest is off 
collecting provisions steals in and lays its egg, which the unconscious 
owner walls in with her own egg. Sometimes the cuckoo-wasp larva eats 
the rightful occupant of the nest, and sometimes starves it by eating up 
the food provided for it. The bees and wasps know this foe very well, 
and tender it so warm a reception that the brilliant-coated little rascal 
has reason enough to double itself up so the righteous sting of its assail- 
ant can find no hole in its armor. There is one instance on record where 
an outraged wasp, unable to sting one of the cuckoo-flies to death, 
gnawed off her wings and pitched her out on the ground. But the un- 
daunted invader waited until the wasp departed for provisions, and then 
crawled up the post and laid her egg in the nest before she died. 


Family Tiphiids 
The Tiphiids 

The tiphiids are mentioned mainly because of the species, Tiphia 
inornata, which is parasitic on white grubs, the larvae of May-beetles. In 
order to reach the grubs, the wasp has to burrow into the soil until she 
finds her victim which she seizes with her mandibles and stings it in 
order to quiet its struggles. She then lays an egg on 
the back of the grub. The egg hatches and the larva 
eventually destroys its host. 

The female tiphia is a black shining wasp about 
one-half an inch in length (Fig. 6qo) . The male is smaller 
and has an upward projecting spine near the tip of the 
abdomen. 


Fig. foo. — Tiphia 
inornaia. 


Family Mutillid^ 

The Velvet-ants 

These handsome insects resemble ants in the general form of the body, 
but lack the scale-like knot of the pedicel of the abdomen characteristic 


HYMENOPTERA 357 

of the true ants, although there is sometimes a constriction between the 

first and second abdominal segments (Fig. 601). The body is often 

densely clothed with hair, which gives the insects the 

appearance of being clothed in velvet; and as the body ^S^feM&^ 

is usually ringed or spotted with two or more strongly ^T ^\^^) 

contrasting colors, they are very conspicuous. But in many 

species the body is naked. The colors most commonly 

worn by the velvet-ants are black and scarlet. The males are winged and 

frequent flowers. The females are wingless, but they run very rapidly 

and they sting severely. In the western states there are many straw 

yellow species, which are nocturnal. 

These insects are abundant in the warmer portions of our country, 
and several species occur in the North. A large species, Dasymiitilla 
occidentalism which measures from \ to \\ inches or more in length, is 
known in the South as the " cow-killer ant " because of the popular 
superstition that its sting is very dangerous to live stock. 

The mutillids of which the habits have been observed are parasites of 
nest-building Hymenoptera in the cells of which they deposit their eggs. 
The larvae attack those of the owners of the nest without touching the 
provisions which the cell may contain. 

Family Scoliid^e 
The Scoliids 

The scoliids are quite closely related to the preceding family but dif- 
fer in their general appearance, resembling wasps rather than ants. 
They are parasitic on white grubs, the larvae of Scarabaeidae. In their 
habits they do not exhibit as much intelligence as do most digger wasps; 
for they do not build nests and transport prey to them for their carniv- 
orous larvae. Instead of this they dig in the ground where the white 
grubs are, and finding one they sting it in order to paralyze it, work out 
a crude cell about it, and attach an egg to a ventral abdominal segment of 
the grub. The larva of the scoliid consumes the grub and then spins a 
cocoon and completes its development in this place. 

The members of this family are very striking in appearance, being of 
large size and with the abdomen marked with conspicuous spots. Two 
genera are represented in our fauna, Scolia and Campsomeris (Elis). 

Family Formicid^e 
The Ants 

The great number of ants and their wide distribution render them the 
most familiar of all insects except perhaps the housefly. As has been 
said by Professor Wheeler, an indefatigable investigator of these insects, 
" Ants are to be found everywhere, from the arctic regions to the tropics, 
from timberline on the loftiest mountains to the shifting sands of dunes 
and seashores, and from the dampest forests to the driest deserts. Not 
only do they outnumber in individuals all other terrestrial animals, but 
their colonies even in very circumscribed localities often defy enumera- 
tion." The present time has been termed the " age of insects " and of 
all insects the Formicidae is the dominant family. 


358 THE STUDY OF INSECTS 

Ants are easily recognized by the well-known form of the body. The 
most distinctive feature is the form of the pedicel of the abdomen; this 
consists of either one or two segments, and these seg- 
ments are either nodiform or bear an erect or inclined 
scale (Fig. 602). 

When the pedicel of the abdomen consists of a single 

ric. 602. . . , r . ., . . . f 

segment it is known as the petiole; when it consists 01 two 
segments the first segment is termed the petiole and the second segment 
the postpetiole. The swollen portion of the abdomen behind the pedicel is 
known as the gaster. 

Another striking characteristic of ants is that in the antennas of 
females and workers and of the males of some species the basal joint, the 
scape, is long and the antennas are abruptly elbowed at the extremity of 
this joint. 

The ants are all social insects, there being no solitary species. Each 
colony consists of three castes, the males, the female or queen, and the 
workers. As with the social bees and the social wasps, the workers are 
all modified females. With most ants the males and the queens are 
winged and the workers wingless; the wings of queens, however, are de- 
ciduous. In certain genera that live as parasites in the nests of other 
ants the worker caste is wanting, and in some species the females are 
wingless. 

With many ants the polymorphism is not restricted to the presence 
of three uniform castes for one or more of the castes may be represented 
by more than one form. Of the males there may be either an unusually 
large form, or dwarfs, or ergatoid males, that is, males that resemble 
workers in having no wings and in the structure of the antennas. The 
queens exhibit a similar series of forms; those of unusually large stature; 
dwarfs which are sometimes smaller than the largest workers; and er- 
gatoid queens, which are a worker-like form, with ocelli, large eyes, and a 
thorax more or less like that of the normal queens, but without wings. 
In many species the workers are of two distinct sizes, the worker majors 
and the worker minors. In colonies that are founded by an isolated 
female the first brood of workers is of the worker minor form. With 
many species a worker form exists in which the head and the mandibles 
are very large, the soldier caste. 

Although all ants are social, great differences exist among them as to 
the size of their colonies. In the more primitive species the fully de- 
veloped colony consists of only a few dozen individuals with com- 
paratively feeble caste development ; while in the more highly specialized 
forms a colony may consist of hundreds of thousands of individuals and 
exhibit an elaborate polymorphism. 

The different species of ants differ also in their nesting habits. By 
far the greater number of species excavate their nests in the ground. 
Certain species are often seen burrowing in paths or other open places; 
but many more are to be found under small flat stones or other objects 
lying on the ground. Some species, especially those in which the colonies 
become large, build large mounds of the excavated material. These 
mounds are very familiar objects in many parts of our country. 

While most species of ants nest in the soil, there are many that build 
their nests in wood, in timbers, in the trunks of decaying trees, in or 
under bark, or in hollow stems. Others, especially certain tropical spe- 


HYMENOPTERA 359 

cies, build in cavities of living plants; and still others, as Crematogaster, 
build carton nests. 

A striking difference between the nests of ants and those of wasps and 
bees is that the ants do not construct permanent cells for their brood. 
The eggs, larvae, and pupae are stored in chambers of the nest and are 
moved from one to another in order to take advantage of the changes in 
temperature and moisture. Thus the brood may be brought near the 
surface of the nest during the warmer portion of the day and removed to 
deeper chambers at nightfall. 

Large swarms of winged ants are often seen. These are composed of 
recently matured males and females that have emerged at the same 
time from many different nests, probably from all of the nests of the 
particular species involved that exist in the immediate region, and in 
which young queens and males have been developed. The object of these 
flights is mating, and they render probable the pairing of males and 
females from different nests, thus preventing too close interbreeding. The 
factors that determine the occurrence of the nuptial flights from all the 
nests of a species in one locality at the same time are not understood. In 
the case of those species in which the female is wingless the mating must 
take place either in the nest or on the ground outside. 

After the pairing of the sexes the males soon die and each female 
proceeds to found a new colony if she is not captured by workers and 
taken into a colony already established or finds her own way into one. 
Except among the parasitic ants the method of founding a colony is as 
follows: The female breaks off her wings; then seeks out a small cavity 
under a stone or under bark or makes one in the ground. She closes 
the entrance to this cavity and remains isolated without food for weeks 
or months while the eggs in her ovaries are developing. During this 
period there is a histolysis of the large wing-muscles the products of 
which are used as food. When the eggs are mature they are laid and the 
larvae that hatch from them are fed by the female, or queen as she is 
termed, with her saliva till they are ready to pupate. As the young 
queen takes no food during this period, the excretion fed to the larvae 
must be derived from the fat in her body and the dissolved muscles. 
The adults that are developed from this first brood or larvae are workers, 
but owing to the limited amount of food that they have received they are 
abnormally small; that is, of the form known as worker minors. These 
open the chamber in which they were developed and go forth to collect 
food for themselves and for the queen, and they take charge of the sec- 
ond brood of larvae, which being supplied with abundant food develop into 
larger workers. The nest is now enlarged by the addition of new cham- 
bers and the growth of the colony continues. A few years later numerous 
males and females are developed, which at the proper time leave the nest 
for their nuptial flight. 

The method of founding colonies described above is the usual one. 
But in some species the females have lost the power of establishing a 
colony unaided and must be adopted by workers of her own species or by 
workers of an alien species. The adoption of a queen by workers of an 
alien species explains the existence of some of the mixed colonies which 
are sometimes observed. The practice of slave-making described later, 
is the explanation of others. In certain parasitic species workers are 
wanting and the queens must find homes in nests of alien species. 


3 6o THE STUDY OF INSECTS 

The worker ants are so-called because upon this caste devolve all the 
labors of the colony after they appear on the scene in the foundation 
chamber. As a rule workers are sterile; but sometimes, as with bees, 
and wasps, fertile workers occur. It is believed that only males are 
developed from eggs laid by workers. 

Without attempting to lead the beginning student through the maze 
of subfamilies, tribes, subgenera and subspecies into which the family of 
ants has been divided in an effort to classify the different forms, we shall 
simply discuss a few of the more common ants and some of those that 
have interesting and rather striking habits of living. 

THE LEGIONARY OR VISITING ANTS 

The members of this subfamily are largely confined to Equatorial 
Africa and tropical America. The colonies are nomadic, wandering from 
place to place in search of prey, and forming only temporary nests. 
Some of the species travel in vast armies and often overrun houses in the 
tropics, clear out the vermin with which they may be infested, and com- 
pel the human inhabitants to leave for a time. _ 

The subfamily is represented in our fauna by a single genus, Eciton, 
species of which occur from North Carolina and Colorado southward. 
Our species, however, do not form large armies, though they hunt in 
files like the tropical species, and the colonies of some of the species may 
consist of thousands of individuals. Some of the species are fond of 
kidnapping the brood of other ants. The females are wingless and much 
larger than the workers. The workers are polymorphic. 

THE MYRMICINE ANTS 

In this subfamily the pedicel of the abdomen consists of two segments 
(Fig. 603). This is a large subfamily; more than half of the species of 

ants found in America north 
of Mexico belong to it. The 
following species will serve to 
illustrate the remarkable differ- 
ences in habits of its different 
members. 

The little yellow house-ant, 
Monomdrium pharaonis. — This 

Fig. 603. - A myrmicid ant. j g ^ species com monly known 

as the " little red ant " although it is light yellow in color. It is the 
most troublesome of all ants that invade our dwellings. It is only about 
one-sixteenth of an inch long and often occurs in great numbers. This 
ant will eat almost any household food but is especially fond of sweet 
substances. Its nests are often made within the walls of a house in which 
case it is nearly impossible to destroy them. 

The harvesting ants. — Several genera of myrmicine ants feed on seeds, 
and as they collect these seeds and store them in their nests they are 
known as harvesting ants. It was to these ants that Solomon referred. 
They have also been known as agricultural ants; for it was formerly 
believed that they sow around their nests seeds of the plants from which 
they collect the grain that they use. But this has been disproved. 


HYMENOPTERA 


361 


One of the characteristic harvesting ants of this country is Pogond- 
myrmex barbatus and its subspecies. It occurs in Texas and is known as 
the " agricultural ant." It forms rather large colonies and its nest pre- 
sents a bare, circular area from five to ten feet in diameter produced by 
destroying all of the plants around the central opening. The sting of 
this ant is as severe as that of the bumblebee and its bare areas in fields 
of alfalfa, corn, and cotton bring about considerable loss to the farmer. 

The shed-builder ant, Crematogaster lineolata. — In the tropics, ants 
belonging to several genera build carton nests attached to branches of 
trees. We have this one common species in the Northern States and 
Canada. This is a small ant, the workers measuring from § to £ of an 
inch in length. It is usually yellowish-brown, with a black abdomen; 
but it varies greatly in color. Its favorite nesting-place is under stones 
or underneath and within the decayed matter of old logs and stumps. 
Out of this material the ants sometimes make a paper-like pulp with 
which they build a nest attached to the side of a log, or even to the 
branches of a shrub at some distance from the ground. While such nests 
are uncommon these ants often build small sheds at some distance from 
the nest, over the herds of aphids or coccids from which they obtain 


Fig. 604. — A "cow-shed" built by ants. (From A. B. Comstock, Handbook 
of Nature Study.) 

honey-dew (Fig. 604). In these cases the aphids or coccids are huddled 
together on a branch, from which they are deriving their nourishment, 
and are completely covered by the " cow-shed " built by the ants. 


THE FUNGUS-GROWING ANTS 


Among the many remarkable examples of insect behavior none is 
more remarkable than the habits of the fungus-growing ants. These ants 
cut pieces of leaves from various plants and carry them to their nests 


362 THE STUDY OF INSECTS 

where certain workers take them and chew them into fine bits which are 
then used as a medium on which to grow fungi as food for the members 
of the colony. 

One common species, Atta texdna, occurs in central Texas. It is 
known as the parasol ant because files of the individuals may be seen, 
each with a piece of leaf held over its back like a tiny parasol, which it 
is carrying to its nest. This ant is often destructive to cotton, corn, 
fruit-trees and other plants for where it is abundant it will soon strip a 
plant of its leaves. 

Most of the fungus-growing ants are confined to tropical and sub- 
tropical America but one species is found as far north as New Jersey. 

THE ARGENTINE ANT AND ITS ALLIES 

In this subfamily the pedicel of the abdomen consists of a single 
segment and there is no constriction between the first and second seg- 
ments of the gaster. These ants often possess in addition to the poison 
glands, anal glands which excrete a foul smelling, sticky fluid, which is 
used as a means of defense in their combats with other ants. 

Only about a dozen species have been described from our fauna and 
most of these are southern. Certain tropical species build carton nests 
attached to trees and some of our species make carton nests under stones. 
The members of this subfamily are especially fond of honey-dew and 
attend aphids and coccids to secure it. The most important species of 
the subfamily in our fauna is the following. 

The Argentine ant, Iridomyrmex humilis. ■ — This is an introduced 
species, which has become an exceedingly serious pest in the Gulf States 
and in Southern California. Its injuries are of two kinds: first, as a 
household pest, entering and overrunning dwellings; and second, as an 
orchard pest. Its injuries in orchards are due to the fact that it protects 
aphids and coccids in order to secure the honey-dew that they excrete. 
The ants drive away the insect enemies of the aphids and coccids, which 
gives the latter a chance to multiply to an abnormal extent. 

THE TYPICAL ANTS 

The typical ants form a large subfamily containing many of our field 
ants and also those very interesting slave-making ants and the honey- 
ants. The pedicel of the abdomen 
consists of a single segment (Fig. 605). 
In this respect the typical ants are like 
the preceding subfamily. 

The following are some of our more 
common species. 

The carpenter ant, Camponotus Jier- 
_ t . , culcamis pennsyhanicus. — This is one 

Fie. 60s. — A typical ant. - ,, , ' -- , T , 

of the largest of our common ants. It 
is the large black species that builds its nests in the timbers of build- 
ings, in logs and in the trunks of trees. Frequently it builds in the 
dead interior of a living tree, excavating a complicated series of chambers. 
The mound-building ant, Formica exsectoides. — This .species is the 
builder of our largest ant-hills; these are often three feet in height and 


HYMENOPTERA 363 

six feet across, and sometimes they are much larger than this. New- 
colonies are often formed by fission, a portion of the colony emigrating 
and founding a new colony with one or more queens. In this way many 
colonies are often established in a limited area. The head and thorax of 
this ant are rust-red, while the legs and abdomen are blackish-brown. 

The blood-red slave-maker, Formica sanguined. — More than a cen- 
tury ago Pierre Huber called attention to the fact that this species which 
is common in both Europe and America, keeps in its nests the workers of 
other species of Formica, which aid in performing the labors of the col- 
ony. The relations of the two species thus associated have been com- 
monly regarded as that of slaveholders and slaves. The slaveholders 
obtain their slaves by making periodical forays on the colonies of the 
common black Formica fusca, and of other species of Formica, and bring- 
ing to their own nest the worker larvae and pupae. Some of these are 
eaten, but others are reared, and these knowing no other home take their 
place as active members of the colony. 

