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Property of

li 6: eOLLEGE OF AGRICULTURE
;:t fel loo^o^ and Entoniologv

ELEMENTARY ENTOMOLOGY

BY
E. DWIGHT SANDERSON

DEAN OF THE COLLEGE OF AGRICULTURE, WEST VIRGINIA UNIVERSITY
DIRECTOR WEST VIRGINIA AGRICULTURAL EXPERIMENT STATION

AND

C. F. JACKSON

PROFESSOR OF ZOOLOGY ANU ENTOMOLOGY, NEW HAMPSHIRE COLLEGE

GINN AND COMPANY

BOSTON • NEW YORK • CHICAGO ■ LONDON

COPYRIGHT, 1912, BY E. DWIGHT SANDERSON AND C. J. JACKSON

ALL RIGHTS RESERVED

812.7

Ctie gtftenaeum J^rtii

GINN AND COMPANY • PRO-
PRIETORS • BOSTON • U.S.A.

PREFACE

During recent years there has been increasing demand for
short courses in elementary entomology. For several years past
the authors have been endeavoring to present such courses to
their students, but have encountered the difficulty that no textbook
was available which met their needs. This book is, therefore, the
authors' effort to furnish such a text for beginners, and if it is
found useful to them and to the increasing number of teachers
who are endeavoring to instruct them in the subject, the authors
will feel well repaid. The work is confessedly very largely a com-
pilation from the works of others (as, indeed, any such work must
be), and it is obvious that many errors and defects may have been
overlooked, although the authors have spared no pains to eliminate
them. To those who observe such shortcomings, or who may be
able to offer suggestions for the improvement of the book when
revised, the authors will be under great obligation.

It was originally intended to include several chapters treating of
the various insect pests affecting crops and domestic animals, but
it was found that such a work would be too cumbersome ; indeed,
it is usually not possible to cover both elementary and economic
entomology in a single course. The economic side of the subject
has, however, been made the dominant note in the following pages,
and the forms discussed are mostly those of economic importance.
There is a popular belief, often held by young agricultural stu-
dents, that the chief subject matter of a course in entomology
should be a discussion of the common injurious insects. Expe-
rience has shown that such an idea is fallacious, and that, from the
standpoint of practical utility as well as from that of general cul-
ture, a knowledge of the structure, habits, and classes of insects
in general is much the more important phase of entomology for
academic study. Economic entomology is important and should

iv ELEMENTARY ENTOMOLOGY

not be neglected, but general entomology is the foundation upon
which it must be erected, and without a knowledge of the elements
of entomology a course in economic entomology will have but
little meaning to the average student, whereas if the more general
knowledge of the subject has been mastered, the study of the
various insect pests may be profitably pursued by the individual,
even if he has not been able to take a systematic course in that
phase of the subject.

Students should be encouraged to make free use of the standard
textbooks for reference and to aid in the identification of speci-
mens. Much interest may be added to the course by securing the
available entomological publications of the state agricultural experi-
ment stations (a list of which stations may be found in the
Appendix) and those of the Bureau of Entomology, United States
Department of Agriculture, Washington, D.C., many of which may
be had free of charge.

The work outlined in the study of life histories, in collecting,
and in the identification of insects is necessarily largely suggestive.
The amount and nature of such work must depend upon the time
available, the equipment, the time of year, and the local surround-
ings of the school, and must be determined by every teacher to
suit his own conditions. It should be emphasized, however, that
a maximum of laboratory and field work and a minimum of book
work will probably give the average student a better knowledge of
insect life than the opposite arrangement, as the subject is one in
which the student must secure his knowledge directly from the
material, if it is to have much real meaning to him.

The senior author is entirely responsible for the preparation of
Parts I and II, and the junior author for Part III, although they
have consulted together on all parts of the work.

Many of the half-tone illustrations are from photographs by
the senior author or from those of Dr. C. M. Weed, his prede-
cessor at the New Hampshire Agricultural Experiment Station,
while several new line drawings have been prepared for the work
by Alma Drayer Jackson and Iris L. Wood, for whose generous
aid the authors are greatly indebted. The remaining illustrations

PREFACE V

have been drawn from various sources, as indicated in the titles,
but the authors are under particular obligations to the following
persons for the loan of cuts for electrotyping : Dr. L. O. Howard,
Chief of the Bureau of Entomology, United States Department
of Agriculture ; Professor F. L. Washburn, State Entomologist of
Minnesota ; Dr. J. B. Smith, State Entomologist of New Jersey ;
Dr. V. L. Kellogg, of Leland Stanford Junior University ; Dr.
W. E. Britton, State Entomologist of Connecticut; Dr. E. P.
Felt, State PZntomologist of New York ; Professor G. W. Herrick,
of Cornell University ; Professor C. P. Gillette, Director of the
Colorado Agricultural Experiment Station ; P. Blakiston's Son
& Co., and D, Appleton and Company.

The authors are also greatly indebted to the following entomolo-
gists for reading portions of the manuscript and criticizing the keys
for the identification of insects, which criticisms have added greatly
to the accuracy and reliability of the work : Professor Herbert
Osborn, Dr. C. T. Brues, Mr. C. W. Johnson, Mr. Nathan Banks,
Dr. J. B. Smith, Dr. Harrison G. Dyar, and Dr. A. D. MacGillivray.

E. DWIGHT SANDERSON
C. F. JACKSON

f

CONTENTS

CHAPTER PAGE

I. IXTROnUCTIOX I

PART I. THE STRUCTURE AND GROWTH OF INSECTS

H. Insects and their Near Relatives 5

III. The Anatomy of Insects — External 10

I\'. The Anatomy of Insects — Internal 28

V. The Growth and Transformations of Insects ... 45

PART II. THE CLASSES OF INSECTS

Vl. The Classification of Insects 67

VII. Bristletails and Springtails {Aptera) 73

Vni. Cockroaches, Grasshoppers, Katydids, and Crickets

(Okthoptera) 76

IX. The Nerve-Winged Insects, Scorpion-Flies, Caddis-
Flies, May-Flies, Stone-Flies, and Dragon-Flies . 89
X. TheWhite Ants, Book-Lice, AND BiRD-LicE(/'L^7"r/'r£"/i'.4) 103
XL The True Bugs. Aphides, and Scale ly^sECTS{HEM/pp£RA) 107
XII. The Beetles {Coleoptera) 136

XIII. The Butterflies and Moths {Lepidoptera) .... 172

XIV. The Flies, Mosquitoes, and Midges {Diptera) . . . 218
XV. The Saw-Flies, Ichneumons, W^-\sps, Bees, and Ants

{Hymenoptera) 243

PART III. LABORATORY EXERCISES

XVL The External Anatomy of the Locust 275

X\TI. A Comparison of the Different Types of Arthropoda 284
XATII. A Comparison of Different Types of Insects; Struc-
ture of the Bee, Fly, and Beetle 287

XIX. The Internal Anatomy of the Locust 290

XX. The Mouth-Parts of Insects 294

XXI. The Life History of Insects 298

XXII. The Classification of Insects 302

XXIII. Methods of Collecting Insects 330

XXIV. Methods of Preserving and Studying Insects . . . 343

APPENDIX 359

INDEX AND GLOSSARY 363

ELEMENTARY ENTOMOLOGY

CHAPTER I
INTRODUCTION

A professor of entomology in one of the leading universities
has recently been quoted as saying that this is " the age of in-
sects." Doubtless most of us have been accustomed to consider it
"the age of man," but although man's sway is dominant in all
parts of the earth, there is considerable evidence that, from a purely
biological standpoint, insects are the most characteristic form of
life of the present age, and the statement quoted challenges our
attention for more than a passing consideration.

That such a statement should be made by a well-known ento-
mologist, and should be widely quoted, is significant of the present
attitude of the public toward insect life, which has changed radi-
cally during the last generation. Not many years ago the entomol-
ogist, or " bug collector," was looked upon as a harmless individual
who amused himself with his hobby ; and as he was met with his
butterfly net, the passer-by might lift his eyebrows as if questioning
whether a grown man who would devote himself to such insignifi-
cant creatures was really quite normal.

To-day the public has come to appreciate that insect life plays a
most important part in the economy of our civilization. Some of
the problems which require the work of the trained entomologist are
worthy of the highest scientific training and best executive ability.

Insects and disease. The modern methods of sanitation for the
control of malarial fe\'er and yellow fever involve the control of
mosquitoes, which transmit these diseases. More and more the
sanitary measures which are making the tropics habitable for the
more northern races of man are being made possible by a knowl-
edge of the relation of insect life to the transmission of disease.
Even the common house-fly, formerly considered a mere nuisance,

2 ELEMENTARY ENTOMOLOGY

is now known to carry typhoid fever and probably various intestinal
disorders, to which a large part of our infant mortality is due ;
and it has been well said that, during the Cuban War, probably
more American soldiers were killed through the agency of flies
carrying typhoid germs than by Spanish bullets.

Injury to crops. In their economic relations the insects affect-
ing crops are by all odds of the most importance, many of them
causing a loss of several million dollars a year to the farmers of the
United States. The boll weevil destroys over $25,000,000 worth
of cotton in Texas and Louisiana alone, and 10 per cent of the
wheat crop of the entire country, valued at $60,000,000, is usually
destroyed by insect pests. It has been estimated by competent
authorities that 10 per cent of the total value of the farm products
of the United States is annually lost by the ravages of insect
pests, amounting to nearly $800,000,000 per annum.

Injury to domestic animals. Domestic animals are affected by
various insects, such as the warble, or ox-bot, and the screw worm,
— which affect catde, — the sheep maggot, and many others, in-
cluding the ticks, which carry Texas fever and other diseases ; so
that the annual loss to live stock through insects is estimated at
$175,000,000 per year.

Injury to household and stored goods. Housekeepers, manufac-
turers, and wholesale dealers must take into consideration the insect
life which affects all sorts of vegetable and animal products, and the
aggregate loss due to the insect pests of household and stored goods
must in the aggregate be a considerable item in domestic economy
and mercantile business.

Productive insects. A few insects contribute directly to the
wealth of the world : the silkworm produces over $200,000,000
worth of silk annually, and the product of the busy honey-bee
amounts to over $20,000,000 per year in the United States alone.

Beneficial insects. The direct relations of insects to mankind are
by no means the most important phases of their ecology. The role
of insects in the pollenization of fruits and flowers is fundamental
to the successful fruiting and perpetuation of a large proportion of
common plants. Again, a large number of insects prey upon or live
within the bodies of other insects, and constitute the most impor-
tant factor in the natural control of injurious species. Were it not

INTRODUCTION 3

for these beneficial forms, which prevent the normal increase, many
of our common injurious insects would become so numerous as to
practically prohibit the growth of crops affected.

Value of study of insects. The strictly economic aspect of insect
life is not, however, the only phase worthy of our attention and
study. The apathy with which the study of entomology was for-
merly treated was unquestionably due to the general lack of interest
in biology until recent years. During the last generation it has been
more and more appreciated that man is but a child of nature, and
that he can learn much in the proper conduct of his affairs by a
study of the laws of life in general, whether of the uncivilized races
of mankind, of insects, or of microscopic bacteria or protozoa. Our
grandfathers hardly knew that bacteria existed ; to-day most of the
science of patholog"}-, and much of the practice of medicine, is based
on an understanding of their life. It would seem, therefore, that
insect life should furnish a large field for the student of general
biolog}', and more and more biological problems of fundamental
importance are being worked out through studies of insects.

That this should be the case is extremely obvious when we
remember that there are over 300,000 known species of insects,
including over four fifths of the described species of animals, and
that at the rate at which they are being described, it has been esti-
mated that over a million species exist. The immense number of
insects, both of species and of individuals, is undoubtedly due to
their varied structure, which enables them to live under all possible
conditions. Thus the larvae of many different species are adapted
so that they live entirely in water, others bore in trees and plants,
some are subterranean, while still others inhabit the tissues of do-
mestic animals or of other insects. By the aid of their wings the
adults spread rapidly and are thus able to migrate when necessity
arises. Thus the insects possess such diversity of structure and
habit that they are able to live under all external conditions, and
on account of their immense numbers they have been able to adapt
themselves to a changing environment which would have entirely
obliterated classes or species few in number.

Not only are insects the most abundant form of animal life, but
they exhibit the highest degree of intelligence of any of the lower
or invertebrate animals. The wisdom of the ant and the industry

4 ELEMENTARY ENTOMOLOGY

and domestic economy of the honey-bee are proverbial, and new
observations are constantly showing the wonderful intelligence, if
it may be so called, evinced by many insects hitherto but little
known. No class of animals is more fascinating or better rewards
the study of the nature lover, as may be slightly appreciated from
the perusal of the habits described in succeeding pages. ,

It may now be evident, in view of the immense preponderance
of species and individuals of insects in the animal kingdom, and
their important role in the economy of nature, that there is some
ground for describing the present as " the age of insects," though
the term is of course used from a purely biological standpoint.

PART I. THE STRUCTURE AND
GROWTH OF INSECTS

CHAPTER II

INSECTS AND THEIR NEAR RELATIVES

If we are to study insects, it is necessary that we should have a

clear conception of just what an insect is and how insects may be

distinguished from other animals. Most of us recognize bees, flies,

beetles, and butterflies as insects, but other forms of insect life we

c

m

Fig. I. Earthworm
m, mouth ; r, girdle, or clitellum. (After Jordan and Heath)

should probably call "worms," and various insectlike animals are
commonly termed " insects."

The animal kingdom is divided into two large groups of animals,
— those having a backbone, the Vertebrates, and those without a
backbone, the Invertebrates. In the former are included all the

Fig. 2. Diagram to express the fundamental structure of an arthropod

(7, antenna ; a/, alimentary canal ; b, brain ; d, dorsal vessel ; ex, exoskeleton ; /, limb ;
«, ner\-e chain ; .f, subesophageal ganglion. (After Schmeil, from Folsom)

higher animals, such as the fishes, reptiles, birds, and mammals ;
while in the latter are included all the lower forms of life, which
are usually smaller in size and soft-bodied, as the molluscs, echino-
derms, worms, insects, and their relatives.

5

6 ELEMENTARY ENTOMOLOGY

The Invertebrata are divided into several branches, or phyla (sin-
gular, phylum), which divisions are based on fundamental differences
in the body structure of the animals in these groups. Of these
phyla there are two which have the body made up of a series of
segments and were at one time classed together as the Artiadata.

Fig. 3. A lobster; a typical crustacean

The first of these two phyla, the Vermes, or worms, has no jointed
appendages, while the second, the Arthropoda, is characterized by
having jointed appendages on either several or all segments of the
body, from which the term "Arthropoda," from artJiron (joint)
and pojis (foot), is derived. The Arthropoda include the insects,
spiders, myriapods, and crustaceans, all of which are related by the
possession of these jointed appendages. The distinctions between

INSECTS AND THEIR NEAR RELATIVES

7

these four classes are based largely upon the manner in which
the different segments are grouped together to form compact and
distinct parts of the body, and by the number and position of the
appendages.

The Crustacea include the lobsters, crabs, crayfish, shrimps, bar-
nacles, sow-bugs, etc., and are primarily distinguished from all other
arthropods by the fact that they breathe by means of gills and live
either in the water or in damp places. The body is divided into
two main regions, the

anterior segments be-
ing usually covered by
a single large shell
forming the head-tho-
rax, or cephalothorax,
while the remaining
segments form the ab-
domen. Each segment
usually bears a pair of
appendages. On the
head are found two
pairs of antennas, and
on the thorax and ab-
domen are numerous
appendages fitted for
walking or swimming.

The only crustacean commonly mistaken for an insect is the little
sow-bug, or pill-bug, found in greenhouses, under boards, or in
damp places (Fig. 4). These rarely do any damage and may be
readily distinguished from insects by the two pairs of antennas
and the numerous appendages. The gills are to be found under
plates on the lower side of the abdomen.

The Arachnida include the spiders, scorpions, ticks, and mites,
and are almost entirely terrestrial. The body is divided into the
cephalothorax and abdomen, as in the Crustacea, but there are no
antennae and but four pairs of legs. Although ticks and mites are
not insects, yet they are so nearly related, and their injuries to plants
and animals are so similar to insect depredations, that they are com-
monly included in economic entomology. Spiders are, if anything,

Fig. 4. Sow-bug, or pill-bug {Porcellis laevis)
Enlarged. (After Jordan and Heath)

ELEMENTARY ENTOMOLOGY

beneficial, though they feed on beneficial as well as on injurious
insects, while scorpions are found only in tropical countries and

are chiefly a nuisance on account
of their poisonous sting.

The Myriapoda include the myri-
apods and centipedes, commonly
called thousand-legs. Their body
consists of a distinct head and a
long abdomen, all of the segments
of which are similar, and each of
which bears a pair of legs, so that
they are readily distinguished from
all other arthropods. In many ways
the myriapods are more closely re-
lated to the insects than either of
A few species sometimes
injure vegetables or fruits lying on or in the ground, and these
are considered as within the
sphere of economic entomol-
ogy ; but for the most part
myriapods are harmless, al-
though the house centipede

Fig. 5. A spider; a typical arachnid

the Other classes mentioned above.

Fig. 6. A myriapod

Fig. 7. A parasitic fly, showing
parts of a typical insect

an/, antennae ; /i, head ; /, thorax ;
aid, abdomen ; zf^, wings ; /, legs

is a nuisance and is abhorred by the
housekeeper. Some of the tropical
myriapods reach relatively enormous
size, being several inches long, and
bear poison fangs in connection with
the mouth-parts.

The Insecta, or Hexapoda, include
the true insects, which form the largest
group of animals as far as both the
number of different species and the
number of individuals are concerned.
About 300,000 different species have
already been described, while there is
probably a total of 1,000,000 species
in existence. The known species form
over four fifths of the total number of

INSECTS AND THEIR NEAR RELATIVES 9

animals now described. The adult insects are readily recognized
from the other classes of a;-thropods, but many of the immature
forms, such as maggots, lack the typical characteristics of the
group. The segments of the body of an insect are grouped into
three distinct regions, — the head, the thorax, and the abdomen.
The head bears a single pair of feelers, or antennae, the mouth-parts,
and the compound eyes. The thorax bears three pairs of jointed
legs and in the adult stage usually two pairs of wings, though in
the flies there is but a single pair and in a few orders wings are
lacking. The abdomen is usually without appendages in the adult
state, although on caterpillars and other immature stages prolegs,
or false legs, which are not segmented, are often found.

Comparative Structure of the Classes of Arthropoda

Class

Pakts of

Body

An'TENN.B

Eves

Legs

in;; or,,/

I 2

3

Insecta

Head, thorax.

abdomen

One pair

Compound

Six

Myriapoda

I
Head,

abdomen

One pair

Compound

One pair per
segment

Arachnida

Head-thorax,

abdomen

None

Simple

Eight

Aguah'c

I

2

Crustacea

Head-thorax,

abdomen

Two pairs

Compound

Many

CHAPTER III

ANATOMY OF INSECTS — EXTERNAL

Body structure. The extinct ancestors of the insects were
doubtless elongate, wormlike animals composed of a series of
cylindrical segments very similar in structure and with a pair of
jointed appendages attached to each segment. The mouth being

Fig. 8. Types of insect antennae

A, filiform, from grasshopper {Sckisiocoxa mnericana) ; B, clubbed, or clavate, from teneb-

rionid beetle {Xyctobates fcnnsylvatiiats) ; C, pectinate, or feathered, from a moth ; Z), aris-

tate, with dorsal plumose arista, from a fly ; E, lamellate, from a May-beetle {Lachnosiema

fused) ; F, moniliform, from a beetle

at the anterior end, the appendages near it were developed to
secure and tear up the food. Thus the mouth-parts were gradu-
ally evolved, and -the segments bearing them grew closer together
until they coalesced and formed a single well-defined region, the
head. With the development of wings the appendages of the pos-
terior segments were useless and soon disappeared, and the legs
on the three segments immediately back of the head became

ANATOMY OF INSECTS — EXTERNAL 1 1

further specialized as organs of locomotion. With the development
of the large muscles necessary for the propulsion of the wings and
legs, these three segments back of the head became sharply differ-
entiated from the rest, so that they now form a quite distinct
region, the thorax. The remaining posterior segments, called the
abdomen, having lost most of their appendages, are quite similar
in form, with the exception of those at the extreme posterior end,
where the shape of the segments and of their appendages has
been modified in connection with the external sexual organs. The
insect is therefore divided into three well-defined parts, — the head,
the thorax, and the abdomen, — which are composed of more or
less visible segments.

The head. The embryolog}'
and nen'ous system of the head
show that it was originally com-
posed of six segments, almost
no traces of which are now
discernible except their append-
ages, of which four pairs are rec-
ognizable as homologous with
the thoracic legs and the ab-
dominal appendages of lower ' , I'Xir,!'"
forms. These appendages con-

. , r ,, r 1 . FiG- Q- Head of drone bee, showing:

SlSt of the feelers, or antennas, compound and simple eyes

and three pairs of mouth-parts. ^^^^^^ ^ ^ Comstock)

The head also bears a pair of

compound eyes and often a variable number of simple eyes, or ocelli.
Antennae. The antennae are often called feelers, indicating their
principal function as sense organs, which will be discussed in con-
sidering the senses. The shape of the antennae is very different
in different groups of insects, as is also the number of segments,
both of which characters are of the greatest importance in dis-
tinguishing the various groups. In the case of the katydid the
threadlike antennae are much longer than the body, while in some
flies they are reduced to mere knobs with a single strong bristle.
The different shapes of the segments give rise to many different
characteristic types of antennae, some of the more important of
which are shown in Fig. 8. In many cases, notably in the moths

12

ELEMENTARY ENTOMOLOGY

and mosquitoes, the antennse of the sexes are quite different, so
that the sexes are readily distinguishable.

Eyes. On either side of the antennae are found the large com-
pound eyes, often forming the larger part of the side of the head,
and sometimes, as in the dragon-fly and horse-fly, forming the
major portion of the head. The compound eyes are usually oval
or circular in outline, and are called compound because, when
examined under a lens, they are seen to be composed of large
numbers of hexagonal areas, called facets. The number of these
facets varies from 50 in certain ants to 4000 in the house-fly and

-mx.p

lab

Hb.p

Fig. 10. Face of grasshopper

ani, antenna ; c/, clypeus ; eye, compound eye ; /al>, labium : /fir, labrum ; 3./, labial palpi ;
mx.f, maxillary palpi ; oc, ocellus

27,000 in certain sphinx moths. Between the compound eyes,
on the front, or vertex, of the head, are two or three small oval
or circular simple eyes, called ocelli. Caterpillars and other larvae
have no compound eyes, but on either side of the head have a
group of from four to six ocelli. In many flies and bees the com-
pound eyes of the male are larger and closer together than those
of the female, this being due, possibly, to the male's leading a
more active life.

Mouth-parts. The mouth-parts are of prime importance, both
from an economic and from a systematic standpoint. Upon their
structure depends the kind of insecticide which may be effectively

ANATOMY OF INSECTS — EXTERNAL

13

used, and their structure is so constant and characteristic in different
groups as to furnish one of the best means of classification. Most
of the orders possess
one of the two main
t}'pes of mouth-parts,
— -those^^foffBe^— for-
Hting /mandibulatej,
a«4 those formed -^or
■sneking (suctorial; or
haustellate)*. The bit-'
<iffig type, as found in
the grasshopper, is the
more typical, and will
therefore be discussed
first.

The labnivi, or up-
per lip, is a simple
flap projecting over
the upper part of the
opening of the mouth
and covering the man-
dibles. It is hinged on
the posterior margin, but otherwise is free and may be slightly
protruded or retracted, to aid in bringing food to the mandibles.

Fig. II. Mouth-parts of grasshopper, typical biting
or mandibulate mouth-parts

Ibr. labrum, or upper lip ; md, mandible ; w.v, maxilla ; lab,

labium, or lower lip ; /, palpus ; g, galea ; /, lacinia ; lig,

ligula ; hyp, hypopharj-nx

Fig. 12. Various forms of mandibles

A, grasshopper {Melanoplits) ; B, tiger beetle {Cicmdelidae) ; C, bee {Apis) ■' D, Onthopha-
gus ; E, lace-winged fly {Oiiysopa) ; F-I, soldier termites. (.After Hagen, from Folsom)

The mandibles, or jaws, are composed of a single toothlike
piece and move in a transverse plane. The form of the mandibles

14

ELEMENTARY ENTOMOLOGY

is modified according to the food of the insect. Thus, in the grass-
hopper and similar insects feeding upon vegetation the mandibles
are short, with strong teeth at the tip and behind them a crushing
or grinding surface. In carnivorous and pre-
dacious insects the mandibles are usually
long, slender, and sharply toothed, adapted
for grasping the prey or tearing flesh. In
certain of the Neuroptera, as in the aphis-
lion (see page 92), the mandible has a
deep groove on the inner surface, through
which the juices of the plant-lice are sucked.
In soldier ants the mandibles are developed
as effective weapons, while in other forms
they are otherwise specialized according to
the food habits of the insect ; but they are
always essentially biting organs.

Beneath the mandibles are the inaxillce, or
under jaws. The
maxillae are much
more complex, con-

FiG. 13. Maxilla of a
ground beetle {Harpa-
Itis caligitiosits), ventral
aspect

sisting of a basal

c, cardo; g, galea; /, la-

cinia ; /, palpus ; pf, palpi-

fer ; s, stipes ; sg, subgalea

(After Folsom)

bears three lobes, -

portion (stipes)

which is hinged to

the • head (by the

cardo) and which

the palpus, galea,
and lacinia. The palpus is composed
of four or five segments, resembles a
miniature antenna, and, like it, is a
sensory organ. The inner lobes, the
lacinia, are usually provided with teeth
or spines and aid the mandibles in hold-
ing and masticating the food.

The third pair of mouth-parts have
grown together on the median line so as
to form a single piece, known as the
labium, or underlip. In the embryo this is composed of a pair of
appendages similar to the maxillae, and for this reason is sometimes

Fig. 14. Labium of a ground

beetle (Ha)palus caliginosus),

ventral aspect

g, united glossas, termed the glos-
sa ; m, mentum ; /, palpus ; pg,
palpiger; /;•, paraglossa ; sm, sub-
mentum. The median portion of
the labium beyond the mentum is
termed the ligula. (After Folsom)

ANATOMY OF INSECTS — EXTERNAL

15

termed the scccvid inaxillcs. The labium forms the floor of the
mouth and assists the mandibles and maxillae with the food. It is
hinged to the head at its base (by the inaitum), and projecting
from either side is a palpus, similar in form and function to the
maxillary palpi. Between the palpi are one or two pairs of lobes,
the ligjila.

Projecting into the cavity of the mouth from the inner sur-
face of the labium is the hypophaijnx, or tongue. This in the

Fig. 15. Mouth-parts of the squash-bug

lab, labium, forming a sheath for the other parts ;
Ibr^ labrum, fitting into the lower part of the
suture of the labium : wi/, mandible : w.x', ma.x-
illa. Mandibles and maxilte pulled out of labium

Fig. 16. Side view of head

of butterfly, with part

of antennas {a) removed,

showing mouth-parts

;«.v, maxillae ; /, labial palpus

grasshopper is a fleshy, tonguelike organ, but in some orders it
is quite differently developed. The salivary glands open near its
attachment.
\,c^ '-^"^ Suctorial type of mouth-parts. The mandibulate mouth-parts
of the different orders are all of so similar a type as to be appar-
ently homologous. The Siietocial mouth-parts consist of several

i6

ELEMENTARY ENTOMOLOGY

very distinct types, entirely dissimilar in structure and origin,
resembling each other only in that they enable the insect to suck
or lap its food rather than to bite it.

Fig. 17. Cross section of proboscis of cotton-worm moth, showing concave inner

faces of maxillae locked together to form the sucking tube

(After Comstock)

Fig. 18. Mouth-parts of female mosquito {Culex pipiens)

A, dorsal aspect; B, transverse section; C, tip of maxilla; D, tip of labrum-epipharynx ;

a, antenna ; e, compound eye ; /i, hypopharynx ; /, labrum-epipharj'nx ; /i, labium ; mx,

maxilla ; m, mandible ; /, maxillary palpus. (After Folsom and Dimock)

ANATOMY OF INSECTS — EXTERNAL

17

Hemiptera. In the Hcmiptera, or bugs, the labium forms a long,
jointed beak, or rostrum (Fig. 15). This rostrum is cylindrical in
section, and its evolution from the type of labium found in the grass-
hopper may be understood by concei\ing the labium of the latter
to be greatly elongated and then curled up on either side until the
lateral margins meet
on the median line
above, forming a su-
ture, as seen in the
hemipterous beak. At
the base of this suture
is found a triangular la-
brum closing the base
of the tube. The man-
dibles and maxillae are
long, bristlelike or
needlelike structures,
sharply pointed and
often bearing barbs at
the tip, and the max-
illae are locked to-
gether so as to form a
tube through which
the juices are sucked.

Lepidoptera. The
moths and butterflies
possess a very different
style of sucking tube,
or proboscis, which is
curled up under the head like a watch spring. This is composed
of the two maxillae, whose inner faces are concave and which lock
together so as to form a tube which opens into the mouth. All
the other mouth-parts are almost entirely absent in most forms,
except the labial palpi. It is evident' that this type of mouth-part is
only adapted to sucking nectar from flowers and is never injurious
to vegetation, while often adapted for pollenizing flowers which the
moths frequent. The caterpillars of moths and butterflies have
biting mouth-parts similar to those of the grasshopper.

Fig. 19. Side view of head of a fly
(7, antenna ; wa/, maxillary palpus ; lab, labellum

ELEMENTARY ENTOMOLOGY

Diptera. The flies have several types of mouth-parts, all essen-
tially suctorial. Those of the horse-fly and mosquito are good
examples of the piercing type (Figs. 15, 18, 20). Superficially they
resemble those of the Hemiptera, but the sheath of the beak is not
so strong and is quite open above, and there are six lancetlike or-
gans which in the horse-fly
are quite strongly devel-
oped. The esophagus is
controlled by sets of mus-
cles which make it an effec-
tive bulb for pumping up
the food. The common
house-flies and blow-flies
have mouth-parts (Fig. 19)
adapted for rasping or lap-
ping rather than for pierc-
ing, though the liquid food
is sucked up in much the
same way. The proboscis
consists principally of the
very complex labium, or
lower lip, which is very
much expanded at the tip
to form a pair of fleshy
lobes. When looked at
under the microscope, the
tip of the proboscis is
seen to contain a series
of grooves and transverse
horny ridges with sharp,
projecting edges. With
these rasplike projections the fly is enabled to scrape the surface
of the food and gradually loosen small particles, which are dissolved
or carried in the saliva to the mouth.