In the blood-red slave-maker the gaster is black or brown and there 
is a notch in the margin of the clypeus. The nests of this species are 
low obscure mounds of earth or are excavated under stones or logs or 
around stumps. Many subspecies and varieties of this species are recog- 
nized, some of which do not keep slaves. 

The shining amazon, Polyergus liicidus. — The species of the genus 
Polyergus were named amazons on account of their warring habits. 
Species of this genus occur in this country as well as in Europe. The 
shining amazon is a beautiful, brilliant red species widely distributed in 
the Eastern and Middle states. The species of this genus are slave- 
makers that have become absolutely dependent on their slaves. They 
cannot build their own nests or feed themselves or care for their young, 
but have only retained the power of fighting to get more slaves. Their 
mandibles are sickle-shaped and fitted only as weapons of offence. These 
ants also make periodical forays on the colonies of other species of 
Formica and carry home the worker larvae and pupae. The workers 
developed from these perform all of the labors of the colon}' - except that 
they take no parts in the forays on the colonies of other ants. The young 
queens of Polyergus, being unable to work, establish new colonies of their 
species by securing adoption in some small weak colony of another 
species of Formica after killing its queen by piercing her head. 

The corn-field ant, Lasius niger americanus. — To the genus Lasius 
belong several common species of small brow T n ants that make small 
mounds in various situations. These ants are fond of honey-dew and 
not only care for the aphids from which they obtain it but collect the 
eggs of the aphids and store them in their nests through the winter, and 
in the spring place the recently hatched plant-lice on the stems and roots 
of the plants on which they feed. A well-known species of this genus is 
the corn-field ant which cares for the corn-root aphid and places it on the 
roots of corn in the spring. 

The honey-ants, Myrmecocystus. — The ants of this genus are found 
in the arid regions of the Southwest, from the city of Mexico to Southern 
California and to Denver, Colorado. They have received the name of 
honey-ants from the remarkable fact that with them some of the workers 
function as honey-pots or reservoirs for storing the honey-dew collected 
by other workers, from nectar excreting galls on trees and from aphids 


364 


THE STUDY OF INSECTS 


and coccids. The individuals in which the honey-dew is stored are kn< iwn 
as repletes. The workers that collect the honey-dew swallow it and carry 
it in their crop to the nest. There they regurgitate it and feed it to a 
replete, which in turn swallows it and retains it in its crop. The crop of 
the replete becomes so greatly distended that the gaster becomes a trans- 
lucent sphere, as large as a pea, on the surface of which the sclerites 
appear as isolated patches separated by the tense, pel- 
lucid, yellowish, intersegmental membrane (Fig. 606). 
The repletes are unable to go about but remain quietly 
clinging to the roof of a chamber of the nest. When 
the season for obtaining honey-dew is passed, these living 
cells disgorge their supply through their mouths, for the 


Fig. 606. 


use of the colony. 


Family Vespid^e 

The Typical Wasps or Diploptera 

The family Vespidas includes our most familiar wasps, the hornets, 
and the yellow-jackets, and their near allies. All members of this family 
are winged and nearly all of them when at rest fold their wings length- 
wise like a fan; for this reason they are often termed the Diploptera or 
the diplopterous wasps. In the habit of folding their wings when at rest, 
the typical wasps differ from nearly all other Hymenoptcra. The vena- 
tion of a member of the Vcspidae is illustrated in Figure 607. 


Fig. 607. — Wings of Vespa diabolica: pr. I, preanal lobe; pr. exc, pre- 
axillary excision. (From Bradley.) 

If we take into account only the habits of these insects the sub- 
families of the typical wasps can be separated into two groups, the 
solitary wasps, those in which a single female makes a nest for her young, 
and the social wasps, in which many individuals work together to make a 
nest. This grouping of the subfamilies, however, is not regarded as a 
natural division of the family Vespidae, but this grouping is useful in a 
discussion of the habits of these insects. 


THE SOLITARY VESPID WASPS 

Most of our species of the solitary vespid wasps belong to the group 
known as the eumenids. The females of these wasps work alone, each 


HYMENOPTERA 365 

one building its own series of cells in each of which is placed an egg 
together with provision for the young. The cell is then closed and 
probably forgotten by the mother wasp. An African eumenid wasp has 
been observed, however, which does not gather provision in advance but 
leaves the cell open and feeds the larva from day to day. 

The different species of eumenids differ greatly in methods of nest- 
building; many are miners digging burrows in the earth leading to cells 
in -which provisions are placed for their young; some make burrows in 
wood, which they divide into cells by partitions of mud; some build their 
nests in the stems of pithy plants or make use of any suitable cavity that 
they find ; and others are mason or potter-wasps, making cells of earth, 
which are built in holes, or on the surface of the ground, or attached to 
twigs. 

Although the adult eumenids do not confine themselves to a carniv- 
orous diet but often visit flowers to obtain nectar, they all provision 
their nests with insects, which they have paralyzed with their sting; 
usually only a single species of caterpillar is used for this purpose by each 
wasp. 

Odynerus. — The greater number of our species of eumenids belong to 
the genus Odynerus. In this genus the abdomen is sessile. The shape of 
the body and frequently the coloration resemble those of the social wasps 
known as yellow-jackets, although usually the body is more slender and 
smaller. The common species are quite neighborly; and, owing to this 
resemblance to the yellow- jackets they inspire us with a fear that is out of 
all proportion to their will or ability to inflict pain. 

Many species of Odynerus are miners. Their burrows are to be found 
both in level ground and in the sides of cliffs. Branching from these 
burrows are short passages, each leading to a cell, from the ceiling of 
which an egg is suspended by a slender thread; jM^fa 

and in which food is stored for the larva. In S^Wim 

the species that have been studied, this food JlPilk^ 

consists of small, paralyzed caterpillars. Some ""^^^^^^p^^^Zr^" 
of the mining species while digging the burrow 
build a turret over the entrance of it, made of :z - ~~ 

pellets of mud removed from the burrow (Fig. FlG 6o8 _ Tun . et over the 
60S). The material of which the turret is com- ^[™ R ^ anTllT) S geminus ' 
posed is used to fill up the burrow after the cells 

are finished. In digging the burrow and in tearing down the turret the 
earth is softened with water, which the wasp brings in her mouth from 
some pool or stream. 

Not all species of Odynerus mine in the ground; many burrowin the 
stems of pithy plants, making a series of cells separated by partitions of 
mud; other species will avail themselves of any convenient cavity in 
which to make their nest, frequently utilizing the deserted nests of the 
sphecoid-wasps known as mud-daubers. In this case a single cell of a 
mud-dauber is divided by a transverse partition, making two cells for the 
smaller Odynerus. One year these wasps plastered up many of the key- 
holes in our house, including those in bureaus. 

The jug-builders, Eumenes. — The wasps of the typical genus_ of this 
subfamily are potter- wasps which build nests that appear like miniature 
water-jugs. The nests of our common species, Eumenes fraternus, are 
often found attached to twigs (Fig. 609). In this genus the abdomen of 


3 66 


THE STUDY OF IXSECTS 


the adult is petiolate. These wasps provision their nests with caterpillars 
and frequently with cankerworms. 


Fig. 6oq. — Eumenes fralernus and its nests. 


Ml 


M 


Fabre, who studied the habits of a European 

species of Eumenes observed what goes on within 

the nest by making a window in the side of it. The 

egg is suspended from the ceiling of the nest by a 

slender thread; when the larva hatches, it at first 

makes use of the egg-shell as its habitation and 

stretches down to feed on the caterpillar below it; 

if disturbed it retreats up its support. Later when 

the larva has increased in size and strength it de- 
scends to the mass of food. 

Monobia quadridens . — This species (Fig. 610) is 

common in most of the states east of the Mississippi. 

It is larger than the jug-builders, and the abdomen of 

the adult is sessile. Figure 61 1 represents a nest of this 

species, now in the Cornell University collection, which 

was made in a board in the side of a barn. The par- 
titions are made of mud. 
Each cell contained a pupa 
when the nest was opened, 
hence it was not evident 
what the food of the larva? 
had been; but several ob- 
servers state that this 
species stores its nests with 
large cutworms; and it is 
doubted that this species is 

a carpenter- wasp. It seems probable that the nest figured here was made 

in a deserted burrow of the large carpenter-bee, Xylocopa virginica. It 

differs from a nest of this bee only in that the partitions are made of mud. 


Fig. 6io. — Monobia quadridens. 


Fig. 6ii. — Nest of 
Monobia quadridens. 


THE SOCIAL VESPID WASPS 


Since these are the only wasps that are social they are commonly 
referred to as the social wasps instead of by the more technical name. 


HYMENOPTERA 


367 


As with the ants the colonies of social wasps consist of three castes, 
the female or queen, the workers, and during the later part of the season, 
the males. The workers are females in which the reproductive organs are 
imperfectly developed. 

In the temperate regions the colonies exist for only one season; the 
males and the workers die in the autumn; the females hibernate and 
each starts a new colony in the spring. At first the female performs the 
functions of both worker and queen, starting the building of the nest and 
laying the eggs. In the early part of the season only workers are de- 
veloped; after they appear they carry on the labors of the colony, ex- 
panding the nest and procuring the food for the larvas; the only function 
of the queen then is to produce the eggs. In the later part of the season 
males and females are developed. 

The social wasps are predacious, and they feed their larva? upon in- 
sects which they have malaxated. The wasps are also fond of the sweets 
of flowers, the juices of fruits, and of honey-dew. 

In the temperate regions the multiplication of colonies is brought 
about by the production of many males and females in the nest in the 
later part of the season; these pair, the females hibernate, and each 
female founds a new colony in the spring. But in the Tropics certain 
species form large perennial colonies, which from time to time give off 
swarms, in a way quite similar to the well-known swarming of the honey- 
bee. 

The Social Polistes. — The wasps 
of the genus Polistes and their nests 
are very familiar objects. The nests 
consist each of a single horizontal 
comb suspended by a peduncle, and 
the comb is not enclosed in an enve- 
lope (Fig. 612). These nests are often 
built under the eaves of buildings, in 
garrets, and in shedsand barns; they are FlG - 612. — Nest of Polistes. 

also often made under flat stones infields, and sometimes attached to bushes. 

. The nests are made of a grayish paper-like 
material, composed of fibers of weather- worn 
wood, which the wasps collect from the sides 
of unpainted buildings, fences, and other 
places, and convert into a paste by the action 
of the jaws and the addition of some fluid, 
probably an oral secretion. The nests of 
Polistes are usually comparatively small ; but 
some have been found in Texas that measured 
more than a foot in diameter. 
In this genus the abdomen 
is long and spindle-shaped (Fig. 613). 

Several of the species are known to store small quan- 
tities of honey in their combs. 

These wasps are often infested by stylopids. 
The Social Hornets and Yellow-jackets. — This subfamily 
includes those wasps that are commonly known as hornets . 
and the yellow-jackets. With these insects the body is 
comparatively short and rather stout (Fig. 614); the abdomen is at- 


Fig. 613. — Polistes. 


THE STUDY OF INSECTS 


tachcd to the thorax by a very short pedicel; and the color is black, 
spotted and banded with yellow or yellowish-white. The members of 

thjs subfamily differ from 
other vespoid wasps in that 
the hind wings are without 
an anal lobe (Fig. 607). 

These wasps make their 
nests of paper, which in 
some cases is composed of 
fibers of weather-worn 
wood, like that of Polistes 
described above, in other 
cases of fragments of more 
or less decayed wood. 
These nests consist of a 
series of horizontal combs 
suspended one below an- 
other and all enclosed in 
a paper envelope (Fig. 

615)- 

When the wasps wish 
to enlarge their nest they 
remove the inner layers of 
the envelope, and add to 
the sides of the combs, build 
additional combs below, 
and put on new layers on 
the outside of the envelope. 
By these additions the 
nest may become of large 
bv the end of the 


Fig. 615. — Nest of Vespa, with side removed, 
stock, Handbook of Nature Study.) 


(From A. B. Com- size 


season. 

Very small empty nests consisting of a single comb with but few cells 
and enclosed in an envelope of only one or two layers of paper are often 
found (Fig. 616). Such a nest is evi- 
dence of a tragedy. A queen wasp, 
in the spring, had started to found a 
colony. It was necessary for her to 
go back and forth in the fields collect- 
ing material for her nest and food for 
her larvae. ; and before a brood of 
workers were developed to relieve her 
of this dangerous occupation she be- 
came the prey of an enemy and the de- 
velopment of the colony was wrecked. 

Two quite different types of nests 
are made by different species of these 
wasps, and these are made in quite 
different situations. One kind is 
built above ground; these are at- 
tached to bushes or trees, or beneath 
the eaves of buildings; they are fig. 616. — Early stage of nest of vespa. 


HYMENOPTERA 369 

made of a grayish paper composed of fibers of weather-worn but not de- 
cayed wood. This paper is comparatively strong, so that the envelope 
of the nest is composed of sheets of paper of considerable size, a single 
sheet often completely enveloping the nest. The wasps which build this 
type of nest are commonly known as hornets. 

The other kind of nest is built in a hole in the ground, which is en- 
larged by the wasps as they need more room for the expansion of the 
nest. The paper of which these nests are made is brownish in color and 
is made out of partially decayed wood; it is very fragile and would not 
be suitable, therefore, for use in nests built in exposed places. Even 
though the nest is built in a protected place, the use of this fragile ma- 
terial necessitates a different style of architecture. The enveloping layer 
of the nest, instead of being composed of sheets of considerable size, are 
made up of small, overlapping, shell-like portions, each firmly joined by 
its edges to the underlying parts. The wasps which build these under- 
ground nests are commonly known as yellow-jackets. 

It has been found that at least two species of this subfamily are 
social parasites. In these species the worker caste has been lost, there 
being only males and females. The female enters the nest of another 
species of Vespa and lays her eggs, and her larvas are reared by the right- 
ful owners of the nest. 

The members of the social hornets and yellow-jackets found within 
the limits of our territory are commonly included in a single genus, Vespa. 
Only a few of our species can be mentioned here. 

The giant hornet, Vespa crabro. — This is our largest species, measur- 
ing about f of an inch in length. It is brown and yellow in color and is 
found around New York City, on Long Island, and in Connecticut. It 
builds its nests in hollow trees and within buildings suspended from the 
roof. It came to this country from Europe. 

The white-faced hornet, Vespa maculata. — This is the common, large 
black and white hornet. It is widely distributed in the United States 
and Canada. The nest, which is sometimes very large, is usually attached 
to the limb of a tree. 

A common yellow-jacket, - Vespa maculifrons. — This is one of the 
common species that builds its brown paper nests in the ground or be- 
neath some object on the ground or, occasionally, in a stump. In the 
height of the season there may be several hundred individuals in a nest 
which they will defend against an intruder with wild fury. Another 
common yellow-jacket is V. diabolica with similar nesting habits but 
which also, at times, builds aerial nests. 

THE DIGGER-WASPS OR SPHECOID WASPS. 

The wasps in this group are perhaps more properly known as sphecoid 
wasps but since most of them make nests for their young by burrowing 
in the ground or in wood they may very properly be called digger-wasps. 
There are three families in the group of which the first, Ampulicidas, is 
small and its members rare; the second, Dryinidse, is composed of para- 
sitic forms; and the third, Sphecidae, is a large one and contains many 
species of varied habits. 


370 THE STUDY OF INSECTS 

Family Dryinid^e 
The Dryinids 

This family is composed of small parasitic wasps of remarkable habits; 
it is widely distributed over the world and is represented in our fauna by 
many genera. 

The fore wings have a lanceolate or ovate stigma; the hind wings are 
without closed cells; the antennae consist of ten segments, the anterior 
tarsi of the female are usually chelate. The females of the genus Gonato- 
pus are wingless, ant-like, and are without a scutellum. 

These parasites confine their attacks to the homopterous insects 
belonging principally to the families, Fulgoridae, Membracidae, and 
Cicadellidae. 

The female dryinid seizes her victim with her raptorial fore legs; one 
pair of pincers usually grips the neck of the prey, the other pair grips the 
abdomen towards the apex or the hind legs. The wasp then inserts her 
egg into the body of the bug. A few days later the immature larva of 
the parasite appears outside the body of its host enclosed in a sac com- 
posed of molted skins. Here it remains, with its head in the opening in 
the body -wall of its host, until it has completed its growth. It then 
leaves its host and spins a silken cocoon, which in some cases is furnished 
with an outer covering formed of the larval sac or of round patches of 
epidermis stripped off from the leaf surface. 

Family Sphecid^; 
The Typical Sphecoid Wasps 

In this family the hind wings have an anal lobe and some closed 
cells; the abdomen of the male has seven exposed tergites. All members 
of the Sphecidae are winged. 

To this family belong all of our common nest-building sphecoid wasps. 
These differ from the bees in that they provision their nests with animal 
food, insects or spiders, which they have paralyzed by stinging them. 
Different members of the family differ greatly in their nesting habits; 
some are mason-wasps, building cells of earth; many burrow in the 
ground; and others burrow in the stalks of pithy plants or make use of 
cavities that they find. 