Hymenoptera. The mouth-parts of the Hymenoptera include
both biting and sucking types. The saw-flies and ants (Fig. 22)
have well-developed biting mouth-parts, which are used as such,
while in the wasps and bees the maxillae and labium form a tube

Fig. 20. Mouth-parts of horse-fly {Tabanus)

Upper figure showing mouth-parts separated, and

lower figure showing lancets dissected out. (After

J. B. Smith)

ANATOMY OF INSECTS — EXTERNAL

19

around the greatly elongated tongue (hypopharynx) which is used
for lapping and sucking, though the mandibles are still functional
and are used in shaping wax and pollen.

It should be noted that in several of these orders having suctorial
mouth-parts in the adult stage the larvae have true biting mouth-
parts. Caterpillars of all the Lepidoptera and the larvae of many

Fig. 21. Mouth-parts of the honey-bee

a, antenna ; /, labellum ; g, glossa, or tongue ; Im, labrum ; Ip, labial palpi ; w, mandible ;
mx, maxilla ; mxp, maxillary palpus ; pg, paraglossa

families of flies and Hymenoptera have biting mouth-parts and are
injurious to vegetation, while the adults may be entirely harmless.
This difference in the mouth-parts of the same insect in different
stages must be borne in mind in considering insecticides for them.

20

ELEMENTARY ENTOMOLOGY

We have stated that the structure of insects often determines
the method of treating them. This may now be understood, for

it is evident that
./ a poison such as

Paris green, ap-
pHed to the food
of a sucking in-
sect, such as a
plant-louse, would
not be taken into
the mouth through
the sucking mouth-
parts, which ex-
tract only the juices
beneath the sur-
face, while it might
be entirely effect-
ive against an
insect with biting
mouth-parts, which
consumed the sur-
face covered by the
poison. A better
understanding of
these simple facts
of insect anatomy
would save Amer-
ican farmers thou-
sands of dollars
every year, now lost
through ignorance.
Thorax. The thorax is the middle region of the body, composed
of the three segments back of the head, which are called the/;v-
thorax, vicsot/iorax, and vietathorax respectively. As previously
indicated, the differentiation of the thorax has been incidental to
the development of the wings, and the structure of the thorax is
determined by the development and use of the organs of locomo-
tion. A pair of jointed legs is attached to each segment and

Fig. 22. Mouth-parts of an ant {Myrmica 7iibra

A, seen from the lower side in situ; B and D, maxillae;
C, labium seen from the upper side, detached ; «, mandible ;
b, maxilla ; c^ mentum ; d^ maxillary palp ; c, labial palp ; /,
glossa or tongue ; g, adductor muscle of mandible ; //, abductor
muscle of mandible ; ?, labium ; k, gustatory organs ; /, duct
of salivary glands ; m, maxillary comb ; «, gular apodeme.
(After Janet, from Wheeler)

ANATOMY OF INSECTS — EXTERNAL

21

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the mesothorax and
metathorax of most
adult insects bear a
pair of wings. The
prothorax is usually
smaller than the
two posterior seg-
ments, the relative
size of which de-
pends upon which
pair of wings is the
better developed.
The dorsal surface,
or back, of a tho-
racic segment is
called the tcrgutn,
or notiiin, the ven-
tral or under sur-
face is the stejiinni,
and each side is
a plcnnnn. These
parts are further
divided by sutures
into distinct plates,
or sclcrites, to which
the appendages are
articulated. The de-
velopment, shape,
size, and position of
these sclerites are
characters of such
uniformity that the
sclerites are used
in classifying in-
sects, in much the
same way as are
the bones of the
vertebrate animals.

22

ELEMENTARY ENTOMOLOGY

Emp^

--Cla

Fig. 24. Typical insect lej

C.v, coxa ; C/a, claws ; Emp, empodia ; F^ femur ; Tar, tarsal

segments ; Tb, tibia ; 7)-, trochanter. (After Snodgrass,

United States Department of Agriculture)

Legs. The legs articulate with the sternum and pleurum and con-
sist of five parts, — the coxa, trochanter, femur, tibia, and tarsus.
The base of the coxa forms the joint of the leg to the body, which

is either of the ball-
and-socket or of the
hinge type. The tro-
chanter is a small, in-
termediate segment,
which in parasitic Hy-
menoptera is double.
The femur is the
largest segment in
the leg, and in grass-
hoppers and other
jumping insects is
strongly developed
by the muscles with-
in. The tibia is usu-
ally long and slender. The tarsus is usually composed of several
similar segments, five being the typical number. The last segment
usually bears a pair of sharp claws in adult insects and a single
claw in larvae. Between the claws of most adult insects is a little
pad, called a pulvilhis, or enipodijim, a suckerlike organ which
enables them to walk upon smooth surfaces and to cling to objects
when upside down.

Nearly all adult and most larval insects have three pairs of
thoracic legs, but many boring and parasitic larvae have lost them
entirely. The legs are often greatly modified according to the habits
of the insect, not only for locomotion, but for grasping, digging, and
other purposes. The legs of most beetles are typical of walking
insects. In jumping insects, like the grasshopper and flea beetles,
the hind femora are greatly developed. In digging insects, such as
the mole cricket and cicada nymphs, the tibia and tarsus of the fore-
legs are developed as shovels. The forelegs of many predacious
insects, such as the mantis, assassin bugs, and others, bear teeth
upon the opposing surfaces of the tibia and femur, which make
them efficient grasping organs. The legs of the bees are highly
developed : the forelegs bear a comb for cleaning the antennae,

ANATOMY OF INSECTS — EXTERNAL

-J

the metatarsi bear a series of spines used as a pollen comb, and
the metatibiae bear a fringe of hairs on the outer surface surround-
ing what is called the pollen basket, adapted for carr)'ing pollen.

Fig. 25. Types of insect legs

A, grasshopper {Schistoccrca amcjicaua) ; B, a cicindelid beetle {C'uhidela b-giittata) ; C, a
gyrinid beetle {Dinculcs vittatiis) ; /?, a ) oung mantis ; £', a mole cricket (Giyllotalpa borcalis)

In aquatic forms the legs are variously developed for swimming or
skimming over the surface. The males frequently have the fore-
legs developed for grasping the females, as in the suckerlike disks
on the fore tarsi of the predacious diving beetles {Dytiscidac). In
general, insects which are strong fliers and are usually on the wing
have weak legs.

Wings. Millions of years ago insects became the pioneers in
aerial navigation by the development of wings, which have un-
doubtedly been chiefly responsible for the enormous development
of insects as a class, living in
all latitudes and environments.
The largest existing insects are
certain tropical moths whose
wings expand nearly a foot,
but fossils from the coal age
show that immense phasmids
(nearly related to grasshoppers)
then existed, with a wing ex-
panse of over two feet. The

largest wings are not, however, always the most serviceable, and
the strongest fliers are usually of medium size. The wings pre-
sent a variation of structure in almost every group, and, with the

Fig. 26. Hypothetical type of wing
venation

(Adapted from Comstock and Needham)

24

ELEMENTARY ENTOMOLOGY

mouth-parts, form the most important basis for classification. Thus
most of the orders are distinguished by differences in the wings, as
indicated by their names, which usually end in -ptera (from ptcron,
a wing), and many insects may be classified to the genus or even to
the species by the wings alone, this being particularly true of fossil
forms, in which the wings are often the only parts well preserved.
Most adult insects possess two pairs of wings, borne by the meso-
thorax and metathorax, but in some parasitic orders the wings have
been lost, and one order, the Thysanura, represents the primitive
insect without wings. In the flies (Diptera) only the mesothoracic
wings are developed, and the metathoracic wings are represented by
clublike appendages, called Jialtcrcs, or balancers. The relative shape

and size of the two pairs vary
greatly, and frequently the
two wings of each side over-
lap or are held together by
various structures, so that
they act as a single organ.
The wings are strengthened
by numerous thickenings,
called veins, whose number
and position form the basis of
the classification of families,
genera, and species. It has
been shown by Professors Comstock and Needham that the prin-
cipal veins are homologous in all the orders of insects, and that
they have been derived from one original type, either by the disap-
pearance of certain veins, by their growing together, or by the
addition of supplementary veins. The typical longitudinal veins, as
shown in Fig. 26, are the costa, snbcosta, radius, media, cubitus,
and anals. The costa {c) is unbranched and strengthens the
anterior margin of the wing. The subcosta {sc) is typically two-
branched, though often single, and, where the costa is small or
wanting, appears to be the first, or anterior, vein. The radius (/-) is
typically five-branched, the base of the second principal branch,
from which the four posterior branches divide, being known as the
radial sector. The media {m) is typically four-branched, though
often but two or three branches are present. Cubitus {cu) has

Fig. 27. Wing of house-fly (Ahtsca doniesii-

ca), showing speciahzation of wing venation

through reduction of veins

c, costa ; r, radius ; m, media ; ai, cubitus ; a,
anal. (After Comstock)

ANATOMY OF INSECTS — EXTERNAL

25

usually two branches. The anal veins (a) are typically three in
number, but often one or two are lost, and in other groups the
anal area is greatly expanded and they become many-branched.
Specialization by reduction in the number of veins is seen in the
wings of the flies, bees, and butterflies and moths, while special-
ization by addition is found in the wings of Orthoptera and the
neuropterous orders.

In several orders the front wings are modified to form wing-
covers for the hind wings and are not used in flight. Thus the
front wings of the beetles, called elytra, are hard and horny, those of
the grasshoppers are
leathery, and those
of the bugs are leath-
ery at the base, with
membranous tips.

In addition to be-
ing organs of flight,
the wings sometimes
have other functions.
Thus in crickets and
other Orthoptera the
wings bear sound-
producing structures,
and the honey-bee
maintains the temperature of its hive by the body heat derived
from the incessant motion of the wings.

Abdomen. The ten segments of the abdomen are the most dis-
tinct and simple of the body. The jointed appendages have been
almost entirely lost in adult insects, and the abdomen merely houses
the respiratory, digestive, and genital systems, the posterior seg-
ments being modified in connection with the external sexual organs.
In the lowest order, the Thysanura, rudimentary abdominal append-
ages still exist, and caterpillars and other larvae frequently bear
several pairs of fleshy, unsegmented prolegs, or false legs, bearing
a circlet of hooks at the tip. In several orders the females bear an
ovipositor, or ^gg guide, which has been developed from a speciali-
zation of the appendages of the seventh, eighth, and ninth seg-
ments. The females of many grasshoppers and crickets bear large

Fig.

;8. Wing of May-fly, showing specialization of
wing venation by addition of wing veins

Lettering as in Fig. 27. (After Folsom)

26

ELEMENTARY ENTOMOLOGY

ovipositors, with which they are enabled to insert their eggs in the
ground or in wood, but the greatest development of the ovipositor
is found among hymenopterous insects in which it is formed for
sawing, boring, or stinging. Another pair of jointed appendages,

Fig. 29. Ovipositor of periodical cicada
At rest at A, and exserted at B

called ccrci, are frequently found attached to the tenth abdominal
segment. They are quite variable in length, but in May-flies are
as long as the body and resemble very slender antennae projecting
backward from the abdomen. In most cases they are tactile organs,

but in the cockroach they assist in
smelling.

The number of visible abdom-
inal segments varies from five to
eleven in different orders, and fre-
quently the number is different on
the upper, or dorsal, and under, or
ventral, sides. The structure of the
anal segments is usually different
in the sexes and furnishes impor-
tant characters for classification.

Integument. Before studying
the internal anatomy, the skin, or
integument, of the insect should
be considered. This has become
hardened so that it forms a firm outer skeleton, to which the mus-
cles and internal organs are attached. Thus the parts of the insect
skin, as have been described, are analogous to the bony skeleton

Fig. 30. Section through skin of a
beetle ( Cluysohothris)

b, basement membrane ; c', primary cutic-

ula ; C-, secondary cuticula ; h, hypoder-

mis cell ; ?i, nucleus. (After Tower, from

Folsom)

ANATOMY OF INSECTS — EXTERNAL 27

of higher animals in that they support the tissues of the body, and
their structure is characteristic of the different groups. This hard-
ening of the skin is found in all arthropods and is due to a sub-
stance, called cJiitin, which is formed by the lower layer of cells of
the skin, the hypodermis, and which forms an impervious, hard
layer over the body of the entire animal, though but slightly devel-
oped in the membranous joints between the segments. Chemically,
chitin is somewhat akin to silk, or to the spongin of the sponge skele-
ton. It is unaffected by ordinary acids and alkalies, though soluble
in sodic or potassic hypochlorite. The insolubility of chitin is of
importance in the consideration of insecticides, for there is hardly
anything that can be applied to any but the most soft-bodied insects
which will corrode the skin without injuring the foliage of the
plants upon which they feed. The surface of the chitinous skin
may be smooth or pitted, wrinkled, striated, granulated, or marked
in various characteristic ways. The chitin is not only developed
by the outer skin but is formed on the surface of the entire epider-
mis, including the lining of the anterior part of the alimentary tract
and the respiratory tubes, or trachea, as can be seen by the exam-
ination of a cast skin after an insect has molted.

CHAPTER IV

ANATOMY OF INSECTS — INTERNAL

The general arrangement of the internal organs of an insect
may be understood by a study of transverse and longitudinal sec-
tions, as shown in Figs. 31 and 32, Attached to the inside of

Fig. 31. Ideal section through an insect

a, alimentary canal ; h, heart ; n, nerve cord ; s, stigmata, or spiracles ; /, tracheal tubes ;
/, legs; 7(', wings. (From Riverside Natural Histor)')

the body wall are found layers of longitudinal and vertical mus-
cles which control the body movements. Through the center of
the body runs a large tube, the alimentary canal, or digestive tract.
» _ »» h

Fig. 32. Ideal longitudinal section of an insect, showing relative position of organs

a, alimentary canal ; //, heart ; Jii, muscle bands ; «, nerve cord ; r, reproductive organs.

(After Comstock)

Just beneath the back is a small, transparent tube, the dorsal blood
vessel, or heart. Along the median line, close to the ventral wall,
is a series of small white knots, or ganglia, connected by a double

28

ANATOMY OF INSB:CTS — INTERNAL

29

cord, which form the nervous system. On either side of each seg-
ment is a small opening through the body wall, called a spiracle,
through which air is admitted to the breathing tubes, which branch
to all parts of the body and form the respiratory system. The re-
productive organs are found in the posterior segments of the abdo-
men and have a separate opening just below the anus.

The digestive system. The digestive tract, or alimentary canal,
consists of a more or less straight tube, occupying the larger part of
the center of the body and divided into parts with special functions,
whose development depends upon the food habits of the insect.

Pharynx. The food, after being torn to pieces and ground up
by the mouth-parts, is received into the pharynx (often called the

Fig. TyTj. Digestive and excretory system of a grasshopper

c, crop; g^ gizzard, or proventriculus concealed by caeca; g.c^ gastric caeca; /./, large intes-
tine ; m, mouth ; ;«./, Malpighian tubes ; 0, esophagus ; r, rectum ; s, stomach ; s.g, salivary
glands ; j./', small intestine

mouth), lying within the head, and in which it is acted upon by the
saliva. In sucking insects the pharynx acts as a pumping organ, as
already described. The saliva is secreted by the salivary glands,
which lie along the esophagus in the thorax, whose ducts open at
the base of the tongue (hypopharynx). The saliva acts on starch,
changing it into glucose as in the vertebrates ; in some carnivorous
insects it acts on the proteids and is sometimes used to poison the
prey ; in mosquitoes the poisonous saliva prevents the coagu-
lation of the blood of animals, though its original function may

so

ELEMENTARY ENTOMOLOGY

..a/.C

have been to act on the proteids of plant juices. In most cater-
pillars, of which the silkworm is the best example, and in many
other insect larvae, certain salivary glands have become specialized
so that their secretion hardens upon coming in contact with the air
and forms the silk of which their cocoons are spun.

Esophagus. The esophagus is a straight tube passing from the
pharynx to the crop or gizzard, or directly into the stomach.

Crop. The crop is practically a dilation of the posterior end of
the esophagus and in herbivorous insects forms the larger part

of the digestive tract. The food is
stored in the crop until the action
of the saliva has been completed,
changing the starches into glucose
sugar and the albuminoids into as-
similable, peptonelike substances.
In many insects which feed on
liquids, the storage capacity of the
crop is increased by a lateral
pocket, which in some cases forms
a separate sac communicating with
the crop by a short neck. The
walls of the crop contain a layer of
muscles which force the food back
into the gizzard when it is suffi-
ciently digested.

Gizzard. The gizzard {provoi-
tricnhis) is found best developed
in biting insects, such as grass-
hoppers and beetles, which feed
on coarse food, and is but slightly
developed or absent in many orders. It is termed "gizzard" because
it somewhat resembles the gizzard of a bird and was supposed to
function similarly. It is a small, very muscular organ, lined within
with strong chitinous teeth, or ridges, which strain the food, pre-
venting the passage of large particles into the true stomach. Some
have thought that these ridges aid in grinding the food, but this
seems doubtful. Usually a valve allows the food to be forced from
the gizzard back into the stomach, but prevents its return.

Fig. 34. Cockroach dissected to show
ahmentary canal and bands of muscles

(xl.c, alimentary canal. (After Hatshek and
Cori, from Jordan and Kellogg)

ANATOMY OF INSECTS — INTERNAL

Stomach. The stomach {ve7itric?iliis) is usually a simple tube
somewhat larger in diameter than the esophagus or intestine, but
of variable size and strength. As the food passes into the stomach
it is acted upon by the secretions of the ccecal tubes {gastric caca)
which are glandular pouches, or tubes, opening into the anterior
end of the stomach. Their number, size, and shape are quite vari-
able, and they secrete a weak acid which emulsifies fats and con-
verts albuminoids into peptones. The stomach is not lined with
chitin, as is the rest of the alimentary tract, but is glandular and
secretes a neutral or alkaline fluid which aids in the further diges-
tion of the food. The chief function of the stomach, however, is
to absorb the digested food and pass it into circulation.

Fig. 35. Digestive canal of a carabid beetle

h, esophagus : c, crop ; d, proventriculus ; f, stomach with its caeca ; g, posterior portion
of stomach ; //, intestine ; /, two pairs of Malpighian tubes ; k, rectum ; /, anal glands.

(After Dufour)

Intestine. The food passes from the stomach into the intestine
through a pyloric valve which prevents its passage backward. The
intestine is divided into three fairly distinct parts, the ileum, colon,
and rectum. The length and size of these parts varies greatly ac-
cording to the food of the insect, the ileum often being considerably
coiled. In the ileum the digested food materials are absorbed and
passed into the blood circulation ; the colon, which is often absent,
contains undigested matter and waste products ; while the rectum
has thick, muscular walls and expels the feces through the anus,
which opens through the last segment of the abdomen.

Malpighian tubes. Opening into the intestine, just back of the
stomach, are several small, slender tubes, variable in number, in
which uric acid is found, and which are considered to be excretory
organs similar in function to the kidneys of higher animals.

32

ELEMENTARY ENTOMOLOGY

When arsenical insecticides are applied to the food of biting

insects, the arsenic must be in the most insoluble form, to avoid

burning the foliage, and it is therefore not dissolved until it
reaches the stomach, when, having been mixed
with the digestive juices mentioned, it becomes
sufficiently soluble to be absorbed by the walls
of the stomach and ileum. Some insects are
able to consume a large amount of poison before
an amount sufficient to kill them is dissolved
and absorbed. In such cases poisons are some-
times of no avail, because serious injur}' is
done before the pest is brought under control,
and other means must be employed.

In the young
stages of insects
the digestion,
and consequent
growth, is ex-
tremely rapid.
A caterpillar
will frequently
eat and digest

two or three times its own weight

in a day. Thus the silkworm,

when it hatches from the egg,

weighs but one twentieth of a

grain, but in 56 days, when full

grown, it has consumed 120 oak

leaves, weighing three fourths of

a pound, and half an ounce of

water, or 86,000 times its original

weight, of which food 207 grains

have been assimilated, one fourth

of a pound has been voided as

excrement, and five ounces have

evaporated as water.

Circulatory system. The d/ood vessels of an insect are exceed-
ingly simple, consisting of a single dorsal tube, or heart, which

Fig. 36. Diagram

of a portion of the

heart of a dragon-fly

nymph

o, ostium ; v, valve.
The arrows indicate
the course of the blood.
(After Kolbe, from
Folsom)

Fig. 37. Diagram to indicate the

course of the blood in the nymph of

a dragon-fly

a, aorta ; /;, heart. The arrows show the
direction taken by currents of blood. (After
Kolbe, from Folsom)

ANATOMY OF INSECTS — INTERNAL 33

extends the length of the body along the median line just beneath
the notum. In the abdomen of adult insects this tube is divided
into several chambers, each of which has a valve at either side,
allowing the blood to flow into it but preventing its escape. The
chambers are also separated by valves which allow the blood to
flow forward but prevent its backward passage. The abdominal
part of the tube, the heart proper, pulsates and drives the blood
toward the head, while the forward part is a simple blood vessel,
called the aorta, which usually divides in the head, where it ends
abruptly, allowing the blood to flow into the body cavity. Thus the
blood is admitted to the heart by the lateral valves, is forced forward
to the head, and thence flows in more or less defined currents

F^iG. 38. Portion of a trachea of a caterpillar, with its branches
(After Leydig, from Gegenbauer)

throughout the body, bathing all the organs. The pulsation of the
heart and the flow of the blood may be observed in many thin-
skinned larvae and nymphs.

The blood consists of a watery fluid, — the plasma, or serum, —
and the white corpuscles, or leucocytes. Usually colorless, it is
often yellowish or greenish. The blood has almost nothing to do
with the aeration of the tissues, that being done by the respiratory
system, as described below, its chief function being to nourish the
tissues with the food materials that it carries.

Respiratory system. Insects have no lungs, but breathe through
a system of tubes, called tracJica, which extend to all parts of the
body, bringing fresh air to the tissues and carrying off the carbon
dioxide. On either side of two thoracic segments, and on all the

ELEMENTARY ENTOMOLOGY

abdominal segments but the last two or three are small openings
called spiracles, or stigmata, which are the external openings
through which air is admitted to the trachea. The spiracles are
guarded by hairs and other devices, to prevent the ingress of dust
and foreign matter, and each has a valve operated by a special muscle
which opens and closes it. From each spiracle a short tube extends
inward and opens into a main tracheal tube which extends along
the side of the body. There are commonly two of these main tubes,

or tracheal trunks, on either side of
the body, which give off three main
branches in each segment. The upper
branch goes to the dorsal muscles, the
middle one branches to the alimentary
canal and reproductive organs, and the
lower one supplies the nerve cord and
ventral muscles. These branches divide
and subdivide into the finest tubes,
which penetrate all the tissues, run-
ning between the muscle fibers ; some
authorities state that they may even en-
ter individual cells. They do not end
blindly, but anastomose so as to form
a capillary network, so that a contin-
uous circulation of air is possible. By
opening the spiracles the air enters
the tracheal system, and it is expelled
by muscles which cause a vertical con-
traction of the body walls and thus
force it out. The rhythmic expansion
and contraction of the body occurs at
a regular rate, dependent upon the
temperature and the activity of the insect, and resembles the
breathing of higher animals. Many insects are provided with
large air sacs which serve as air reservoirs. The trachea are
readily recognized by their striated appearance, which is due to
a thickening of the cuticle into a thread, which lies on the inner
surface in a compact spiral, like a compressed spiral spring, and
thus prevents the collapse of the tubes.

Fig. 39. Diagram of tracheal
system in body of a beetle

j/, spiracles ; /;•, trachea. (After
Kolbe)

ANATOMY OF INSECTS — INTERNAL

35

In aquatic insects various respiratory devices have been developed.
Many of them (May-fly, dragon-fly, stone-fly, and mosquito nymphs)
bear tracheal gills which consist of a leaflike expansion, or a tuft of
thin filaments, into which the trachea extend and divide into a fine
network. The oxygen of the water passes through the gill mem-
brane into the air of the trachea, and thus the air of the tracheal
system is purified. No true gills, — that is, gills carrying blood
vessels, like those of fishes, — are found in insects. Other aquatic
insects carry a thin film of air with them, either by means of a
thick coating of fine hairs to which air bubbles
adhere, or beneath the wing-covers. The trachea
are sometimes prolonged into tubes which pro-
ject beyond the tip of the abdomen and extend
to the surface of the water or mud in which
these insects live.

From the above description it is evident that
insects possess the best-developed type of respir-
atory system, _ extending as it does to all the
tissues of the body, giving them a constant
supply of fresh air and carrying off the waste
gases. \\'ith an ample food supply this makes
possible a rapid oxidation of the tissues, and
undoubtedly is one of the chief reasons for the
wonderful muscular activity, working power, and
endurance of insects.

The structure of the respiratory system is of great practical im-
portance in combating insect pests. Many insects which cannot
be destroyed with arsenical poisons are killed by contact insecti-
cides in either a spray or a dust form. These contact insecticides
destroy the insect by entering or clogging the spiracles or trachea.
Oils are particularly valuable because they spread and pass readily
through the hairs which guard the spiracles. Soap solutions leave a
gummy deposit, when the water evaporates, which clogs the trachea.
Finely divided dusts, such as fine tobacco dust, pyrethrum, and
even air-slaked lime or road dust, will clog the spiracles of many
insects. Insects living in grain, stored products, and other inac-
cessible places are often destroyed by the use of poisonous gases,
such as carbon bisulphide and hydrocyanic acid gas, which quickly

Fig. 40. Diagram

of trachea in head

of cockroach

/, trachea, or air tubes.
Note branches to all
the mouth-parts and
the antennas. (After
Miall and Denny)

36

ELEMENTARY ENTOMOLOGY

asphyxiate them through the well-developed tracheal system, though
occasionally the valves of the spiracles are so well developed that
an insect may keep them closed for a long time, so that fumiga-
tion, in order to be fatal, must be prolonged.

Muscular system. Insects are well provided with powerful mus-
cles, a caterpillar having some two thousand. The muscles are
yellowish in color, and the fibers are striated as in the voluntary
muscles of vertebrates. The simplest type of muscles is found in
larvae and in the abdominal segments of adult insects, where the

adc

abc

Fig. 41. Muscles of cockroach, of ventral, dorsal, and lateral walls, respectively

«, alary muscle : abc, abductor of coxa ; adc, adductor of coxa ; h, longitudinal sternal ; //,

longitudinal tergal ; ////, longitudinal thoracic ; os, oblique sternal ; ts, tergo-sternal ; ts^,

first tergo-sternal. (After Miall and Denny)

muscles of each segment are very similar, forming segmented
bands on the inside of the body wall. The longitudinal muscles
beneath the tergum and above the sternum are arranged so that,
when they contract, the body bends in that direction, and by their
rhythmic contraction the looping walk of the caterpillar is produced.
Oblique-sternal muscles bend the abdomen laterally, and vertical
muscles draw the tergum and sternum together in expiration. The
thorax of adult insects is filled with the strong muscles which
operate the wings and legs, and the muscles which operate the
mouth-parts occupy the back of the head.

ANATOMY OF INSECTS — INTERNAL

;7

The work performed by the muscles of insects appears prodigious
compared with that done by higher animals. Thus the weakest
insect can pull over twenty times its weight. A house-fly can
carry a match, to equal which a man would need to carry a timber
thirty-five feet long and as large around as his body. An earwig can
lift twelve times its weight, and a honey-bee, in flight, carries four
fifths of its weight. A small insect is relatively stronger than a large
one, and the relative strength of insects is largely accounted for by
their small size. This is due to the fact that the weight increases as
the cube of a single
dimension, while the
strength of a muscle
increases as the square
of its diameter. The
endurance and rapidity
of muscular action of
insects is no less mar-
velous. By determin-
ing the pitch of the
note made by the wing
vibrations of a gnat,
physicists have shown
that its wings may move
as much as fifteen thou-
sand times per minute.
The prolonged vibra-
tion of the honey-bee's
wings is another instance of remarkable muscular endurance.

Nervous system. The nervous system consists of a series of
small white ganglia which are connected by a double nerve cord
lying along the bottom of the body cavity. In the larvae there is
usually one ganglion to each segment, but in the adult insects
the ganglia are often fused together, those of the thorax and an-
terior abdominal segments having grown together, as well as those
toward the tip of the abdomen. In the head the ganglia have
grown together to form the brain, which lies just above the esoph-
agus and which is connected with the subesophageal ganglion by
a double nerve cord, one commissure of which passes on either side

Fig. 42. Nervous system of honey-bee, at a, and

of its larva, at h, showing the simple type of the

larva and the specialization in the adult due to

fusion of the ganglia

38

ELEMENTARY ENTOMOLOGY

of the esophagus, thus forming a nerve collar. The brain gives
off nerves to the eyes, antennae, palpi, and other sensory organs
of the head, receiving the sensory stimuli and controlling the coor-
dinated muscular movements. In a general way the brain is the
seat of whatever "' will " an insect may have. The subesophageal
ganglion coordinates the movements of the mouth-parts, as well
as some bodily movements. The thoracic and abdominal ganglia
give off nerves to all parts of their segments, the movements of
which they control. They are more or less independent, each

Fig. 43. Nervous system of head of cockroach

a, antenna! nerve ; ag, anterior lateral ganglion of sympathetic system ; /', brain ; d, salivary
duct ; /, frontal ganglion ; h, hypopharj'nx ; /, labrum ; //, labium ; ;«, mandibular nerve ; mx,
maxillary nerve ; «/, nerve to labrum ; «//, nerve to labium ; 0, optic nerve ; oc, esophageal
commissure ; oe, esophagus ; pg, posterior lateral ganglion of sympathetic system ; ;-,
recurrent nerve of sympathetic system ; s, subesophageal ganglion. (After Hofer, from

Folsom)

forming a nerve center for its segment. Thus a decapitated
insect will walk or fl)', and the abdomen of a grasshopper will
continue to breathe, these functions being controlled by the seg-
mental ganglia, though lacking coordination. In addition to the
main nervous system there is a sympathetic system, one part of
which runs along the upper part of the alimentary canal and con-
trols the digestive process, while a small ventral sympathetic nerve
gives off branches which control the spiracle muscles.