Most members of the Sphecidae, after preparing their nest, rapidly 
accumulate an amount of prey sufficient to enable the young to develop 
to maturity, lay an egg with it, and then close the cell before the egg has 
hatched. This method is termed mass provisioning. But certain mem- 
bers of the family, Bembex, and some others, feed their young from day 
to day as long as they remain in the larval state. This method is termed 
progressive provisioning. As each larva requires constant attention for a 
considerable time only a few young can be reared by a single female in 
this way. 

Many of these wasps after stinging their prey and before placing it in 
their nest malaxate {i.e., chew) its neck or some other part of the body 
and lap up the exuding juices. 

Only a few of the more common members of the family can be dis- 


HYMENOPTERA 


37i 


cussed here although they are among the most interesting of the Hymen- 
optera because of their remarkable nesting habits. 

Wasps of the genus Trypoxylon. — These are black slender 
wasps of medium size one of which, T.fngidum, makes its nests 
here in New York, very commonly in the branches of sumac 
(Fig. 617). The cells of these nests are separated by partitions 
of mud and are stored with spiders. 

Mr. and Mrs. Peckham who studied two other species, T. 
albopilosum and, T. rubrocinctum, in Wisconsin give a very 
interesting account of the cooperation of the males and fe- 
males during the nest-building period as follows: 

" With both species when the preliminary work of clear- 
ing the nest and erecting the inner partition has been per- 
formed by the female, the male takes up his station inside 
the cell, facing outward, his little head just filling the 
opening. Here he stands on guard for the greater part of 
the time until the nest is provisioned and sealed up, occa- 
sionally varying the monotony of his task by a short flight." 
" We have frequently seen him drive away the brilliant green 
Chrysis fly which is always waiting about for a chance to 
enter an unguarded nest." " In one instance, with rubro- 
cinctum where the work of storing the nest had been delayed by 
rainy weather, we saw the male assisting by taking the spi- 
ders from the female as she brought them and packing them 
into the nest, leaving her free to hunt for more." 

Some species of Trypoxylon are mud-daubers. Trypoxylon 
albitarsis, a shiny black species with white tarsi, builds large 
nests of mud, which consist of several parallel tubes, often 
three inches or more in length, placed side by side. These 
nests are known as pipe-organ nests. Each tube is divided 
by transverse partitions into several cells, which are provisioned 
with spiders. The tubes when completed are not covered 
with an extra layer of mud as is commonly the case in the 
nests of other mud-daubers. When an adult is ready to emerge n&t'^Tn- 

from the cell in ^ rylon Ms ' 
which it was de- 
veloped, it makes a hole through 
the exposed side of the tube. 

The thread-waisted wasps. — 
These are the most commonly 
observed of all of our sphecoid 
wasps, as certain species build 
their mud nests in the attics of 
our houses; and, too, the pecu- 
liar shape of the body makes 
them very conspicuous. Most 
of the species burrow in the 
ground and store their nests ei- 
ther with caterpillars or with Or- 
thoptera. But those best known 
to us are the mud-daubers. 
The mud-daubers make nests of mud attached to the lower surface of 


a. b. c. d* 

Fig. 618. — Nest' of a mud-dauber removed from a wall 
exposing the cells: a, larva full-grown; b, cocoon, r, young 
larva feeding on its spider-meat; d, an empty cell. (From A. 
B. Comstock, Handbook of Nature Study.) 


372 THE STUDY OF INSECTS 

flat stones or to the ceilings or walls of buildings. These nests usually 
consist of several tubes about one and one-fifth inches in length placed 
side by side (Fig. 618) and are provisioned with spiders. The mud- 
daubers may be seen in damp places collecting mud for their nests, or 
exploring buildings in search of a place to build. They have a curious habit 
of jerking their wings frequently in a nervous manner. There are in this 
country two widely distributed and common species of 
mud-daubers; these are the blue mud-dauber, Chalybion 
cam Hum, which is steel blue with blue wings, and the yel- 
Vig. 6iQ.—Scdiphron low mud-dauber, Sceliphron cementarium, which is black 
cemeniarium. or brown with yellow sp< )ts and legs (Fig. 619). The lat- 

ter of these species has been commonly described under the generic name 
Pelopczus. 

The tool-using wasps, Ammophila. ■ — Among the members of the 
sphecoid wasps that burrow in the ground and store their nests with 
caterpillars arc certain species of the genus Ammophila. These are of 
especial interest on account of the habit first observed by the Peckhams, 
of pounding down the earth with which they close their burrow by tak- 
ing a stone or some other object in their mandibles and using it as a hammer. 
The genus Chlorion, formerly known as Sphex, includes species which 
are among the most common of flower visitors in the warmer parts of our 
country, and are among the largest and most handsome, and therefore 
most often observed of our wasps. In the West the common, very large, 
all metallic green, Chlorion cydneum, is a very striking insect; and in the 
East, Chlorion ichneumoneum, which is brownish-red with the end of the 
abdomen black, is the most noticeable. 


Fig. 620. — Sphccius speciosus. 

The cicada-killer, Sphecius speciosus.- This is a large handsome wasp 
about i£ inches in length (Fig. 620). It is black sometimes of a rusty 
color, and has the abdomen banded with yellow. It is particularly 
abundant in July from New Jersey southward. It digs its burrows 
usually in the drier situations and stores at the bottom in enlarged cells 
one or more cicadas. The wasp locates a cicada in a tree, suddenly 
stings it, thus paralyzing it when both fall to the ground. The wasp 
then laboriously drags the cicada to its burrow, perhaps flying part of the 
way, the whole operation often taking an hour or more. When the 
cicada is finally stowed away at the bottom of the burrow the wasp lays 
an egg on its body where it hatches and the young wasp larva feeds on 
the paralyzed victim. 


HYMEN OPT ERA 


373 


Wasps of the genus Bembex. — These are stout-bodied wasps, usually 
black with greenish or greenish-yellow bands. They burrow in the sand 
and provision their nests with flies. Some species at least practise pro- 
gressive provisioning. After excavating its burrow and making a cell, 
the wasp captures a fly and stings it to death, then places it on the floor 
of the cell and attaches an egg to it. After the larva has hatched, the 
mother collects flies from day to day, feeding the larva till it is ready to 
change to a pupa, closing the nest behind her each time she leaves it. 

A common and well-known related wasp in the South is Sticta Carolina 
which is called the " horse guard." This is a large species which hunts 
about horses in order to capture flies. 


THE BEES 

The bees constitute a very large group of insects, including besides 
the well-known honey-bee and the bumblebees thousands of other species, 
many of which can be observed visiting flowers on any pleasant summer 
day. An authority states that 12,000 species of bees have been described, 
of which 2,500 are from North America and estimates that there are 
20,000 living species in the world. 

The bees differ from all other Hymenoptera, except a few vespoid 
wasps, in that they provision their nest with pollen and honey instead of 
with animal food, as do other nest-building Hymenoptera. The honey is 
obtained from flowers in the form of nectar, which is swallowed and 
transported to the nest in the crop. While in the crop the nectar undei- 
goes a chemical change, which is probably 
due to a mixture with it of a ferment de- 
rived from the salivary glands, and becomes 
what is known as honey. 

A characteristic of bees found in only a 
few other Hymenoptera is the presence, espe- 
cially on the thorax, of plumose hairs. 
Many forms of these hairs exist; some of 
them are represented in Figure 621. It has 
been suggested that the plumose hairs serve 
to hold the grains of pollen that become en- 
tangled among them when a bee visits a 
flower; but they occur in males and in 
parasitic bees neither of which gather pollen ; 
they are lacking, however, in some parasitic 
bees. 

Female bees, excepting those of the genus 
Prosopis and of the parasitic bees, are fur- 
nished with pollen-brushes or scopes, for collecting and transporting pol- 
len. In most bees these consist of brushes of hairs borne by the hind legs, 
but in the Megachilidae the brush is on the ventral side of the ab- 
domen. 

In some bees the pollen brushes are restricted to the tibia and the 
metatarsus of the hind legs, in others they are borne on these two seg- 
ments and on the femur, trochanter and coxa as well (Fig. 622). With 
the queens and workers of the nest-building bumblebees and with the 
workers of the honey-bee the pollen-carrying apparatus is very highly 


a b 


f 


Fig. 621. — Hairs of bumblebees. 
(After John B. Smith.) 


374 


THE STUDY OF INSECTS 


/hi terror ? 


Fig. 622. — Hind leg of female 
of Colletes with brushes on all seg- 
ments. (From Brane.) 


P/anfa 


Fig. 623. — A. Inner surface of the left hind leg of a worker 
honey-bee; B. Outer surface of the same. (After D.B. Casteel.) 


specialized (Fig. 623). On the outer sur- 
face of the tibia of the hind legs there is 
a smooth area which is margined on each 
side by a fringe of long curved hairs ; this 
structure is known as the pollen basket 
or corbicula; and on the inner surface of 
the metatarsus, termed planta by some 
writers, there is a brush of stiff hairs by 
means of which the bee gathers the pollen 
from its body. In the honey-bee the hairs 
composing this brush are arranged in 
transverse rows and are termed the pollen 
combs. 

The mouth-parts differ greatly in form 
in the different groups of bees ; this is espe- 
cially true of the maxillae and labium, 
which together constitute the proboscis, 
used for extracting nectar from flowers. 
The mandibles are fitted for chewing and 
do not vary so much in form. 

In the most generalized bees, the pro- 
boscis is comparatively short and the la- 
bium is either notched at the tip, or is quite 
deeply bifid (Fig. 624). In all other bees the labium is 
pointed at the tip. Among the bees with a pointed labium 
the proboscis varies greatly in length; in some it is 
comparatively short, while in the more specialized forms 
(Fig. 625) it is greatly elongate. 

The two sexes of bees differ in the number of abdominal 
tergites exposed to view; in the male there are seven, in the female, only six 


— Proboscis 
(After Saun- 


Fig. 625. — La- 
bium of the honey-bee. 
(After Saunders.) 


HYMENOPTERA 375 

The different species of bees exhibit great differences in habits; some 
are solitary, each female providing a nest for her young; some are para- 
sitic, the females laying their eggs in the nests of other bees and the 
larvae feeding on the provisions stored by their hosts; and some are 
social, living in colonies consisting of many individuals. 

The nests of solitary bees, like those of the digger-wasps, are of many 
forms. The mining-bees dig tunnels in the ground; the mason-bees build 
nests of mortar-like material; the carpenter-bees make tunnels in the 
stems of pithy plants or bore in solid wood; and some bees make nests of 
comminuted vegetable matter. The distinctive characteristic of the 
nests of bees is the fact that they are always provisioned with honey and 
pollen. In many cases closely allied species of bees differ in their nesting 
habits; for example, different species of the genus Osmia build very 
different kinds of nests. 

The social bees are the honey-bees, the bumblebees, and the stingless 
honey-bees of the Tropics. In all of these, as with the social wasps and 
the ants, there is in addition to the males and the egg-laying females a 
worker caste ; with all other bees there are only two forms, the males and 
the females. 

Family Andrenid^e 

The Andrenids 

The family includes those solitary nest-building bees and their para- 
sitic allies in which the tongue is either short or long but is pointed at the 
apex, and in which the pollen-brushes of the nest-building females are borne 
by the hind legs. To this family belong a large portion of the species and 
genera of our bees. Space can be taken here to discuss only a few of these. 

Halictus. — Among the more common of our mining bees are those of 
the genus Halictus. This is a large genus including very many species, 
among which are the smallest of our bees. The nests of some species are 
excavated in level ground; other species dig tunnels in the vertical sides 
of banks. These bees are often gregarious, hundreds of nests being built 
near together in the side of a bank. 

If these nests be studied in midsummer, each will be found to consist 
of a burrow extending into the bank and, along the sides of this main 
burrow or corridor, smaller short burrows each leading to a cell, the sides 
of which are lined with a thin coating of firm clay (Fig. 626). In each of 


Y'^l 


j 


rv 


j^J 


Fig. 626. — Diagram of part of a nest of Halictus. 


376 


THE STUDY OF INSECTS 


those cells that is closed will be found either a mass of pollen and nectar 
with an egg upon it or a larva feeding on the food stored for it. 

The most striking feature of these nests is the fact that several 
bees use the corridor as a passage-way to the cells they are building and 
provisioning. But this corridor is not a public one; it is constricted at 
its outer end and is guarded by a sentinel whose head nearly fills the 
opening. When a bee comes that has a right to enter, the sentinel backs 
into the wider part of the corridor and allows it to pass and immediately 
thereafter resumes its guarding position with its head closing the opening 
of the corridor. 

Anthophora.- — -The genus Anthophora is widely distributed and in- 
cludes many species, more than eighty have been described from North 
America alone; but the habits of only a few of these have been described. 

The nests of those American species the habits of which are well 
known are usually built in steeply inclined or perpendicular banks of 
earth, preferably in those of compact clay; they are also excavated in the 
clumps of clay held between the roots of stumps in stump-fences. In the 
West a favorite nesting place of these bees is in the walls of sun-dried 
bricks of the adobe houses. Like Halictus and Andrena, the bees of this 
genus are gregarious, hundreds of individuals building their nests close 
together in the same bank of earth. 

A striking feature of these nests is the presence of a cylindrical tube 
of clay extending outward and downward from the entrance of the tunnel. 
This tube is rough on the outside but smooth within. It is composed of 
small pellets of earth compacted together. These pellets when brought 


Fig. 627. — Section of a bank with nests of Anthophora. (Photographed by Miss P. B. Fletcher.) 

out from the tunnel are wet and easily molded into the desired form, but 
soon become dry and firm (Fig. 627). 

Andrena. — Among the larger of our common mining bees are certain 


HYMENOPTERA 


377 


species of the genus Andrena; some of these nearly or quite equal in size 
the workers of the honey-bee. They build their nests in road sides and in 
fields that support a scanty vegetation. They sink a vertical shaft with 
broad cells branching from it. These bees, though strictly solitary, each 
female building her own nest, frequently build their nests near together 
forming large villages. We once received from a correspondent a descrip- 
tion of a collection of nests of this kind which was fifteen feet in diameter, 
and in the destruction of which about two thousand bees were killed; 
what a terrible slaughter of innocent creatures! 

The small carpenter-bee, Ceratina dupla. — The nests of this bee are 
built in dead twigs or sumac and in the hollows of brambles and other 
plants. They are more common than those of any other of our solitary 
bees that build in these situations. This is a dainty little bee, about \ of 
an inch in length, and of a metallic blue color. She always selects a 
twig with a soft pith which she excavates with her mandibles, and so 
makes a long tunnel. Then she gathers pollen and nectar and puts it in 
the bottom of the nest, lays an egg on it, and then makes a partition out 
of pith-chips, which serves as a roof to this cell and a floor to the one 
above it. This process she repeats until the tunnel is nearly full, then 
she rests in the space above the last cell, and waits for her young to grow 
up. The lower one hatches first; and after it has attained 
its growth it tears down the partition above it, and then 
waits patiently for the one above to do the same. Finally 
after the last one in the top cell has matured, the mother 
leads forth her full-fledged family in a flight in the sunshine. 
After the last of the brood has emerged from its cell, the sub- 
stance of which the partitions were made, and which has 
been forced to the bottom of the nest by the young bees 
when making their escape, is cleaned out by the family, the 
old bee and the young ones all working together. Then the 
nest (Fig. 628) is used again by one of the bees. 

The large carpenter-bee, Xylocopa mrgmica. — This is a 
large insect, measuring from about an inch in length and re- 
sembling a bumblebee in size, and somewhat in appearance. 
But it can be easily distinguished from a bumblebee, as the 
female has a dense brush of hairs on the hind leg, instead of 
a basket for carrying pollen. This bee builds its nest in 
solid wood, and sometimes excavates a tunnel a foot in 
length, which it divides into several cells. The partitions 
between the cells are made of chips of wood, securely ce- 
mented together, and arranged in a closely wound spiral. This 
arrangement of chips is easily seen when the lower side of 
a partition is examined ; but the upper side of a partition which 
forms the floor of the cell above it is made concave and very smooth, so 
that the arrangement of the chips is not visible. 


Family Megachilid^; 

The Leaf-cidter Bees and their Allies 

To this family belong those bees in which the pollen brush of the 
female is borne on the ventral side of the abdomen and the parasitic 


378 


THE STUDY OF INSECTS 


bees that are allied to them. In this family the tongue is long and there 
are only two submarginal cells of approximately equal size in the fore 
wings. Among the better-known representatives of the family are the 
following. 

The leaf-cutter bees, Megachile. — The bees of the genus Megachile 
have a curious habit of making cells for their young out of neatly-cut 
pieces of leaves. These cells are packed away in such secure places that 
one does not often find them; but it is a very easy thing to find frag- 
ments of leaves from which the pieces have been cut by bees. The 


Fig. 629. — A leaf-cutter bee, MegachiU latimanus, its nest, and rose-leaves cut by the bee. 

leaves of various plants are used for this purpose, but rose-leaves are used 
more frequently than any other kind. In Figure 629 there are repre- 
sented one of these bees, its nest, and a spray of rose-leaves from which 
pieces have been cut by the bee. 