Dr. J. B. Smith, in his "" Economic Entomology," gives an
interesting account of some experiments which show the relation
of the brain and ganglia to the body :

ANATOMY OF INSECTS — INTERNAL

I found that if I cut off the abdomen completely, the fly would live for
twenty-four hours thereafter ; with practically no digestive system, and with
most of its heart gone. Turning the matter, 1 cut off the head, and found that
it would live without a head for just about as long a time as it would without
an abdomen. Of course death was bound to result from this mutilation in
time, but the interesting feature is that no apparent symptom of pain developed.
I found, however, that just as soon as I cut the large ganglion in the middle
of the thorax I terminated life. Whatever sentimental feeling there may be
in the matter of causing unnecessary pain, there is no reason to believe that
insects have any well-developed sensitiveness, as we understand that term.
The character of the insect nervous system is so entirely different from that
of our own that we are left without real guides in our interpretation of the
various sensitive structures. Man judges most things by himself, and where
this guide fails, he is at a loss and cannot be certain that he interprets what he
sees correctly.

The senses of insects. Sight. Attention has already been called
to the simple eyes, or ocelli, and the compound eyes. An ocellus
consists of a lens, vitreous
body, retina, and nerve, much
like the eye of vertebrates,
but its form is fixed, and as
there is therefore no power of
accommodation to the distance
between it and the object seen,
its power of vision must be
extremely limited. As far as
the ocelli are concerned, in-
sects must be very nearsighted,
for they are quite convex and
will only focus at one distance,
which must be short. Ex-
periments have shown that
light and darkness are distin-
guished by the ocelli, for if the
compound eyes of a grasshop-
per are covered with varnish,
it can find its way out of a box
with a single opening. Prob-
ably the ocelli are of more service in this way than in forming
definite images, though insect larvae possess only ocelli.

Fig. 44. Structure of median ocellus of
honey-bee, in sagittal section

/;, hypodermis ; /, lens ; «, nerve : /, iris pig-
ment ; ;-, retinal cells ; v, vitreous body. (After
Redikorzew, from Folsom)

40

ELEMENTARY ENTOMOLOGY

I <-.

The surface of the compound eye is composed of numerous

hexagonal facets, each of which is the end of a single eye element

called an ommatidium, which is prac-
tically a separate and distinct eye.
Each ommatidium is composed of the
various optical elements necessary for
vision, but it receives impressions only
in a straight line, which form only a
very small part of the total field of the
insect's vision. This is due to the fact
that each ommatidium is surrounded
by black pigmented cells, which ab-
sorb or reflect the light, as shown in
Fig, 46, so that only those rays which
come in a straight line impress the
retina. Thus the whole view formed
by the images from all the ommatidia
as they reach the optic nerve must be
like that of a mosaic.

Insects are able to distinguish forms
at but relatively short distances, vary-
ing from two to five feet, and to

see distinctly only near-by objects.

Large eyes, as those of the dragon-
fly, give a wide field of vision,

and numerous facets would give a

greater distinctness of vision. In-
sects' eyes are well adapted to

detect motion, as a moving object

affects the facets in succession, and

motion is thus observed without

moving the eyes. They are able

to distinguish colors and often

respond quite definitely to them,

but their color sense seems to

have a different range from that

of man, as ants are sensible to the

ultra-violet rays.

Fig. 45. Portion of compound

eye of fly (Calliphora vomitoria),

radial section

c, cornea ; /', iris pigment ; n, nerve
fibers ; >ic, nerve cells ; r, retinal pig-
ment; /, trachea. (After Hickson,
from Folsom)

Y\G. 46. rilustrating mode of vision
in compound eye

" The light enters through the cornea.
The rays which strike the sides of each
tube or cone are absorbed by the black
pigment which surrounds the tube. Ac-
cordingly those rays of light only which
pass through the crystalline cones directly
(or are reflected from their sides), such
as a-a' , b-b' , c-c' , d-d' , e-e' , will ever affect
the nerves at a', b', c', d\ c'." (After
Lubbock, from S. J. Hunter)

ANATOMY OF INSECTS — INTERNAL

41

Touch. The sense of touch is very highly developed in many
insects, sensory tactile hairs commonly occurring over the whole
body, and the antennae, palpi, and
cerci being specially developed as
tactile organs.

Taste. Both observation and
experiment have shown that in-
sects have a well-developed sense
of taste, though it is often quite
different from that of man, as
they detect some substances but
fail to perceive others, and often
seem to relish substances wholly
repugnant to us. The sense of
taste is located in sensory hairs or microscopic pegs borne upon
the tongue (see Fig. 47), or hypopharynx, on the epipharynx (a

Fig. 47. Tip of tongue of honey-bee

Showing labellum (LM), guard hairs (//r),

and ventral groove {A), from above and

below. (After Snodgrass, United States

Department of Agriculture)

Fig. 48. Nerve gndings in tip of maxillary palpus of (a) Loctista viridissima,
and in labial palpus of {h) Alachilis polypoda. (Greatly magnified)

sh, sense hairs ; sc, sense cells ; be, blood cells. (After \'om Rath, from Kellogg)

sensory portion of the roof of the pharynx similar to the palate of
higher animals), and on the maxillary and labial palpi. Probably the
sense of smell is used more than the taste organs in choosing food.

42

ELEMENTARY ENTOMOLOGY

Fig. 49. Sensory cells

in antennas of aphides.

(Greatly magnified)

Smell. Most insects depend upon their sense of smell to find
their food and to discover the opposite sex. Thus beetles and flies
are drawn to carrion and to decaying vegetation,
and in almost all cases it seems probable that
the food plant of an insect is distinguished by
smell rather than by sight. A confined female
Cecropia moth will often draw numerous males
from a considerable distance. Experiments
have shown that the antennae are the chief
organs of smell, though the maxillary palpi
and cerci detect certain
odors and enable certain
insects to smell when the
antennae are removed.
The olfactory function
of the antennas can be
very easily shown by taking an insect which
is definitely attracted to some substance by
smell and removing the antennas or covering
them with shellac, when
it will be found wholly
indifferent to what was
previously so attractive.
Vile-smelling substances
which are supposed to
repel insects are usually
of no value, not affect-
ing the insect as they do

man. Some attempts have been made to utilize
the sense of smell in luring insects to destruc-
tion, but as yet with no very marked success,
though there is promise of possible control of
some pests in this way.

Hearing. There is no evidence that hearing

is generally developed in insects, but in many

groups we naturally infer its presence from the

fact that characteristic noises are produced, as the "singing" of

the cicada and katydid. These noises are produced in various

Fig. 50. Antenna of la-
mellicorn beetle

Showing smelling pits on the
expanded terminal segments.
(.\fter Jordan and Kellogg)

Fig. 51.
face of

Under sur-
right wing
of the male cricket.
(Enlarged)

7, rasp ; 2, position of
scraper, only scraper of
the left wing used; j,
attachment of wing. (Af-
ter Linville and Kelly)

ANATOMY OF INSECTS — INTERNAL

43

ways. Thus flies and bees buzz with their wings in rapid vibra-
tion, and the singing of the male cieada is produced by the rapid
vibration of a pair of membranes on the first abdominal segment.
Many beetles squeak by rubbing the wing-covers against some rasp-
like part of the body. But the grasshoppers and crickets are the
leaders in the insect orchestra. Grasshoppers often produce noises
in flying by rubbing

the wmg-covers or
by rubbing together
the front and hind
wings. Katydids
and crickets have
the best-developed
musical apparatus,
having a scraper
on the base of one
wing-cover and a
vein ridged like a
file on the base of
the other, which,
when rubbed to-
gether, vibrate the
neighboring mem-
brane and produce
the strident song,
or the shrill chirp,
so characteristic of
these insects.

That these sounds are heard by their mates is shown by the
answering call of one to another, and to similar tones produced
artificially. In grasshoppers a large auditory organ, or " ear," is
found on either side of the first abdominal segment. It consists of
a surface membrane, or tympanum, stretched over a* cavity, on the
inner surface of which rest two processes, analogous to the small
bones of the human ear, which carry the vibration to a delicate
vesicle which connects with an auditory nerve. Similar small
membranes are found on the fore-tibia of certain insects and are

Fig. 52.

Ear of locust {Calopteinis italictis) seen from
the inner side

Ty tympanum : TK^ its border : 0, 11, two bonelike processes ;
/'/', pear-shaped vesicle ; n, auditory nerve ; ^^'^(7, terminal gan-
glion ; sf, stigma, or spiracle ; ;//, opening muscle, and ;«l,
closing muscle of same ; .1/, tensor muscle of the tympanic
membrane. (After Ciraber)

44

ELEMENTARY ENTOMOLOGY

considered probably auditor)'. In male mosquitoes, and probably in
some other forms, the antennae have an auditory function which
enables them to find the females, as is shown by their vibrating in
unison with a tone produced by a tuning fork of the same pitch
as that made by the female with her wings.

Fig. 53. ^I^male mosquito

Showing auditory hairs {a/i) on the
antennae. (After Jordan and Kellogg)

Fig. 54. Diagram of longitudinal section
through first and second antennal segments
of a mosquito {]\Iochlo7tyx atlicifomiis), male,
showing complex auditory organ composed
of fine, chitinous rods, nerve fibers, and nerve
cells. (Greatly magnified)

(After Child, from Kellogg)

CHAPTER V '
THE GROWTH AND TRANSFORMATIONS OF INSECTS

Stories of the lives of insects, or their " hfe histories," are
among the most interesting and marvelous to be found in the
realm of science, furnishing themes for poet, philosopher, and
scientist. c-<^ ^

Egg. AH begin life in the egg stage. The shape, size, number,
and position of the eggs are as different as are the many families
of insects, and cannot be described in general terms. Usually they

m n o p q r s

Fig. 55. Eggs of different insects. (Enlarged)

a, Toi-trix ; b, Liparis ; c, a Noctuid ; d, usual shape of those of a bark borer ; e. May-beetle
(Lachnosternd) ; f, midge (Chironomus) ; g^ Lyda; Ii, fly {Miisca) ; /, honey-bee ; /', gall-fly
{Rkodites rosac) ; /, lace-winged fly (Cluysopd) ; ?«, pomace-fly {Drosophild) ; ;;, Pentatoma :
0, back-swimmer (JVepn) ; p, butterfly {Pieris crataegi) ; </, bedbug ; ;-, louse, fastened to a
hair; y, bot-fly {Hypodenna). (After Judeich and Nitsche, from Packard)

are laid upon the food plant, or host, but occasionally their position
could not be accounted for were the habits of the young not known.
The number laid by a female may vary from one or two, as in the
case of some aphides, to many thousands, as in bees and termites,
but a fair average would probably be about one hundred. The size
varies inversely with the number produced, and the shape and struc-
ture are largely influenced by the environment in which the eggs are
laid. In a few cases the eggs hatch within the body of the female,
which thus gives birth to live young, as do the aphides. Those
eggs which hatch during the summer have an incubation period of
from a day or two, as do those of certain flies and mosquitoes, to

45

46

ELEMENTARY ENTOMOLOGY

three or four weeks, while very many remain dormant over winter
and hatch when sufficient temperature occurs the next spring or
summer.

Transformations. Upon hatching from the egg the young grass-
hopper is of much the same general appearance as when full grown,
and is readily recognized as a grasshopper ; but if we did not

Fig. 56. Molting of the full-grown nymph of the periodical cicada, showing process
of emerging from the skin of the nymph, with the soft white adults below

The adults become black after hardening for -a few hours

know that the little caterpillar, after completing its growth, finally
transforms into a butterfly, we should never suspect them to be
different stages of the same insect, and a lack of knowledge of
these transformations has caused many strange superstitions con-
cerning insects.

The tra:nsformation of the butterfly from the caterpillar is a
-^eeufiste one, and is known as yLirerfflijffi/irfe inctamorpJiosis. The

GROWTH AND TRANSFORMATIONS OF INSECTS

47

growth of the grasshopper, on the other hand, is gradual and
presents no striking changes, and is known as ^it^4no«mpt€te
metamorphosis.

Growth. The hard, chitinous skin which serves the insect as
an outer skeleton has already been described, and furnishes an obvi-
ous obstacle to its rapid growth. When the insect has grown to

the limit of this outer
shell, its predicament
is solved in the only
possible way, by the
skin splitting down the
middle of the back
and being sloughed
off, while the new skin
formed beneath the
old one allows further

Fig. 57. Nymph of lubber grasshopper (Z?.V/y.//...^ ^^^^^j^_ This proCeSS,
reticulata) ; similar to the adult (rig. 105) in general ° .

form, except in lacking wings called molting, OCCUrs

in all insects, as well
as among other Arthropods, the skin being usually shed some
four or five times during growth, though some species molt from
ten to twenty times.

T Incomplete metamorphosis. Young insects which resemble the
adults, as those of the grasshopper, are termed nymphs. After the sec-
ond or third molt, small wing
pads appear on the back,
becoming much larger with
the fourth molt, and upon
the fifth molt the adult
winged insect emerges, to

Fig. 58. A typical larva, the cotton bollworm

or corn-ear worm ; totall)- unlike the adult

moth in form

feed and reproduce.
^•^^empiete metamorphosis. The caterpillar, maggot, or grub bear-
ing no resemblance to its parents is called a larva. The larva
grows and molts several times, and although its new clothes are
sometimes of a different color, they are all cut on the same pattern,
and there is usually no marked change in shape or structure until
the larva is full grown. Upon reaching its growth the larva molts for
the last time and transforms into a pupa. The pupa is a dormant

48

ELEMENTARY ENTOMOLOGY

Fig. 59. Cocoon of the rusty tussock moth, made of silk
with the hairs of the caterpillar intermingled. (Enlarged)

Stage, usually inactive and taking no food, resembling neither larva

nor adult, in which the tissues and organs of the larva are re-
constructed into
those necessary
for the winged
adult. In many
pupae the wings
and legs of the
adult are clearly
distinguishable,
closely folded
to the sides of
body, but in the
others the outer
skin of the pupa

is only a firm shell with bare outlines of the adult forming within.

Before the last molt many larvae burrow into the ground, where

they hollow out cells, sometimes

lined with silk or cement, or find

other suitable secluded places

in which to pupate. The cater-
pillars of moths and many other

larvae spin a firm casing of silk,

called a cocoon, in which they

pupate. Butterfly caterpillars lash

themselves to the food plant by

one or two thick strands of silk,

and the pupa, which is known

as a chrysalis, hangs suspended

by the tip of the abdomen with

no cocoon. In many cases in-
sects hibernate over winter in

the pupal stage, so that the time

of the pupal life varies from a

few days in summer to nine or

ten months, according to the

habit of the species. Finally, tt,^ ^ r- t ^- ..u .

f^ -' ' i" IG. 60. L ocoons of tiger moth cater-

the pupal shell splits open and pillars on underside of loose bark

GROWTH AND TRANSFORMATIONS OF INSECTS

49

the adult insect emerges, with wings soft and Hmp but expand-
ing and hardening in a few hours, when it is ready to seek food
and a mate.

Thus the stages of growth of those insects having a complete
metamorphosis are essentially different from those having the in-
complete type, as indicated in the following summary :

jj,^!.,.^^:^/ t-i»eomplGtc metamorphosis : Egg, Nymph, Adult.

^' -^

metamorphosis : Egg, Larva, Pupa, Adult.

An insect never grows after it reaches the adult stage. The
little files which appear on the window in early spring are not
"baby" flies and do not grow larger, but are entirely different
from other larger species
which supersede them
later in the season.

The life histories of
insects are as diverse as
are the species, no two
being quite alike. To
study and carefully deter-
mine the time, place,
and manner of the trans-
formations is one of the
most important duties
of the economic ento-
mologist, for by ascer-
taining them the means
of control of injurious
species are often dis-
covered. Many insects
may thus be controlled
by simply changing gen-
eral farm methods, such
as the rotation of crops,
the time of plowing, etc., which result in the prevention or miti-
gation of the pest ; or a knowledge of the feeding habits may indi-
cate the most promising means of attack, and successful methods
may be determined by subsequent experiments.

% %h.

if

■»^--^^-.

'

^. f

y%

^H

f \\' '\^

\:...IP^^^^

Vf

Fig. 6i. Chrysalis of black swallow-tailed butterfly

( Pap ilio polyxen es )

Showing attachment of tip of abdomen to mass of silk

threads which have become torn from around the

stem, and the silken loop which supports the thorax.

(Photograph by Weed)

50

ELEMENTARY ENTOMOLOGY

A better appreciation of these general facts concerning insects'
growth will be secured by a more intimate study of the life of one
or two of each of the types of metamorphosis.

The life of a squash-bug (Anasa tristis). Ifieemplete metamor-
phosis. About the time that squash, cucumbers, and melon vines
begin to " run," there is found here and there a wilted leaf, which
examination shows to be due to the common grayish- or brownish-
black squash-bug which has just emerged from hibernation. If
search be made in the early morning, the bugs will usually be

found secreted under
clods of earth, or what-
ever rubbish may be
near the vines, from
which they emerge to
feed during the day,
flying about with a
characteristic buzz.

£^£: For the next
month or six weeks the
females deposit their
eggs, mostly on the un-
dersides of the leaves.
The eggs are oval,
about one sixteenth
inch long, attached on
one side, and laid in
irregular-shaped clus-

FiG. 62. The squash-bug, adult and nymphs of first,
third, and fifth stages. (About twice natural size)

(Photograph by Quaintance)

ters arranged in rows as shown in Fig. 63, from three or four to
forty eggs being found in a cluster. Newly laid eggs are a pale
yellow-brown, which grows darker a day or two before hatching,
so that the approximate development may be determined by the
color, which is the case with many insects' eggs.

NympJi. In about eleven days, the exact time varying from six
to fifteen days according to the temperature, a small, disk-shaped
piece of the shell is forced open toward one end of the ^gg and
the little nymph emerges. The newborn buglet is brilliantly col-
ored and is quite conspicuous against the green leaves, the antennae
and legs being a bright crimson, the head and anterior thorax a

GROWTH AND TRANSFORMATIONS OF INSECTS 51

Fig. 63. Egg masses of squash-bug. (Twice natural size
(Photograph by K. I. Smith)

lighter crimson, and the posterior thorax and abdomen a bright

green ; but in an hour the crimson darkens, and in a few hours

changes to a jet-
black. The young
bugs hatching from
a cluster of eggs
remain together in
a sort of family dur-
ing their infancy,
each inserting its
tiny beak in the
succulent leaf from
which it vigorously
sucks the juice. In
about three days
the abdomen be-
comes distended, in-
dicating the need of a larger suit of clothes to allow further

growth. The nymph now assumes a quiet position, the skin splits

down the middle of the back

along the thorax and anterior

abdomen, and gradually the little

bug pulls itself out of its baby

clothes, the time required for

this change of costume vary-
ing from a half-hour to several

hours. A few hours later the

skin, now much lighter in color,

has hardened, and the insect is

about one fifth inch long. The

nymph now becomes more active

and alert and continues to feed

some nine days before molting

again. In the third stage it is

considerably larger and flatter,

and darker in color. Eight days

later the third molt takes place, and the new clothes of the fourth

stage differ in having small but distinct wing pads extending back

Fig. 64. Squash-bug

a, mature female ; /', side view of head, show-
ing beak ; c, abdominal segments of male ;
d, same of female, {a, twice natural size ;
l>,c,d, more enlarged.) (After Chittenden,
United States Department of Agriculture)

(

Fig. 65. Squash-bugs and nymphs at work on a young plant. (Natural size)

52

GROWTH AND TRANSFORMATIONS OF INSECTS 53

from the thorax. In another week the skin is shed for a fourth
time, and the fifth stage is easily recognized as a full-grown nymph,

being one third inch long, and
the wing pads and thorax
being much enlarged. After
feeding for another nine days
it molts for the last time and
transforms to the winged adult,
the whole growth having re-
quired from four to five weeks.
Adult. The new adults be-
come numerous in August, but
neither mate nor lay any eggs
during that season, continuing
to feed until the first frosts of
autumn blacken the leaves,
when they rapidly disappear
into winter quarters.^ During
the middle of the day they fly
here and there in search of
suitable hibernating places, and
finally hide along the edges of
woodlands, or beneath leaves,
under logs, boards, or whatever
shelter may be adjacent to the garden, where they remain dormant
until called back to activity by the warm sunshine of late spring.
Life history of the differential locust (Melanoplus differentialis).
IjM^^ttj^ete metamorphosis. Through-
out the Mississippi Valley, from Illi-
nois southward, the differential locust
is one of the most common and de-
structive grasshoppers, and is an excel-
lent example of several of our more
abundant and injurious species whose
life histories and feeding habits are, in general, ver}' similar.

Fig. 66. First three stages of the nymphs
of the differential locust. (Much enlarged)

Fig. 67. Egg mass of the
differential locust

1 The life history as given is for New England ; farther south the transforma-
tions take place earlier and more rapidly, and in the extreme south there may be
more than one generation.

54

ELEMENTARY ENTOMOLOGY

XympJts. The little grasshoppers hatch about the middle of May
(though we have observed hatching by the middle of March in
central Texas) and are of a dusky brown color marked with yellow.
The head and legs are the most prominent features of the young
nymph. During their subsequent growth they molt five times, at
inten^als of from ten days to two weeks, the relative size and appear-
ance of the different stages being shown in Fig. 6^ . Professor
H. A. Morgan, who made a careful study of an outbreak of this

species in Mississippi in
1900, has given an inter-
esting account of their
growth and habits, from
which the following is
quoted :

Growth. The young on first
emerging from the eggs are
sordid white and after an airing
of an hour or two are darker,
assuming a color not unHke the
dark gray alluvial soil over
which they feed. There are
changes of color as the earlier
stages are assumed, but until
the close of the third stage these
changes are not readily percep-
tible in the field to the naked eye.
At the close of stage four the
greenish-yellow color becomes
prominent on many forms, and
in stage five the greenish-yellow and yellow ground colors predominate. The
vigorous feeding and rapid growth of the young in stages four and five, and
the prominence of the wing pads in stage five, cause the grasshoppers in
these conditions to appear almost as conspicuous as adults.

Habits. The habits of the young are interesting, and a knowledge of some
of them may be helpful in developing remedies. After hatching they remain
for several hours in close proximity to the egg pod from which they emerged.
With this period of faint-heartedness over they may venture out for a few yards
each day into the grass, weeds, or crop neighboring the egg area. Upon being
disturbed they invariably make the effort to hop in the direction of their so-
called nest. Nymphs emerging from eggs on a ditch bank, if forced into the
water will seldom make the effort to reach the other side, but w-ill turn back to
the bank from which they were driven. As development takes place the extent

P'iG. 68. Last two stages of nymphs of differ-
ential locust. (Enlarged)

CrROWTH AND TRANSFORMATIONS OK INSECTS

55

of their peregrinations into the crop is easily traced by the shot-hole appearance
of the leaves upon which they feed. The tender leaves of cocklebur are
always preferred by the grasshoppers in the early stages. Young Bermuda grass
is also a favorite food, and succulent grasses of all kinds are freely eaten. In
the third, fourth, and fifth stages, as grass, weeds, and even shrubs disappear
along the ditch banks and bayous, the crops of corn and cotton adjacent
begin to show signs of vigorous
attack, and the march of destruc-
tion commences. ... A few hours
before molting the grasshoppers
tend to congregate and become
sluggish. Molting varies as to
time, and slightly as to manner,
with different stages. In the early
stages less time is required, and
the operation occurs on the ground
or upon low bunches of grass and
weeds. Every effort of the grass-
hoppers at this time seems to be
to avoid conspicuity, and in doing
so spare themselves, in a man-
ner, enmity of parasites. After the
molting of the first, second, and
third stages it is not long before
the young grasshoppers are suf-
ficiently hardened to begin feed-
ing again, but after the molt of the
fourth and fifth stages, particularly
the last molt, some time is required
to extend the wings and dry and
harden the body before feeding is
reassumed. The last molt usually
occurs on the upper and well-
exposed leaves of corn and other
plants upon which they may be
feeding, though it is not uncom-
mon for the grasshoppers to drop
to the ground during the maneu-
vers of the process. The reason for the selection of the more exposed places
for the last molt is obvious. The bodies are large, and rapid drying protects
them from fungous diseases which lurk in the more shaded and moist sections
during the months of June and July. The last prominent habit to which we
call attention is that of the fully grown grasshoppers to seek the shade offered
by the growing plants during the hottest part of the day.

Fk;. 69. Nymph of last stage of differential
locust with cast skin, on tip of corn plant

(Authors' illustration, United States Department
of Agriculture)

56

ELEMENTARY ENTOMOLOGY

Adults. The hoppers become full grown about the first of July.
The adult is about one and one half inches long, its wings expand
two and one half inches, and it is of a bright yellowish-green color.

Fig. 70. The differential locust. (Enlarged)
(Authors' illustration, United States Department of Agriculture)

The head and thorax are olive-brown, and the fore-wings are of
much the same color, without other markings than a brownish
shade at the base ; the hind-wings are tinged with green ; the

hind thighs are bright
yellow, especially below,
with four black marks;
the hind shanks are yel-
low with black spines
and a ring of the same
color near the base. The
adults at once attack any
crops available, often
finishing the destruc-
tion of those injured
by them as nymphs, but
in a few days their ap-
petites seem to become
somewhat appeased and
they commence to mate
and to wander in search
of suitable places for
laying the eggs.

Egg laying. Rela-
tively few eggs are laid in cultivated ground, the favorite places
being neglected fields grown up in grass and weeds, the edges of

Fig. 71. Grasshopper ovipositing in a stump
(Photograph by Weed)

GROWTH AND TRANSFORMATIONS OF INSECTS 57

cultivated fields, private roadways, banks of ditches and small
streams, and pasture lands. Alfalfa land is a favorite place for

oviposition, and alfalfa is often seriously
injured by this species. It is doubtless
due to these egg-laying habits, and to
the abundance of food on uncultivated
land, that this species always increases
enormously on land which has been
flooded and then lies idle for a year or
two. Most of the eggs are laid in Au-
gust and early September, Each female
deposits a single egg mass of about one
hundred eggs just beneath the surface
of the soil. During this season the fe-
males may frequently be found with their
abdomens thrust deep in the soil, as the
process of egg laying requires some time.
The eggs are
arranged in an
irregular yel-
low mass which
is coated with
Fig. 72. Egg mass of the ^ aluey Sub-
Stance, to which
the earth ad-
heres and which protects them from
changes of moisture and temperature.
Life history of the tent caterpillar
{Malacosoma americand). fi^mplet©' meta-
morphosis. With the bursting of the leaf
buds in early spring the tips of the
branches of apple and wild cherry trees
are festooned by the small, tentlike webs
of the tent caterpillar. Usually the web is
formed on a small crotch, which gives it
the tent shape, and farther out on the twig
will be found the egg mass from which

72. Egg mass of the
tent caterpillar

(Photograph by Weed)

Fig. 73. Web of young tent

caterpillars over the egg mass

(Photograph by Weed)

the little caterpillars hatched, just before the leaf buds opened.

58

ELEMENTARY ENTOMOLOGY

The egg mass is from one half to three fourths of an inch long
and forms a grayish-brown, knotlike band around the twig, closely
resembling the bark in color. Each mass contains from one hun-
dred fifty to two hundred fifty eggs, placed on end, packed closely
together, and covered with a layer of light brown, frothy glue, which
gives a tough, smooth, glistening surface to the whole mass. The
eggs are deposited by the female moths by early midsummer ;

when fresh the egg mass is
white, but in a few days the
color darkens.

Larva, or eaterpillar. Dur-
ing late summer the little cater-
pillars are formed within the
eggs, but do not hatch until
the next spring. Often they
emerge before the leaf buds
have expanded sufficiently to
furnish any food, in which case
they satisfy their appetites with
the glutinous covering of the
egg mass, spinning over it a
thin web. Soon they are able
to bore into the swollen buds,
when a web is commenced at
the nearest crotch. Wild cherry
and apple, which are often
stripped of their foliage year
after year, are the favorite foods,
but all the common fruit trees
are more or less frequented, and sometimes the common shade trees
are attacked and occasionally one is defoliated. The family instinct
is very strong with the young caterpillars and all from one egg mass
cooperate in spinning the tent which furnishes them shelter at night
and during cold or wet weather. The tent is gradually enlarged by
new layers of silk, which cover the masses of excreta in the lower
layers, the caterpillars living between the outer layers. They com-
mence feeding soon after sunrise, but often retire to the nest during
the heat of the day, and always seek its shelter during cold days or

Fiu. 74.

Partly formed web of the tent
caterpillar

(Photograph by Weed)

GROWTH AND TRANSFORMATIONS OF INSECTS 59

Fig. 75. Tent caterpillars about half grown
on web

(Photograph by Weed)

when the sky 'becomes clouded
and rain threatens. While
young they feed together, each
little caterpillar spinning a fine
strand of silk wherever it goes,
which forms a sort of trail for
the others. They become full
grown in six or seven weeks,
during which time they have
molted some four or, excep-
tionally, five times, at intervals
of eight or nine days, though
the length of time between
molts varies widely according
to the food supply and weather
conditions. After the fourth
molt the fifth stage occupies
about two weeks before the
caterpillar transforms to the
pupa. When full grown they
become extremely restless, wan-

der away from the nest, and are frequently encountered on walks
and roadsides,
and feed on al-
most any plant
found. They
are now about
two inches in
length, deep
black in color,
thinly covered
with yellowish
hairs, with a
white stripe
down the mid-
dle of the back.

At the middle Fig. 76. Full-grown tent caterpillars on web. (Reduced)
of the side of (Photograph by Weed)

d^ ^^^

7 «ii^

fc*,a^^^

l^^^v.— _

t •iJ^KlBi^HBd^^BHBB

■UB^^KIIiKmi<II^B!lto!<&9P4^^^!9|

*'* s^^BB^SBkBsI^^

ui^^^^^l^^^^^^^

^sgHpHH^SH

RS% '- ^^, ^^Q^K^^dr^^x^^B^SS

WW^

6o

ELEMENTARY ENTOMOLOGY

each segment is an oval, pale blue spot with a broader, velvety black
spot adjoining it in front, giving somewhat the effect of an eyespot.
Cocoon and pupa. Having found a suitable place under loose
bark, in a fence, in the grass or rubbish beneath the tree, or in the
shelter of some neighboring building, the caterpillar settles down
and proceeds to encase itself in a thin cocoon of tough white

silk. In forming the cocoon
the caterpillar rolls its head
from side to side, the silk being
drawn out from the lower lip
and hardening as soon as it
comes into contact with the
air. With wonderful contor-
tions it gradually shapes the
oval cocoon, the outer part of
which is composed of coarse,
loose white threads, with a
yellowish powder intermixed,
while the inner layer forms a
tougher, parchmentlike lining.
Frequently, when the caterpil-
lars are abundant and there is
desirable shelter near the nest,
several cocoons are formed en
masse.

Exhausted by its labors, the
caterpillar now becomes quiet,
the body shortens to about an
inch long, and, finally, the skin

Fig. 77. Web of tent caterpillars which
has been riddled by birds. (Reduced)

(Photograph by Weed)

splits down the back, is sloughed off into one end of the cocoon,
and the transformation to a brown, oval object, t\\e ptipa, is accom-
plished. The pupa is about an inch long, and the surface markings
of the solid shell outline the legs and wings of the adult moth, but
otherwise there is no indication of any relationship to the larva or
to the adult, and, had we not seen it emerge from the larval skin,
it would be difficult to believe that it is the same animal.

Moth. In about three weeks the pupal shell splits open and the
adult moth works its way out of one end of the cocoon. Like all moths

GROWTH AND TRANSFORMATIONS OF INSECTS 6 1

the adults are night fl)'ers and are frequently attracted to lights.
They are stout-bodied, of a reddish-brown color, with two nearly

Fig. 78. Tent caterpillar from above and from side. (Slightly enlarged)

parallel white bands extending obliquely across the fore-wings.
The males are much smaller and may be distinguished by the more

Fig. 79. Cocoons of the tent caterpillar. (Natural size)
(After Lowe)

feathery antennae. The sexes soon mate and the females deposit the
eggs, which remain on the twigs over winter, as already described.

Fig. 8o. Female tent caterpillar moth at rest on leaf. (Slightly enlarged)

(After Lowe)

Fig. 8i. Mourning cloak butterfly depositing eggs
(After Weed)

GROWTH AND TRANSFORMATIONS OF INSECTS 63

The life of the spiny elm caterpillar (Euvanessa antiopa). Qam.-..
plet-e- metamorphosis. What boy does not remember, when the first
warm days of sprhig hired him to a tramp in the woods, that a large,
dark purple, yellow-bordered butterfly, usually found sipping the sap
from a newly cut tree stump, was the first to greet him ? It is one
of our commonest butterflies, and we have translated its German
name of Trmiermantcl to "mourning cloak butterfly," though it is
also often known as the Antiopa
butterfly, from its specific name. It
is a most cosmopolitan insect, occur-
ring throughout North America as
far south as Mexico and Florida, and
is found over northern Europe and
in Asia.

Egg laying. Unlike most butter-
flies it hibernates over winter, which
accounts for its early and often some-
what battered appearance in spring.^
When the leaves of the elm and poplar
are nearly expanded, the female may
be found laying her eggs upon the
twigs of elm, poplar, and willow.
Standing with wings spread, she de-
posits the eggs in clusters around the
twig, as shown in Fig. 81, rt-. In about
two weeks the small, blackish cater-
pillars emerge through round holes
eaten out of the upper surface of the
eggs, and crawl to the nearest leaf,
where they range themselves side by

side, with their heads toward the margin of the leaf. Feeding in
this position, they nibble the green surface of the leaf but leave
the network of veins untouched.

Larva, or caterpillar. They continue to feed side by side for
about a week, marching in processions from leaf to leaf as the food
supply is exhausted. Each little caterpillar spins a silken thread

1 We are indebted, for much of the hfe history, to the account given by
Dr. C. M. Weed in Bulletin 67, New Hampshire Agricultural Experiment Station.

Fig. 82. Eggs of the spiny elm

caterpillar, or mourning cloak

butterfly, on willow twig

(Photograph by Weed)

64

ELEMENTARY ENTOMOLOGY

Fig. 83. The spiny elm caterpillar, or mourning cloak

butterfly. (Slightly reduced)

Partly grown caterpillars, chrysalis, empty chrysalis, and adults.

(After Britton)

wherever it goes,
so that the many
threads soon make
a fine silken car-
pet, which serves
as a foothold. At
the end of a week
they molt ; the skin
of each caterpillar
splits down the
back, and it crawls
out with a new and
larger skin, which
has been forming
beneath the old
one. The caterpil-
lars remain quiet
during molting,
but they soon be-
come active again
and feed with in-
creased voracity.
Every week for the
next three weeks
this molting proc-
ess is repeated,
the cast skins
decorating the de-
foliated twigs, as
shown in Fig. 84.
As they grow, the
caterpillars scatter
over the neighbor-
ing leaves, but still
remain in colonies.
Their appetites
seem to increase
as they grow, and

GROWTH AND TRANSFORMATIONS OF INSECTS 65

they eat more of the leaf sub-
stance, devouring all but the
midrib and veins when half
grown, and, when larger, leave
only the midrib. The carpet-
like web which they spin also
becomes more evident as they
grow older, often binding to-
gether the ends of near-by twigs,
especially where the caterpillars
rest after feeding. The full-
grown caterpillar is about two
inches long, with numerous
branched black spines. It is
blackish in color, with a row
of red spots down the back,
and with transverse rows of
minute white spots.

Pupa, or cJirysalis. The
caterpillars are full grown in
about four weeks. Dr. Weed, in his interesting account of this spe-
cies, describes its transformation as follows :

They then leave the tree or shrub on which
they have been feeding, and scatter about, seeking
some sheltered situation. Having found this, —
perhaps beneath a stump or along the underside
of a fence, --= each caterpillar spins a web of silk
along the surface. It then entangles the hooked
claws of its hind legs (anal prolegs) in this silken
web and lets its body hang vertically with the head
end curved upward. It remains in this position
for some hours before the skin along the back just
behind the head splits apart, and is gradually
wriggled upward until it is finally all removed,
and there hangs in place of the caterpillar a
peculiar object having no definite form — that of
the chrysalis}

In this quiet chrvsalis the insect is apparendy ^^°- ^5- Mourning cloak
1 X ■ ^ ' Tr .. 1 -^ •.. butterfly emerging from

almost as niert as a mummv. If you touch it, it -^ , f. '^

•' chrysalis

1 See Fig. 83. (Photograph by Weed)

Fig. 84. Twigs denuded by spiny elm cater-
pillars, bearing their cast skins. (Reduced)

(Photograph by Weed)

66

ELEMENTARY ENTOMOLOGY

will wriggle a little, but otherwise it hangs there mute and helpless. On the
inside, however, the tissues are being made over in such a wonderful way
that in about two weeks, from the mummy case into which the caterpillar
entered, there comes a beautiful butterfly. When it first breaks the mummy
shell its wings are very small, although its body, " feelers," and legs are well
developed. By means of the latter it clings to the empty chrysalis while the wings
expand. A butterfly in this position, with its wings nearly expanded, is shown
in Fig. 86, from a photograph taken from a living specimen. In the course of half

an hour the wings become fully de-
veloped, and the butterfly is likely
to crawl to some firmer support,
where it will rest an hour or so
before venturing on its first flight.

In New Hampshire there
seems to be but a single gen-
eration a year, the newly
emerged butterflies appear-
ing in July or August and dis-
appearing during August and
September, though they are
seen occasionally on warm
days in late fall. Under the
side of a log, beneath the
loose bark of a dead tree, in
woodpiles, and in similar sit-
uations the butterflies are to
be found during the winter
lying flat on the side, sus-
pended under a culvert, or
in a hollow tree. Apparently
they are dead, but if taken
into a warm room, they will
quickly revive and fly about, and if given a little sugar-water for
food, will live for some time. Often in summer they will drop on
one side, motionless, evidently feigning death, and if lying on a
background of dead leaves, are very difficult to see.

Fig. 86. Newly emerged mourning cloak

butterfly hanging to empty chrysalis while

its wings expand and harden

(Photograph by Weed)

PART 11. THE CLASSES OF INSECTS

CHAPTER \T

THE CLASSIFICATION OF INSECTS

Identity of insects. If a crop of potatoes is being destroyed by
the Colorado potato beetle, it is at once recognized as the cause
of the injury, and the method of control is known or may be ascer-
tained from books or bulletins. In many cases, however, insects
are found abundant upon a crop which is evidently being injured,
but the casual observer may not be able to determine just which
are responsible for the injury without devoting more time to the
matter than is available, or without more knowledge of the habits
of insects than he possesses. Thus, when a colony of plant-lice is
found ruining a crop, there are usually found with them various in-
sects which are either preying upon them, as do the ladybird beetles,
aphis-lions, and syrphus-fiy larvae, or caring for them, as do the ants.
No one would consider the ants as producing the aphides, but it is
not at all uncommon for those unacquainted with the life history of
plant-lice to assert that they are produced by the ladybird beetles
or other insects which are found associated with them, w'hich are
consequently destroyed when they should be protected. If the insect
is very evidently the cause of the injury, but of unknown iden-
tity, it is of the utmost importance to identify it, so that its habits
and the best means of control may be ascertained. A knowledge of
the different kinds of insects is thus seen to be not only a matter
of theoretical or biological knowledge, but of considerable practical
importance.

The classification of insects and the manner in which they may
be identified may be illustrated by a study of the ladybird beetles
already mentioned. Upon examining a ladybird beetle, we at once
recognize it as a beetle from the hard wing-covers, with the mem-
branous hind-wings folded beneath them, and the biting mouth-parts,

67

68 ELEMENTARY ENTOMOLOGY

Thus we ascertain that it belongs to one of the several divisions,
called orders, into which all insects are divided, known- as the
order Coleoptera. Some nineteen orders of insects are now recog-
nized by entomologists, but only six or seven are of any economic
importance. Most of the orders are distinguished by the structure
of the wings, and the names of the orders usually end in the syl-
lable//^/vz, irom pteron, meaning "a wing." A brief survey of the
beetles shows that the order Coleoptera consists of numerous fami-
lies, which are grouped together according to the number of seg-
ments in the hind tarsi. An examination of the hind tarsus of a
ladybird beetle reveals that it is composed of but three segments,
which is characteristic of only one family, the Coccinellidae, the
family of the ladybird beetles. A brief account of this family indi-
cates that nearly all of its members are predacious upon plant-
lice or other small insects, and that the more common forms are
small yellow or red beetles with black spots, like the specimen in
hand. It is evident, therefore, that our ladybird beetle is feeding
upon the plant-lice and is in no way responsible for them, for a
similar study of the plant-lice would show that they belong to an
entirely different order (the Hemiptera), which has sucking mouth-
parts and an entirely different life history. We should also learn
from the account of the Coccinellidae that the little long-legged,
blackish, brilliantly marked larvae which accompany the ladybirds
are the young stage from which they develop, and that these larvae
also feed upon the plant-lice. Probably we should find several
different kinds of beetles, evidently all of the ladybird family, but
differing in size, shape, and coloration. Should we desire to speak
exactly of any one sort, we should be obliged to determine to what
genus of the family it belonged, and then to which of several
species in that genus. Usually the amateur will not be able to
identify an insect farther than to its family, but in the case of
common forms, especially those commonly injurious, the illustra-
tions or descriptions of the insect or its characteristic work as given
in textbooks, or the comparison of the specimen with those of
a named collection, if one is available, will make it possible to
definitely determine the species.

Scientific names. The name of the gemis and species together
is commonly called the scientific name, and is in Latin and usually

THE CLASSIFICATION OF INSECTS 69

printed in italics for its easy recognition. Scientific names are a
necessity, because the common name of an insect in one commu-
nity may often be applied to an entirely different species in some
other section, or different common names may be applied to the
same insect ; and they are written in Latin because that is under-
stood by scientists in all countries, and is common to them all,
which is true of no other language. The ladybird beetle in ques-
tion may have been of the species novcmnotata, meaning nine-
spotted, and of the genus Coccinella, which is the typical genus of
the family. This name is written Coccinella noveumotata Herbst.
The name of the genus is always placed first and commenced with
a capital letter, the name of the species following and commencing
with a small letter. Botanists often commence the specific name
with a capital letter if it is named for some person or country, but
zoologists commence all specific names with small letters to dis-
tinguish them readily from the generic names. After the scientific
name proper is often placed the name, or an abbreviation of the
name, of the author who originally described the species (as Herbst,
in the above), for not infrequently different authors will use the
same name for different species, which often results in endless
confusion when the name of the author who has described each
species under the name is not given. Thus the generic and specific
names of a plant or animal are analogous to the Christian name
and surname of a man, except that in the case of the latter the
name applies to an individual, while in the former it applies to a
large number of individuals. The scientific name also has a some-
what analogous significance and use. Thus, if we speak of Patrick
O'Connor or Napoleon Bonaparte, we at once think of the individ-
uals known to us by those names. But the name also tells us that
Patrick is of the O'Connor family, with their general characteris-
tics, and we know the O'Connors to be from the Emerald - Isle,
which we know to be inhabited by people of the Caucasian race,
and, similarly, we know the Bonapartes to be Corsican. In the same
way the specific name of a plant or animal signifies its relationship
to those acquainted with the different sorts. Thus the specific
name novemnotata (or g-notatd) at once signifies that this particular
species of beetle has nine spots and is a separate species from bi-
pnnctata, which has but two spots, while the generic name indicates

70

ELEMENTARY ENTOMOLOGY

that it belongs to the genus Coccinclla, to which this species and
many others belong, and which we recognize in this case as prob-
ably belonging to the family Coccitiellidae, w^hich we know to be a
family of predacious beetles of the order Coleoptera.

Thus animals and plants are divided into the following succes-
sive groups :

Group Examples
Phylum {ArtJiropodd)
Class {Inscctd)

Order (Coleoptera)

Fam ily { Coccin ellidae)
Genus {Coccinella)

Species {iwveninotata)

Coccinella Jiovemnotata Herbst.

Species. The exact definition of a species has worried naturalists
since the time of Linnaeus and is still under dispute, so that no
exact definition will be attempted. It is evident that, inasmuch as
it applies to a large number of individuals, and as we know that
individuals vary exceedingly, it is largely a conception for our
convenience in designating forms of life. Inasmuch as we now
believe that all forms of life have had a common origin and have
been gradually evolved from one or at least a very few original
ancestors of all life during the millions of years of the earth's
history, and as we know that species of plants and animals are now
being formed, while others have disappeared from the earth, it is
evident that the species now^ being formed will be very similar to
each other and will be separated with great difficulty, if at all ;
whereas those species which have existed for a long period of time,
and whose nearly related species have disappeared, will be easily
recognizable and form very distinct species. In short, it may be
said that a species is an aggregation of individuals of so similar
a strtictnre that they might all have been derived from the same
parent, tvhich are more similar to each other tJian to any other in-
dividuals, and which, zvhen bred together, produce progeny of the
same degree of likeness, zuhich ivill also be fertile and produce their
kind. The number of individuals in a species and their distribution

THE CLASSIFICATION OF INSECTS 71

over the earth depend upon its habits and food supply. Some
species are exceedingly limited in their distribution, — as, for in-
stance, the little butterfly Oencis scinidea, which inhabits only the
highest peaks of the White Mountains, — while others are quite
cosmopolitan, living in many distant parts of the world and with
quite different food habits, an example being the bollworm {Hcli-
otJiis obsolcta), which is found on every continent. Some species
are so rare that but one or two specimens have ever been taken,
while others occur in such countless myriads as to become the
worst pests of crops.

Genus. As a species is composed of individuals of similar struc-
ture, so a genus is formed of a number of species having some
common characteristics which make them more nearly related to
each other than to any other species. In the same way genera are
grouped together into families, which have some common charac-
teristics distinguishing them from other families of genera, and
families are likewise grouped into orders. Frequently, various other
subdivisions are made for the purpose of bringing out certain re-
lationships, which are evident but which do not seem to warrant
definite rank. It should be observed that no standard exists as to
what structural characters are sufficient for establishing a species,
genus, or family, and that structures which will separate species in
one order are of sufficient importance to separate families in another
order, this all depending upon the constancy and relative importance
of the character. Thus, orders are commonly divided into sub-
orders, families into subfamilies, and genera into subgenera, while
we recognize varieties and races of individuals within a species, as,
for instance, the varieties and races of garden plants and domestic
animals. In each case the subgroup is composed of a portion of
the larger group, which has some common characters distinguish-
ing it from the other subgroups of the same rank. Such terms as
sections, divisions, tribes, and sej'ies are also used in the same sense.

Inasmuch as some three hundred thousand species of insects have
been described, it would evidently be impossible for any one person,
or any one library, to have all the descriptions which are scattered
throughout the scientific books and journals of all countries and
languages. Hence most entomologists acquire a general knowledge
of the larger groups and then make a special study of some one

72 ELEMENTARY ENTOMOLOGY

family or small portion of a family, sending the insects of other
groups to specialists of those groups for determination, and thus
building up collections which they may use for the subsequent
determination of specimens by comparison. The common families,
and particularly those of economic importance, may usually be
recognized by the amateur, and the identification of the family will
usually indicate the possible economic importance of a given insect,
and may lead to its definite identification, if it is a common form.
In the following pages we have endeavored to give a very brief
account of the characteristics of the more common orders and
families of insects. Keys for their determination will be found
in Chapter XX.

CHAPTER VII

BRISTLETAILS AND SPRINGTAILS (APTERA)

Characteristics. Wingless insects which have no metamorphosis. Mandi-
bles and maxillae retracted within the head, but used for bttfeg-^Tid chewing
soft substances. True compound eyes rarely present ; a group of simple eyes
on each side of head in some genera. Abdomen sometimes furnished with
rudimentary jointed appendages.

This is a relatively unimportant order from the economic stand-
point, but is of interest from the fact that it includes the most

Fig. 87. Silver fish-moth [Lepisma sacchariiia). (Enlarged)

A household nuisance and a good example of the bristletails. (After Marlatt, United .States
Department of Agriculture)

primitive insects now in existence. The name Aptera is given on
account of the entire absence of wings, in consequence of which

73

74

ELEMENTARY ENTOMOLOGY

a

there is no metamorphosis. In some forms there are rudimentary
appendages on the underside of the abdomen, which are supposed
to be degenerated abdominal legs, though not now capable of being

used as such. The order is divided
into two distinct suborders, sometimes
considered separate orders.

Bristletails {Thysanurd). One of the
commonest bristletails is the little shiny
fish-moth, which annoys housekeepers
by getting into starched clothes, among
books, papers, etc. It is about half an
inch long, with long antennae and three
bristles extending half the length of
the body from the tip of the abdomen,
and is covered with silvery scales which
glisten as it darts around in a book-
case or drawer, reminding one of a
fish's scales flashing in the sunlight.
They are very soft-bodied little insects,
more abundant in warm climates, and
feed on starchy matter or soft paper.
In some species of bristletails the bris-
tles have been modified into forcep-
like appendages. Most bristletails are
much smaller
than the fish-
moth, and are
found beneath
stones, logs, and
loose bark, and
in similar situ-
ations ; and one genus {Machiiis), found in
many parts of the world, has rudimentary
abdominal appendages, as shown in Fig. 88.

Springtails {Collembold). Every boy who
northern maple-sugar "bush" knows the little snow fleas, large
numbers of which jump around on the snow and have a propen-
sity for getting into the sap buckets. Other species are found on

Fig. 88. Underside of abdomen
of a female Machiiis maritima,
to show rudimentary limbs {a)
of segments 2 to 9 ; <:, cerci.
(Enlarged)

(After Oudemans, from Folsom)

Fig. 89. The pond-sur-
face springtail (^Smyn-
thiinis aquaticits) with
spring extended. (Much

enlarged)
(After Schott, from Kellogg)

has worked in a

BRISTLETAILS AND SPRINGTAILS

75

the surface of stagnant pools, in manure piles, in the decaying
hollows of trees, in gardens, hotbeds, window boxes, and, in general,
in moist places where decaying vegetation
is found. They are usually microscopic in
size, from one tenth to one twentieth of an
inch long, but have an exceedingly inter-
esting structure. Projecting forward from
the underside of the next to the last ab-
dominal segment is a long abdominal ap-
pendage, or spring, by the extension of
which the insect is enabled to shoot for-
ward as if shot from a catapult, jumping a
considerable distance. As the springtails
feed only on decaying vegetation, they are
never injurious, unless exceptional num-
bers render them a nuisance. Occasionally
such immense numbers of small spring-
tails are found in manure heaps or on the
surface of stagnant pools or ponds as to attract attention to them.
Many of these little springtails are prettily colored with patterns
composed of very minute scales. For this reason they are often
used as test objects for microscopes, the quality of the lens being
determined by its efficiency in revealing the very fine markings on
these tiny scales.

Fig. 90. Underside of the
American springtail [Lepido-
cyiiiis america>nis) with the
spring folded underneath the
body. (Much enlarged)

(After Howard and Marlatt)

CHAPTER VIII

COCKROACHES, GRASSHOPPERS, KATYDIDS, AND CRICKETS
{ORTHOPTERA)

Characteristics. Insects with four wings : the first pair, more or less leathery,
not used for flight, and forming wing-covers for the hind-wings : the second
pair membranous, larger, with numerous veins, and folded Uke a fan. Mouth-
parts formed for biting; Metamorphosis, in60iiH^<Jte-

The members of this order are among the best known of any
of our common insects, possibly because many of them form the

Fig. 91. The German roach [Ectobia germatiicd)

a, first stage ; b, second stage : c, third stage : d, fourth stage : e, adult : /, adult female with
egg-case ; g, egg-case (enlarged) ; //, adult with wings spread. (.\11 natural size except g.)

(From Riley)

main strength of the insect orchestra of a drowsy summer even-
ing, while others are among the most destructive pests. We have
already become fairly well acquainted with a common grasshopper
(pp. 53-56) which forms a good t\'pe of the order. The biting
mouth-parts, leathery fore-wings, and fanlike hind-wings make the
order easily distinguishable, and from the latter characteristic comes
the name " Orthoptera," from orthos (straight) and />Uron (wing),
referring to the straight-folded wings.

The order is divided into six families, which are readily distin-
guished as regards both structure and habits.

76

ORTHOPTERA

11

Cockroaches, or running Orthoptera {Blattidae). The Croton bug,
or German cockroach, is a famihar pest in all eastern cities,
wherever kitchens, pantries, and living rooms are not kept scru-
pulously clean. The name "Croton bug," as well as that of
" water bug," comes from the fact that it was introduced into
New York City about the same time as the Croton water system,
with which it was associated in the popular mind. Roaches not
only rriake themselves a nuisance by getting into everything, but

Fig. 92. The oriental roach [Peripla?teta orientalis). (Natural size)

<7, female : b, male : c, side view of female ; </, half-grown nymph. (After Marlatt, United
States Department of Agriculture)

often do serious damage by gnawing the bindings of books, eating
off wall paper, etc. Our common native species are larger, almost
black, and live under stones and logs ; they are of no economic
importance.

The body of a roach is flattened, due to its habit of living in
narrow cracks and similar out-of-the-way places, and the legs are
long and enable it to run with remarkable swiftness for so awkward-
looking an insect. About two dozen eggs are laid together in a
single pod-shaped mass, which is covered with a brown cement,
making it look much like a large bean, and is left lying in a crack
or quite exposed.

78

ELEMENTARY ENTOMOLOGY

The mantids, or grasping Orthoptera {Mantidae). Mantids are
found commonly throughout the southern states, and form the only

Fig. 93. The common European praying mantis (Mantis religiosa). (Natural size,

from life)

i7, adult mantid patiently waiting or " praying " for its prey ; /', busily engaged in eating a
live grasshopper. (After Slingerland)

family of Orthoptera which is strictly predacious, as they feed en-
tirely on other insects, and are therefore beneficial . They are curious-
looking insects and are called praying mantes, from the prayerlike

ORTHOPTERA

79

attitude assumed by the forelegs, which really, however, are merely
held ready to quickly grasp any unwary insect prey which may

come within reach.

Early writers on natural history
had many curious fancies concern-
ing this insect, which are evinced by
the name of our most common spe-
cies, Alantis rcligiosa {mantis, "a
prophet"), the name undoubtedly
referring to the pious attitude.

Fig. 94. Egg mass of the praying
mantis. (Natural size)

(After Slingerland)

There are many local names
for them, such as rear-horses,
devil-horses, etc., while the
southern negroes know them
as mule killers and other sim-
ilar names, from the supersti-
tion that the brown saliva from
their mouths will kill a mule.
The eggs are laid in shingled
masses, attached to a twig or
weed, and are coated with a
hard, gummy covering. The
young, as well as the adults,
feed on insects and are ex-
tremely difficult to rear, as
they are rabid cannibals, eating

Fig. 95. Walking-stick resting on birch

twig, the leaves of which were attacked by

the birch-leaf skeletonizer

(After Weed)

8o

ELEMENTARY ENTOMOLOGY

,

C

^^ '« ^^Rlife^

T

^

H

r '

Fig. 96. A pair of walking-sticks on a birch twig
(Photograph by Weed)

each Other with avidity. The
adults have an extremely
long prothorax, with a small
transverse head, and long
legs. In many tropical
forms the wings are bright
green and closely resemble
leaves, thoroughly protect-
ing the insect as it awaits
its prey.

Walking-sticks, or walk-
ing Orthoptera (Phasmidae).
The walking-sticks are aptly
described by their name ;
so closely do they resemble
the twig of a bush or tree
that they are found with
difficulty and usually quite
by accident. Only one spe-
cies occurs in the northern
states, which feeds upon
the foliage of forest trees
and is particularly common
on hazel and beech, the
body color varying from

greenish to brown according to the surroundings. In the tropics
are many phasmids of large size and having wings which closely
resemble leaves in both color and shape.
The large, oval eggs are dropped loose
upon the ground, where they pass the
winter and hatch the next summer.

The next three families all have the hind
legs adapted for jumping, and are com-
monly grouped together as the jumping
Orthoptera. Most of the forms in these
three families also have the ability to
produce sounds either by their legs or
wings.

Fig. 97. Eggs of the walk-
ing-stick

ORTHOPTERA

Fig. 98. The red-legged locust.
(Natural size)

(After Riley)

The short-horned grasshoppers, or locusts (Acrididae). The word
"grasshopper" is an American term for the insects which in the

Old World are called Ioc?/sts, as they
are termed in the Biblical account of
the Egyptian plague of locusts. The
locusts include all of our more com-
mon grasshoppers, which have the
antenncc shorter than the body, and
a short ovipositor. Many of them are
seriously injurious. Their structure
and life habits have already been sufficiently discussed (Chaps. V,
XVI), so that we shall merely consider a few of the more common
and important forms. The
most common throughout
the East is the small red-
legged locust {Melanophis
fannr-rjibnnn) and the
nearly related lesser migra-
tory locust {Mclanopliis at-
lantis), hardly distinguish-
able from each other by the
casual observer, both of
which are abundant in our pastures, and often do serious injury to
grass and garden crops. One of the most common forms east of

Fig. 99. Two-striped grasshopper (Melanoplus
bivittatiis). (Natural size)

(After Riley)

Fig. 100. The bird grasshopper, or American locust. (Natural size)
(.After Riley)

the Rockies is the Carolina locust, which flies up along the roadside
and in waste places where it lives. It closely matches its surroundings

82

ELEMENTARY ENTOMOLOGY

in color, but the hincl-vvings are black, with a broad yellow edge
quite conspicuous in flight. Throughout the Mississippi Valley

the differential locust
{Mclaiiophis dijfcr-
cntialis) is one of
the most destructive
forms, being particu-
larly injurious after
floods, when it multi-
plies rapidly on the un-
cultivated land which
has been flooded. A
generation ago (1874
-1877), the crops of
the western part of
the Mississippi Val-
ley were utterly de-
stroyed for several
or migratory locusts

Fig. ioi. Rocky Mountain locust laying eggs

«, females ovipositing, with earth cut away to show tip of

abdomen placing eggs at d, and completed egg mass at c ;

c, eggs, (.\fter Riley)

years by the clouds of Rock\
{Mclanophis spretus) wh ich
swooped down from the
tablelands of the northwest,
where they bred and mul-
tiplied. Accounts of the
numbers and voracity of
these locusts seem almost
incredible to-day, except to
those who have seen an
occasional outbreak in the
northwest, for with the set-
tling and development of
the western plateau they
have become less abundant,
and are now injurious only
in Minnesota, the Dakotas,
and Manitoba. In the mid-
dle and southern states the
large bird grasshopper, or

Mountain

Fig. 102. The Carolina locust {Dissosietra
Carolina), female. (Slightly enlarged)

(After Lugger)

ORTHOPTERA

83

American Acridium {Sc/iistocara avicricana), is common, but
rarely becomes numerous enough to be seriously injurious. It is
one of our largest species (nearly three inches long) and makes as
much commotion as a small bird as it flies up before one. In the
Gulf States, and on the plains of the southwest, occur our two larg-
est species, known as the lubber grasshopper and the clumsy locust,
so called from their clumsy movements. Both are short-winged
and unable to fly, but manage to travel considerable distances.