The nests are made in various situations. The specimen figured was 
taken from a piece of hemlock timber in which many of these bees had 
bored tunnels to receive their cells. We have also found nests of these 
bees in a tunnel in the ground under a stone, between shingles on a roof, 
in the cavity of a large branch of sumac, in the cavity of a lead pipe, and 
in Florida in the tubular leaves of a pitcher-plant. 

When a suitable tunnel has been made or found the bee proceeds to 
build a thimble-shaped tube at the bottom of it. For this purpose it 
cuts from leaves oblong pieces, each of which forms a part of a side and 
the bottom of the thimble-shaped tube. Two such pieces had been cut 
from the lower leaf on the left side of the spray figured here. When the 
thimble-shaped tube is completed, the bee partially fills it with a paste of 
pollen and honey, and then places an egg upon the supply of food. She 


HYMENOPTERA 379 

then cuts several circular pieces of leaves, the diameter of which is a 
little greater than the diameter of the tube, and forces them into the 
open end of it, thus making a tightly fitting plug; three of these circular 
pieces have been cut from the spray figured. Usually several cells of this 
kind are placed end to end in a burrow; and sometimes many bees will 
build their nests near together in the same piece of wood. 

Family Bombid^e 
The Bumblebees 

The family Bombidse includes the well-known nest-building bumble- 
bees and certain parasitic bumblebees, Psithyrus, that infest the nests of 
the nest-building species. The members of this family are large bees or 
of medium size; they are robust with oblong bodies and a rather dense 
covering of hair. They are common, and are conspicuous on account of 
their noisy flight and striking coloration, which is usually yellow and 
black. They are called bumblebees on account of the sound they make 
in flight; in England they are commonly known as humblebees. 

The nest-building bumblebees, Bomb us. — The members of this genus 
are social insects, each species consisting as in other social insects of three 
castes, the queens, the workers, and the males. In this genus the queens 
as well as the workers possess pollen-baskets or corbiculae on the hind 
legs; as the queen when founding a colony must collect pollen. 

With the bumblebees the queens are larger than either the workers or 
the males and, in temperate regions, are the only ones that live through 
the winter; as in these regions the colonies, like those of our northern 
species of social wasps, break up in the autumn and all of the bees, ex- 
cept the young queens perish. These crawl away into some protected 
place and pass the winter. In the spring each queen that has survived 
the winter founds a new colony, performing, until a brood of workers has 
been developed, both the duties of queen and of worker. In South 
America, where according to von Ihering, bumblebee colonies are peren- 
nial, new nests are formed by swarming as among the social wasps of the 
same region. 

In selecting a place for her nest the queen usually chooses a deserted 
mouse-nest, within which she builds her nest; sometimes an old bird's 
nest is used for this purpose. In certain European species the queen, 
sometimes at least, constructs her nest entirely without making use of a 
nest of another animal. This she does by making use of moss or soft 
dead grass, which she combs together with her mandibles and legs; for 
this reason these species are often known as " carder-bees." 

Many observers have studied the founding and development of col- 
onies of bumblebees; among these is Sladen who has made very detailed 
studies of the species found in England. The following condensed sum- 
mary is based on the statements of this author. 

Having found a suitable nest the queen spends a good deal of time in 
it, the heat of her body gradually making its interior perfectly dry. She 
then gathers the finest and softest material she can find into a heap and 
in the center of this makes a cavity with an entrance at the side just 
large enough for her to pass in and out. In the center of the floor of this 
cavity she forms a lump of paste made of pollen moistened with honey. 


380 


THE STUDY OF INSECTS 


Upon the top of this lump she builds with her jaws a circular wall of 
wax, and in the little cell so formed she lays her first batch of eggs, and 
seals it over with wax. The queen now sits on her eggs day and night to 
keep them warm, only leaving them to collect food when necessary. In 
order to maintain animation and heat through the night and in bad 
weather when food cannot be obtained, it is necessary for her to lay in a 
store of honey. She therefore sets to work to construct a large waxen 


honey-pot 


honey poi 
5 pollen and eqps 

Fig. 630. — Honey-pot. (From Sladen.) 


pot to hold the honey. This pot is built in the entrance passage of the 
nest (Fig. 630). 

The eggs hatch four days after they are laid. The larvae devour the 


Kowey-pcbt 


&* 


Old eccccTt 

conlccining- 

pcllcrv 


honey -pots 


m§ * 


bunch, cf I 
lobruae 

U ' 7'' 


:tv 


™ Old cccoons I 

r; filled 

with h.cwey 


I \ clusters 
of coccon 3 


FlG. 6.31. — Nest in midsummer. (From Sladen.) 


paste which forms their bed and also fresh food furnished by the queen. 
To feed the larvae the queen makes a small hole with her mandibles in 
the skin of wax that covers them. While the larvae remain small they 
are fed collectively, but when they grow large they are fed individually. 


HYMENOPTERA 381 

As the larvae grow the queen adds wax to their covering, so that they 
remain hidden. When the larvse are full-grown, each one spins around 
itself an oval cocoon, which is thin and papery but very tough. The 
queen now clears away most of the brown wax covering, revealing the 
cocoons, which are pale yellow. These first cocoons number from seven 
to sixteen, according to the species and the prolificness of the queen. 
These cocoons are incubated by the queen, who spends much time sit- 
ting on them, with her abdomen stretched to about double its usual 
length so that it will cover as many cocoons as possible. 

The bees that are developed during the early part of the summer are 
all workers; these relieve the queen of all duties except laying the eggs. 
They feed the larvae, construct honey-pots and special receptacles for 
pollen or store these substances in cocoons from which workers have 
emerged. Later in the summer males and queens are developed; and in 
the autumn the colony breaks up. A nest in midsummer is shown in 
Figure 631. 

The bumblebees play a very important role in the fertilization of 
certain flowers, as those of red clover, in which the tubular corolla is so 
long that the nectar cannot be reached by bees with shorter tongues. 

The parasitic bumblebees, Psithyrus. — To this genus belong those 
parasitic bees that infest the nests of bumblebees. They closely resemble 
bumblebees in appearance and in structure,, except that, as in other para- 
sitic bees, the females do not possess organs for collecting and carrying 
pollen. Although the females of Psithyrus are easily distinguished from 
those of Bombus by the absence of the pollen-baskets or corbiculae in the 
former, the males of the two genera are very similar. In Psithyrus there 
is no worker caste. 

Family Apid^e 
The Honey-bees 

The family Apidae, as restricted here, includes only a single genus, 
Apis, of which only four species are known, and one of these is doubt- 
fully distinct. In this country a single introduced species, the honey- 
bee, Apis mellifica, is found. This species has been widely distributed 
over the world by man. 

This family consists of social bees in which the hind tibiae are without 
apical spurs; the workers are furnished with pollen-baskets or corbiculae 
on the hind legs, but the queens are without functionally developed ones. 
Unlike the queen of the nest-building bumblebees the queen of the honey- 
bee is unable to found a colony or even to exist apart from workers of 
her own species. 

The honey-bee was introduced into America more than three centuries 
ago, and escaping swarms have stocked our forests with it; for when 
free, swarms almost invariably build their nests in hollow trees. These 
nests include a variable number of vertical combs, which have cells on 
both sides, instead of a single series as is the case in the combs of our 
native social wasps. The cells of which the comb is composed are used 
both for storing the food of the colony and for rearing the brood. 

The three castes of bees of which a colony is composed are easily dis- 
tinguished. The workers are the well-known form that we see collecting 


3«2 


THE STUDY OF INSECTS 


pollen and nectar from flowers and entering and leaving the hive in large 
numbers. They constitute the greater part of the colony; an average 
strong colony will include from 35,000 to 50,000 workers. They are 
females in which the reproductive organs are imperfectly developed; t hey 
do not ordinarily lay eggs, and when they do the eggs develop only into 
males. The workers do not pair with males, consequently their eggs are 
unfertilized, and unfertilized eggs of the honey-bee produce only males. 
The workers are so-called because they perform all the labors of the col- 
ony. Young workers attend to the inside work of the hive; they take 
care of the young brood, and for this reason are termed nurse-bees, they 
build combs, and protect the entrance of the hive against robbers. The 
older workers go into the field to collect pollen, nectar and propolis. 

The drones are larger than the workers, and are reared in larger cells. 
If honeycombs be examined, some sheets will be seen to be composed of 
larger cells than those of the more common type. It is in cells of this 
kind that the eggs are laid which are to develop into males. In shape 
the drones are broader and blunter than the workers. They are few in 
number and are only present in the hive during the early summer. After 
the swarming season is over, these gentlemen of leisure are driven out of 
the hive by the workers or are killed by them. 

The queen is larger than a worker, and has a long pointed body. She 

is developed in a cell which differs 
greatly from the ordinary hexagonal 
cell of honeycomb. This cell is large, 
cylindrical, and extends vertically. 
In Figure 633 the beginnings of two 
queen cells are represented on the 
lower edge of the comb, and a com- 
pleted cell extends over the face of 
the comb near the left side. From 
the lower end of this cell hangs a 
lid, which was cut away by the work- 
ers to allow the queen to emerge. 

The queen larva is fed with a sub- 
stance called royal jelly. This is a 
substance which resembles blanc-mange in color and consistency. It is 
excreted from the mouth by the nurse-bees, and is very nutritious food. 
The origin of this food, whether it is a secretion from special glands of 
the nurse-bees, or is regurgitated from their stomachs is not at present 
known. During the first three days of the larval stage of worker bees 
they are also fed with royal jelly after which they are fed with honey and 
bee-bread. 

It has been demonstrated that in the egg-state there is no difference 
between a worker and a queen. When the workers wish to develop a 
queen they tear down the partitions between three adjacent cells contain- 
ing eggs that under ordinary conditions would develop into workers. 
Then they destroy two of the eggs, and build a queen-cell over the third. 
When the egg hatches they feed the larva with royal jelly, and it de- 
velops into a queen. 

In early summer several queen-cells are provided in each colony. 
As soon as a queen is developed from one of these the old queen attempts 
to destroy her. But the young queen is guarded by the workers, and 


Fig. 632. — Comb of honey-bee with queen-cells. 


HYMENOPTERA 383 

then the old queen with a goodly portion of her subjects swarms out, and 
they go to start a new colony. 

The swarming of the honey-bee is essential to the continued existence 
of the species; for in social insects it is as necessary for the colonies to be 
multiplied as it is that there should be a reproduction of individuals. 
Otherwise, as the colonies were destroyed the species would become ex- 
tinct. With the social wasps and with the bumblebees the old queen and 
the young ones remain together peacefully in the nest; but at the close 
of the season the nest is abandoned by all as an unfit place for passing 
the winter, and in the following spring each young queen founds a new 
colony. Thus there is a tendency towards a great multiplication of 
colonies. But with the honey-bee the habit of storing food for the winter, 
and the nature of the habitations render it possible for the colonies to 
exist indefinitely. And thus if the old and young queens remained to- 
gether peacefully there would be no multiplication of colonies, and the 
species would surely die out in time. We see, therefore, that what appears 
to be merely jealousy on the part of the queen honey-bee is an instinct 
necessary to the continuance of the species. 

The sting of a queen-bee is no ignoble weapon, but it is rarely used 
except against a rival queen. When several young queens mature at the 
same time there is a pitched battle for supremacy, and the last left living 
on the field becomes the head of the colony. One morning we found the 
lifeless bodies of fifteen young queens cast forth from a single hive — a 
monument to the powers of the surviving Amazon in triumphant posses- 
sion within. 

The materials used by bees are wax and propolis, which serve as 
materials for construction; and honey and bee-bread used for food. 

The comb is made of wax, which is an excretion of the bees. When 
a colony needs wax, many of the workers gorge themselves with honey 
and then hang quietly in a curtain-like mass, the upper bees clinging to 
the roof of the hive, and the lower ones to the bees above them. After 
about twenty-four hours there appear on the lower surface of the abdo- 
men of each bee little plates of wax that are forced out from openings 
between the ventral abdominal segments called wax-pockets. Other 
workers attend to this curtain and collect the wax as fast as it appears, 
and use it at once in constructing comb. 

Propolis is a cement used for cementing up crevices, and is made of a 
resin which the bees collect from the buds of various trees, but especially 
of the poplar. 

Honey is made from the nectar of flowers. The nectar is taken into 
the crop of the bee, and there changed into honey, and then regurgitated 
into the cells of the comb. 

Bee-bread is made from the pollen of flowers, which the bees bring in 
on the plates fringed with hairs on the hind legs, the corbiculae. 


Families of the Hymenoptera not discussed 

The order Hymenoptera contains a large number of families the mem- 
bers of which are rarely seen. The following list includes those families 
of which no account is given here. The student can find them discussed 
in "An Introduction to Entomology" by J. H. Comstock. 


3*4 


THE STUDY OF INSECTS 


Xyelidae 

Xiphydriidae 

Argidae 

Aulacidae 

Gasteruptionidae 

Trigonalidae 

Stephanidse 

Ampulicidse 


Vanhorniida3 

Heloridae 

Roproniidae 

Platygasteridae 

Scelionidae 

Ceraphronidac 

Belytidae 

Evaniidae 


Embolemidae 

Cleptidac 

Bethylidas 

Anthoboscidae 

Thynnidas 

Sapygidae 

Rhopalosomida: 

Prosopidac 


Fig. 633. — Nests of wall-bee on the Temple of Dendera. 

A remarkable accumulation of the nests of an Old World species of mason- 
bee, known as the wall-bee, Chalicoderma muraria, was observed by the sen- 
ior writer on the walls of the Temple of Dendera in Egypt. This temple, 
which was buried by drifting sands long ago has been excavated by modern 
archaeologists; but the inscriptions on the walls are being rapidly buried 
again beneath a layer of the cement-like nests of the wall-bee (Fig. 633). 
This bee is a member of the family of leaf-cutter bees, Megachilidas. 


INDEX 


Abbot's bag- worm, 201 

Abedus, 100 

Acalyptrate flies, 315 

A carina, 18 

Achorutes nivicola, 47 

Acilius, 139 

Acorn- weevil, 171 

Acrididae, 56 

Acroceridae, 308 

Acrolophidae, 285 

Acronycta, 239 

Abdomen, 34; appendages of the, 

segments of the, 34 
Adalia bipunctata, 153 
Adelges abietis, 118 
Adelgids, 118 
Adelocephala bicolor, 240 
Adephaga, 128, 131, 134 
Adipose tissue, 36 
Adirondack black-fly, 304 
Aedes cegypti, 299 
i^geriidae, 207 
&olothrips nasturtii, 89 
Mollis dor salts, 147 
^Eschnidae, 78 

Agamic forms of aphids, 115 
Agaristidas, 241 
Agelena navia, 11 
Agelenidae, 11 
Aglais milberti, 271 
Agrilus anxius, 149; A. ruficollis, 149 
Agrionidas, 79 
Agriotes mancus, 148 
Agromyzidae, 318 
Agrotis ypsilon, 235 
Ailanthus webworm, 207 
Ailanthus-worm, 255 
Alabama argillacea, 237 
Alans ocidatus, 148 
Alder blight, 116 
Aleyrodidag, 118 
Alimentary canal, 35 
Alitrunk, 332 
Alleculidae, 175 
Allocapnia pygmcea, 81 
Alsophila pometaria, 223 
Alternation of generations, 350 
Alula or alulet, 289, 3 1 5 
Alypia octomacidata, 241 ; larva, 242 
Alula, the, 289 
Ambient vein, 290 
Amblycheila cylindriformis, 136 
Ambrosia-beetles, 172, 173 
Ambrysus, 107 
Ambush-bugs, 104 
American sawfly, 341 


34; 


385 


Ammophila, 372 

Ampelceca myron, 221 

Amphibolips conjluens, 351 ; A. inanis, 351 

Amphidasis cognataria, 227 

Amphizoidae, 175 

Ampulicidae, 369, 384 

Anabrus, 53 

Ancea, 276; A.andria, 277; A. morrisonii, 
276; A. portia, 276 

Anal angle, 32 

Anal lobe, 332 

Anarsia lineatella, 205 

Anasa tristis, 106 

Anatomy, external, 27; internal, 34 

Anchor process, 301 

Ancyloxipha numilor, 261 

Andrena, 376 

Andrenidae, 375 

Andricus erinacei, 350; A. calif ornicus, 352 

Androconia, 280 

Angles of wings, 32 

Angle-wings, the, 270 

Angoumois grain-moth, 205 

Angulifera-moth, 254 

Anisandrns pyri, 175 

Anisolabis maritima, 126 

Anisomorpha buprestoides, 58 

Anisopidae, 295 

Anisoptera, 77 

Anisopus, wing of, 289 

Anisota rnbicunda, 249; A. senatoria, 
248; A. stigma, 249; A . virginiensis, 248 