Fig. 103. The southern lubber grasshopper {Diciyophom reticulata).
(About natural size)

The long-horned grasshoppers (Locustidae). The katydids and
meadow grasshoppers form another family readily distinguished
by their slender antennae, which are much longer than the body
and give the group the name " long-horned," in contrast to the
short antennae of the grasshoppers, or locusts. The ovipositor of
the female is also long and sword-shaped. Unfortunately, the
scientific name of this family, Locustidae, has the same root as the
true locusts, or grasshoppers, with which they should not be con-
fused on that account. The base of the wings of those males
which have well-developed wings is usually constructed for sound
producing, so that when the wings are rubbed together and set
vibrating, the characteristic note is made. The Japanese inclose

84

ELEMENTARY ENTOMOLOGY

some of the best of these in-
sect songsters in small cages,
in much the same manner
as we do song birds. The
"ears," or auditory organs,
of the long-horned grass-
hoppers, instead of being in
the first abdominal segment,
as in the locusts, are situated
on the tibia of the forelegs.
The light green or red-
dish-brown meadow grass-
hoppers are common occu-
pants of our meadows, where
they may be heard calling
to each other at dusk. The
antennae are usually very
long, and often the ovipositor
is as long as the body, being
adapted for placing the eggs
in the stems and roots of
grasses, where they are usu-
ally laid.

The katydids are larger, of a bright green color, and with much
broader wings, which are frequently quite leaflike in both shape
and color. The katydids feed mostly in trees, though some prefer

Fig. 104. A common katydid. (Natural size
(Photograph by Weed)

Fig. 105. A katydid (Uliovceii/riiiji hnirifolhim) and its eggs. (Natural size)

(After Riley)

ORTHOPTERA

85

bushes and shrubs. The eggs are laid along the edge of a leaf or
along a stem, slightly shingled, as shown in Fig. 105, being

quite different
from those of
any similar in-
sects and thus
easily recogniz-
able.

In this fam-
ily there are
two groups of
wingless forms:
the cricketlike
grasshoppers,
which are to
be found under
stones and rub-

FiG. 106.

The western cricket {Anabrus simplex), adult
female. (Natural size)

(After Gillette)

bish, particularly in woodlands, and the shield-backed grasshoppers,
which look very much like crickets. One of them, known as the
western cricket {Anabrus), which is about one and one half inches
long, often becomes so
abundant in the northwest-
ern states as to be \txy de-
structive to crops.

The crickets (GrylUdae).
The common black or
brownish crickets, with
their familiar chirp, are well
known to every one. The
wings are laid flat on the
back when at rest, instead
of meeting like a roof as
in the grasshoppers, the an-
tennae are long, and the
ovipositor is long, but cylindrical in section, being lance-shaped
rather than sword-shaped as in the grasshoppers. Our common
crickets usually feed upon vegetation, and very rarely become inju-
rious, though some are predacious and at times are uncompromising

Fig. 107. The black cricket, male and female
(After J. B. Smith)

86

ELEMENTARY ENTOMOLOGY

Fig. ioS. > emale of Grvlliis assiinilis, with inner and outer

views of auditory membranes on front tibias, at c and d

(After Marlatt, United States Department of Agriculture)

cannibals. The eggs are laid in the ground in the fall and hatch
the next summer. The males have the best-developed musical

apparatus of all
the orthopteran
orchestra. The
principal vein,
which extends
along the base of
the wing-cover,
is ridged like a
file, and on the
inner margin of
the wing-cover,
a short distance
from the base,
the edge is hard-
ened so that it
may be used as a

scraper, or rasp. Elevating his wings to an angle of forty-five degrees,
and arranging them so that the
scraper of one rests on the file
of the other, he moves them to
set the neighboring wing mem-
branes into vibration, thus pro-
ducing the shrill call or the
faint chirp, according to his
mood.

The tree crickets are quite
different from the common
black sorts and are arboreal, as
their name indicates. They are
of a creamy-white or light yel-
lowish color, often slightly
tinged with green, and the wings Fig
are transparent. The antennas

are much longer than the body, ^'^^'^■' bugger)

which is about half an inch long, and the ovipositor is well devel-
oped. The wings when at rest are usually held so as to form a long

109. A tree cricket (GEcanthits fasci-
atiis), male and female
(After Lug

ORTHOPTERA

^7

wedge tapering toward the head. The young tree crickets are
somewhat beneficial, as they feed upon plant-lice, but the adults
do considerably more injury by slitting the
twigs of cane fruits, fruit trees, cotton, etc.,
in which their eggs are deposited, and beyond
which the twigs usually die.

One small group of crickets, called mole
crickets, are wingless and live in the ground,
burrowing here and there by means of the
front tibiae, which form shovels admirable for
that purpose. Mole crickets are more abun-
dant in the South and Southwest, where they
feed upon the roots of plants, but are very
rarely injurious. In Porto Rico, however, the
cJianga is the most serious insect pest of the
island, annually doing one hundred thousand
dollars' worth of damage to the staple crops.

Fig. no. Eggs of

the snowy tree cricket

{(Ecaiitkus nivetis)

a, blackberry cane, show-
ing egg punctures ; b, the
same split, to show the
arrangement of the eggs ;
c, egg very much en-
larged ; if, its tip still more
enlarged. (After Riley)

Earwigs (Euplexopterd).

The earwigs are nearly re- figiu. ch^Lng^iiScapteriscus didactyius'L2.tr.)
lated to the Orthoptera, , , . , , . , . ^

^ A mole cricket which is the most serious insect pest

though they are often placed in Porto Rico. (After Barrett)

in a separate order, Euplex-

optera, which means "well-folded wing," referring to the wing,
which is folded lengthwise, like that of the grasshopper, and
then crosswise. They are small insects, our common species

88

ELEMENTARY ENTOMOLOGY

being from one fourth to one half an inch long. The wing-covers
are short and thick like those of some beetles, and at the tip of
the abdomen is a pair of strong, forceplike appendages. Earwigs

Fig. 112. An earwig {Forficula taeniaia). (Enlarged)

I, male ; 2, female ; 3, wing showing fanlike folds and joints where the
tip is folded on the base

are rare in the United States, except in the South, and are not
injurious. The common name "earwig" arises from an old super-
stition that they crawl into the ears of sleepers and kill them. In
the South they often fly into lights, and in Europe and subtropical
countries they sometimes become injurious.

CHAPTER IX

THE NERVE-WINGED INSECTS, SCORPION-FLIES, CADDIS-FLIES,
MAY-FLIES, STONE-FLIES, AND DRAGON-FLIES

The earlier naturalists grouped all of the insects having four
membranous wings with numerous fine cross veins, or nervures, as
they were then called, into the order Neuroptera, or nerve-winged
insects, from neuron (nerve) ^.nd pteron (wing). Further study has

Fig. 113. The adult male dobson-fly and its larva, the hellgramite
(After Comstock)

shown that these insects are not so nearly related, and that they
should be divided into several distinct orders, to exhibit their true
relationship. Few of them have any economic importance, and

89

90

ELEMENTARY ENTOMOLOGY

they may conveniently be considered together and termed ' ' neu-
ropteroid insects."

True Neuroptera. In the true Nenroptera the wings are usually
of equal size, with numerous cross veins, the mandibles are well
developed, and the metamorphosis is complete. The larvae are
carnivorous, and the mandibles are usually long and pointed. One
of the best-known forms is the large hellgramite {Corydahis cor-
mitd), whose larvae, known as dobsons, are the favorite bait of
the bass fisherman. The larvae live under stones in swift-flowing

Fig. 114. Cluster of eggs of the lace-winged fly {Chrysopa). (Greatly enlarged)

(After S. J. Hunter)

streams, where they feed on the young of various aquatic insects.
They are readily recognized by the leglike appendages and a large
tuft of tracheal gills on either side of each abdominal segment
(Fig. 113). It requires nearly three years for the larva to become
full grown, when it forms a cell beneath a stone, or some object
near the bank, and pupates, the adult appearing about a month
later. The adults are readily recognized, as they have a wing ex-
panse of from four to five and one half inches and the males have
remarkably long mandibles. On the rocks under which the larvae
live the eggs are laid in chalklike masses of from two to three
thousand.

-^ C u

« 1)

— 2

3 "O

91

92

ELEMENTARY ENTOMOLOGY

The aphis-lions {Chrysopidac) are among the most important
enemies of the noxious plant-Uce. The larvae are small, dark-colored,

spindle-shaped insects, from
one fourth to one third of an
inch long, with large, pincer-
like jaws, much longer than the
head, with which they grasp
the aphides. On the inside
of each mandible is a deep
groove, against which the max-
illa fits, thus forming a tube
through which the juices of the

(Photograph by Weed) ^^^^^ ^^^ SUCked iutO the mOUth.

When full grown, the larva spins a small, globular cocoon of
pure white silk, in which it pupates. Frequently the old cocoons
will be found with a small, circular lid which the adult has opened

Fig. ii6. A Myrmeleonid, the adult of
the ant-lion

Fig. 117. The ant-lion

a, lan'a of Myrmeleon sp. (three times natural size) ; b^ pit of ant-lion, Mynuclcon sp., and

below a pupal sand-cocoon from which the adult has just issued, the pupal skin remaining

(natural size). (After Kellogg)

in making its escape. The adults are about an inch long, of a deli-
cate pale green color, with brown antennae and finely veined wings,
which are held like a roof over the back, and which have given
them the name of "lace-winged flies." The eyes are a glistening

THE NERVE-WINGED INSECTS

93

Fig. ii8. A scorpion

fly {Panorpa riifesce)is)

(Twice natural size)

(After Kellogg)

gold, from which they are sometimes called golden-eyes. The larva:
feed not only upon plant-lice, but upon any soft-bodied insects which
they can overpower, or on soft insect eggs, and
will not infrequently attack their own species.
The adults seem fully aware of these canni-
balistic tastes, for they lay the little white eggs
on stalks about half an inch high, placing them
out of the reach of the larvae.

In the undisturbed dust beneath an old shed,
or beneath cliffs, or along warm banks, one
will frequently find the little funnel-shaped
pits of the ant-lions {Myj'viclcouidac), some-
times locally known as " doodle bugs." At
the bottom of the pit may be seen two out-
stretched jaws awaiting any unwary insect
which may slide down the crumbling sides. The larvae are not
unlike those of the aphis-lions in general appearance, but have a
larger abdomen and a small thorax and slender legs. The adults are
dusky-colored, with long, narrow, delicate wings. They are poor
fliers and are often attracted to lights (Fig. 1 16).

The scorpion-flies (order Mecoptera) are readily distinguished by
the long head, which is prolonged into a beak, at the end of which
are the biting mouth-parts. They receive their common name
"scorpion-flies" from
the terminal segment
of the males of the
most common forms,
which is enlarged and
bears clasping organs,
so that it looks like the
fang at the tip of the
body of a scorpion. They are entirely harmless, however, being car-
nivorous both as adults and as larvae. The adults are most commonly
found on foliage in shady places, though they not infrequently fly into
lights, while the larvae look much like caterpillars and live in the soil.
The caddis-flies (order Trichopterd) i have wings with but few cross
veins but more or less densely clothed with hairs, thus being related

1 From t/irix (a hair) a.x\d pieroii (a wing).

Fig. 1 19.

.Scorpion-fly larva [Panorpa sp.).
times natural size)

(After Felt, from Kellogg)

(Three

94

ELEMENTARY ENTOMOLOGY

to both the neuropterous insects and the Lepidoptera. The mouth-
parts of the adults are quite rudimentary. The hind-wings are often

somewhat larger than the
fore-wings and are then
folded under them in repose,

the fore-wings

being held

Fig. 120. Caddis-fly larval cases. (Enlarged)
(After Furneaux)

like a roof over the back.
The antennae are usually very
long and slender. The lar-
vae are aquatic and form an
important item of fish food.
Some of them build most
interesting little cases from
grains of gravel, small shells,
bits of twigs, pine needles,
or whatever rubbish may be
at hand, lined within with
silk, which they carry around
with them, the head and
thorax projecting out as they
move or feed. Every small pool or brook harbors some of these
interesting case bearers, which will hardly be distinguished except by
closely watching the bottom until they are seen in motion. Most of
these larvae are herbivorous, feeding on whatever vegetable matter
is available, and look like small
caterpillars. The caddis-worms of
one group construct silken nets
across small rapids, between stones,
or upon the brink of little water-
falls, which are doubtless of serv-
ice in catching the tiny insects
which float downstream, as the lar-
vae which make them are known
to be carnivorous. When ready to change to a pupa, the caddis-
worm closes up the entrance to its case, but leaves an opening for
the water to flow through so that the pupa can breathe, sometimes
making a simple grating of silk over the entrance. Upon trans-
forming to the adult the caddis-fly secures almost immediate use

Fig. 121. Adult caddis-fly (Goii/otau-

liiis dispechts Walk). (Enlarged)

(.\fter Xeedham)

THE NERVE-WINGED INSECTS 95

of its wings, as is highly necessary if it is not to be drowned. Most
insects require several minutes or even hours for the wings to ex-
pand and harden, but Professor Comstock observed a caddis-fly
which took flight immediately upon emergence from the water.
The adults are usually grayish, brownish, or dusky in color, marked
with black or white, and are rarely observed except as they fly
into lights.

Pseudoneuroptera, with incomplete metamorphosis. All of the
three orders just considered have a complete metamorphosis and are
more or less closely related. The next three orders are all aquatic
and have an incomplete metamorphosis, for which reason they are
often grouped together as false Neuroptera {Pseudoneuroptera).

The May-flies (Ephemerida) ^ are well /ipy^^inzr

named, for they are the most ephemeral /i*/ ^ '■''^^ ,

of insects. The wings are exceedingly ^.WrWiMj^"""" ifh /
delicate and the fore-wings are much the ' l>^^f:-^-^*»« f' ^' i I
larger, the hind-wings sometimes being * ' "'' '

entirely wanting. The mouth-parts of
the adults are exceedingly rudimentar\-,
and they probably take no food. The
antennae are short, but at the end of ^'^ '" ^f^ ^^ ^ netbuiidmg

caddis worm

the lono:, soft abdomen are two or three

1 ■ • . J .1 in 1 (After Comstock)

long, many-jomted, threadlike append-
ages, the cerci, which are cjuite characteristic of the May-flies. On
warm nights of late spring and early summer the lights of towns
near rivers and lakes are often darkened by myriads of May-flies.
They are light brown or dusky colored, with wings expanding from
one to one and one half inches, and with cerci fully as long. The
nymphs live at the bottom of ponds, streams, and lakes, feeding on
small insects and vegetable matter in the ooze. Along either side of
the nymph's abdomen is a row of delicate, platelike, fringed tracheal
gills, through which it breathes, and at the tip of the abdomen are
three feathery appendages. The legs are strong and enable it both
to walk and to swim. The nymphs molt very frequently, there being
as many as twenty molts in some species. After about the ninth
molt the wing pads commence to appear on the back, and become

1 From ephemeras (lasting but a day).

Fig. 123. May-flies {Ej>/ie»iera varia Etn.)

/, 2, side and back views of nymph ; ^, ^, side and back view of adult male {Sifhlnnis
alteniatus Say); j, 6, side and back view of nymph; 7, side view of adult male. (After

Needham)

96

THE NERVE-WINGED INSECTS

97

Fig. 124. A stone-fly (Pieronarcys 7-egalis).
reduced)

(After Newport, from Folsom)

(Slightly

larger with each successive molt, until the water nymph sheds its
skin for the last time, the gills and mouth-parts are left behind, and

the winged May-
fly comes forth.
After flying a
short distance it
alights and again
sheds its skin, a
thin layer coming
off from all parts
of the body, even
from the wings,
which process
must certainly be
the " exception
which proves the
rule, "for no other
insects ever molt
after becoming winged. The eggs are now deposited by the females
either on the surface of the water or on stones beneath the surface,
and in a few hours, or at most in a day or two,
the adults die. The nymphs live from one
to three years, according to the species, and
form an important item of the food of fishes,
but are othenvise of no economic importance.
The stone-flies (order Plecopterd) ^ are quite
similar to the May-flies in their general hab-
its, but quite unlike them in appearance. The
hind-wings are much larger than the fore-
wings and are folded beneath them in plaits
when at rest. The mouth-parts of the adults
are of the biting type, but are often poorly
developed. The antennae are rather long and
slender, and usually there are two many-
jointed cerci extending from the tip of the
abdomen. The nymphs live beneath stones
in swift-running streams and are from one

1 Yrom pieces (plaited), ^ndpieron (wing). (After Comstock)

Fig. 125. A stone-fly
nymph

98

ELEMENTARY ENTOMOLOGY

half to one and one half inches long ; with their long legs, and anten-
nas and cerci projecting from either end, they have a very distinctive
appearance, as shown in Fig. 125. Behind each leg is a clump of
hairlike tracheal gills, very similar to those found on the dobson,
through which they breathe. They are a favorite food of fishes,
particularly of brook trout, and make excellent bait. When full
grown the nymphs crawl upon rocks or reeds and transform to the

adult stone-flies, the old skins
being frequently found in such
places. The adults are dull
grayish or brownish, the more
common forms being from one
to one and one half inches long,
and are usually found on foliage
in shady places along streams.
They probably take no food and
live only long enough to lay the
eggs. Some of the smaller spe-
cies, about one fourth of an inch
long, of a blackish color, are
often common on snow in early
spring, and frequent windows
at that time.

The dragon-flies and damsel-
flies (order Odonata) are readily
recognized by their long, nar-
row, powerful wings, which are
about equal in size and on the
front marjrin of which is a little

Fig. 126.

A damsel-fly (Lesies tuicata
Kirby), female

(After Needham)

notch and strong cross vein, called the nodus. The mouth-parts are
well developed and are of the biting type, both larvae and adults being
predacious upon other insects. The dragon-flies and damsel-flies
are distinguishable both as adults and as nymphs. The adult damsel-
fly holds the wings vertically over the back when at rest, like a butter-
fly ; the fore and hind wings are similar in shape, and the nymphs
have three long, leaf like tracheal gills projecting from the tip of the
abdomen. The dragon-flies hold their wings horizontally when at
rest, the hind wings are usually much broader at the base, and the

Fig. 127. Nymph of a damsel-fly
(Lestes sp.). (Twice natural size)

Showing the three leaflike tracheal

gills at the tip of the abdomen. (After

Kellogg)

Fig. 128. Early stages of nymph of a
dragon-fly {Aiiax jimiiis I)ru.). (All en-
larged)

Showing changes of color pattern : A, newly

hatched ; B, one fourth grown ; C, one half

grown. (After Needham)

Fig. 129. A dragon-fly and its development

Nymphs feeding at / and j, showing extension of underlip or mask and the way prey is

grasped by it ; 2, mature nymph ready to molt ; 4, skin of nymph from which the adult ( j)

has emerged. (After Brehm)

99

lOO

ELEMENTARY ENTOMOLOGY

nymph has five converging, spinehke appendages at the tip of
the abdomen. The dragon-flies are among the swiftest fliers, dart-
ing here and there after small flies, and are important enemies of
mosquitoes. They have received many local names, such as darning
needles, snake doctors, etc., with which are connected many curious

superstitions of sewing up people's
ears, bringing snakes to life, etc., of
which they are of course entirely in-
nocent. They are usually dark colored,
though often brilliantly marked with
metallic blue, green, and red. The
damsel-flies are more slender-bodied
and fly lazily about. The eggs are
laid in the water or fastened to aquatic
plants. From them hatch the little
long-legged nymphs which may be
found browsing in the ooze and mud
of any pond. Dark-colored, flat, and
spiny, they are hardly distinguishable
from the debris of the bottom. They
have a peculiar underlip, remarkably
extensile, with two powerful hooks
at the tip, which, when thrown for-
ward from the head, grasps the un-
suspecting prey. When drawn in,
the labium covers the front of the
face and gives the nymph an exceed-
ingly comical appearance, with its
large, shrewd eyes on either side.
The nymphs of the damsel-flies
breathe through the tracheal gills at
the tip of the abdomen, but the
dragon-fly nymphs have a peculiar way of drawing water into the
rectum, whose walls are very thin and lined with numerous tra-
chea, so that the air in the trachea is purified through the wall of
the rectum as if it were a tracheal gill. The water from the rectum
may be ejected forcibly, so as to drive the nymph suddenly for-
ward. When full grown the nymph crawls up" on a reed or plant

Via. 130. J, part of two rows of
respiratory folds from cuticular
lining of rectum of dragon-fly
nymph (^'Esc/iita). The shaded
parts are abundantly supplied with
tracheal tubes, as shown at B, a
small part of one leaflet highly
magnified, showing many fine tra-
cheal branches

(Redrawn from Miall)

Fig. 131. Development of a dragon-fly {Leiicorhinia glacialis Hagen)

/, two nymphs on the bottom of the pond ; 2, the empty nymphal skin left clinging to a
branch after transformation ; j, the adult female ; 4., 5, back and side views of the adult male

(After Needham)
loi

I02

ELEMENTARY ENTOMOLOGY

and molts for the last time, the adult quickly flying away and
leaving the cast skin, which is often found intact and gives an
excellent idea of the structure of the nymph, so remarkably unlike
the adult in both form and habit.

Fig. 132. Dragon-fly {Libelliila ptikhella). (Slightly reduced)
A, last nymphal skin ; B, adult. (.Xfter Folsom)

Summary of the Nerve -Winged Insects and their
Relatives

A. With oomplcte metamorphosis:

Order N'europtera. Wings equal ; numerous cross veins.
The dobsons {Sialidae). Larvae aquatic.
The aphis-lions {Chrysopidae). Feed on aphides, etc.
The ant-lions {Mynneleonidae). Larvae make pits in soil.

Order Mecoptera. Scorpion-flies. Elongate head, and tip of abdomen fang-
like. Larvae live underground.

Order Trichoptera. Caddis-flies. Wings with few cross veins and clothed
with hairs. Larvae live in water, many being case bearers.

B. With i»e«ntlfrfete metamorphosis {Pseudoneuropterd) :

Order Ephemerida. May-flies. Fore-wings much larger ; mouth-parts rudi-
mentary. Nymphs aquatic.

Order Plecoptera. Stone-flies. Hind-wings larger and plaited beneath the
fore-wings when at rest. Nymphs aquatic.

Order Odonata. Dragon-flies and damsel-flies. Wings about equal in size,
with a nodus on the front margin. Nymphs aquatic.

CHAPTER X

THE WHITE ANTS, BOOK-LICE, AND BIRD-LICE (PLATYPTERA)

Characteristics. Insects with t\vo pairs of delicate, membranous wings equal
or the hind pair smaller, and with the principal veins few and simple, or entirely
wingless ; mouth-parts, mandibulate ; body, flattened ; prothorax, broad ; meta-
morphosis, jnrnrQpjgl;^

The Platyptera (from platys, "flat," and//r;w/, "a wing," allud-
ing to the wings of the white ants, which he flat on the back when
at rest) include three groups, which are often considered as separate
orders and are quite dis-
tinct in appearance and
habits, but may well be
placed in a single or-
der based upon the stiTic-
tural characters given
above. When present
the wings are never net-
veined, and the book-lice
and bird-lice are wing-
less. The body is usually
flattened and the pro-
thorax is usually well-
developed and distinct.

The white ants {Ter-
mitidae) are well-known
inhabitants of fallen logs
and decaying wood, and
are readily mistaken for
ants by the casual observer. The light yellowish color and the fact
that the abdomen is broadly joined to the thorax, with no toothed
constriction, as in the true ants, easily distinguish them. Though
entirely unrelated to the true ants, they have a very similar social
organization, with several distinct castes, of which only the so-called

Fig. 133. White ants, or termites.

queen ; ^, male ; <", worker ; </, soldier,
and Kellogg)

Enlarged)
(.\fter Jordan

I04

ELEMENTARY ENTOMOLOGY

kings and queens are winged. The wings are long and narrow,
somewhat leathery in texture, and are furnished with numerous

but somewhat indistinct
veins, are about equal in
size, and are laid flat on
the back when at rest.
They have well-devel-
oped biting mouth-parts,
the mandibles of the sol-
diers projecting well for-
ward of the huge head.
They are most abundant
in the tropics, where
they are serious pests of
all kinds of woodwork,
mining into foundations,
posts, furniture, and
whatever happens in
their way. The nests of
the tropical species are
often of large size, form-
ing mounds sometimes twelve feet high, or huge, roundish masses
several feet thick attached to trees. But one species ( Tcrnicsflavipes)

Fig. 134. White ants' nest on trunk of tree (at
arrow) in Cuba

(Photograph by Slingerland)

Fig. 135. Psocits Hiicatiis. (Much enlarged)
(After J. 15. Smith)

is common throughout the United States ; it is usually found in
old logs and stumps, but sometimes establishes its nests beneath

THE WHITE ANTS, BOOK-LICE, AND BIRD-LICE 105

Fig. 136. A psocid (side

view), showing position of

wings at rest. (Thirteen

times natural size)

(After Kellogg)

buildings, whose wooden foundations are then attacked and often

so mined as to necessitate their removal. Such instances are more

common in the South, but even in the North porch timbers are

often attacked, and now and then the white ants invade a building
and thoroughly tunnel the studding and even
y^ ^y the lathing. The workers of both sexes are

wingless, of a dirty white color, and busy
themselves in building their nests, caring for
the young termites, and securing food for
the whole colony. The soldiers are also of
both sexes, wingless, and resemble the work-
ers, except that the heads are of immense
size, being frequently as large as the rest of
the body, and bear very strong mandibles,
which form effective weapons. The kings

and queens are really merely fathers and mothers, for they produce

the colony but do not rule it. In early summer the kings (males)

and queens (females) swarm forth from the nest and, after a short

flight, shed their wings. Individual males

and females now mate and are ready to start

a new colony, but unless they are found and

established by some workers they perish, and

thus only few of them ever sur\'ive. If a

pair are fortunate enough to be discovered

by some workers, they are provided with

food and are imprisoned in a circular cell.

The queen now commences to develop eggs,

and her body enlarges enormously, finally

becoming nothing but a huge sack, often

six inches long, filled with eggs. She is fed

by the workers, who carry away the eggs and

rear the young, which resemble the adults in

general form. Thus the domestic economy

of these colonies is hardly less interesting than that of the true ants.
Book-lice. In neglected libraries or in old books which have been

stored are to be found the tiny book-lice (Psocidac) which feed upon

the paper bindings. They are exceedingly wise-looking little insects

when examined with a lens, having all the appearance of being

Fig. 137. A wingless book-
louse (.-//w/cj-sp.). (Greatly
enlarged)

(After Kellogg)

io6

ELEMENTARY ENTOMOLOGY

adapted to their surroundings. Other members of this family, called
psocids, are winged and look much like large plant-lice. The wings
are of a dusky color, have a very characteristic venation, and are
held roof-shaped over the back. Psocids feed on lichens and decay-
ing wood and are fre-
quently found in large
masses on fences or
tree trunks, where they
are suspected of doing
mischief, but they are
entirely harmless and
need not be disturbed.
The tttting bird-lice
(Mallophagd) are curious
looking, wingless para-

FiG. 138. Biting lice (J/(?//^//i«^tf). (Greatly enlarged) gites which infeSt the

a, turkey-louse {Goniodes stylifer Nitsch) (after Cuvier); fp^^-Up-.^ ,,f ^^oiiltrv anH

b, the biting dog-louse {Trichodectes latus Nitsch) (after ^t^^Lneib Ui |*UUUTy MUi
Denny). (From Osborn, United States Department of birds, whilc SOmC infcSt

Agriculture) , 1 ,

ssHfiwaMa mammals.
They have biting mouth-parts and feed on feathers, hair, and bits
of skin, thus differing from the true lice (see p. 121), which have
sucking mouth-parts with which they extract the blood. The flat-
tened bodies and curiously shaped heads enable one to identify
them readily. A dust bath, with a frequent thorough cleansing of
the poultry house by spraying with kerosene and then whitewash-
ing, will usually prevent serious annoyance to poultry.

CHAPTER XI

THE TRUE BUGS, APHIDES, AND SCALE INSECTS {HEMIPTERA)

Characteristics. Insects with four wings, except in the parasitic forms ; fore-
wings, thickened at the base, with membranous tips and overlapping on the
back in the Heteroptera, but entirely membranous and sloping at the sides of
the body in the niJorder Homoptera ; mouth-parts, suctorial ; antennae, few-
jointed ; metamorphosis, incomplete.

Ordinarily all insects or small, insectlike animals are called
bugs by the uninitiated, but when the entomologist speaks of a

Fig. 139. Fore-wings of Heteroptera, showing thickened veins and arrangement
of veins in membranous tip characteristic of various families

/, Capsidae ; 2, Pyrrhocor'idac ;

Lygaeidac ; 4, Coreidac ; j, \abidae ; 6, Acaiitliidac
(.\fter Comstock)

bug he refers to an insect of the Q«:der Hcmiptera. The insects
of this order are readily recognized by the strong, pointed suck-
ing beak which extends from the head between the legs, and in
which are inclosed the other mouth-parts, as already described (see
p. 17). They develop with an incomplete metamorphosis, as has
been described for the squash-bug (p. 50), which is a good ex-
ample of one group. The name of the oedfer, Hemiptera, is de-
rived from Jicjiii (half) and ptcron (wing), but is really applicable
to only one aitborder, the Heteroptera. The name Heteroptera has
a similar significance, referring to the fore-wings, which have the

107

io8

ELEMENTARY ENTOMOLOGY

Fig. 140. A winged pea aphis, illustrating the uni-
form translucent, membranous texture and vena-
tion of the wings of the Homoptera. (Much
enlarged)

beak arises from the back of the head
sit a, are entirely wingless, degen- -«=—
erate forms which are parasitic
on man and other mammals.

S^ORDER HeTEROPTERA

The aquatic bugs. Several
families of true bugs inhabit our
streams, ponds, and lakes. The
water-boatmen [Corisidac) are
from one fourth to one half an
inch long, and of a brownish
color, but appear like glistening
silver as they dive through the
water, carrying with them a thin
coating of air which they breathe.
Their near relatives, the back-
swimmers [Notonectidae), differ
in that they swim upside down
on their backs, which are shaped
like the keel of a boat instead of
being flat. The water-scorpions

basal half thickened and
the tips membranous
and overlapping, while
the hind-wings are en-
tirely membranous, so
that the wings are unlike
{hcteros), and the beak
arises from the front of
the head. In the other
principal s;^order, the
//fw^/z'rr^z, the wings are
membranous throughout
and slope at the sides of
the body like a roof, both
pairs of wings being
alike {Jiomoios), and the
A third saiDorder, the Para-

FiG. 141. Back-swimmers {Xotonecta)

A, A', and water-boatman (Corixa) B.

(Slightly enlarged)

(After Linville and Kelly)

THE TRUE BUGS

109

{Nepidac) are so called from the long tube extending from the tip
of the abdomen, which is thrust to the surface of the water for
breathing. They are elongate insects, with long legs, the front

Fig. 142. A water-scorpion [Kniiatra fusca). (Enlarged)
(.-\fter Lugger)

pair being fitted for grasping their prey, and live on the stems of
plants, which they closely resemble.

The giant water-bugs {Bclostomidac) are probably better known
to most boys as electric-light bugs,
for with the advent of the arc light
they have become very numerous on
the streets on warm summer even-
ings. The largest are over two
inches long and can inflict a pain-
ful wound with their strong beaks,
which they use for preying upon
other insects and small fish. These
larger water-bugs, as well as the back

swimmers, often become a serious ^

pest where the artificial propagation of fish is attempted. Many of the
females fasten their eggs to thei^-owft backs .with a waterproof glue.

Every one who has been fishing knows the water-striders {Hydro-
batidac) which dart here and there over the surface and suddenly

Fig. 143. The undulating back-
swimmer (lYoio)iecia itndiilata).
(Twice natural size)

(After Weed)

B

Fig. 144. A, the giant water-bug or electric-light bug (Behstoma americana) ; B,

the western water-bug (Serphiis sp.), male, with eggs deposited on its back by

the female. (Natural size)

(After Kellogg)

Fig. 145. A water-strider {Hygroirec/ius remigiis Say). (Enlarged)

(After Lugger)

1 10

■;i't!fi'S'(i('iii*';'iii;'W'«*^

Fig. 146. The masked bedbug hunter [Opsicoetus personatus Linn.), adult and
dust-covered nymphs. (Enlarged)

(After Brehm)

Fig. 147. The big bedbug or bloodsucking cone-nose (Conor/iinus sanguisuga).

(Enlarged)

a, b, last stages of nymphs ; c, d, adults. (After Marlatt, United .States Department of

Agriculture)

I 12

ELEMENTARY ENTOMOLOGY

leap for some unwary midge or other small insect. They usually
occur together in some numbers, and some kinds have been seen
on the ocean hundreds of miles from land.

All of the aquatic bugs are predacious upon other insects or upon
small aquatic animals or fish, and may therefore be either beneficial
or injurious, according to the nature of the food.

Fig. 148. The wheel-bug {Prionidus cri status ■'Limn.), eggs, nymphs, and aduhs
(After Glover, United States Department of Agriculture)

The predacious bugs. Several terrestrial families are predacious
and may be conveniently considered together. The assassin-bugs
{Rcdiiviidac) are well named in this respect. They feed on soft-
bodied insects, but unfortunately are not discriminating in their
choice, so that frequently beneficial insects are destroyed in large
numbers. They are more common in the South, where one of the
largest species is known as the wheel-bug {Arilus cristatJis) from
the large hump, like a cogu^heel, on the back. In the North are
several species, commonly found around houses, one of which is

THE TRUE BUGS

"3

known as the masked bedbug hunter, from the habit of the nymph
of covering itself with dust and rubbish so as to be thoroughly con-
cealed as it waits in dusty corners for its prey. This species, with

Fig. 149. Thread-legged bug [Emesa longipes De G.)
(After Lugger)

another {Melanolestcs picipcs), was the subject of considerable
newspaper notoriety a few years ago as the kissing bug, since it not
infrequently attacks the lips of people while they -are asleep. The

Fig. 150. A damsel-bug {Coriscus subcoleopteiiis Kby.)
(After Lugger)

thread-legged bugs {Evicsidac) are well described by their name, all
of the legs being long and threadlike. The forelegs are fitted for
grasping the prey, resembling those of the mantis, and the anten-
nae are bent so as to simulate forelegs. They are sometimes found

114

ELEMENTARY ENTOMOLOGY

Fig. 151. Phymata wolfii

a, b, side and back views ; c, front leg ; d,

beak. (After Riley, United States Department

of Agriculture)

around barns and sheds, where they are said to rob spiders' webs
of their prey. The damsel-bugs {Nabidae) frequent flowers and
vegetation, feeding on any small insects they may conquer. The
blond damsel-bug {Coriscns fen is) is a light yellowish color, with

numerous brown dots, and is
often taken in sweeping grass
with a net. The other most
common species, the black
damsel-bug {Coi'iscus subcole-
op trail Ls), receives its specific
name from the fact that at first
glance it closely resembles a
beetle, the wings being mere
rudiments and the body shin-
ing black, with yellowish legs.
A single species {PJiyniata xvolfii) of the ambush-bugs {PJiymati-
dae) is found very commonly lurking in the flowers of the golden-
rod. It is yellowish or greenish in color, with a broad black band
across the abdomen, and the front legs are strongly developed for
grasping, so that it is able to overpower much larger insects. The
bedbug and its relatives the flower-bugs {AcaiitJiidac) are also
predacious. The former is too well
known to need description, and an-
other similar wingless form attacks
swallows, bats, pigeons, etc. The
jlower-bugs have well-developed wings
and lurk in blossoms, where they at-
tack small insects.

The stink-bugs, or shield-shaped
bugs (Pentatomidae), are a large fam-
ily readily distinguished by their
shape, and, with two or three nearly
related but small and unimportant families, may be distinguished
from other terrestrial Heteroptera by having antennae of five seg-
ments instead of four. The term "stink-bug" is not definite, for
many other families have very characteristic " buggy " odors, but
as these insects frequently attack berries, which retain their odor, we
have become better acquainted with this disagreeable characteristic

Fig. 152. Bedbug. (Enlarged)

<?, nymph ; /', adult, with outstretched
beak

THE TRUE BUGS

115

in their case, — hence the name. They have small heads with broad,
prominent shoulders, and the large, triangular scutellum occupies

f

Fig. 153. The green soldier-bug (A'ezara hilaris). (Enlarged)

a, adult ; /', beak ; <-, eggs ; d, single egg ; e, young nymph ; /, last stage of nymph.
(After Chittenden, United States Department of Agriculture)

the center of the back between the wings, which are rounded at the
tip of the abdomen, giving the whole body a characteristic shield-
shaped appearance. From an economic stand-
point the family is divided, some species being
predacious upon other insects and others
being serious crop pests, while some have
both habits, as circumstances may offer food
of one kind or the other. The predacious
species are commonly known as soldier-bugs
and feed mostly upon caterpillars. The com-
mon green soldier-bug {Xczara hilaris) feeds
upon the larvae of the Colorado potato-beetle,
cotton-leaf caterpillars, and other injurious
forms, but unfortunately it not infrequently
attacks cotton bolls, ripening oranges, and Fic. 154. Spined soldier-
various fruits and vegetables, doing consider- "^ ' '^'?" ■»/""'■*■'")•

. . (Enlarged)

able injury by sucking the juices and causing

malformations. The spined soldier-bug {Po-

disus spinosjis) is a common enemy of leaf-eating caterpillars, such

as the tussock moths, gypsy and brown-tail moths, and of many

soft-bodied grubs, like those of the potato-beetle. Other species,

like the harlequin cabbage-bug {Murgantia histrionica), which is

ii6

ELEMENTARY ENTOMOLOGY

black with numerous red or orange markings and is one of the
most serious pests of cabbage throughout the South, feed wholly
on vegetation. Small green species {Thyanta custator ^wd Pcnta-
toma sayi) have done serious injury to grain and forage crops in
Texas and Colorado in recent years. The little Negro-bugs of a
nearly related family {Corimelaenidac) are jet-black and have the

r>

f^ Fig. 155. The harlequin cabbage-bug

a, b, adults (natural size) ; r, side view of head with mandibular and maxillary setae out of

bealc ; il, eggs with newly hatched young ; e, nymphs ; /, egg masses with one egg hatching

and newly hatched nymph on lower right mass

scutellum enlarged so that it covers nearly the whole abdomen
and gives the bug the appearance of a beetle, for which it is fre-
quently mistaken by a beginner. They infest various plants and
often injure berries by imparting their disagreeable odor, as do
the stink-bugs.

Plant-bugs. The remaining families of Heteroptera feed entirely
on vegetation and may for convenience be grouped together as
plant-bugs. They are all more or less elongate in form, with slender
legs, and antennae about half the length of the body. The families

THE TRUE BUGS

117

Fig. 156. Lace-bug (Coryt/mca arctiala
adult, eggs, and nymph

Say),

(After Comstock, United States Department of

Agriculture)

are most readily distinguished by the venation of the front wings,
several of which are shown in Fig. 139, p. 107.

The lace-bugs (Tingiti-
dae) are found commonly
on the leaves of bass-
wood, hawthorn, and
quince, occasionally in-
juring the latter. " One
glance at the fine white
meshes that cover the
wings and spined thorax
is sufficient," says Pro-
fessor Comstock, "to dis-
tinguish them from all
other insects, for these are
the only ones that are clothed from head to foot in fine white
Brussels net." They are small insects, about the size of plant-lice,
and suck the juices of the
leaves. The eggs are cov-
ered with a sticky , sub-
stance and look like fungi
on the undersurface of
the leaf.

The leaf-bugs (Capsidae)
form the largest family of
Heteroptera, having over
two hundred fifty species
in this country. One of
the most common species
is the tarnished plant-bug
{Lygtis pratensis). This
is yellowish- or greenish-
brown in color, about
one fourth of an inch
long (Fig. 157), and at-
tacks a great variety of plants, being injurious to nursery trees,
sugar beets, strawberries, and • various vegetables and flowering
plants, causing the tips of plants like the dahlia and potato to

(About four times

Fig. 157. Tarnished plant-bug.
natural size)

(7, b, c, d, four stages of nymphs ; c, adult hug.
Forbes and Chittenden)

(After

ii8

ELEMENTARY ENTOMOLOGY

wither beyond the point where the httle bug has inserted its beak.
The four-hned leaf-bug {Poecilocapsus lineatics) is yellowish or

Fig. I 58. The four-lined leaf-bug

a^ adult (enlarged) ; h^ adult (natural size) ; c, single egg (greatly enlarged) ; d, lengthwise
section of stem, showing eggs in position (enlarged). (After Slingerland)

greenish, with four black stripes (Fig. 158), and is often a serious
enemy of currants, laying its eggs in the stalks and thus killing
the tips. The cotton leaf-bug is found throughout the country on

Fig. 159. Cotton leaf-bug (Calocoris rapidiis)

a, mature bug ; i, young nymph ; c, fourth stage of nymph ; d, fifth stage of nymph
(Authors' illustration, United States Department of Agriculture)

THE TRUE BUGS

119

various flowers and is sometimes an enemy of the sugar beet, but
in the South it is best known for causing the cotton squares to drop
and producing black spots and distortions of the bolls. It is dark

Fig. 160. A stilt-bug {Jalysus sj'inostis Say). (Enlarged)
(After Lugger)

brown, with a narrow yellow border, the prothorax being yellow and
red with two black spots. Nearly related is the red-bug family {Pjr-
rJiocoridac), named after the red-bug, or cotton-stainer {Dysdcrcns

Fig. 161

Much enlarged)

Adult at left ; «, ^, eggs ; c, newly hatched nymph ; d, its tarsus ; f , /, g, second, third, and

fourth stages of nymph ; //, leg of adult ; y, tarsus of same ; /, proboscis, or beak. Hair lines

indicate natural size. (After Webster and Riley)

snturelhts), an insect of a reddish color, with pale yellow stripes,
with habits very similar to the one last mentioned, staining the cot-
ton where it punctures the bolls. Though common, it is by no
means a serious pest of cotton, but is often injurious to ripening

I20

ELEMENTARY ENTOMOLOGY

oranges. The family is a small one of relatively large, bright-colored
bugs, with few species in the North. The stilt-bugs {Bcrytidac)
are well named from their long, stiltlike legs. They resemble the
thread-legged bugs in this respect, but are much smaller, being

only about one third of
an inch long. Only two
species are known in the
United States; these fre-
quent the undergrowth
of woodland and pas-
tures. The chinch-bug
is the best-known exam-
ple of one of the larg-
est families {Lygaeidae),
with nearly two hundred
species in this country. The chinch-bug is about one sixth of an
inch long, of a jet-black color, with the fore-wings white with a
distinct triangular black spot at the middle of the outer margin.

Fig. 162. The false chinch-bug (i\3o/«j^r/W?^Schill.).
(Much enlarged)

a, injured leaf ; b, last stage of nymph ; r, adult.
(After Riley)

Fig. 163. a, the northern leaf-footed plant-bug [Leptoghsstis opposittis); l>, the
banded leaf-footed plant-bug {Leptoglossiis pkyliopjis). (Twice natural size)

(After Chittenden, United States Department of Agriculture)

The young stages are red but become gray or blackish as they
grow older. It is found in all parts of the United States, but has
been most seriously injurious in the Mississippi Valley.

THE TRUE BUGS

121

The squash-bug and its relatives form another large family
{Corcidac) of some two hundred species, of which the common
squash-bug {Aiiasa tristis), which we have already considered
(p. 50), is the best-known example. In the middle and southern
states there are several nearly related species
which have the hind tibia flattened and ex-
panded somewhat like a leaf, and are known
as leaf-footed plant-bugs. The box-elder bug
iyLcptocoris trivittatns) is a common species
throughout the Mississippi Valley and Great
Plains, where it is a serious enemy of the
box elder, which is planted largely for shade.
It is blackish, with three bright red lines on the
prothorax, and with fore -wings having edges
Fig. 164. Box-elder and veins of a dingy red.

bug (Lepiocoris trivit-
tatns). (Twice natural
size)

(After Kellogg)

ORDER PaRASITA

As their name indicates, the members of
this suborder are parasites upon man and other
mammals, being commonly known as lice. They may well be called
the true lice, or sucking lice, to distinguish them from the bird-lice
{Mallophaga), plant-
lice {Aphididac), and
other insects com-
monly called lice.
They are small, soft-
bodied, wingless in-
sects, with a stout,
unsegmented beak,
either without eyes or
with only simple eyes,
and the tarsi bear but
a single claw, all of
these characters indi-
cating a degenerate
group. The head-louse infests the hair of man, and the body-
louse, or grayback, as soldiers term it, lives in and lays its eggs in
the seams of clothing. The general appearance, greatly enlarged.

man. (Greatly

lice affecting
enlarged)

<?, crab-louse {Pthirius 'mguhialis Leach) ; h, head-louse""

{Prttiailiis caf'His De G.). (<?, after Denny ; b, after Packard ;

from Osbom, United States Department of Agriculture)

122

ELEMENTARY ENTOMOLOGY

of these vermin is sliown in Fig. 165. Similar species infest horses,
cattle, and other domestic animals, as well as many wild mammals.

Suborder Homoptera

The cicadas {Cicadidae). The common dog-day harvest-fly
(Fig. 166) is the best known example of this interesting family;
and although we seldom see it, we are made aware of its presence
on a hot summer day by the shrill calls answered back and forth
from the tree tops. It is black and green in color, more or less
powdered with white beneath. The most remarkable member of

Fig. 166. Dog-day harvest-fly [CicaJn t/biieii), female
(After Lugger)

the family is the periodical cicada, often improperly called the
seventeen-year locust, from its habit of appearing in immense
numbers every seventeen years. It is of course entirely unrelated
to the true locusts, or grasshoppers. The adults lay their eggs in
the twigs of trees, often seriously injuring young fruit trees, as the
twigs or stems die beyond the point of the egg puncture. The
nymphs drop to the ground upon hatching and, burrowing into
the earth, feed upon the roots of trees for sixteen years. The
seventeenth year they emerge in immense numbers within a few
days, crawl up the trunks of trees, fences, buildings, etc., and trans-
form to the adults, which are blackish, with orange markings on
the wings. For the next few weeks the air is filled with their
shrill cries, and soon many affected trees turn brown as a result of

Fig. 167. Periodical cicada

tr, adult; ^, young nymph (enlarged); c, cast skin of full-grown nymph; d, side view of

female to show beak, e, and ovipositor, /. (Natural size except /'.) (After Marlatt and Riley,

United States Department of Agriculture)

Fig. 168. Buffalo tree-hopper and twig of apple tree showing eggs and adult

Adult (enlarged) at left ; a, adult (natural size) ; i, recent egg punctures ; c, bark reversed

with eggs in position; d, single row of eggs (enlarged); e, wounds of two or three years'

standing on older limbs. (After Marlatt, United States Department of Agriculture)

123

124

ELEMENTARY ENTOMOLOGY

Fig. 169. The bittersweet tree-hopper {Ein-henopa

binoiata Say). Adult (side and back views) and egg

mass. (Much enlarged)

(.\fter Lugger)

their ^^^ laying. The different broods have been carefully mapped,

so that it is possible to foretell the appearance in any given locality

where the insect occurs.^

Plant-hoppers. The next three families may be grouped together

under the term "plant-hoppers," as they jump off suddenly when

disturbed. They are
small insects, usually
not over one fourth
of an inch long, and
suck the sap from the
leaves and stems of
their food plants. The
tree-hoppers {Mcvi-
bracidac) have been
called the "brownie
insects," for their bi-
zarre shapes are often

comically grotesque. The prothorax is prolonged back over the

abdomen and is often produced forward or up-
ward into horns or crests, as shown in Fig. 169.

One of the most common species is the buffalo

tree-hopper (Cercsa bnbabis), which lays its eggs

in the stems of weeds and young fruit trees,

causing large knotty scars on the twigs. Another

small brown species {EncJicnopa binotatd) is

common on the bittersweet vine, the projecting

prothorax looking exactly like a thorn on the

stem. Few species of this family are sufficiently

numerous to do serious damage.

Here and there on weeds, grass, and tree

foliage will be found a little mass of froth, within

which may be found a small nymph, which is

busily pumping the sap out of the plant, thus

causing the froth which was formerly supposed

to be voided by tree frogs and was termed ' ' frog

spittle," — hence the insects of this family

Fig. 170. Mass of spit-
tle produced by the
nymph of a frog-hop-
per, or spittle-insect

^ vSee Bullethi A'c. 7/, Bureau of Entomology, United States Department of
Agriculture, for a very complete and interesting account.

THE TRUE BUGS

125

(Cercopidae) are called "' frog-hoppers " or "spittle-insects." Within
this frothy mass the little nymph molts and grows and finally
forms a little clear space about its body, around which the foam dries,
forming a little chamber within which it transforms to the adult.
Though very commonly in evidence, few of this family are injurious.
The leaf-hoppers {Jassidae) are among the most abundant of the
Homoptera. Take a net and sweep back and forth in any meadow
and you will secure hundreds of
them. Professor Herbert Osborn
having estimated that frequently
over a million live on an acre of
grassland. They are more slender
than the two preceding families,
from an eighth to a fourth of an
inch long, and of a brownish,
green, or red color, the green and
red often being arranged in stripes,
giving a very striking coloration.
The grape leaf-hopper {TypJilo-
cyba comes), commonly called the
grape thrips (although it is not a
true thrips), is one. of the most
serious enemies of the vine. In
late summer the foliage will often
be brown as a result of their work,
and a slight jar will cause them
to fly off in clouds. They are
small yellowish hoppers, scarcely
an eighth of an inch long and
strikingly marked with red and black. A yellowish-green species,
the rose leaf-hopper {Eiupoasca jvsac), often does considerable
injury to rose foliage, and a similar one, the apple leaf-hopper
{Eiupoasca mali), is found on the apple and frequently becomes a
serious pest in the nursery. The presence of these leaf-hoppers
is always indicated by the numerous white cast skins of the nymphs
clinging to the undersides of the leaves. Leaf-hoppers fly to lights
in large numbers. They hibernate as adults, and the eggs are
usually laid just beneath the surface of the leaf of the food plant.

Fig. 171. ApJnvphora 4-notata Say,
a common frog-hopper

(After Lugger)

Fig. 172. Three cotton leaf-hoppers, commonly called "sharpshooters."
(Much enlarged)

«, Aulacizes irroraia ; b, Oiicoinciopia undata : c, Oncivneiopia lateralis. (Authors' illustra-
tion, United States Department of Agriculture)

Fig. 173. Grape leaf-hoppers. (Much enlarged)

a and b are female and male of typical comes variety ; c represents the vitis variety ; rt', newly

hatched nymph ; e, last stage nymph ; /, injured leaf ; g, cast skins. (After Marlatt, United

States Department of Agriculture)

126

THK TRUE BUGS

127

The psyllas, or jumping plant-lice {Psyllidae), look much like
miniature cicadas, but are more nearly related to the true plant-lice,
exuding sweet honey-dew like the plant-lice but differing from them
in being very agile in the adult stage, giving a quick jump with their
strong hind legs and flying off at the slightest disturbance, whereas
the true plant-lice are exceedingly sluggish. The best-known example
is the pear psylla {Psylla pyricola), the adult of which (Fig. 174, a)
is not over a tenth of an inch long but which occurs in such enormous
numbers that it sometimes entirely ruins large pear orchards by
sucking the sap from the foliage. It has been most injurious in
the Middle Adantic States. It exudes a large amount of honey-dew,

Fig. 174. The pear psylla. (Greatly enlarged, in different proportions)
a, adult ; b, full-grown nymph from above ; c, egg. (.After Slingerland)

which covers the foliage and bark, on which grows a sooty black
fungus which is a good indication of the presence of the pest.

The plant-lice, or aphides (Aphididae), are the most abundant and
possibly the most destructive family of all the Hemiptera. Florists
commonly call them green-flies, which term may refer to several
species. Usually they are not over a tenth of an inch long, and
the wingless forms are more or less pear-shaped, with long legs
and antennae, and the common forms have two tubes projecting
from the abdomen, called honey-tubes. The vast amount of
injury done by them is chiefly due to their remarkably rapid power
of reproduction. During the summer the females will give birth
to from fifty to seventy-five young during a week or two, which
will become full grown in from one to two weeks. All of these

128

ELEMENTARY ENTOMOLOCxY

prove to be females, there usually being no males during the
summer, and each gives birth to a similar number of young, the
egg stage being passed within the body of the female and the young

being born alive. Thus
generation after gener-
ation is produced, and a
simple arithmetical cal-
culation will show that
the resulting progeny
must soon become suf-
ficiently numerous to
entirely destroy the veg-
etation from which the
myriad little beaks are
pumping out the sap.

Fig. 175. Wingless female pea aphis and newly
born young. (Enlarged)

In the fall true males and females usually appear, and eggs are
laid which hatch in the early spring. Most species are wingless
until the food supply commences to get short, when the next gen-
eration develops wings and migrates to new food plants. Many
species have winged generations in the spring and fall, which

Fig. 176. Apple aphis, last stage nymphs of winged females on undersurface of

apple leaf

migrate to and from the summer food plants to others upon which
they feed in fall and spring, and upon which the winter eggs are
deposited. Many plant-lice exude an abundance of a sweet liquid

THE TRUE BUGS

129

o.M

Fig. 177. Aphis

eggs on twig.

(Natural size)

(After Weed)

called honey-dew, and are constantly attended by ants, which
eagerly devour it. In the case of several species the ants care for
them almost as if they were their domestic animals,
and very commonly ants are responsible for carrying
the aphides from one plant to another as the food
supply becomes exhausted, as in the case of the melon
aphis and the strawberry root-louse. Among the more
common species are the common green apple aphis
{Aphis ponii), the cabbage aphis, the pea aphis, which
often destroys entire crops of garden peas in the At-
lantic states, the green bug ( Toxoptera graviiiiiim),
which has recently been so
injurious to grain crops in
the southwest, the melon
aphis, the rose aphis, the
chrysanthemum aphis,
and a host of others. The
foliage of almost every
plant is attacked by one
or more species, and many of the most in-
jurious attack the roots, as the corn root-
aphis {Aphis inaidi-radicis), which is one
of the most serious corn pests in the Miss-
issippi Valley. The grape phylloxera, an
American species attacking the roots of
the grape, was imported into Europe and
soon became the worst enemy of the vine
in France, where it has caused the loss
of millions of dollars. Several species
exude a cottony mass of wax over the
body, so that they appear like a mold.
Among these the woolly apple aphis is
often seen on the leaves and on wounds
and scars on the bark of apple trees, and
a similar species covers the twigs of alder
as if they were wound with cotton.

The scale insects (Coccidae). Some of the worst insect pests of
the fruit orchard belong to the scale insects, which are so peculiar

Fig. 178. Tip of dock stem
covered with black aphides

Fig. 179. Melon aphis. (Greatly enlarged)

rt, winged female ; a' , enlarged antenna of same ; ab, dark female (side view), sucking juice

from leaf ; b, young nymph ; <:, last stage of nymph of winged form ; d, wingless female.

(After Chittenden, United States Department of Agriculture)

Fig. 180. Mealy-bug {Daciylopius longifilis), female and winged male. (Enlarged)
(After Comstock, United States Department of Agriculture)

THE TRUE BUGS

131

in form that they would not be readily recognized as insects, were
their complicated life histories not known. Three quite distinct

Fig. 181. The cochineal insect
a, on cactus ; b, male : c, female (enlarged). (From Riverside Natural History)

groups may be readily distinguished. The mealy-bugs are fre-
quently found on greenhouse plants, and are so named from their
mealy covering of wax and the numerous white, waxy filaments

Fig. 1S2. The peach lecanium, or terrapin scale

Adults at left (much enlarged and natural size) ; young at center and unfertilized female at
right (much enlarged). (.After Howard, United States Department of .Agriculture)

which are given off from their bodies. They are from an eighth to
a quarter of an inch long, and move about slowly over the plant,
retaining: their les:s throughout life. The soft scales include those

132

ELEMENTARY ENTOMOLOGY

Fig. 183. The hemispherical scale
{Lecanium hemisphaericum Targ.)

(T, scales on olive (natural size); b, three
female scales (considerably enlarged); r,
female scale lifted from leaf, showing mass
of eggs (enlarged). (After Marlatt, United
States I3epartment of Agriculture)

of the genus Lecaninni and their
near relatives, and are known as
Lccaniums. They are usually of
a brownish color, quite strongly
convex (often ridged), and are
soft and easily crushed, — hence
the name. The upper surface
of the female gradually hardens,
and upon ma-
turity she dies
and the old skin
forms the scale
which covers the
eggs laid be-
neath it. The
Lecaniums occur upon various greenhouse plants
such as crotons, upon the peach and plum,
and upon citrous fruits. The
cottony maple scale is a
species common on maple
shade trees and gives off
a mass of cottony wax in
which the eggs are laid.

The. armored scales are
much smaller, flat, circular,
or elongate in outline, and
include our most common
species. Upon hatching, the
young scale insect crawls about for an hour or
two and then settles down, inserts its beak in
the leaf or bark, and henceforth the females
remain in the same place. Soon waxy fila-
ments commence to exude from the body,
which mat down into a small scale covering
the insect. When the skin is molted, it is

added to the center or one end of the scale,
Fig. 185. The oyster- , . , . , ,, , , ,

shell scale on poplar twig which IS gradually enlarged and assumes a

(Photograph by Weed) characteristic shape. With the first molts the

Fig. 184. The cot-
tony maple scale
(Enlarged)

(After Comstock)

THE TRUE BUGS

133

female loses her legs and eyes, and the body becomes a mere mass
of yellowish protoplasm with long, threadlike mouth-parts and a
characteristic fringe of plates
and hairs at the tip of the abdo-
men, by which the species is
principally distinguished. They
are named armored scales be-
cause the scales of this group
are mere coverings and form no
part of the insect. The scales
of the males are much smaller
than those of the females, and
after the second molt the male
goes into a true pupa stage
(otherwise the Hemiptera have
incomplete metamorphosis), the
legs, wings, and antennae being
outlined, and with the next molt
the adult male emerges from the scale and flies to fertilize the fe-
male. The adult males of all the Coccidae have but a single pair of

Fig. 186. Female San Jose scale, mature
female insect removed from beneath it.

(Greatly enlarged)

(After Alwood)

Fig. 187. (7, winged male San Jose scale (much enlarged); b, young scale insect
(enlarged 125 times)

(After Alwood)

wings, like the flies {Diptera), and bear long antennae and usually
one or two long processes from the tip of the abdomen. They are
very small whitish or yellowish insects, and usually fly at night, so

134 ELEMENTARY ENTOMOLOGY

that they are rarely seen unless reared from the scales. Among the
most common of the armored scales are the oyster-shell bark-louse (so
called on account of the resemblance of the brown scale to an oyster

Fig. i88. Peach twigs infested with San Jose scale. (Much enlarged)

At left, large mature female and small young scales are clustered in a groove of the

twig. At right is shown a large female scale with the scale proper raised, showing the

insect beneath. (After Britton)

shell), which is common on apple and several shade trees ; the San
Jose scale, possibly the most serious pest of fruit trees ; the rose scale,
common on roses, raspberries, and blackberry canes ; and the various
flat scales found on palms and other greenhouse and house plants.

THE TRUE BUGS
Summary of the Hemiptera

I. Spborder Heteroptera. Wings unlike.
I. Aquatic bugs.

The water-boatmen (Corisidae).
The back-swimmers {Notoiteciidae).
The water-scorpions {Xepidae).
The giant water-bugs {Belostomidae).
The water-striders {Hydrobatidae).

2. Predacious bugs.

The assassin-bugs {Rediiviidae).

The long-legged bugs {E/;iesidae).

The damsel-bugs {A'adidae).

The ambush-bugs {Phytnatidae).

The bedbugs [AcantJiidae).

The^Trk-bngsror-sfeteki-ghaped bugs (/^£/iiiz/<Jw»Vjfetf).

3. Plant bugs. ,

The stink-bugs, or-^hield-shaped bugs {Pent(itomida&).
The lace-bugs {Tingitidae).
"^-' The leaf-bugs {Capsidae).

The red-bugs {Pyrr/iocon'dae).
The stilt-bugs {Berytidae).
The chinch-bugs {Lygeidae).
, ■ The squash-bugs {Coreidae).

II. Suborder Parasita'. Wingless parasites of animals.

III. Saborder Ho mop fern. Wings alike, translucent.

1. The cicadas (Cicadidae).

2. The plant-hoppers.

The tree-hoppers {Membracidae).

The frog-hoppers, or spittle insects (Cercopidae).