Annulata, 1 

Anobhdas, 175 

Anopheles, 298, 299 

Anoplura, 92 

Ant, see Ants 

Antecoxal piece, 129 

Antelope-beetle, 160 

Antennae, 3, 30, 128, 288 

Antenna cleaner, 331 

Antennaria, 270 

Anthicidas, 175 

Anthoboscidas, 384 

Anthocoridae, 102 

Anthocharis genutia, 267 

Anthomyidae, 319 

Anthonomus grandis, 170; A. signatus, 170 

Anthophora, 376 

Anthrenus mnseorum, 150; A. scrophnla- 
Hce, 150; A. verbasci, 150 

Ant-lion, head and mouth-parts of, larva 
of, 66 

Ant-lions, 70 

Ants, 329, 357; legionary, 360; harvest- 
ing, 360; fungus-growing, 361; shed- 


3 S6 


INDEX 


building, 361 ; Argentine, 362; typical, 

362; carpenter, 362; Amazon, 363; 

mound-building, 362; slave-making, 

363; honey, 363; corn-field, 363 
Anuraphis matdiradicis, 116; A. roseus, 

116 
Aorta, 36 

Apantesis virgo, 243 

Apatela morula, 239; A. americana, 239 
Apex of the wing, 32 
Aphelinus jucundus, 353 
Aphididae, 109, 114 
Aphidius, 346 
Aphid, 116; apple, 116; hickory, 116; 

corn-root, 116; strawberry-root, 116; 

potato, 116; woolly, 116; spring grain, 

116; cabbage, 115 
Aphis forbesi, 116 
Aphis-lions, 69 
Aphycus emptor, 353 
Apidas, 381 

Apis mellifica, 381, 382 
Apioceridae, 325 
Aplopus mayeri, 59 
Apple bucculatrix, 202 
Apple-fruit miner, 207 
Apple-maggot, 315 
Apple-worm, red-humped, 230 
Apterygota, 39, 40 
Arachnida, 2, 3 
Aradidas, 108 

Araocerus fascicidatus, 169 
Araneida, 6 
Ar chips argyrospila, 21 1 ; A. cerasivorana, 

210; A. rosaceana, 210 
Arctiidas, 242 
Argentine Ant, 362 
Argidas, 384 
Argiopidas, 15 
Argynnis cybele, 269 
Argyresthia conjugella, 207; A. thuiella, 

207 
Argyroneta aquatica, 11 
A 11I its cristatus, 103, 108 
Arista, the, 288 
Armored Scales, 122 
Armyworm, 240 
Arthropoda, 1 
Ascalaphidas, 73 
Aschiza, 313 
Asilidae, 309 
Asparagus-beetle, 165 
Aspidiotus perniciosus, 124 
Assassin-bugs, 103 
Asteiidas, 325 

Asterochiton vaporariorum, 119 
Ateuchus sacer, 154 
Atlanticus, 53 
Atlides halesus, 282 
Atropidae, 83, 84 
Alropos pulsatoria, 84 
Atrytone conspicua, 261 
Alia texana, 362 
Atteva punctella, 207 
Attidae, 18 


Aulacidae, 384 

A utographa brassicce, 237 ; A . fulcifera, 237 

Automeris io, 250 

Aviculariidae, 10 

Axillary excision, 288; 332 

Back-swimmers, 98 

Bad-wing, 225 

Bag-worm Moths, 200; Abbot's, 201; 
evergreen, 201 

Balaninus nasicus, 171; B. proboscideus, 
171 

Baliosus rubra, 167 

Baltimore, the, 269 

Bark-beetles, 173; fruit-tree, 173; peach- 
tree, 173 

Bark-lice, 119 

Basement membrane, 28 

Basilarchia archippus, 275; B. arthemis, 
274; B. astyanax, 275 

Basilona imperialis, 246, 247 

Basswood leaf -roller, 213 

Bean- weevil, 168 

Bean leaf-roller, 260 

Bedbug, 102, 103 

Bedbug, big, 103 

Bedbug-hunter, masked, 103 

Bedellia somnidentella, 202 

Bee-bread, 383 

Beech-tree blight, 117 

Bee-flies, 308 

Bee-lice, 324 

Bee-moth, 216 

Beet or Spinach leaf- miner, 319 

Beetles, 127 

Beetle, ventral aspect of a, 129 

Bees, 2, 32, 329, 373; hairs of, 373; 
mining, 275; leaf-cutter, 378; nurse, 
382; honey, 381 

Beggar moth, 225 

Belidae, 170 

Bellura diffusa, 239 

Belostoma flioninea, IOO 

Belostomatidae, 99 

Belytidae, 384 

Bembex, 373 

Benacus griseus, IOO 

Berothidas, 73 

Bethylidae, 384 

Bibionidas, 302 

Bibio, 303 

Big-eyed Flies, 313 

Birds, 1 

Bird-lice, 85 

Bittacomorpha clavipes, 294 

Bittacus, 179 

Blackberry-crown borer, 208 

Black-dash, 261 

Black-flies, 303; innoxius, 304; white- 
stockinged, 304; Adirondack, 304 

Black witch, 236 

Blastobasidae, 285 

Blastophaga psenes, 354 

Blatta orientalis, 61 

Blattella germanica, 61 


INDEX 


3*7 


Blattidao, 60 

Blepharocera tenuipes, wing of, 305 

Blepharoceridae, 304 

Blissus leucopterus, 105 

Blister-Beetles, 145, 147 

Blood, 37 

Blood-worms, 297 

Blow- fly, family, 321 

Blues, the, 283 

Blue, tailed, 284 

Bluebottle-fly, 321 

Body-louse, 93 

Body-segments, 28 

Body-wall, 27 

Bolitotherus cormitus, 151 

Bollworm, pink, 206 

Bombardier-beetles, 137 

Bomb-fly, 321 

Bombidae, 379, 380 

Bombus, 379 

Bombycidae, 255 

Bombyliidas, 308 

Bombylius, 308 

Bombyx mori, 255 

Book-lice, 84 

Book-louse, 84 

Book-lungs, 3 

Boophilus annulatus, 19 

Borboridae, 325 

Boreus, 179 

Bostrichidae, 285 

Bot-flies of Horses, 319, 320; red-tailed, 

320; sheep, 320; stomach, 319 
Brachelytra, families of the, 131 
Brachinus, 137 
Brachycera, 293, 306 

Brachyrhinus ovatus, 170; B. sulcatus, 170 
Brachystola magna, 57 
Braconidas, 346 
Brathinidas, 175 
Braula cceca, 325 
Braulidae, 325 
Breast-bone, 301 
Brentidae, 169 
Brevicoryne brassiccB, 115 
Brine- flies, 317 
Bristle-tails, 45 
Brown-tail moth, 234 
Bruchophagns funebris, 354 
Bubonic plague, 327 
Bucculatrix, apple, 202; B. pomifoliella, 

202 
Bud-moth, 211 
Buffalo-gnat, southern, 304 
Bugs, ambush-, 104; assassin-, 103; 

chinch-, 105; creeping water-, 107; 

flat-, 108; flower-, 102; four-lined 

leaf-, 102; giant water-, 99; harlequin 

cabbage-, 106; insidious flower-, 102; 

lace-, 104; leaf-, 101; many-combed, 

107; negro-, 108; shield-backed, 108; 

shore-, 100; squash-, 106; stilt-, 107; 

stink-, 106; tarnished plant-, 102; 

thread legged, 103; toad-shaped, 100; 

unique-headed, 107 


Bumblebees, 379; parasitic, 379 
Buprestidae, 148 
Buprestid, Virginian, 149 
Burdock moth, 206 
Burying-beetles, 142 
Butterflies, 183, 185, 261 
Byrrhidae, 175 

Cabbage-butterfly, 266 

Cabbage looper, 237 

Cabbage-root maggot, 319 

Cabbage web worm, 214 

Caccecia, 210 

Caddice-flies, 180 

Caddice- worms, 180, 1 81 

Canurgia crassiuscula, 238; C. erechtea, 238 

Calamistrum, 8,' 12 

Calandra granaria, 171; C. oryzce, 171 

Caliroa cerasi, 343 

Calliphora vomitoria, 322 

Calliphoridse, 321 

Callosamia angulifera, 254; C. promethea, 

253; cocoon of, 254 
Calocalpe undulata, eggs and nest of, 225 
Calosoma calidum, 137; C. scrutator, 137; 

C. sycophanta, 137 
Calypteres, 315, 318 
Camel-crickets, 53 
Campodea staphylinus, 46 
Camponotus herculeanus pennsylvanicus, 

362 
Campsomeris, 357 
Canaceidae, 325 
Candle-fly, Chinese, 113 
Canker-worm, spring, 224; fall, 223 
Cantharidae, 145 
Cantharis, 145 
Canthon Icevis, 155 
Capnia, 81 
Capniidag, 82 
Caprification, 355 
Caprifigs, 355 
Capsidae, 101 
Carabidas, 136 
Cardo, 129, Fig. 214a 
Caripeta angustiorata, wings of, 223 
Carolina locust, 57 
Carpenter-bee, large, 377; small, 377 
Carpenter-moths, 196 
Carpenter-moth, locust-tree, 196 
Carpenter-worm, lesser oak, 197 
Carpet beetle, 150 
Carpocapsa pomonella, 211 
Carposinidae, 285 
Carrion -beetles, 142 
Carrot rust-fly, 317 
Case bearer, cigar, 205 
Cassida nigripes, 167 
Cat-flea, 327 
Caterpillars, 184 
Catocala ilia, 238 
Catocalas, 237 
Catopsilia eubule, 268 
Cave-crickets, 53 
Cebrionidas, 175 


388 


INDEX 


Cccidomyidas, 301 

Cecropia-moth, 254 

Cedar tineid, 207 

Celerio lineata, 222 

Celery looper, 237 

Cells of the wing, terminology of the, 34, 

330 
Centipedes, 1, 21 
Cephaloidae, 175 
Cephidae, 340 
Cephas pygmcens, 341 
Cerambycidae, 160 
Cerambyeids, typical, 160 
Ceraphronidae, 384 
Ceratina dupla, 377 
Ceratitis capitala, 316 
Ceratophyllus midtispinosus, 326 
Cerci, 34 
Cercopidae, 1 1 1 

Cercyonis alope, 277; C. alope nephele, 278 
Ceresa bubalus, 112 
Cerophytidas, 175 
Chcetopsis cenea, 315 
Chain-dotted geometer, 226 
Chalastogastra, 338 
Chalcid-flies, 352 
Chalcid-fly, wing of, 353 
Chalcididas, 352 

Chalicodoma muraria, nests of, 384 
Chalcophora virginica, 149 
Chalybion carulium, 372 
Chamccsphecia tipuliformis, 209 
Chauliodes pectinicornis, 68 
Chauliognathus marginatus, 145; C. penn- 

sylvanicus, 145 
Cheese-maggot, 316 
Cheliceras, 3, 7, 17 
Chelonariidae, 175 
Chelone glabra, 270 
Chermidse, 114 
Cherry-fruit-flies, 316 
Cherry-tree ugly-nest tortricid, 210 
Chigoe, 328 
Chilopoda, 2, 20, 21 
Chinch-bug, 105 
Chin-fly, 320 
China wax, 119 
Chionaspis furfura, 120, 124 
Chionaspis pinifolicz, 123 
Chironomidae, 296 
Chironomus, 296 
Chitin, 27, 28 
Chlorion cyaneum, 372; C. ichneumoneum , 

372 
Chlorippe clyton, 276 
Chloropidae, 317 
Chordata, 1 
Chrysalis, 26, 280 
Chrysanthemum gall-midge, 302 
Chrysidida?, 356 
Chrysis nitidida, 356 
Chrysobothris femorata, 149 
Chrysomelidae, 164 
Chrysomyia macellaria, 322 
Chrysopa, 69, 70 


( 'hrysopida?, 69 

( 'hrysops, 306 

Cicada, head of, 109 

Cicadas, no 

Cicada-killer, 372 

Cicada, periodical, III 

Cicadidaj, 109, no 

Cicadellidae, 112 

Cicindela, 135; maxilla of , 129,135 

Cicindelidae, 135 

Cigar case-bearer, 205 

Cimbex americana, 341 

Cimbicidae, 341 

Cimex lectularius, 102; C. pilosellus, 102 

Cimicidae, 102 

Cingilia catenaria, 226 

Circular-seamed Flies, 312 

Circulation of the blood, 36 

Circulatory system, 36 

Cirphis unipuncta, 240 

Cisidae, 175 

Citheronia regalis, 246, 247 

Citheroniidae, 246 

Cladius isomerus, 343 

Clambidae, 175 

Clams, 1 

Clavicornia, 131, 132 

Clavigeridse, 175 

Clavus, 94 

Clear-winged moths, 207 

Clear-wing, thysbe, 222 

Cleptidae,.384 

Cleridas, 175 

Click-beetles, 147 

Clistogastra, 345 

Cloaked knotty-horn, 162 

Close- wings, 215 

Clothes-moths, 200; case-bearing, 200; 

naked, 200; tube-building, 200 
Clouded sulphur, 267 
Cloudy-wing, northern, 260 
Clover-flower midge, 302 
Clover-hay worm, 215 
Clover-looping-owlets, 238 
Clover-root borer, 172 
Clover-worm, green, 235 
Clusiidse, 325 
Cluster-fly, 322 
Coarctate larva, 146 
Coccidae, 109, 119 
Coccid-eating pyralid, 217 
Coccids, the Cochineal, 119; motile, 120; 

non-motile, 121 
Coccinella novemnotata, 153 
Coccinellidae, 152 

Cockroach, American, 61; oriental, 61 
Cockroaches, 49, 60 
Coccus cacti, 1 19 
Cock's-comb gall, 117 
Cocoon, 26, 185 
Codling-moth, 211 
Ccelenterata, 1 
Ccenagrionidae, 80 
Ccenomyiidas, 307, 325 
Coffee-bean weevil, 169 


INDEX 


389 


Coleophora fletcherella, 205; C. malivorclla, 

204 
Coleophoridag, 204 
Coleoptera, 127 

Colletes, leg of, 374; proboscis of, 374 
Collembola, 23, 47 
Collophore, 47, 48 
Colopha ulmicola, 117 
Colorado potato-beetle, 165 
Colydiidae, 175 
Colymbetes, 139 
Comma, green, 273 
Complete metamorphosis, 25 
Compound eyes, 29; absence of, 45 
Compton tortoise, 272 
Coniopterygidas, 73 
Conopidas, 325 
Conops, wing of, 289 
Conotrachelus nenuphar, 170 
Contarinia pyrivora, 362 
Copper, American, 283; bronze, 283 
Coppers, 283 
Copris, 155 
Corbicula, 332, 374 
Cordyluridae, 318 
Coreidae, 106 
Corethrinae, 298, 299 
Corium, 94 
Corixa mercenaria, 98 
Corixidae, 97 

Corn-borer, European, 214 
Cornea, 29, Fig. 60 
Corneal hypodermis, 29, Fig. 60 
Corn-borer, European, 214 
Corn ear-worm, 241 
Cornicles, 34 

Corn stalk-borer, larger, 215 
Corrodentia, 83 
Corydalus comutus, 37, 68 
Corylophidae, 175 
Corynetidae, 175 
Corythucha arcuata, 104 
Cosmopterygidae, 285 
Cossidae, 196 
Costa, 33 
Costal margin, 32 
Cotalpa lanigera, 156 
Cotinus nitida, 158; C. mutabilis, 158 
Cotton-boll weevil, 170, 171 
Cotton-boll worm, 241 
Cotton-moth, maxillae of the, 184 
Cotton-stainer, 104 
Cotton-worm, 237 
Cottony cushion scale, 121 
Cow-killer ant, 357 
"Cow- shed" built by ants, 361 
Coxa, 31 

Coxal cavities, 130 
Crabs, 2 
Crab-louse, 93 
Crambus caliginosellus, 215; C. hortnellus, 

215 

Cranberry-fruit worm, 217 

Cranberry girdler, 215 

Crane-flies, 293; primitive, 294; so-called 


false, 295; phantom, 294; typical, 293 
Cray-fishes, 2 
Crematogaster lineolata, 361 
Creophilus maxillosus, 143 
Crescent-spots, 269 
Cribellum, 8, 12 
Crickets, 49; cave, 53; camel, 53; field, 

55; mole, 55 
Cnoceris asparagi, 165 
Crop, 36 
Cross-veins, 33 
Croton-bug, 60, 61 
Crustacea, 2, 3 
Cryptophagidas, 175 
Cryptothrips floridensis, 91 
Crystalline cone-cells, 29, Fig. 60 
Ctenidia, 327 

Ctenocephalus canis, 327; C.felis, 327 
Ctenothrips bridwelli, 91 
Cubitus, 33 
Cuckoo-wasps, 356 
Cucujidas, 152 
Cucumber fleabeetle, 166 
Culex, 298, 299 
Culicidas, 297 
Culicinae, 299 
Cidicoides, 297 
Cuneus, 95 
Cupesidae, 140, 175 
Curculio, plum, 170 
Curculionidae, 169 
Currant borer, imported, 209 
Currant-fruit fly, 316 
Currant-moth, pepper-and-salt, 227 
Currant-stem girdler, 341 
Currant-worm, imported, 343 
Cuticula, 28 
Cutworms, 241 
Cybisier, 139 
Cyclorrhapha, 312; with a frontal suture, 