The leaf-hoppers (Jassidae).

3. The psyllas, or jumping plant-lice {Psyllidae).

4. The plant-lice {Aphididae).

5. The scale insects (Coccidae).

135

CHAPTER XII

THE BEETLES {COLEOPTERA)

Characteristics. Fore-wings, horny or leathery, forming wing-covers (elytra),
which meet in a straight line down the back ; hind-wings, membranous, tips
folded back under the wing-covers when at rest ; mandibulate mouth-parts ;
metamorphosis, complete.

The hard wing-covers of this order are so characteristic that a
beetle is commonly recognized as such, and they have given the

Fig. 189. A water-scavenger beetle with wing-covers and wings expanded
as when in flight. (Natural size)

(After Folsom)

order its scientific name, from colcos (a sheath) and pteroii (a
wing). The beetles form one of the largest orders, with over twelve
thousand species in America north of Mexico, belonging to some
eighty families, only the most common of which will be mentioned.
They have a complete metamorphosis, the larvae being commonly
called grubs, and the pupae are usually found either in the ground

136

THE BEETLES

137

or in the foodstuff of the larvae. Both larvae and adults have biting
mouth-parts, similar to those of the grasshopper, the structure vary-
ing with the food habits of the species.

The families of beetles are divided into several groups, based
largely on the structure of the tarsi and antennas, which aid the
student in their identification. The order is primarily divided into
the typical beetles (Colcoptcra gcjuiina), in which the head is nor-
mal, and the snout-beetles {RJiyncJiopliora), in which the head is
prolonged into a snout, or beak, at the tip of
which are the biting mouth-parts.

The Typical Beetles {Coleoptera

GENUIX.A)

Four principal sections of the families of
typical beetles are distinguished by the num-
ber of segments in the tarsi.

I. BEETLES WITH FIVE-JOINTED TARSI
(PEA'TAMERA)

The first section is distinguished by all of
the tarsi being composed of five segments,
and is divided into four tribes according to
the structure of the antennse.

The Carnivorous Beetles {Adephagci)
The carnivorous, or predacious, beetles
include several families, all of which feed
upon other insects and are therefore bene-
ficial. The antennae are threadlike, with dis-
tinct, cylindrical segments.

P^iG. 190. A tiger-beetle
{Cicindela livibata). (Hair
line shows natural size)

(After Bruner)

The tiger-beetles {Cicindelidae). Along sandy paths, roadsides, rail-
road embankments, and in similar open, sunny spots, the tiger-
beetles fly up and dart swiftly ahead as one approaches. They
are swift runners and stalk their prey on foot. Most of our com-
mon species are either a brilliant, metallic green or a brownish-
bronze, banded or spotted with yellow. The larvae live in little
burrows in the ground, the head appearing at the opening so that
the eyes command the surroundings, and any unwary passing insect
may be seized with the strong jaws. Toward the tip of the abdomen

1^.8

ELEMENTARY ENTOMOLOGY

is a decided hump, and surmounting it are strong, curved spines
which serve as an anchor, so that a captured insect cannot drag the

larva from its burrow. The vo-
racity of these beetles makes the
name "tiger-beetle" fitting, but un-
fortunately they are of little bene-
fit to the farmer, as they do not
frequent cultivated fields, and though they de-
stroy many insects, but few of them are of any
economic importance. The brilliant green species
are favorites of collectors, and one must be some-
thing of a sportstnan to secure many of them, so
readily do they fly. Like many other active insects
they may often be easily caught towards sundown.
Ground-beetles. LTpon turning over a stone
or a log, one frequently sees small, flat, black
beetles scurrying away, which belong to the fam-
ily of ground-beetles (Carabidac). Their name is
Fig. iqi. A tiger- . ' ,. . .,.,,. i • i i n

beetle and its lar- mdicative ot their habits, as their long legs nt

va in its burrow.

(Natural size)

(After Linville and
Kelly)

them for chas-
ing rapidly over
the ground in
pursuit of small
insects, though
some of them
ascend trees in
search of cater-
pillars. This is
a large family,
which has some
twelve hundred
species in this „ . ju .1 /^ / x ^ j-

^ riG. 192. A ground-beetle (Caiosoma sp.) feeding

country, and as cutworm ; below, a species of Carabits

both larvae and (After Brehm)

THE BEETLES

139

adults feed on many of our most noxious insects, ground-beetles
must rank among the farmer's best friends. The larvae livejn the
ground, or in places similar to those of the -adults, and are also pre-
dacious. The larvae are elongate, the body tapering slightly at either
end, with the strong jaws projecting in front and^wo bristly append-
ages at the tip of the abdomen. Our largest common species is the
searcher [Calosoma scrutator), whose wing-covers are a beautiful,
green or violet, mar-
gined with reddish, and
whose body is , marked
with blue, gold, green,
and copper. It fre-
quently ascends trees in
search of caterpillars,
and, with nearly related
species, often does good
work in destroying large
numbers of them when
they become overabun-
dant. A European spe-
cies of this genus has
recently been imported
into Massachusetts to
prey upon the gypsy-
moth caterpillars. A
medium-sized species
with yellowish-red head
and thorax and bright
blue wing-covers {Lclna
grandis) (Fig. 195) has

made a name for itself as an enemy of the eggs and lar\'ae of the
Colorado potato-beetle. Our most common species are from one
fourth to one half -an inch long, either shining black or with
greenish, bluish, or coppery reflections, and very frequently fly to
lights in considerable numbers. Their larvae feed on soft-bodied
insects which go into the ground to pupate, such as the plum
curculio and others, while the larger ones are among the most
important enemies of cutworms and various caterpillars.

P'lG. 193. European ground-beetle [Calosoma

syccphaiita) imported to prey on the gypsy

and brown-tail moths

(After Howard, United States Department of Agriculture)

140

ELEMENTARY ENTOMOLOGY

The predacious diving-beetles (Dytisci-
dae) are to be found in any pond, where
they may be seen suspended at the sur-
face of the water with the tip of the abdo-
men thrust up so that air may be drawn
in under the elytra, or diving here and
there after their prey, which consists of
any insects that they can overpower, small
aquatic animals, and occasionally small
fish. The largest species are about an
inch long, while the commoner ones are
one half or three fourths as large and are
brownish-black, often marked with dull
yellow. The hind legs are long, flattened,
and fringed with hairs,
forming admirable swim-
ming organs. The larvse are elongate, spindle-
shaped grubs, with strong, ferocious-looking jaws,
with which they grasp and suck out the juices of
their prey, which has given them the name of
water-tigers.

Whirligig-beetles. Every pool is the home of
a school of the well-known whirligig-beetles {Gyj-i-
nidac), which chase each other over the surface,
where they feed on small insects which fall into
the water. They are usually much smaller than the last-named
family, are oval in shape, much flattened, of a jet-black color, and

Fig. 194. A ground-beetle

(Calosoma calidiim). (Natural
size)

Fig. 195. Lebia
graiidis, an im-
portant enemy of
the potato-beetle
(Enlarged)

Fig. 196. A common ground-beetle (Harpahis caliginostis). (Enlarged)
A, its larva; B, head of larva, showing mouth-parts. (After Riley)

THE BEETLES

141

are readily recognizable by the front margin of the head extending
across the eyes so that there seems to be a pair of eyes on both
the upper and the under surface.

The Chib-Horncd Beetles {Clavieoriiia)

The antennae of the beetles of this tribe are either
"^ gradually or abruptly thickened toward the tip so as

to form a club. The
common families
either live as scav-
engers or feed on
stored products,
but there is a large
series of small fam-
ilies with the most
varied habits, al-
though not many
include species of
serious economic
importance.

The water-scavenger beetles (Hydrophilidae) closely resemble the
predacious diving-beetles, but are more convex above and more
flattened below, have more highly polished wing-covers, and have

Fig. 197. A predacious diving-beetle (Dyliscits sp.)
(Natural size)

a, larva, or "water-tiger" ; /', pupa ; r, adult. (After Kellog

Fig. 198. \\'hirligig-beetles (ojvv/.-a/... ;. ^.\J,u.„l ,~:.,c;
(After Linville and Kelly)

antennae that are decidedly clubbed, though often concealed beneath
the head. They feed on decaying animal and plant tissues, though
they not uncommonly catch small insects, and the larvae feed

142

ELEMENTARY ENTOMOLOGY

entirely on insects, snails, tadpoles, etc. Both middle and hind
legs are developed for swimming and are used alternately.

Fig. 199. Water-scavenger beetles [Ilydrophihis sp.), larva, and peculiar
egg mass on leaf

(After Brehm)

Carrion-beetles {Silphidae). Wherever a dead animal has been
left exposed, the carrion- or burying-beetles may be found feeding

upon it. The more com-
mon carrion-beetles of the
genus SilpJia are of a
. broad, oval shape, much
- flattened, with small heads,
and feed beneath the car-
rion. The burying-beetles
I^NecropJionis) are much
larger, from an inch to an
inch and a half long, with
thick, stout, rectangular
bodies, and with large
.,.,,, ,^ , , heads. The common spe-

A burying-beetle {Aecrophomx sp.). ^

(Slightly enlarged) cies are blackish, marked

(After Linviiie and Kelly) with dull red. Their name

Fig. 200.

THE BEETLES

14:

Fig. 201. A carrion-beetle

{Silpha novaboraccn s is) and

larva. (One and one half times

natural size)

(After Kellogg)

is derived from their habit of excavating beneath dead animals,
which they gradually drop beneath the surface and then cover
with soil. Both adults and larvae feed on decomposing animals
and are among the chief natural agents for their sanitary disposal,
though some species are predacious and others feed on decaying

fungi. The larvae are black, flattened,
with the segments sharply marked, and
are found with the adults.

The rove-beetles {Staphylinidae). The
rove-beetles are readily recognized by
the very short wing-covers, usually not
over a third of the length of the abdo-
men. Most species are ver}^ small, but
the more common ones are from half an
inch to an inch long, with narrow, parallel-
sided bodies. They run about swiftly and
when disturbed curl up the abdomen as
if to sting. The larger common species are found with the SilpJiidae
feeding on carrion or decaying organic matter, being commonly
found in dump heaps, while the smaller
species feed on pollen, fungi, or small
insects.

Cucujidae. The saw-toothed grain-beetle
{Silvajiiis surinamensis) , which is one of
our commonest grain pests, is a good ex-
ample of the small family Cnaijidae. It
is a small, flat beetle, an eighth of an
inch long, and readily distinguished
from other small grain insects by the ser-
rated edges of the thorax. It feeds also on all sorts of fruits, seeds,
and dry pantry stores, as do the little whitish larvae. The other com-
rhon species are much-flattened beetles which live beneath bark and
feed upon small insects and fungi. One of these {Cticnjns clavipes)
is a bright red, with eyes and antennae black and tibiae and tarsi
dark, and is readily recognized by the thin body.

Larder-beetles. Every housewife knows that she must be on the
lookout for the small carpet-beetle, often called the buffalo-moth
{Anthrcjiiis s crop hit I an a), and for the larder-beetle {Dcrmcstes

Fig. 20:

A rove-beetle and
its larva

144

FXEMENTARY ENTOMOLOGY

lardarius), in stored meats or feathers. These are typical represent-
atives of a small family, Dcrmcstidac, of oval, plump beetles, the
largest being about one third of an inch long. They are usually
grayish, brownish, or blackish, marked with colors due to minute
scales with which the body is covered. All of this family feed on

Fig. 203. The saw-toothed grain-beetle. (Much enlarged)
a adult; /', pupa; r, lar\'a. (.^fter Chittenden, United States Department of Agriculture)

dried animal substances, and some of the smaller species are par-
ticularly noxious to the entomologist, as they are the worst pests
which he has to combat in his collection cases.

TJic Saxv-Honicd Beetles {Serrieornia)

The tribe of saw-homed beetles includes several families of quite
different habits, which are very loosely related by all having serrated
antennae, the segments of the antennae being prolonged inward so
as to give the whole antenna a saw-toothed or serrate appearance.

Click-beetles. Every boy knows the long click-beetles, or snap-
ping beetles [Elateridae), which, when placed on their backs, will
flop up in the air with a decided click, or snap. They are fiat,
elongate beetles, the commoner forms being about three fourths
of an inch long and of a dull brown color. The head is small and
the posterior angles of the thorax are much prolonged, giving it

Fig. 204. The carpet-beetle, or buffalo-moth. (Enlarged)
a, larva ; /', pupa in lan'al skin ; c, pupa from below ; d, adult. (After Riley)

Fig. 205. The larder-beetle. (Enlarged)
a, larva ; i, pupa ; c, adult beetle. (.Vfter Howard, United States Department of Agriculture)

145

146

ELEMENTARY ENTOMOLOGY

a characteristic shield shape. The larvae are known as wire-worms

and are among the worst pests of corn and small grains. Some

wire-worms live under bark and in
decaying wood, the adult of one of
these being the common eyed elater
{Alans ociilatits), a large species an
inch and a half long, blackish, flecked
with gray, with two large, velvet-black,
white-rimmed eyespots on the thorax,
which give it a very wise appearance.
The metallic wood-borers (Bupres-
tidae) have much the same general
shape as the click-beetles, but the
tips of the elytra are more pointed,
the beetles are
unable to spring,
and their colors
are metallic. The
adults are medi-
um-sized beetles,
often found on
flowers or bark,

and do no harm as adults. The larvse are

fiat, whitish grubs with small, brown heads

Fig. 206. The eyed elater {A/ai
ociilatus.) (Slightly enlarged)

(After Linville and Kelly)

Fig. 207. «, beetle of wheat wire-worm [Agriotes mancus) ; /', beetle of Drasterius
elegans ; c, larva of same. (Much enlarged)

(After Forbes)

thp: P]p:etles

147

Fk;. 20S. Flat-headed apple-tree borer.
(Twice natural size)

and with the prothorax greatly widened, giving them the name
'" flat-headed borers," which is also often applied to the family.

They are to be found beneath
bark, making irregular cham-
bers in the sapwood and in the
inside of the bark. Some feed
only on dead or dying tim-
ber, while others, like the
flat-headed apple-borer, attack
healthy trees and often cause
their destruction. One of the
common smaller species is the
red-necked blackberry-borer,

a, larva: /', beetle; r, Head of male; ./, pupa ^\ ^^ ^ third of an inch long,
(After Chittenden, United States Department with black Wing-COVCrS, dark
of Agriculture) , i 1 i

bronze head, and coppery
bronze prothorax. The larva bores in the sapwood of the rasp-
berry and blackberry, causing a gall-lik^ swelling, and when full
grown bores into the pith,
where it pupates.

The fireflies (Lampyri-
dae) which twinkle in the
dusk of a warm summer
evening are not really /r^? ^ ^ c

flies, but beetles, though Yig. 209. A firefly beetle {Phothius pyralis)
their bodies and wing- ,,^ la^v-a ; /», pupa in cell ; r, adult. (After Riley)

covers are much softer .

in texture than those of most beetles. Most of the fireflies are

medium-sized beetles, about half an
inch long, of dull colors, with the pro-
thorax expanded so as to cover the
head. They are nocturnal in habit,
the phosphorescent glow being pro-
duced by the underside of the ter-
minal abdominal segments. Many of

Fig. 210. Soldier-beetle {Chauii- ^j^^ females are wingless and are also

o'^)iathits pennsylvainciis) i • i i

phosphorescent, bemg known as glow-
er, larva ; l>, its head enlarged ; c, '■ '^

adult. (After Riley) worms. The larvae are predacious.

148

ELEMENTARY ENTOMOLOGY

Another group of this family, known as soldier-beetles, fly by day
and are commonly found feeding on pollen, which they carry from
flower to flower, thus aiding pollination. The common species are
yellowish with black markings and with a prominent head. The
larvae are predacious and are among the important enemies of the
larvae of the codling moth and plum curculio.

The Lcaf-Honicd Beetles {luiviellieornid)

The tribe of leaf-horned beetles includes two families in which
the terminal segments of the antennae are greatly expanded and
flattened, like plates or leaves, forming a club.

The stag-beetles (Lucanidae). There are some fifteen species of
stag-beetles in this country, which receive their name from the

Fig. 211. Stag-beetles. (Natural size)
At the left, Lucantis clcf/ias, male ; at the right, Litcaniis liama, male. (After J. B. Smith)

enormous jaws of some of the males, which are branched so as to
have a fancied resemblance to the antlers of a stag. They are
large brown or black beetles, from an inch to an inch and a half
long, and the large mandibles have given them the name of "pinch-
ing-bugs." The beetles feed on sap and decaying wood, and the
larvae, which are much like white grubs, are found in decaying
trunks and stumps. A shining black species, bearing a short horn

THE BEETLES

149

bent forward on the head, is frequently found beneath the bark
of stumps and in rotting wood, and has been termed the horned

passalus {Passaliis cofinitus).

Scarabaeidae. With over five hun-
dred species in this country, the Scar-
abaeidae form one of the largest and
most important families of beetles.
They are thick-bodied beetles of the
May-beetle, or June-bug, type, strong
but clumsy, and many have the an-
terior tibias broadly flattened for dig-
ging. They may be divided into two
main groups, the scavengers and the
leaf-chafers. The larvae of all of the
species are commonly called white
grubs, for although they vary greatly
in size and structure, they all have the
same general appearance of the white grub, with its large yellow
or brown head with strong mandibles, long legs, thick, whitish

Fig.

212. Pas sal II s corn ijtus.
(Slightly enlarged)

(After J. B. Smith)

Pig 213 bcarab beetle (4(euckus vuiiolosus) rolling egg-balls of dung, and
Egyptian sculptures of Sacred Scarab

(After Brehm)

I50

ELEMENTARY ENTOMOLOGY

body, curved, wrinkled, more or less clothed with hairs, and with
the tip segment of the abdomen enlarged. Of the scavengers, the

tumble-bugs are well known, as they
are often seen rolling balls of manure
along the roadside, which are finally
buried and in which the eggs are
laid. The fat grub feeds within this
ball until ready to pupate. The fa-
mous sacred scarabaeid was held in
high veneration by the ancient Eg}^p-
tians, who placed it in their tombs
and carved it on sarcophagi, stones,
and gems. With the first spring
days one encounters swarms of little
brown, black-spotted beetles which
fill the air. They belong to numer-
ous species of the genus Aphodius, the larvae of which develop in
manure and are often found in the dung of horses and cattle in
pastures. Some of the scavengers make burrows in the soil under

Fig. 214. A dung-beetle {Apho-
dius graiiai-iiis Linn.). (Greatly
enlarged)

(After Forbes)

Fig. 215. May-beetle [Lachnostema sp.). showing larva (or white grub),
pupa, and adult. (Natural size)

(After Linville and Kelly)

THE BEETLES

151

di'oppin<2[s. which they carry in for food for the larvae which hve
in the burrows, while others, known as skin-beetles, feed on dried
or decomposing animal matter, frequenting the refuse of tanneries
and eating the hoofs and hair of dead animals. Thus the scaven-
gers ma}' be considered as somewhat beneficial, but the leaf -chafers
include man)- of our worst pests. The June-bugs, or May-beetles,

Fig. 216. The rose-chafer

a, adult ; ^, larva ; c, d, mouth-parts of same ; e, pupa : f, injured leaves and blossoms of

grape, with beetles at work. <7, b^ <-, much enlarged ; r, d, more enlarged ; /", slightly reduced.

(After Marlatt, United States Department of Agriculture)

are among the best-known representatives of this group. They
are stout, brown, or blackish beetles nearly an inch long, which fly
in and buzz around the lights in early summer. There are some
sixty species belonging to this genus {Lachjiostcrna), the larvse of
which are the tvpical white grubs which attack the roots of grass,
corn, and garden crops. These beetles feed at night on various
shade and fruit trees, ragging the foliage as if it had been torn.
The rose-chafer is another well-known species, which destroys the

152

ELEMENTARY ENTOMOLOGY

flowers and leaves of roses and grapes. It is a pale yellowish
beetle, three eighths of an inch long, somewhat hairy, with long,
pale red legs. All of the leaf-chafers have long, spiny legs, whose
use they do not seem to have mastered, for they are ridiculously

Fig. 217. The rhinoceros beetle [Dinastes tityrus). (Natural size)
(After Kellogg)

awkward in walking. The largest beetle of this country is the rhi-
noceros beetle {Dynastcs titynis), which is two and one half inches
long, greenish-gray with black spots, and is named from the large
horn on the head, which meets a median horn extending from the

prothorax. It occurs in the South and
West, and in the West Indies there is a
similar species six inches long. Their
larvse live in the roots of decaying trees.
Another series of species are known as
flower-beetles, from their habit of feeding
on pollen, which they carry from flower to
flower. A common species of this sort is
the yellowish-brown bumble flower-beetle
{Eitphoria inda). It is half an inch long,
quite hairy, and flies from flower to flower
with a loud buzzing like that of a bumble-
bee. Occasionally these beetles assemble
on ripening peaches or other soft fruits, or lap up the sap from a
wounded tree. A bright-green species {AllorJiina nitida), two
thirds of an inch long, is very common in the South, where it is
often called the green June-bug, and frequently attacks ripening
fruits. The larvae are white grubs which live in grasslands and
often injure lawns.

Fig. 218. The bumble flower-
beetle {£■?(■/ /^^;7(Z inda). (Twice
natural size)

(After Chittenden, United States
Department of Agriculture)

THE BEETLES 1 53

II. BEETLES WITH FOUR-JOINTED TARSI {TETRAMERA)

The tarsi of the famiUes of this section are apparently composed
of but four segments, the fourth being very small and closely joined
to the last, or fifth, segment, and concealed by
the third segment, which is deeply bilobed. This
section is often called the PJiytophaga, as all of
the families attack vegetation.

The leaf-beetles (Chrysomelidae) are one of the
largest and most injurious families, there being
some six hundred species in this country, a large
number of which injure cultivated crops, while
those which normally feed on various weeds often
change their food habits and become crop pests.
The Colorado potato-beetle {Lcptinotarsa decem-
lincata) is one of the best-known species, and is
fairly typical of the family, except that it is much
larger than the average. The little black, red-and-
yellow-spotted asparagus-beetles which, with their
dark grayish, sluglike larvae, eat into young aspar-
agus, are well known throughout the East, as are
the twelve-spotted asparagus-beetles, which are red with twelve
black spots.

Fig. 219. Tarsus
of phytophagous
beetle, showing
indistinct fourth
segment

(After Comstock,
from Hunter)

Fig. 220. The common asparagus-beetle, — eggs, larva, and adult. (Much enlarged)

(After Britten)

154

ELEMENTARY ENTOMOLOGY

From North Carolina and Ohio to Maine the elm leaf-beetle
(Galeriicella Inteola) is the worst insect pest of elm foliage, both

Fig. 221. The Colorado potato-beetle. (Enlarged)

rt, beetle; /', eggs; r, young lar\'a; d, full-grown larva. (.After Chittenden, United States
Department of Agriculture)

adults and larvae skeletonizing the leaves and so defoliating trees
that, where injured annually, many are killed. The beetles are
one fourth of an inch long, yellowish-brown, with black stripes at

THE BEETLES

155

the outer margin of the wings, and the full-grown larvae are half
an inch long, orange-yellow, with numerous black tubercles. The

Fig. 222. The elm leaf-beetle

I, cluster of eggs; la, single egg; 2, newly hatched lan^a : s, full-grown larva; 4, pupa;

J, overwintered beetle ; 6, newly transformed beetle ; 7, leaf showing work of grubs and a few

holes eaten by beetles ; 8, leaf nearly skeletonized by lar\'as ; 9, leaf showing holes eaten by

beetles. (.•Ml enlarged except 7, 8, g, which are slightly reduced.) (After Felt)

^56

ELEMENTARY ENTOMOLOGY

Fig. 223. Striped
cucumber-beetle

Striped cucumber-beetle {Diabrotica vittatd) is about
the same size, bright yellow with black stripes, and
is one of the worst pests of young cucumber and
melon vines. The larvae are long, slender whitish
grubs which feed on the roots. The twelve-spotted
Diabrotica is green with twelve black spots, with
similar food habits in the adult stage, but in the
South the larvae do serious injury to the roots of
corn, while the larva of another pale green species,
known as the west-
ern corn rootworm,
is one of the worst
pests of corn in
the northern Miss-
issippi Valley. A
large group of small
species, with strong
hind legs which en-
able them to give

1 11 ■ Fig. 224. A, potato flea-beetle ; 7>, egg-plant flea-beetle

remarkable lumps, /« *u ^i i jv

J ^ ' I Both p^reatlv enlarp-edl

are known as flea-
beetles. The potato
flea-beetle (Epitn'x fnscnla) and nearly related species are com-
monly abundant on young potato and tomato plants, and on egg-
plants, the leaves of which are
riddled as if they had been hit
with fine bird shot. The larvae are
small, slender white grubs, which
feed on the roots of various weeds
of the same botanical family, and
are rarely seen. All the garden
\ V^i^^ \S^H^i crops, as well as tobacco and corn,

J ^^Jw \^^^ i 1 are attacked by one or more spe-

cies of these flea-beetles. The lar-
vae of a few species of this family
are leaf miners, the leaves of the
locust being commonly affected by
large, brown, blisterlike mines due

Both greatly enlarged)
(After Chittenden, United States Department of Agriculture)

Fig. 225. Striped turnip flea-beetle
(Greatly enlarged)

.'z, larva ; /', adult. (From Riley, United
States Department of Agriculture)

THE BEETLES

157

to the larvae of the locust-beetle {O don tot a dorsalis). On morning-
glory and sweet-potato vines are found some striking little beetles,

Fig. 226. The leaf-mining locust-beetle (Oiiontota Jorsalis).
(Five times natural size)

a, beetle ; /', lan'a ; r, pupa. (After Chittenden, United States Department of Agriculture)

called tortoise-beetles, from their tortoiselike shape, several of
which are a brilliant gold or silver color. The larvae feed on these

Fig. 227. The golden tortoise-beetle {Coptocycla bicoloy Fab.) ;
egg at right. (Enlarged)

a, b, larvae ; c, pupa ; </, beetle. (After Riley)

plants, and are curious little creatures, canying a mass of excre-
ment over the back, which has given them the name "peddlers."

158

ELEMENTARY ENTOMOLOGY

The pea-weevil family {Bruchidae) includes the small weevils
which commonly infest peas, beans, and other seeds. They are of
much the same general shape as some of the leaf-beetles, but the

head is prolonged into
a blunt snout, and the
wing-covers are square
at the tip, leaving the
tip of the abdomen ex-
posed. They are from
one eighth to one fourth
of an inch long, brown-
ish or ashen gray in
color, with whitish scales
or hairs on the wing-
covers, forming various
markings. Both beetles and larvae feed on seeds of leguminous
plants, of which they are the most serious insect pests.

The long-horned beetles {Cerambycidae) are easily recognized by
the long antennae, which are rarely shorter than the body and
often are twice as long. They are large, stout, cylindrical-bodied

c

(Enlarged)

a, adult beetle ; b, larva ; c, pupa. (After Chittenden,
United States Department of Agriculture)

Fig. 228. The pea-weevil.

a c

Fig. 229. The common bean-weevil. (All enlarged)
a, beetle ; b, larva ; c, pupa. (After Chittenden, United States Department of Agriculture)

beetles, usually strikingly colored and patterned, attracting imme-
diate attention. The larvae are cylindrical white grubs which bore
in the heartwood of trees and are termed round-headed borers, in
contrast to the flattened forms of the Biiprestidac. The family is a

Fig. 230. The round-headed apple-tree borer, — larvas, adults, and exit hole.

(Natural size)

(After Rumsey and Brooks)

Fig. 231. Work of the round-headed apple-tree borer. (Natural size)

«, puncture in which egg is laid ; b, same in section ; c, hole from which beetle has emerged ;
/, same in section ; g^ pupa in its cell. (After Riley)

'59

i6o

ELEMENTARY ENTOMOLOGY

Fig.

232. The giant root-borer
(Friomis laticollis)

(After Riley)

large one and includes many serious pests, such as the round-
headed apple-tree borer and others with similar habits. Three com-
mon blackish species, brilliantly striped
with yellow (Fig. 234), are known as
locust-borer, hickory-borer, and sugar-
maple-borer, after their respective food
plants, which are frequently killed from
the work of their larvae. Among our
largest beetles are the prionids, the larvae
of which infest the roots of various fruit
and shade trees and herbaceous plants.
The broad-necked prionus is from one
to two inches long, pitchy black, with the
thin margin of the prothorax toothed, as
shown in
Fig. 232.
The oak-
pruner is
a slender, brown species, about three
fourths of an inch long, which lays

Fig. 233. The oak-pruner [Elaphi-
dion pai-alklum)

a, larva ; /', pupa in its burrow ; f, beetle ;
k, k, cut ends of twig. (After Riley)

its eggs in the twigs of oak, maple,
and various fruit trees. The larvae
hollow out the interior of the twigs
which are broken off by the winds,
and in these they pupate. One of
our largest species is the common
sawyer, a large gray beetle one
and one fourth inches long, with
very long antennae, whose larvae
bore into the heart of felled pine
and other softwood trees, making
large holes half an inch in diameter.
The raspberry cane-borer {Obcrca

Fig. 234. The hickurx -borer [Cyllcne
p/ctics Dru.). (Enlarged)

(After Webster)

THE BEETLES

l6l

biniacjilatd) is a black beetle half an inch long, with yellow pro-
thorax bearing two black spots. Its larva mines raspberry and
blackberry canes. The red milkweed-beetles ( Tetraopcs tctra-
opJithalmns) are always common on the flowers of the milkweed,
and the larva bore in the roots and stems.