315; without a frontal suture, 313 
Cydnidae, 108 
Cylas formicarius, 169 
Cyllene caryce, 163; C. robinice, 162 
Cynipidae, 349 

Daddy-long-legs, 6 

Dagger, American, 239; ochre, 239 

Dalceridae, 285 

DamseLflies, 77, 79 

Danaus archippus, 275, 279; chrysalis, 

280; larva, 280; D. berenice, 280; D. 

berenice strigosa, 280 
Dance-flies, 311 
Daphnia, 3, Fig. 5 
Darkling Beetles, 151 
Dascyllidae, 175 
Dasymutilla occidentalis, 357 
Dasyneura leguminicola, 302 
Datana ministra, 229; larva, 229 
Deltoids, 235 
Dengue, 299 

Depressaria heracliana, 205 
Dermaptera, 125 
Dermestes lardarius, 150 


39° 


INDEX 


Dcrmestidae, 150 

I >i mdontidae, 175 

Desmia funeralis, 213 

Desmocerus palllatus, 162 

Development without metamorphosis, 85, 

1)2 

Diabrohca, 165; D. duodecim punctata, 
165; D. longicornis, 166; D. soror, 165; 
P. vittata, 165 

Diacrisia virginica, 244 

Dialcurodes citri, 119 

Diamond-back moth, 213 

Diaphania hyalinata, 213; D. nitidalis, 

.214 

Diapheromera femorata, 58 

Diaphragm, Dorsal, 36 

Diarthronomyia hypogcea, 302 

Diatrcca saccharalis, 215; £\ zeacolella, 

. 2I 5 
Dicerca divaricala, 149 

Dictynidas, 8, 11, 12 

Digger Wasps, 369 

Digitus, 129, Fig. 214a 

Dilar americanus, 72 

Dilaridae, 67, 72 

Dineutus, 140 

Dione vanilla, 279 

Diopsidas, 325 

Dioptidae, 285 

Diplopoda, 2, 20 

Diploptera, 364 

Dipsocoridae, 107 

Diptera, 286, 287, 288 

Discal cell, 187 

Dissosteira Carolina, 57 

Diver, brown-tailed, 239 

Diving-beetles, the predacious, 138, 139 

Dixa, 295 

Dixa midges, 295 

Dixidas, 295 

Dog-flea, 327 

Dog's head, 267 

Dog-louse, 93 

Dolichopodidas, 310 

Donacia, 164 

Dorcus parallelus, 160 

Dorsal diaphragm, 36 

Douglasiidae, 285 

Dragonflies, 77, 78 

Dragonfly, exuviae of, 78 

Drepanidas, 285 

Drone-fly, 315 

Drones, 382 

Drosophila ampelophila, 318; D. melano- 

gaster, 318 
Drosophilidae, 318 
Dryinidae, 370 
Dryopidae, 175 
Dung-flies, 318 
Dynastes grantii, 157; D. hercules, 157; 

D. tityms, 157 
Dysdercus suturellus, 104 
Dyspteris abortivaria, 225 
Dytiscidae, 138,139 
Dytiscus, 139 


Ear of grasshopper, 59 

Earthworms, 1 

Earwig, European, 126; hind wing of an, 
125; handsome, 126; little, 125; sea- 
side, 126 

Earwigs, 125 

Eccoptogastcr rugulosus, 173 

Echidnophaga gallinacea, 327 

Echinodermata, 1 

Eciton, 360 

Egg, 25 

Egg-masses of caddice-flies, 180 

Egg-sacs, 9 

Elachistidas, 285 

Elateridae, 147 

Eleodes, 151 

Elephantiasis, 299 

Elm-gall colopha, cockscomb, 117 

Elmidae, 175 

Elytra, 127 

Embia sabulosa, 87 

Embiidina, 87 

Embiids, 87, 88 

Embolemidag, 384 

Embolium, 94 

Emesa brevipennis, 103 

Emperor, tawny, 276 

Empididae, 311 

Empoasca fabce, 1 13 

Empoa rosce, 113 

Empodium, 288 

Enchenopa binotata, 112 

Encoptolophus sordidus, 57 

Endomychidae, 175 

Endrosis lacteella, 205 

Engraver-beetles, 172, 173 

Enicocephalidae, 107 

Ennomos magnarius, 227 

Epargyreus tityms, 260 

Ephemera simulans, 75 

Ephemerida, 24, 74 

Ephemeridae, 75 

Ephestia kuhniella, 216 

Ephydra, 317 

Ephydridag, 317 

Epiccertis imbricatus, 169 

Epicauta vittata, 146, 147; E. cinerea, 147; 
E. pennsylvanica, 14.J 

Epicnaptera americana, 258 

Epilachna borealis, 153; E. corrupta, 153 

Epimerum, 130, Fig. 216 

Epipharnyx, 31 

Epiplemidae, 285 

Epipyropidae, 285 

Episternum, 130, Fig. 216 

Epitrix cHCumeris, 166 

Epochra canadensis, 316 

Erannis tiliaria, 226 

Erebus odora, 236 

Ericerus pe-la, 119 

Eriocraniidag, 192 

Eriophyidag, 18 

Eriosoma lanigera, 1 16 

Eristalis tenax, 315 

Ermine-moths, 207 


INDEX 


39i 


Erotylidae, 175 

Erythroneura comes, 113 

Estigmene acrcea, 243 

Ethmiidse, 285 

Euchcetias egle, 242 

Euchromiidae, 285 

Eucinetidae, 175 

Euclea delphinii, 199 

Eucleidae, 198 

Eucnemidae, 175 

Enetheola rugiceps, 157 

Eudule mendica, 225 

Euglenidae, 175 

Eugonia j-album, 271 

Eulia pinatubana, 211 

Eumenes fraternus, 365, 366 

Eumenids, 364 

Euphoria inda, 158 

Enphydryas phceton, 269 

Euproctis chrysorrhcea, 234 

Eupsalis minuta, 169 

Eupterotidae, 285 

Euptoieta claudia, 269 

Eurema euterpe, 268 

Eurosta solidaginis, 206, 316 

Eurymus eurytheme, 267; E. philodice, 267 

Euryophthalmus succinclus, 105 

Eurypelma hentzi, 10 

Eurystethidae, 175 

Euscelis exitiosus, 113 

Eusimulium pecuarum, 304 

Euvanessa antiopa, 271 

Evaniidae, 384 

Everes comyntas, 284 

Evergreen bag-worm, 201 

Evergreen nepytia, 226 

Evetria buoliana, 212 

Exuviae, 27 

Eye-cap, 187 

Eyed brown, 277 

Eyes of insects, two types of, 29 

Fall webworms, 244 

Fat, 36 

Femur, 31 

Feniseca tarquinius, 284 

Fidia longipes, 165 

Fiery hunter, 137 

Fig-eater, 158 

Fig-insects, 354 

Filariasis, 299 

Fire-brat, 46 

Firefly Family, 144 

Fishes, 1 

Fish-flies, 67 

Fish-moth, 45 

Flannel-moths, 197 

Flannel-moth, crinkled, 198 

Flat-headed apple-tree borer, 149 

Flatworms, 1 

Flea, cat, 327; dog, 327; rat, 327; human, 

327; sticktight, 327 
Fleas, 326 
Fleabeetles, 166 
Flies, 2, 286 


Flour-moth, Mediterranean, 216 

Flower-beetles, 158 

Flower-beetle, hermit, 158 

Flower-bugs, 102 

Footman-moths, 242, 245 

Footman, banded, 246; striped, 245 

Forester, eight-spotted, 241 

Foresters, 241 

Forficula auricularia, 126 

Forked fungus-beetle, 141 

Formica exsectoides, 362; F. sanguinea, 
362 ; F. fusca, 363 

Formicidae, 357 

Four-footed butterflies, 268 

Frankliniella tritici, 90 

Frenatae, 194 

Frenulum, 186, 194 

Frenulum-hook, 194 

Frit-fly, European, 317 

Fritillaries, 268 

Fritillary, great spangled, 269; varie- 
gated, 269 

Frog-hoppers, 1 1 1 

Frontal lunule, 287; suture, 287 

Froth-glands of spittle insects, 1 1 1 

Fruit-moth, oriental, 212 

Fruit-tree bark-beetle, 173 

Fruit-worms, green, 240 

Fulgoridae, 113 

Fungus-gnats, 300 

Fungus weevils, 169 

Galea, 31, 128, 129, Fig. 214a 

Galgulidae, 100 

Galleria mellonella, 216 

Gall-flies, 349 

Gall-gnats, 301 

Galls, 117, 118 

Garden-flea, 48 

Garden web worm, 214 

Gartered plume, 217 

Gaster, 332, 358 

Gasteruptionidae, 384 

Gasterophilidae, 319 

Gasterophilus hcemorrhoidalis, 320; G. in- 

testinalis, 320; G. veterinus, 320 
Gelastocoridae, 100 
Gelastocoris oculatus, 1 00 
Gelechiidae, 205 
Geometridae, 223 
Geometrids, 223 
Geomyzidae, 325 
Georyssidae, 175 
Gerridae, 101 
Gills, 2 
Gizzard, 36 

Glossina morsitans, 324 
Glossina palpalis, 324 
Glowworms, 144 
Glycobius speciosus, 162 
Glyphipterygidae, 285 
Gnats, fungus, 300; gall, 301 
Gnorimoschema gallcesolidaginis, 206 
Goat-weed, butterfly, 277 
Goer a calcarata, case of, 182 


392 


INDEX 


< H ildcnrod-gall, round, 316 

Gonatopus, 370 

Goniodes stylifer, 86 

Goniurus proteus, 260 

Gooseberry-fruit worm, 217 

Gossamer-winged butterflies, 281 

Gracilaria, 203 

Gracilariidas, 203 

Grain-weevils, 171 

Granary- weevil, 171 

Grape-berry moth, 211 

Grape fleabeetle, 166 

Grape-leaf skeletonizer, 197 

Grape-leaf folder, 213 

Grape root worm, 165 

Grasshoppers, 49; long-horned, 50; 
meadow, 52; shield-backed, 53; short- 
horned, 56 

Grayling, 277 

Greenbottle-fly, 322 

Ground-beetles, 136 

Grub, 127 

Gryllidae, 53 

Gryllus domesticus, 55 

Guest gall-flies, 350 

Gula, 128 

Gular suture, 128 

Gypsy moth, 233 

Gyretes, 140 

Gyrinidae, 139 

Gyrinus, 140 

Gyropidae, 337 

Hackled-band, 12 

Hcematobia irritans, 324 

Haematopinidae, 93 

Hcematopinus eurysternus, 93; H. suis, 

93 

Hccmatosiphon inodorus, 102 

Hcemorrhagia thysbe, 222 

Hag-moth, 199 

Hair-streaks, 282 

Hair-streak, banded, 282; olive, 282; 

white-m, 282 
Halictus, 375 
Haliplidae, 175 
Halobates, 101 
Halteres, 286 
Haltica c Italy bea, 166 
Halysidota caryce, 245 
Hamuli, 329 
Handmaid moths, 229 
Haploa contigua, 242 
Harlequin milk-weed caterpillar, 242 
Harmolita, 353; H. grandis, 354; H. tri- 

tici, 354 
Harpalns caliginosus, 138; labium of , 129; 

pro thorax of, 130 
Harrisina americana, 197 
Harvest men, 3, 6 
Hawk-moths, 218, 219 
Head, 29 

Hearing, organs of, 50, 56 
Heart, 35, 36 
Hebridas, 107 


Hcbrus, 107 

Heel-fly, 320 

Heliconians, 278 

Heliconius charitonius, 278 

Helicopsyche, 182 

Heliodinidae, 285 

Heliothis obsoleta, 241 

Heliothrips fasciatus, 90; II. hccmorrhoida- 

lis, 90 
Heliozelidas, 285 
Hell ula undalis, 214 
Helodidae, 175 
Helomyzidae, 325 
Heloridae, 384 
Hemelytra, 94 
Hemerobiidae, 72 
Hemerocampa leucostigma, 232; H. ve- 

tusta, 233 
Hemileiica maia, 250; //. olivice, 250 
Hc-miptera, 94 
Heodes epixanthe, 283; H. heterojiea, 283; 

H. hypophlceas, 283; II. tlwe, 283 
Hepialid, wings of a, 193 
Hepialidae, 192 
Herbivorous beetles, 140 
Hesperia tessellata, 261 
Hesperiidae, 259 
Hesperoctenes longiceps, 107 
Hessian-fly, 302 
Heterocampa bilineata, 230 
Heteroceridae, 175 
Hexapoda, 22, 23 
Hexapoda, sub-classes and orders of, 

.4° 
Hickory-borer, painted, 163 

Hickory horned devil, 246 

Hickory-nut weevil, 171 

Hickory tiger-moth, 245 

Hippoboscidae, 324 

Histeridae, 175 

Hog-louse, 93 

Hog-caterpillar of the vine, 221 

Homoptera, 109 

Honey-bee, 382 

Honey-bees, 382 

Honey-dew, 115 

Honey-pot, 380 

Hop-merchant, 273 

Hopperburn, 113 

Hop vine deltoid, 236 

Hormaphis hamamelidis, 117 

Hornets, 367 

Hornet, giant, 369; white-faced, 369 

Horn-fly, 324 

Horn-tails, 339 

Horse-flies, 306 

Horse-guard, 373 

Hour-glass spider, 1 4 

Housefly, 323 

Human flea, 327 

Humeral angle, 32 

Hump-backed flies, 313 

Hyblaeidas, 285 

Hydras, 1 

Hydromelra, 1 07 


INDEX 


393 


Hydrometridas, 107 

Hydrophilidae, 141 

Hydrophilus, 141; H. obtusatus, 142 

Hydro psyche, net of, 182 

Hydrous triangularis, 141 

Hylastinus obscurus, 172 

Hylemyia antiqua, 319; H. brassica, 319 

Hymenoptera, 329; parasitic, 345 

Hymenopterous wing, typical, 330 

Hypatus bachmanni, 281 

Hypena hamuli, 236 

Hyperceschra stragula, wings of, 228 

Hypermetamorphosis, 145, 146 

Hyphantria cunea, 244; H. textor, 244 

Hypoderma bovis, 321; H. lineatum, 320 

Hypodermis, 28 

Hypopharynx, 31 

Hypoprepia miniata, 245 

Hypopygium, 332 

Hypsopygia costalis, 215 

Hyptiotes cavatus, 13 

Icerya purchasi, 121, 153 
Ichneumon-flies, 347 
Ichneumonidse, 347 
Idiogastra, 343 
Illice unifasciata, 246 
Illinoia solanifolii, 116 
Imago, 26 
Imperial-moth, 246 
Incomplete metamorphosis, 23 
Incurvariidae, 195 
Indian-meal moth, 216 
Inner margin of wing, 32 
Inquilines, 350 
Insects, 22 

Internal anatomy, 34 
Intestine, 36 
Io-moth, 250 
Iphiclides marcellus, 263 
Iridomyrmex humilis, 362 
Isabella tiger-moth, 244 
Isia Isabella, 244 
Isometopidae, 107 
Isoptera, 63 
Isosoma, 353 
Ithycerus noveboracensis, 170 

Jalysus spinosus, 108 

Janus integer, 341 

Japanese beetle, 156 

Japyx, 46 

Jigger, 328 

Joint-worm, wheat, 354 

Jugatae, 191 

Jugates, haustellate, 192; mandibulate, 

192 
Jug-builders, 365 
Jugum of a hepialid, 191, 193 
June-beetle, green, 158 
June-bugs, 154, 155 

Katydid, 51; angular winged, 51; the 

true, 51 
Kelp-flies, 319 


Labia minor, 125 

Labial palpi, 31, 129 

Labium, 31, 129 

Labrum, 31 

Lace-bug, hawthorn, 104 

Lace-bugs, 104 

Lacewing-flies, 66, 69 

Lacinia, 129, Fig. 214a 

Lac-insect, 119 

Lacosomidae, 285 

Lady-bugs, 152; bean, 153; nine-spotted, 
153; two- spotted, 153 

Lcetilia coccidivora, 217 

Lagoa crispata, 198 

Lagriidas, 175 

Lakeflies, 75 

Lamellate, 30 

Lamellicorn beetles, 154; leaf-chafers, 
156; scavengers, 154 

Lamellicornia, the families of, 133 

Lampshells, 1 

Lampyridae, 144 

Lantern-fly of Brazil, great, IJ3 

Lappet-caterpillars, 256; American, 258; 
velleda, 257 

Larder-beetle, 150 

Larva, 25; of moth, 184 

Lasiocampidae, 256 

Lasius niger americanus, 363 

Laspeyresia molesta, 212 

Lathridiidae, 175 

Latrodectus mactans, 14 

Leaf-beetles, 164, 167 

Leaf-beetles, long-horned, 164 

Leaf-bugs, 101 

Leaf-chafers, shining, 156 

Leaf hoppers, 113; destructive, 113; grape- 
vine, 113; rose, 113; potato, 113 

Leaf-insects, 58 

Leaf-miner, morning-glory, 202 

Leaf -roller, oblique-banded, 210; fruit- 
tree, 211 

Leather-jackets, 294 

Lebia grandis, 138 

Lecanium hesperidum, 122, 125 

Legionary or visiting ants, 360 

Legs, 31, 32 

Leopard-moth, 197 

Lepidoptera, 183, 186; frenate, 194; 
metamorphosis of, 184; jugate, 191 

Lepidosaphes ulmi, 122 

Lepisma saccharina,, 45 

Leptinidae, 175 

Leptinotarsa decemlineata, 165 

Lepyronia quadrangularis, 112 

Lethocerus americanus, 99; head of, 95 

Libellulidae, 78, 79 

Lice, true, 92; jumping plant-, 114 

Ligula, 129 

Lime-tree winter-moth, 226 

Linognathus piliferus, 93 

Liparidae, 232 

Lobsters, 1, 2 

Locust borer, 162 

Locust, Carolina, 57; American, 57; 


394 


INDEX 


clouded, 57; red-legged, 56; Rocky 
Mountain, 56; pigmy, 57; seventeen- 
year, 1 1 1 

Locust-sawfly, 342 

Locustidae, 50, 56 

Lomamyia, 73 

Lonchasidae, 325 

Lonchoptera, wing of, 312 

Lonchopteridae, 312 

Long-beaks, 280 

Long-horned beetles, 160 

Longistigma caryce, 1 1 6 

Long-legged flies, 310 

Louse, body-, 92; crab-, 93; dog-, 93; 
head-, 92 ; hog-, 93 ; short-nosed ox-, 93 

Louse-flies, 324 

Loxostege similalis, 214 

Lucanidae, 159 

Lucanus dama, 159; L. elephas, 160 

Lucilia ccesar, 322 

Luna-moth, 252 

Lung-sacs, 7 

Lyccena argiolus, 283 

Lyceenidae, 281 

Lycidas, 175 

Lycosa, 17 

Lycosidae, 17 

Lyctidae, 175 

Lygaeidae, 105 

Lygidea mendax, 102 

Lygris diver silineata, 225 

Lygus pratensis, 102 

Lymantriidae, 232 

Lymexylidae, 175 

Lynchia americana, 325 

Lyonetiidas, 202 

Lyreman, no 

Machilis, 46 

Macrodactylus subspinosus, 156 
Magicicada septendecim, in 
Maia-moth, 250 

Malacosoma americana, 257; M. calij 'ar- 
nica, 257; M. disstria, 257; M. fragilis, 

257 
Malaria, 299 
Malaxate, 370 
Mallophaga, 85 
Mammals, 1 
Mandibles, 31 
Manidiidae, "285 
Mantidas, 59 
Mantis religiosa, 60 
Mantis pa, 71 
Mantispidae, 71 
Many-lined moth, 225 
Many-plume moths, 217 
Maple-borer, beautiful, 162 
Maple-leaf cutter, 195 
Maple-worm, green-striped, 249 
March-flies, 302 
Marginal cells, 330 
Margins of wing, 32 
Mass provisioning, 370 
Mastigopr actus gigantens, 4 


Maxillae, 31; of beetle, 129; of moths, 184 

Maxillary, palpus, 31; tentacle, 195 

May-beetle, heart of a, 36; leg of a, 35 

May-beetles, 154, 155 

Mayflies, 74, 75, 76 

May-fly, metamorphosis of, 76 

Meadow-browns, 277 

Meal-moth, Indian, 216 

Meal snout-moth, 215 

Meal-worm, 216 

Mealy-bugs, 119, 121 

Measuring- worms, 223 

Mecoptera, 178 

Media, 33 

Medial cross-vein, 33, Fig. 66 

Medio-cubital cross-vein, 33, Fig. 66 

Mediterranean flour-moth, 216 

Mediterranean fruit-fly, 316 

Megachile, 378 

Megachilidae, 373, 377 

Megalopyge opercularis, 198; cocoon of, 

198 
Megalopygidae, 197 
Megaphasma dentricus, 58 
Megarhyssa lunator, 347 
Megathymidae, 258 

Megathymus streckeri, 259; M. yuccce, 259 
Melalopha inclusa, 230 
Melandryidae, 175 
Melanoplus, 56 
Melanoplus differ ■entialis, 57; M. femur-ru- 

brum, 56; M. spretus, 56 
Melanotus communis, 148 
Melittia satyriniformis, 209 
Mela- angusticollis, 147 
Meloidae, 145 
Melon-fly, 316 
Melon-worm, 213 
Melophagus ovinus, 324 
Melyridse, 175 
Membracidag, 112 
Membrane, 94 

Menopon biseriatum, 85; M. pallidum, 86 
Mentum, 129 
Merragata, 107 
Mesothorax, 31 
Mesoveliidae, 107 
Metallic wood-borers, 148 
Metamorphosis of insects, 23, 24, 25 
Metathorax, 31 
Metzneria lapella, 206 
Microcentrum retinerve, 51; M. rhombifo' 

Hum, 51 
Microdon, 314 
Microgaster, 346 
Micromalthidas, 175 
Micropezidae, 325 
Micropterygidae, 192 
Microvelia, 101 
Micropteryx, wings of, 191 
Midges, 296 
Migrants, 116 
Milichiidae, 325 
Milkweed-beetles, red, 164 
Milkweed butterflies, 279 


INDEX 


395 


Millers, 185 

Millipedes, 20, 21 

Mineola vaccinii, 217 

Miridae, 101 

Misumena vatia, 1 7 

Mites, 2, 3, 18, 19 

Mitoura damon, 282 ; M. patersoni, 282 

Mnemonica auricyanea, 192 

Mocha-stone moths, 230 

Mollusca, 1 

Molluscoida, 1 

Molting of insects, 27 

Monarch, the, 279 

Monarthrum mail, gallery of, 1 74 

Moniliform, 30 

Monobia quadridens, 366 

Monochamus notatus, 163 

Monomorium pharaonis, 360 

Monommidae, 175 

Monothalamous, 350 

Monotomidae, 175 

Mordellidae, 175 

Morning-glory le?f-miner, 202 

Morns alba, 256 

Mosquitoes, 297 

Moth, pupa of a, 185 

Moth-like flies, 295, 296 

Moth-like fly, wing of, 295 

Moths, 183, 185, 191 

Mourning-cloak, 271 

Mouth-parts, 30, 31 

Mud-daubers, 371 

Murgantia histrionica, 106 

Murmidiidae, 175 

Musca domestica, 323 

Muscidae, 323 

Muscids, typical, 323 

Muscles, 35 

Museum pests, 151 

Musical organs of insects, 51, 54 

Mutillidae, 356 

Mycetaeidae, 175 

Mycetophagidae, 175 

Mycetophilidae, 300 

Mydaidae, 310 

My das, wing of, 310 

Myiasis in man, 322 

Mylabridae, 167 

Mylabris obtectus, 168; M. pisorum, 168 

Myriapoda, 20 

Myrmecocystus, 363 

Myrmeleon immaculatus, 71 

Myrmeleonidae, 67, 70 

Nabidae, 103 

Nabis snbcoleoptratus, 103 
Nagana, 324 
Naucoridae, 107 
Necrophorns, \\2 
Neididae, 107 
Nemathelminthes, I 
Nemestrinidae, 325 
Nemocera, 293 
Nemouridae, 82 
Neoheegeria verbasci, 91 


Nepa apiculata, 99 
Nepidas, 98 
Nepticulidas, 285 
Nepytia semiclusaria, 226 
Nerves, 37 
Nervous system, 37 
Nettle, 270 

Net-winged midges, 304 
Neuroptera, 66 
Neurotoma inconspicua, 339 
New York weevil, 170 
Niggers, 153 
Night-eyes, 77 
Nigronia serricornis, 68 
Nitidulidae, 175 
Noctuidas, 234 
Noctuids, 234 
Northern cloudy- wing, 260 
Norway spruce gall, 1 18 
"No-see-um", 297 
Nosodendridas, 175 
Notched-wing geometer, 227 
Notodontidae, 227 
Notolophus antiqua, 233 
Notonecta, 98 
Notonectidae, 98 
Nurse-bees, 382 
Nymph, the term defined, 24 
Nymphalidas, 268 
Nymphs, 24 

Oak-apples, 351; large, 351; large empty, 

351 

Oak-gall, giant, 352 
Oak hedgehog gall, 350 
Oak-leaf miner, white-blotch, 204 
Oak-slug, spiny, 199 

Oak- worm, orange-striped, 248; rosy- 
striped, 248; spiny, 249 
Oberea bimaculata, 164 
Obtected pupae, 185 
Ocelli, 29 
Ochteridae, 107 
Ochterus, 107 
Ochthiphilidse, 325 
Odonata, 24, yj 
Odynerus, 365 

CEcanthus nigricornis, 55; 0. niveus, 54 
CEciacus vicarius, 10 
CEcophoridae, 205 
(Edemeridae, 175 
CEneis semidea, 278 
(Esophagus, 36 
(Estridae, 320 
CEstrus ovis, 320 
Oiketicus abboti, 201 
Oil-beetles, 147 
Oinophilidas, 285 
Ommatidium, structure of, 29 
Omophronidas, 175 
Oncometopia undata, 113 
Oncoptolophus sordidns, 57 
Onion maggot, 319 
Oniscoida, 3 
Ontholestes cingulatus, 144 


396 


INDEX 


Ootheca of a cockroach, 60 

() phi on, 348 

Orange-tips, The, 266; falcate, 267 ; olym- 

pia, 267 
Orb webs, 15, 16 
Orders of Hexapoda, 39 
( hrgans of sight, 29 
Ormenis septentrionalis, 113 
Orneodidae, 285 
Ortalidse, 315 
Orthezia, 121 
Orthoptera, 49 
Orthorrhapha, 293 
Oryssidae, 344 
Oryssus occidentalis, 344 
OryzcEphihis surinamensis, 152 
Oscinis frit, 317 
Osmeteria, 262 
Ostnia, 375 

Osmoderma eremicola, 158 
Ostia of the heart, 36 
Ostomidse, 175 
Othniidae, 175 
Outer margin, 32 
Ovipositor, 34 
Owlet-moths, 234 
Ox- warble-flies, 320, 321 
Oxyptilus periscelidactylus, 217 
Oyster shell scale, 122 
Oysters, 1 

Pacific peach-tree borer, 208 

Pedogenesis, 302 

Painted beauty, 270 

Paleacrita vernata, 224 

Palpi, 31, 129 

Palpicornia, 131, 132 

Palpifer, 129, Fig. 214a 

Palpus, 129, Fig. 214a 

Pamphiliidas, 339 

Pamphilius persicus, 339 

Panorpa rufescens, 178 

Pantographa limata, 213 

Papaipema nebris, 239; P. nitela, 239 

Papilio glaucus, 263: glaucus glaucus, 263; 

glaucus turnus, 263; polyxenes, 262; zo- 

licaon, 263; thoas, larva of, 1 
Papilionidse, 262 
Papirius fuscus, 48 
Paraclemensia acerifoliella, 195 
Parasitic Hymenoptera, 345 
Parntenodera sinensis, 60 
Parharmonia pint, 209 
Parnassians, 264 
Parnassius, 265 
Parsnip webworm, 205 
Parthenogenesis, 331 
Passalidae, 160 
Passalus cornutus, 160 
Patagia, 187 
Peach sawfly, 339 
Peach-tree borer, 208; Pacific, 208 
Peach-tree bark-beetle, 173 
Peach twig-borer, 205 
Pear-blight beetle, 175 


Pear-midge, 302 

Pear-slug, 343 

Pea- weevil, 167 

Pectinate, 30 

Pectinophora gossypiella, 206; wings of, 

206 
Pedicel, 358 
Pedilidae, 175 
Pediculidae, 92 

Pedicnlus capitis, 92; P. corporis, 92 
Pcdipalpida, 4 
Pedipalpi, 5, 7 
Pegomyia hyoscyami, 319 
Pe-la, 119 
Pelecinidae, 348 
Pelecinus polyturator, 348 
Pelidnota punctata, 156 
Pelocoris, 107 
Pelopceus, 372 
Pentatomidae, 95, 106 
Pepsis, 355 
Pericopidae, 285 
Perillus bioculatus, 106 
Periplaneta americana, 6 1 
Perlidag, 82 
Petiole, 358 
Petroleum-fly, 317 
Phalacridas, 175 
Phalangida, 6 
Phaloniidas, 285 
Phancens, 155 
Pharynx, 36 
Phasmidae, 58 
Phengodidse, 175 
Pheosia rimosa, 228 
Philosamia walkeri, 255 
Phlebotomus, 296 
Phobetron pithecinm, 199 
Phohis pandorus, 221 
Phora, wing of, 313 
Phoridae, 313 
Phthiri-ns pubis, 93 
Phthorimwa operculella, 205 
Phthorophlceus liminaris, 173 
Phycitids, 216 
Phycodromidag, 325 
PhyMum, 58, 59 
Phyllocoptes pyri, 19, 20 
Phyllonorycter hamadryadella, 204 
Phyllophaga ; 155 
Phyllotreta vittata, 166 
Phylloxeridae, 118 
Phylloxera ritifolia, Il8 
Phymata erosa, 104 
Phymatidas, .104 
Phytomyza aquUegice, 318 
Phytophaga, families of the, 131, 134 
Phytophaga destructor, 302 
Pickle-worm, 214 
Pieridae, 265 

Pieris protodice, 266; rapce, 266 
Pigeon horn-tail, 340 
Pinacate-bugs, 152 
Pine clear-wing moth, 209 
Pine-cone willow-gall, 301 


INDEX 


397 


Pine-leaf tube-builder, 211 

Pine-pest, Zimmermann's, 217 

Pine-shoot moth, 212 

Pinipestis zimmermanni, 217 

Pink bollworm, 206 

Piophila casei, 316 

Piophilidae, 316 

Pipunculidse, 313 

Pipunculiis, 313, 314 

Pistol case-bearer, 204 

Planta, 374 

Plant-lice, jumping, 114; 116 

Plastoceridae, 175 

Platygasteridae, 384 

Plathypena scabra, 234 

Platyhelminthes, 1 

Platypodidas, 171 

Platypsyllidas, 175 

Platypus, 171 

Platystomidag, 169 

Plecoptera, 24, 81 

Plodia inter punctella, 216 

Plum- cur culio, 170 

Plume-moths, 217 

Plum web-spinning sawfly, 339 

Plusias, 237 

Pcecilocapsus lineatiis, 102 

Pcecilus lucublandus. 138 

Pogonomyrmex barbatus, 361 

Polistes, 367 

Pollen brushes, 373 

Pollenia rudis, 322 

Polychrosis viteana, 21 1 

Polyctenidae, 107 

Polyembryony, 331 

Polyergus lucidits, 363 

Polyformia, 131, 132 

Polygonia, 273 

Polygonia comma, 273; P. comma comma, 

273; P. comma dryas, 273; faunis, 273; 

P. interrogationis, 273 
Polymorphism, 358 
Polyphaga, 128, 131, 140 
Polyphemus-moth, 251 
Polystcechotes punctatus, 73 
Polystcechotidae, 73 
Polythalamous, 350 
Pomace-flies, 318 
Pompilidse, 355 
Popillia japonica, 156 
Poplar-leaf gall aphid, 117 
Porifera, I 

Porthetria dispar, 233 
Posterior lobe of the wing, 288, 332 
Postpetiole, 358 
Potato aphid, 116 
Potato-tuber moth, 205 
Praying mantes, 59; eggs of, 59 
Preanal lobe, 332 
Preaxillary excision, 332 
Prepectus, 332 
Primitive weevils, 169 
Prionoxystus macmurtrei, 197; P. robinice, 

196; wings of, 194 
Prionus imbricornis, 161; P. laticollis, 161; 


P. californicus, 161 

Prociphilus imbricator, 117; P. tessellatus, 
116 

Proctotrupidae, 348 

Proctotrupoidea, 348 

Progressive provisioning, 370 

Prolabia pidchella, 126 

Prolegs of larva?, 34 

Promethea-moth, 253 

Prominent, two-lined, 230 

Prominents, 227 

Propodeum, 332, 345 

Propolis, 383 

Prosimulium hirtipes, 304 

Prosopidae, 384 

Pros opts, 373 

Prothorax, 31 

Protoparce quinquemaculata, 220; pupa, 
220; P. scxta, 221 

Protozoa, I 

Provisioning, 370; mass, 370; progres- 
sive, 370 

Pselaphidse, 175 

Psephenidae, 175 

Pseudococcus citri, 124; P.longispinus, 121 

Pseudoscorpionida, 5 

Pseudoscorpions, 5 

Psila roses, 317 

Psilidae, 317 

P silo pa petrolei, 317 

Psilopodius sipho, wing of, 31 1 

Psithyrus, 381 

Psocid, wings of, 84 

Psocidas, 83 

Psocids, 83 

Psocus venosus, 83 

Psychidas, 200 

Psychoda, wing of, 295 

Psychodidas, 295 

Psyllia, pear-tree, 114; P. pyricola, 114 

Pteronarcidae, 82 

Pteronidea ribesi, 343; P. trilineata, 342 

Pterophoridae, 217 

Pterophylla camellifolia, 51 

Pterygota, 39, 40 

Ptilinum, 287 

Ptinidas, 175 

Ptychopteridas, 294 

Pulex irritans, 327 

Pulvilli, 288 

Pulvinaria, 122; P.vitis, 122 

Punkies, 297 

Pupa, 26, 185; obtected, 185 

Puparium, 287 

Pupipara, 324 

Pygidial area, 332 

Pygidium, 332 

Pyralididae, 212 

Pyralids, 212 

Pyralis farinalis, 215 

Pyrausta nubilalis, 214 

Pyrochroidas, 175 

Pyromorphidag, 197 

Pyrrhocoridae, 104 

Pythidas, 175 


398 


INDEX 


Queen, the, 64, 358, 379, 382 

Radial cross-vein, 33, Fig. 66 

Radio-medial cross-vein, 33, Fig. 66 

Radius, 33 

Ranatra, 99 

Range-caterpillar, New Mexico, 250 

Rap hid in, 71, Fig. 117 

Raphidiidas, 71 

Raspberry geometer, 224; root borer, 208 

Rat-rlea, Indian, 327 

Rat-tailed maggots, 315 

Red admiral, 270 

Red-bug, apple-, 102 

Red-humped apple-worm, 230 

Red-necked agrilus, 149 

Red spotted purple, 275 

Reduviidae, 103 

Reduvius personatus, 103 

Regal-moth, 246 

Regions of the body, 29 

Replete, 364 

Reproductive organs, 35, 39 

Respiratory organs, 37 

Respiratory system, 37 

Reticulitermes flavipes, 65 

Retinula, 29, Fig. 60 

Rhabdom, 29, Fig. 60 

Rhabdophaga strobiloides, 302 

Rhagionidas, 307 

Rhagium lineatum, 162 

Rhagoletis cingulata, 316; R. fausla, 316; 

R. pomonella, 315 
Rhagovelia, 101 
Rhamphomyia, wing of, 311 
Rhinoceros-beetles, 157 
Rhipiceridae, 175 
Rhipiphoridas, 175 
Rhizophagidae, 175 
Rhodites roses, 352 
Rhopalosomidae, 384 
Rhynchophora, families of, 134, 168 
Rhysodidae, 175 
Ribbed pine-borer, 162 
Rice- weevil, 171 
Riodinidae, 285 
Riper sia, 451 
Roadside butterfly, 267 
Robber-flies, 309 
Rodolia cardinalis, 22, 121, 153 
Roproniidag, 384 
Rose-bugs, 156 
Rose-gall, mossy, 352 
Rose-slug, 343 
Rotifers, I 

Round-headed apple-tree borer, 163 
Roundworms, 1 
Rove-beetles, 143 
Royal jelly, 382 
Royal-moth, two-colored, 248 
Royal-moths, 246 

Sibine slimulea, 199 

Sacred beetle of the Egyptians, 154 

Saddle-back caterpillar, 199 


Saldidae, 100 

Salt-marsh caterpillar, 243 

Samia cecropia, 254, 

Sand-crickets, 53 

Sandflies, 297 

San Jose scale, 122, 123, 124 

Saperda Candida, 163 

Sapromyzidce, 325 

Sapygidae, 384 

Sarcophaga hamorrhoidalis, 322 

Sarcophagidae, 322 

Saturniidas, 249 

Satyrodes canthus, 277 

Sawflies, 338; cimbicid, 341; leaf -rolling, 
339; stem, 340; typical, 342; web- 
spinning, 339 

Sawfly, American, 341; locust, 342 

Sawyer, 163 

Scales of butterflies, 183 

Scale-insects, 119; tortoise, 122; soft, 122; 
armored, 122; oyster-shell, 122; San 
Jose, 122; pine-leaf, 123 

Scalloped owlet, 236 

Scallop-shell moth, 225 

Scape, 358 

Scaphidiidae, 175 

Scarabaeidae, 154 

Scatophaga, 318 

Scelionidas, 384 

Sceliphron cementarium, 372 

Scenopinidae, 309 

Scenopinus, 309 

Schistocerca americana, 57 

Schizophora, 315 

Schizopteridae, 107 

Schizura concinna, 230; 5. ipomecB, 231 

Sciara, 300 

Sciara armyworm, 300 

Sciomyzidas, 325 

Scirtothrips citri, 90 

Sclerites, 28 

Scolia, 357 

Scoliidae, 357 

Scoliopteryx libatrix, 236 

Scolops, 113 

Scolytidae, 172 

Scopas, 373 

Scorias spongiosa, 116 

Scorpion, 1, 3, 4, 5 

Scorpionida, 4 

Scorpion-flies, 178, 179 

Screw-worm fly, 322 

Scurfy scale, 120, 124 

Scutelleridac, 108 

Scut igera forceps, 21 

Scydmaenidae, 175 

Scythrididae, 285 

Sea anemones, 1 

Searcher, the, 137 

Segments of the body, 28 

Scpsidae, 325 

Serrate, 30 

Sheep bot-fly, 320 

Sheep-tick, 324 

Shellac, 119 


INDEX 


399 


Shield-backed grasshoppers, 53 

Shore-bugs, 100 

Shrimps, 2 

Sialidas, 68 

Sialis infumata, larva of, 68 

Sibine stimulca, 199 

Sight, organs of, 29 

Silk of spiders, 8 

Silk-worm, 255 

Silk-worms, giant, 249 

Silpha, 142; 5. bituberosa, 143 

Silphidse, 142 

Silverfish, 45 

Simuliidae, 303 

Simulium, larva of, 304 

Simulium ?neridionale, 304; S. pictipes, 

.304 

Siphonaptera, 326 

Siricidae, 339 

Sisyridae, 67 

Sitophilus, 152 

Sitotroga cerealella, 205 

Skimmers, 79 

Skin-beetles, 159 

Skipper, least, 261; silver-spotted, 260 

Skippers, 183, 185, 258, 259; giant, 258 

Skippers with a costal fold, 259 

Skippers with a brand, 261 

Sleeping sickness of man, 324 

Slug-caterpillar moths, 198 

Small-headed flies* 308 

Smerinthns geminatus, 220 

Sminthurus hortensis, 48 

Smoky-moths, 197 

Snake flies, 71 

Snapping-beetles, 147 

Snipe-flies, 307 

Snout-beetles, 168 

Snout-butterfly, 281 

Snow-flea, 47 

Solatium rostratum, 165 

Soldier-beetles, 145 

Soldier-flies, 307 

Solidago gall-moth, 206 

Solpugida, 3 

Soothsayers, 59 

Sovereigns, the, 274 

Sow-bugs, 3 

Spanish-fly, 145 

Spear- winged flies, 312 

Sphaeriidae, 175 

Sphasritidas, 175 

Sphecidae, 370 

Sphecius speciosus, 372 

Sphecoid-wasps, 369, 370 

Sphex, 372 

Sphindida?, 175 

Sphingidas, 218 

Sphinx chersis, 220; pandorus, 221; pen- 
marked, 220; twin-spotted, 220; white- 
lined, 222 

Sphinxes, 218 

Spiders, 1, 3, 6, 8; orb- weaving, 8, 15; 
aeronautic, 9; hackled-band, 12, 13; 
comb-footed, 14; crab, 16; running, 17; 


jumping, 18; trap-door, 10; triangle, 13; 

funnel- web, 11 
Spider-wasps, 355 
Spinach-leaf miner, 319 
Spinnerets, 7 
Spinning organs, 7 
Spinning tubes, 7 
Spiracles, 37 

Spirobolus marginatus, 20 
Spittle insects, 11 1 
Sponges, 1 
Spongilla-flies, 72 
Spotted pelidnota, 156 
Spring azure, 283 
Spring of the Collembola, 47 
Spring-tails, 47 
Spurious vein, 314 
Squash-bug, 106 
Squash-vine borer, 209 
Stable-fly, 324 
Stag-beetles, 159 
Stagmomatis Carolina, 59 
Stalk-borer, 239 
Staphylinidae, 143 
Staphylinus maculosus, 144; S. vulpinus, 

144 
Starfish, 1 
Stem-mother, 115 
Stenomidae, 285 
Stenopelmatus , 53 
Stephanidae, 384 
Sternal spatula, 301 
Sthenopis pupurascens, 193 
Sticta Carolina, 373 
Sticktight flea, 327 
Stigma, 80 
Stiletto-flies, 309 
Stink-bugs, 106 
Stipes, 129, Fig. 214a 
Stomach, 36 
Stomoxys calcitrans, 324 
Stoneflies, 81, 82 
Stonefly, nymph of, 82 
Straight-seamed flies, 293, 306 
Stratiomyia, wing of, 307 
Stratiomyiidae, 307 
Strawberry crown-girdler, 170 
Streblidae, 325 
Strepsiptera, 176, 177 
Strigilis, 331 
Striped fleabeetle, 166 
Style, 288 
Styli, 45 
Stylopidae, 176 
Stylopids, 176 
Stylus, 120 

Subclasses of Hexapoda, 39 
Subcosta, 33 
Subimago, 74 
Submarginal cells, 330 
Submentum, 129, Fig. 214 
Sugar-cane, beetle, 157; borer, 215 
Sulphur, cloudless, 268; clouded, 267; 

little, 268; orange, 267 
Sutures, 28; humeral, 63 


400 


INDEX 


Swallow-tail, black, 262; larva, 262; 

tiger, 263; zebra, 263 
Swifts, 192 

Symmerista albifrons, larva, 229 
Sympherobiidac, 67, 72 
Symphyla, 23 
Sympliylids, 23 
Synanthedon exitiosa, 208; wings of, 208; 

5. opalescens, 208; pictipes, 209 
Syncldora cerata, 224. 
Syrphidae, 314 
Syrphus, 315 
Syrphus-flies, 314 

Tabanidas, 306 

Tabanus atratus, 306; wing of, 306 

Tachardia lacca, 119 

Tachina-fiies, 323 

Tachinidas, 323 

Taniopteryx pacifica, 81 

Tceniothrips inconsequens, 90 

Tanyderidae, 294 

Tanypezidas, 325 

Tapestry-moth, 200 

Tarantulas, 10 

Tarantula hawks, 355 

Tarsi, 130 

Tarsus, 31 

Tegeticula alba, 195 

Tegmina, 49 

Tegula, 187, 289, 332 

Telamona, 112 

Telea polyphemus, 251 

Tenebrionidae, 136, 151 

Tenebrio molifor, 151 

Tent-caterpillars, 257; apple-tree, 257; 

California, 257; forest, 257; Great 

Basin, 257 
Tenthredinidas, 342 
Terebrantia, 90 
Termatophylidae, 107 
Termite, queen, 64 
Termites, 63, 64, 65 
Tetracha, 136 

Tetraopes tetraophthalmus, 164 
Tettigoniidae, 50 
Tettix, 57 

Thalessa lunator, 347 
Thaumaleidas, 325 
Thecabius populicaidis, 117 
Thecla calanus, 282; T. m-album, 282 
Thecodiplosis mosellana, 302 
Therevidas, 309 
Theridiidae, 14 
Theridion tepidariorum, 14 
Therm obia domestica, 46 
Thomisidas, 16 
Thorax, 31 
Thorybes pylades, 260 
Thread- waisted wasps, 371 
Thrips, bean, 90; greenhouse, 90; onion, 

90; orange, 90; pear, 90; strawberry, 

90; camphor, 90 
Thrips tabaci, 90 
Throat-bot, 320 


Throscidae, 175 

Thyatiridae, 285 

Thyrmidae, 384 

Thyridopteryx ephemeraformis, 201 ; wings 

of, 201 
Thysanoptera, 89 
Thysanura, 23; 45 
Thysbe clear-wing, 222 
Tibia, 31 

Tibicen linnei, no 
Ticks, 19 
Tiger-beetles, 135 

Tiger-moths, 242, 244; hickory, 245 
Timber-beetles, 173 
Tinea parasitella, wings of, 200; T. pellio- 

nella, 200 
Tineidas, 199 
Tineola biselliella, 200 
Tingidae, 104 
Tiphia inornata, 356 
Tiphiidas, 356 
Tipida, 294 
Tipulidae, 293 
Tischeria malifoliella, 202 
Tischeriidas, 202, 285 
Tmetocera ocellana, 211 
Toad-shaped bugs, 100 
Tobacco- worm, 221 
Tolype velleda, 257 
Tomato-worm, 220 
Tomocerns plumbens, 48 
Tool-using wasps, 372 
Tortoise-beetles, 167 
Tortricidae, 209 
Tortricids, 209 
Tortrix, 210 

Toxoptera graminum, 1 16 
Tracheae, 7, 38 
Tracheal gills, 38, 39 
Tracheoles, 38 
Trap-door spiders, 10 
Tree-crickets, 54 
Tree-hoppers, 112; buffalo, 1 12 
Tremex columba, 340, 347 
Triatoma sanguisnga, 103 
Trichocera, 295 
Trichodectes scalaris, 86 
Trichophaga tapetiella, 200 
Trichoptera, 180 
Trigonalidae, 384 
Triphleps insidiosus, 102 
Trithyretts pentapellis, 4 
Tritoxa flexa, 315 
Triungulin, 146 
Trochanter, 31 
Trochelminthes, 1 
Troctes divinatorius, 84 
Trogidae, 159 
Tropcca lima, 252 
Trox, 159 

Trumpet-leaf miner of apple, 202 
Trypetidas, 315 
Trypoxylon albitarsis, 371 ; T. albopilosvm, 

371; T.frigidum, 371; T. rubrocinctum, 

37i 


INDEX 


401 


Tsetse-fly, 324 

Tube-building moth, 200 

Tubulifera, 90, 91 

Tumble-bugs, 154 

Tunga penetrans, 328 

Turkey-gnat, 304 

Tussock-moth, 232; California, 233; old, 

232; white-marked, 232 
Twisted- winged insects, 176 
Two-spotted oberea, 164 
Typhoid-fly, 323 

Uloboridas, 8, 13 
Uloborus, 14 
Underwings, 238 
Utetheisa, 242 

Vanessa atalanta, 270; V. cardui, 271; V. 

virginiensis, 270, 271 
Vanhorniidas, 384 
Veliidas, 10 1 
Velvet-ants, 356 
Verruga, 296 
Vespa crabro, 369; V. diabolica, 369; 

wings of, 364; V. maculata, 369; V. 

maculifrons, 369 
Vespidas, 364 
Vespid wasps, 364 
Viceroy, the, 275 
Violet tip, 273 
Volncella, 314 
Walking-sticks, 58 
Wall-bee, nests of, 384 
Wanderer, the, 284 
Warble-flies, 320 
Wasps, social, 366; typical, 364; solitary, 

364; digger, 369; sphecoid, 369 
Water-boatmen, 97 
Water-bugs, giant, 99 
Water-scavenger beetles, 141 
Water-scorpions, 98, 99 
Water-striders, 101 ; broad-shouldered, 

101 
Water-tigers, 139 
Wax, 383 
Wax-glands, 383 
Webs, orb, 15, 16 
Webworms, cabbage, 214; garden, 214; 

corn-root, 215; fall, 244 
Wedge-shaped leaf-beetles, 167 
Weevil, black vine-, 170; strawberry-, 170 ; 

pea, 168; New York, 170; fungus, 169; 

primitive, 169 


Wheat joint-worm, 354 

Wheat-midge, 302 

Wheat-sawfly-borer, 341 

Wheat straw-worm, 354 

Whip-scorpions, 4 

Whirligig-beetles, 139 

White-ants, 63 

White, checkered, 266 

White flies, 118 

White fly, citrus, 119; greenhouse, 119 

White-grubs, 156 

White-marked tussock-moth, 232 

White Mountain butterfly, 278 

Whites, the, 265 

Window-flies, 309 

Wings of the heart, 36 

Wings of Hymenoptera, 330 

Wings, 32; mounting, 186 

Wing-veins, the chief branches of the, 32, 

33; the principal, 33 
Wireworms, 148 
Witch, black, 236 
Witch-hazel cone-gall, 117 
Wohlfahrtia vigil, 322 
Wood-borers, 148 
Workers, 64, 358, 381, 382 
Worms, 1 

Xenopsylla cheopis, 327 

Xiphydriidae, 384 

Xyelidae, 384 

Xylina antennaria, 240; X. laticinaria, 

240; X. grotei, 240 
Xylocopa virginica, 366, 377 
Xylomyidae, 307, 325 
Xylophagidae, 307, 325 

Yellow-bear, 244 
Yellow-fever mosquito, 299 
Yellow-jackets, 369 
Yellows, the, 267 
Yponomeuta padella, 207 
Yponomeutidas, 207 
Yucca-moths, 195 

Zebra, the, 263 
Zerene ccesonia, 267 
Zeuzera pyrina, 197 
Zophodia grossularice, 217 
Zoraptera, 62 
Zorotypidae, 62 
Zorotypus hubbardi, 62 
Zygoptera, 79