III. BEETLES WITH TIIREE-JOINTEl) TARSI {TRIMERA)

The ladybird-beetles (Coccinellidae) form the only family of the
section Trimera, in which the tarsi have but three segments, and

Fig. 235. The convergent ladybird-beetle [Hippodamia coirjergens)
a, adult ; /', pupa ; c, larva. (After Chittenden)

the head is usually concealed beneath the prothorax. Their small
size (few being over one fourth of an inch long), their broad, oval, or
hemispherical shape,
and their characteris-
tic markings, consist-
ing of "polka-dot"
black spots on a yellow
or red background,
or red or yellow spots
on black, make them
readily recognizable,
though now and then
certain of the leaf-
beetles, which have a
general resemblance,
are mistaken for them .
Nearly all of this

Fk;

236. The spotted ladybird-beetle [Megilla
Diaculata)

«, larva; (!i, pupa ; f, adult. (.After Chittenden, United States
Department of Agriculture)

l62

ELEMENTARY ENTOMOLOGY

Fig. 237. The nine-spotted ladybird-beetle {Cocci-
tiella novemnotata), — adult and larva

(After Chittenden)

family feed on plant-lice, scales, and other soft-bodied insects,
both as adults and as larvae, and may be found wherever their
prey becomes abundant. In general the common yellow or red,

black-spotted species
feed on plant-lice,
while the smaller black
species, marked with
red or yellowish spots,
feed on scales. So
common are the lady-
birds among colonies
of plant-lice that they
are frequently mis-
taken as the parents
of the aphides, and
the misguided grower
carefully picks them off and destroys them, thinking he is elimi-
nating the cause of the aphid infestation, whereas he is really
destroying nature's most efficient agents for its alleviation. The
eggs are laid in little yellow masses on the leaves or bark where-
ever food is abundant. The larvae are commonly about one fourth
of an inch long, strongly tapering at either
end, with long legs, and often marked
with spiny processes. They run here and
there in search of food, feed voraciously
on any unlucky plant-lice or insects' eggs
which fall in their path, and, when full
grown, attach themselves to bark, leaves,
or fences by the tip of the abdomen and
there pupate, the cast larval skin often
remaining over the pupa. The beetles
hibernate over winter. The nine-spotted
ladybird {Coccinclla g-notata) is one of the larger common yellow
species, with nine black spots, and the little two-spotted ladybird
{Adalia bipniictata) is smaller, slightly broader, and frequently
associated with the former species. The twice-stabbed ladybird
{Chilocorus bividncnis) is black with a red spot on each wing-cover.
Its spiny larva is black, and, with the adult, feeds upon scale

Fig. 23S. The twice-stabbed

ladybird-beetle ( Chilocorus

biviihierus Muls.) and larva.

(Enlarged)

(After Riley)

THE BEETLES

163

Fig. 239. Pupae of the
twice-stabbed ladybird-
beetle, in cast larval
skins

IV. BEETLES WITH DIF-
FERENT-JOINTED TARSI
{HETEROMERA)

insects, often checking their increase notice-
ably. Recently a very similar species, the
Asiatic ladybird, was imported from China to
prey upon the San Jose scale, but has not be-
come established in this country. Several very
small, black species of the genus Microiveisea,
with their little black larvae, are also among
the most effective enemies of scale insects.
One of the most remarkable cases of the
utilization of a beneficial insect was the intro-
duction into California of the Australian lady-
bird {J^cdalia cardiiialis), which in a few years
was able to almost entirely subdue the cottony
cushion-scale, which was destroying the orange
trees. Unfortunately, there are some sinners
among the ladybirds, for there are one or two
large, hemispherical, black-spotted, yellow spe-
cies of the genus Epilachna, which defoliate
cucumbers, melons, and beans,

The section Hctcrovi-
era is distinguished by
having the front and mid-
dle feet with five tarsal
segments, while the hind
feet have but four ; hence
the name " different-
jointed." A number of
small, obscure families
are included in this sec-
tion, only two being of
sufficient importance to
warrant consideration.

Fig. 240. Australian ladybird-beetle [N'ovms

lardiiia/is), the enemy of the white scale.

(Natural size)

(7, ladybird larvae feeding on adult female and egg sac ;

/', pupa ; c, adult ladybird ; d, orange twig, showing

scales and ladybirds. (After Marlatt, United States

Department of Agriculture)

Fig. 241. Microweisea misella, a small black ladybird-beetle which
feeds on scales. (All greatly enlarged)

a, beetle ; /', larva ; c, pupa ; (/, blossom end of pear, showino; San Jose scales upon which

the beetles and their larvae are feeding, and pupae in the calyx. (After Howard and Marlatt,

United States Department of Agriculture)

Fig. 242. The squash ladybird-beetle

a, larva ; b, pupa ; c, adult beetle (three times natural size) ; J, egg (four times natural size) ;
e, surface of egg (highly magnified). (After Chittenden, United States Department of

Agriculture)
164

THE BEETLES

165

The darkling beetles (Tenebrionidae) live mostly under bark and
stones, are dull black, and have much the same general appearance
as the ground beetles. They are much more abundant on the

CL

T^

QQ:iX22ci=2==c:0>_

Fig. 243. The meal-worm {Tenebrio niolitor)

a, larva : ^, pupa ; r, female beetle ; r/, egg with surrounding case ; r, antenna. (.Ml except e
about twice natural size ; c, greatly enlarged.) (After Chittenden, United States Department

of Agriculture)

Pacific coast and in the Rockies, relatively few forms being found
in the East. A common species of the typical genus is the meal-
worm beede {Tcnebrio vwlitoi) which infests grain-rooms, stores,

/

Fig. 244. The striped blister-beetle

a, female beetle ; b, eggs ; c, triungulin larva ; d, second or carabid stage of larva ; c, same

as/ doubled up as in pod ; /, scarabaeoid stage ; g, coarctate larva. (All except e enlarged.)

(After Riley and Chittenden, United States Department of Agriculture)

1 66

ELEMENTARY ENTOMOLOGY

Fig. 245. The black blister-
beetle. (Enlarged)

(After Chittenden, United States
Department of Agriculture)

pantries, and wherever meal is stored. The larvae are elongate,
brown, and horny, very much resembling wire-worms, and are
kept by bird fanciers for feeding song
birds in winter. The beetle is from one
half to three fourths of an inch long, dark
brown, with square prothorax and ridged
wing-covers.

The blister-beetles (Meloidae) are so
called because their juices cause a blis-
tering of the human skin, and when
dried and powdered they were formerly
much used by phy-
sicians for blister-
ing. They are soft-
bodied beetles with
the head prominent
and attached to the
thorax by a very distinct neck. The elytra
are flexible and rounded posteriorly, so
that usually they do not cover the tip

of the abdomen,
while in some forms
the wing-covers are
quite short and the
wings are lacking.
Our common spe-
cies are about half

an inch long, dull gray or blackish, often
marked with yellow stripes, while others
are of a brilliant metallic bronze, green,
or blue. The adults often appear in im-
mense swarms and ruin garden crops.
The striped blister-beetle {Epicaiita vit-
tata) was a common pest of potatoes
Fig. 247. The white-pine before the advent of the Colorado beetle,
weevil (Pissodes strobi). (En- ^^^ -^ j^^own as the ' ' old-f ashioned potato-

larged and natural size) , ,, ™, , 1 i- i. j

bug. The larvae have a very complicated

(After Hopkins, United States ° . • .^ .^i. • r

Department of Agriculture) mctamorphosis, owmg to their pcculiar

Fig. 246. The ash-gray
blister-beetle. (Twice nat-
ural size)

(After Chittenden, United
States Department of Agri-
culture)

THE BEETLES

167

Fig. 24S. The straw-
berry weevil. (Greatly
enlarged)

(After Riley)

habits. Some of them are parasitic in the nests of bees, while the
more common forms hve on the eggs of grasshoppers, which they
de\-our in large numbers, and are quite bene-
ficial in spite of the bad habits which they
later acquire as adults.

The Snout-Beetles {Rhyxchophora)

In this suborder the head is prolonged
into a long snout, giving the names "snout-
beetles " "bill-bugs," "weevils," and "cur-
culios " to many of the common forms.
The body is
strongly com-
pact, usually
well rounded
above, and is
more or less covered with scales.
The antennae arise from either
side of the snout, are bent for-
ward, or "elbowed," and end in
a club. The larvae are soft, foot-
less, wrinkled, whitish grubs, with
brown head, often thinly covered
with short, bristh' hair, and live
mostlv in fruits, nuts, or seeds,
or under bark, though a few live
on vegetation externally. All of
the families attack plants and are
therefore more or less injurious, some of our most troublesome

pests being found in this series.
Though there are common ex-
amples of several other families,
only , three families are suffi-
ciently numerous to warrant
mention.

The curculios (Curculionidae)
are the most typical as well as the
largest family of the suborder.

Fig. 249. The cotton-boll weevil.
(Enlarged)

Fig.

150.

Head and mouth-parts of the
boll weevil larva

1 68

ELEMENTARY ENTOMOLOGY

with over six hundred species. With her long snout the female
drills into fruits and stems and drops an egg in the bottom of the

excavation. Here the larva
feeds within the food plant,
well protected against attack.
In the northeastern states a
brownish beetle, about one
fourth of an inch long, with a
white spot on each wing-cover,
known as the white-pine weevil
{Pissodcs strobi), lays its eggs
in the axis terminal of pines,
which the larva tunnels out and
kills, completely spoiling the
The plum curculio

Fig. 251. Larva of the cotton-boll weevil
in opened square. (Natural size)

shape of the tree
is the well-known little Turk which
makes the crescent-shaped punctures
on plums, peaches, cherries, and apples,
and whose grubs feed within. A
small blackish weevil, the strawberry
weevil {AntJiononms signatiis), lays

Fig. 252. The chestnut weevil

{Balanintis proboscideics Fab.).

(Natural size)

Fig. 253. A corn bill-bug

{Sphenophoriis ochreus).

(Twice natural size)

(After Webster)

its eggs in the
strawberry buds,
which it then
cuts off, and the larvae feed on the develop-
ing flowers, often causing serious loss. The
cotton-boll weevil {Authotiovius gj-andis) is
probably the most important species from
an economic standpoint, causing a loss of
over twenty-five million dollars annually.
The most striking of all the weevils are
the acorn and chestnut weevils, with snouts
much longer than the body, enabling them
to drill through the chestnut bur and de-
posit the egg within the nut, in which the
larva develops. Almost all of our common
nuts are attacked by some species of these
weevils, which often are a serious nuisance.

THE BEETLES

169

The bill-bugs (Calandridae) are from one fourth to one half of an
inch long, black, brown, or dark gray, with hard elytra, ridged and

Fig. 254. The granary weevil {Cdi/i!/ii/?-a ^-ii/ia/'ia). (Enlarged)

a, beetle ; i, lana ; c, pupa; d. the adult rice weevil {Calaiidra oryza), (After Chittenden,
United States Department of Agriculture)

sculptured. They attack corn, timothy, and other grasses, particu-
larly the coarse swamp grasses and sedges. The fat white larvae

« led

Fig. 255. The fruit-tree bark-beetle {Scolytus mgnlosus)

a, adult; b, same in profile ; c, pupa; d, larva (about ten times natural size). (After
Chittenden, United States Department of Agriculture)

live in the crowns and stems of the plants. More important are
the small granary and rice weevils {Calandra grafiana and oryza).

I70

ELEMENTARY ENTOMOLOGY

small, slender, brown weevils, one eighth of an inch long, which
are the most abundant pests of granaries.

The engraver-beetles (Scolytidae), or bark-beetles, live on the
inner bark and sapwood of forest and fruit trees, the larvae of
each brood tunneling out their little burrows in characteristic

patterns, giving them the name
of " engravers." They are small
brown or blackish beetles, often
microscopic, rarely over one eighth
and never over one fourth of an
inch long, and with the head very
slightly produced, so that they are
not readily recognized as snout-
beetles. They have stout, cylin-
drical bodies, obliquely or squarely
truncate at the tip. The larvae are
little white grubs, with brown
heads and strong jaws, which
riddle the inner bark of the food
plant and pupate in the burrows.
When the adults emerge, they make
numerous small holes through the
bark, which habit has given them
the name of "" shot-hole borers."
This family includes the most de-
structive of all our forest insects,
the losses due to them being es-
timated at over one hundred million
dollars per. annum. Almost every
tree has species which commonly
attack it in different sections of
the country, some infesting only
sick or dead timber, while others
attack the healthy trees and sweep them off over large areas, the
trees dying and giving rise to forest fires. The fruit-tree bark-
beetle {Scolytus riignlos2is) is a well-known example, infesting our
common fruit trees.

Fig. 256. Typical worK of a scolytid,
the fruit-tree bark-beetle, showing
the main galleries, the side or larval
galleries, and the pupal cells. ( Slightly
enlarged)

(After Ratzeburg)

THE BEETLES

Synopsis of Families of Beetles

Suborder Typical beetles {Coleoptera genuina)

Section i . With five-jointed tarsi {Pentamera)
~l Tribe i. Carnivorous beetles (.4 {fep/iaga)
Tiger-beetles ( Cicindelidae)
Ground-beetles {Carabidae)
Predacious diving-beetles {Dytiscidae)
Whirligig-beetles (Gyrinidae)
Tribe 2. The club-horned beetles {Cla^'iconiid)

Water-scavenger beetles {Hydrophilidae)
Carrion-beetles {SilpJiidae)
Rove-beetles {Staphylinidae)
Cucujid-beetles {Cucujzdae)
D ermestid-beetles [Dennestldae)
Tribe 3. The saw-horned beetles (Serricornia)
- Click-beetles {Elateridae)
"' Metallic wood-borers [Bupreslidae)
Fireflies {Lampyridae)
Tribe 4. The leaf-horned beetles [La/nellicof/ria)
Stag-beetles i^Lucanidae)
Scarabasid beetles [Saimbaeidae)

Section 2. With four-jointed tarsi {Tetraiiiera)
Leaf-beetles ( Chrysomelidae)
Pea-weevils {Bntc/iidae)
Long-horned beetles {Cenunbycidae)

Section 3. With three-jointed tarsi [Trwiera)
Ladybird-beetles ( Coccinellidae)

Section 4. With different-jointed tarsi {^Heteroinerd)
Darkling-beetles ( Teuebrionidae)
Blister-beetles [Meloidae)

Suborder Siiout-beetles {Rhyftchop/iora)

The curculios {Cuinilw/iidae)

The bill-bugs (Calandridae)

The engraver-beetles, or bark-beetles (Scolytidae)

171

CHAPTER XIII

THE BUTTERFLIES AND MOTHS (LEPIDOPTERA)

Characteristics. Insects with four wings, which are membranous and cov-
ered with overlapping scales ; mouth-parts, suctorial ; metamorphosis, complete.

If the wing of a butterfly or a moth is rubbed, the color is quickly
removed as a sort of powder, leaving the transparent membranous
wing. If this powder is examined with a microscope, it will be seen
to be composed of small, finely ridged scales, which are arranged

on the wings in overlapping
rows and give it the charac-
teristic color pattern. Thus
we get the name of the order,
from /epis (a scale) and pteron (a
wing). These scales strengthen
the wings and are also found
on the body and on other ap-
pendages. The mouth-parts of
the adults consist of a long,
tubelike proboscis, which is
coiled under the head when
not in use, looking, in some of
the larger moths, much like a
watch spring. It is composed
of the two maxillae, the inner
faces of which are grooved and
locked together so as to form
a tube, through which the nectar of flowers is sucked. The man-
dibles are entirely wanting. The two brushlike organs on either
side of the proboscis are the labial palpi, the balance of the labium
being poorly developed.

The larvae of butterflies and moths are known as caterpillars.
They are quite variable in shape, but our common forms are readily
recognizable as belonging to this order. They are usually cylindrical,

172

Fig. 257. Portion of wing of monarch
butterfly, with some scales removed to
show insertion-pits and their regular ar-
rangement. (Greatly magnified)

(After Kellogg)

THE BUTTERFLIES AND MOTHS

173

\

\

/

/

/

\ \

^

with a well-developed head bearing biting mouth-parts and small
ocelli on either side. The thorax bears three pairs of jointed legs,
which terminate in a single claw, and the back of the prothorax

forms a hard shield,
thepronotum. Theab-
dominal segments are
very similar and bear
frohi one to five pairs
of short, fleshy, unseg-
mented false legs, or
prolegs, which termi-
nate in a circle of small
hooks, one pair of
which is always borne
by the anal segment.
The caterpillars of
many moths pupate in
little cells, which they
hollow out in the
ground, but most of
them spin silken co-
coons, within which they pupate. Some are thin, flimsy affairs, while
others, like those of the silkworm, contain a large amount of silk
and are very firmly built, forming
a warm home for the hibernating
pupse. Butterfly larvae spin no co-
coons, and the pupa?, or chrysalids,
hang pendent from the food plant
or some near-by object, to which they
are lashed by a strand of silk around
the body.

The order is one of the largest,
including over sixty-six hundred spe-
cies in this country, and contains
many of our most serious pests, while

very few of its members are beneficial. The families are largely
distinguished by the wing venation, which is difficult to see, so that
it is exceedingly hard to arrange them in any natural and easily

f"iG. 258. Luna moth, showing pectinate, or feath
ered, form of moth antennae

(After S. J. Hunter)

Fig. 259. A skipper {Eiidamtis ba-
thyllns), showing recurved tips of
antennae

(After S. J. Hunter)

174

ELEMENTARY ENTOMOLOGY

>-i^

recognizable groups. The caterpillars of the different families may
be recognized, to a certain extent, by their habits and general
appearance. The biitterflics and motJis form two main divisions
of the order, which are readily distinguished.

Butterflies

The butterflies are day fliers, and when at rest the wings are held
in a vertical position over the back. The antennae are threadlike
and are distinctly enlarged at the tip.

The butterflies are much less numerous than the moths, both
in families and in species, and include relatively few species

of any considerable
/ -4^^^^ economic importance.
Two main groups of
butterflies are recog-
nized, — the skippers
(Hcspcriiid) and the
true butterflies {Pa-
pilionind).

SKIPPERS
The skippers are

Fig. 260. ■ Hop-merchant butterfly, showing form of ^^ ^^j^^^ ^^^^ ^^^j^.
knobbed antennas 01 butterflies

peculiar habit of dart-
ing suddenly from
place to place. The wings are held vertically over the back when
at rest, though often the hind-wings are held horizontally. The
antennae are enlarged at the tip, which usually forms a more or
less recurved hook. They have stout bodies, which resemble
moths more than butterflies. Some are blackish or dark, somber
brown, often flecked with grayish or white, while others are tawny
yellow with a blackish discal patch. The latter usually have the
fore-wings much more pointed, and have thick bodies. The larvae
of our common forms have a characteristic appearance (Fig. 261),
with large heads and strongly constricted necks. They feed on
foliage, usually concealing themselves within a folded leaf, which
is tied together with silk and within which they spin a loose cocoon

(Photograph by Fiske)

THE BUTTERFLIES AND MOTHS

175

of silk before pupating. Very few of this group are of any economic
importance, though one larva occasionally attacks the calla lily,

i^^^:4<

Fig. 261. The tityrus skipper {Epargyreiis tiiyrus), — adult, larva, and leaf-cocoon.

(Natural size)
(After Linville and Kelly)

and another sometimes injures corn in the Gulf States, perforating
the leaves with numerous holes before they unfold. The skippers
may be considered as intermediate be-
tween the moths and the true butterflies.

TRUE BUTTERFLIES

The true butterflies include four well-
defined families.

The swallowtails (Papilionidae) include
our common black-and-yellow species,
which have the hind-wings prolonged
into characteristic tails. The only species
of any economic importance is the celery,
or parsley, caterpillar {Papilio polyxenes)
known swallowtail, jet-black with the outer edge of the wings
marked with two rows of yellow spots, and a peculiar eyespot on

Fig. 262. The manataaqua
skipper [Pamphila mana-
taaqua), male. (Natural size)

(After Fiske)

The adult is our best-

Fig. 263. The black swallowtail butterfly {Papilio polyxenes). (Slightly reduced)

rt, egg; b, caterpillar; c, front view of head with osmateria protruded; d, chrysalis; e,f,
adult. (After Webster)

176

THE BUTTERFLIES AND MOTHS

177

the inner margin of each hind-wing. Between the rows of yellow
spots on the hind-wings are bluish scales, which are particularly

Fig. 264. The blue swallowtail butterfly (Laeiiins p/iilt'itor). (Reduced one fifth)
(Photograph by Fiske) -.

prominent in the females. The caterpillar is green, banded with
black and spotted with yellow, and feeds on celer)^, parsley,
parsnips, and nearly related plants. Like other caterpillars of this

Fig. 265. Caterpillar
of the troilus butter-
fly {Papilio troilus)

(Photograph by Weed)

Fig. 266. The tiger swallowtail butterfly
{Papilio glauciis iumus). (Reduced)

(Photograph by Weed) '

178

ELEMENTARY ENTOMOLOGY

Fig. 267. Three common pierid butterflies

a, native cabbage butterfly {Pon/ia napi olei-acca),

male; /', imported cabbage butterfly {Pontia ra/ac),

female ; c, the common sulphur butterfly {Einyinus

p/iilodicc), female. (Photograph by Fiske)

family it has a pair of pecu-
liar, orange-colored, mem-
branous horns, which are
protruded from between
the segments close to the
head and which give off
quite a disagreeable odor.
Evidently these are defen-
sive organs, for they appear
only when the caterpillar
is disturbed. This family
includes our largest and
most brilliant butterflies.
The spring and summer
broods of some species are
so differently colored that
they might be taken for
distinct species.

Pieridae. The family
Picridac includes the yel-
low butterflies (sometimes
called puddle butterflies,
from their habit of swarm-
ing around puddles) and
the common white cabbage
butterfly, which is almost
the only form of economic
importance in the family.
The larvae are slender

green caterpillars, clothed with short, fine hairs,
and are often finely striped, resembling the
cabbage worms. The larvae of the common
clouded sulphur {Euryinus pJiilodicc) feed on
clovers and leguminous plants, but are rarely
numerous enough to be injurious.

The gossamer- winged butterflies {Lycaenidae),
so called on account of their delicate struc-
ture, include the little blue and copper-colored

Fk;. 26S. The common

blue butterfly {Lycatma

pseiidargiolits Boisd.),

underside of female

(After Fiske)

THE r.Uri'KRlLIKS AND MOTHS

179

Fig. 269. The bronze ct
butterfly (C/i>ysop/ia>ins
Boisd.), female

(After Fiske)

ppcr
t/ioe

butterflies which flit along the road-
sides in spring. Others are blackish
or bluish above, often with two or
more fine, threadlike tails extending
from the hind-wings, and are marked
with fine, hairlike streaks on the under-
surface, which has given them the
name of " hair streaks." The larvae
are quite different from other cater-
pillars, being flat, elliptical in outline
(with the head retracted), and quite
sluglike in appearance. Very few of them
are ever injurious, the worst offender being
the cotton-square borer {Unm totes niclli-
uns), which bores into cotton squares and
occasionally attacks beans and cowpeas by
eating into the pods.

The four-footed butterflies (Nymphalidae)
include most of our common larger forms,
and are so called on account of the great
reduction of the fore-legs ; this makes
them of no service in walking, and the
legs are folded on the breast. The common monarch, or milk-
weed, butterfly {Ajiosia
plcxippus), whose green,
black-ringed caterpillars
feed upon the foliage of
the milkweed, is a good
example of the family.
The spiny elm caterpil-
lar, already described (see
p. 63), also belongs here.
The dark, reddish-brown
butterflies of the hop mer-

FiG. 271. The cotton square-borer (i'ranoies ch?int {PolygOuicZ COIHVia)
Die/linns). (All somewhat enlarged) r • . ^ r 1

'^ ' are of mterest, tor when

.dorsal viewof butterfly; ^.butterfly with wings ^j f j^ ^j j^ ragged-

closed : f, larva (side view) ; </, pupa. (After Howard, -' °Y

United States Department of Agriculture) edged wingS and alight

Fig. 270. The acadian hair-
streak (Thecia acadica Edw.),
underside of female

(Photograph by Fiske)

Fig. 272. The monarch butterfly (Anosia
plexipp2is) on thistle. (Reduced)

(Photograph by Weed)

Fig. 273. The viceroy butterfly (Ba-

silarchia archippus) and its chrysahs.

(Reduced)

(Photograph by Weed)

Fig. 274. Caterpillar and chrysalis of the monarch butterfly
(Photograph by Weed)

180

Fig. 275. Caterpillar of the viceroy
butterfly. (Reduced)

(Photograph by Weed)

Fig. 276. The myrina butterfly {.-1/
gynnis fnyrina Cramer), male

(After Fiske)

Fig. 277. Harris's butterfly [Melitaea
harrisii Scud.), undersurface, male

(Photograph by Fiske)

Fig. 278. The tharos butterfly [Phy-

ciodes tharos Dru.), female, upper

and under surfaces

(After Fiske)

Fig. 279. The American tortoise butterfly {Vanessa tnilberti Godart), upper and

under surfaces

(After. Fiske)

181

l82

ELEMENTARY ENTOMOLOGY

Fig.

2S0. Hunter's butterfly {Pyrameis hiiiiicra
Fab.), male

(After Fiske)

among dead leaves, as they frequently do when pursued in

woodland, the underwings so closely resemble the leaves as to

make them quite indis-
tinguishable. A bright,
silvery comma is seen
on the underside of
each hind-wing, which
gives the specific name.
The larvae are red-
dish or yellowish, with
black head and black-
branched spines ; they
feed on elm and net-
tles, though they are
better known as pests
of the hop-vine.
The dull, grayish-brown butterflies, with numerous eyespots on

the borders of their wings, which flit through our woodlands

like changing shadows, are known

as meadow-browns, or satyrs, and

also belong to this large family.

The larvae of the more common

species feed on grass, and may be

recognized by the caudal segment

being bifurcated.

The fritillaries, or argynnids, are

another group of common butter-
flies included in this family. They

are usually of medium size, of a

golden-brown color, marked with

rows of black spots above and with

bright, silvery spots on the under-

surface. There are several species

which are very difficult to distin-
guish, and whose caterpillars feed

on violets. One of the smaller

species, very similar to the larger

forms, is illustrated in Fig. 276.

Fig. 281
show in

Hunter's butterfly at rest,
underwing and chrysalis

(Photograph by Weed)

THE BUTTERFLIES AND MOTHS

iS

Moths

The moths fly by night, are readily attracted to lights, and
are often called millers. When at rest the wings are folded

upon or around the
abdomen. The an-
tennae are thread-
like or feathered,
but are never en-
larged at the tip.

In striking con-
trast to the butter-
flies, most of our
moths are little in
evidence, but al-
most all of their
caterpillars are in-
jurious and require
incessant fighting
to control them.
No attempt will be made to indicate the natural relationships
of the families, which will be grouped and described in such a way
as to best aid in their recogni-
tion. Several of the more un-
common families have been
purposely omitted from the
discussion.

Three large, nearly related
families of small moths are
commonly grouped together as
Microlepidoptera, on account of
their relatively small size in
contrast to the remaining fam-
ilies. The laro^er moths and the

Fig. 28:

The white-banded purple butterfly {Lunenitii
artheviis Dru.), male

(After Fiske)

Fig. 2S3. The canthus butterfly or eyed

brown [Xeoiiynnpha canihits Boisd. and

Lee), undersurface

(After Fiske)

butterflies are termed Macrolepidoptera, This grouping together
of the larger and smaller moths is a classification for the conven-
ience of the collector and is not based on any specific difference
of structure.

1 84

ELEMENTARY ENTOMOLOGY

MICROLEPIDOPTERA

The tineids {Tineidae) are our smallest moths and may be dis-
tinguished by the long, narrow wings having a broad fringe
of hair, particularly on the hind-wings, which are often very

Fig. 284. A tineid leaf-miner of the oak {Lithocolletis hainadiyadella)

a, />, larva, flat and round forms ; c, pupa ; d, moth ; e, oak leaf showing mines, with cocoons
2t/)/- (After Comstock)

narrow, with a fringe several times as broad. Many of the larvae
are leaf-miners, feeding between the surfaces of leaves, in which

they tunnel out mines
whose shape is charac-
teristic of the species;
some are linear, others
serpentine, some are
trumpet-shaped, while
others are irregular
blotches. These little
larvae are usually white,
and are very much
flattened, with small,
wedge-shaped heads,

Fig. 285. The apple leaf-miner. (Greatly enlarged)

a, moth ; i, moth at rest ; c, larva ; d, pupa. (After Quain-
tance. United States Department of Agriculture)

THE BUTTERFLIES AND MOTHS

185

with only rudiments of legs, and with the abdomen constricted
between the segments. Many of them hibernate in the fallen

Fig. 2S6. The cigar case-bearer. (Much enlarged)

(7, female moth : /', side view of pupa ; c, larva ; d, egg ; e, wing venation ; /, upper view of
cigar-shaped case with three-lobed opening at tip ; g, side view of same ; li, the case as it
appears in the spring ; /, the fall and winter case. (After Hammar, United States Depart-
ment of Agriculture)

leaves, in which they pupate and transform the next summer. A
well-known example is the apple-leaf trumpet miner {Tischeria
vialifoliclla), whose brown, trumpet-shaped mines are common in
apple leaves and
often cause con-
siderable damage.
Some of the cat-
erpillars of this
family make little
cases of silk, in
which they reside
and which are
carried over the
abdomen as they
feed on the foli-
age, much like
the shell of a

snail. Common examples are the pistol-case bearer and the cigar-
case bearer, which are common on apple foliage and are so named

Fig. 287. The case-making clothes moth [Thiea
pellionella). (Enlarged)

a, adult ; /', lar\'a ; c, larva in case. (After Riley)

i86

ELEMENTARY ENTOMOLOGY

Fig. 288. The angumois grain-moth {Sitotroga cerealella
01.). (Enlarged)

a, eggs ; b, lar\-a at work ; c, larva : d, pupa ; f ,/, moth. (After
Chittenden, United .States Department of Agriculture)

from the shapes of the cases. Nearly related to them are the little
clothes moths, the plague of every housekeeper, which feed on

woolens, furs, etc.
There are several
species: one makes
a case of bits of
food fastened to-
gether with silk,
another builds a
tube, and a third
feeds unprotected.
The more common
forms are of a
brown color and
may be distin-
guished from other
small moths which
frequent the house
by the broad fringe to the wings already mentioned. Another mem-
ber of this family which is a serious pest of stored corn in the
South is the angumois grain-moth
{GclccJiia ccTcalcUa), whose larvae
live in the kernels of corn and annu-
ally destroy millions of dollars' worth.
The leaf -rollers (Tortriddae). Here
and there on various shrubs and
plants will be found leaves which
have been rolled up and fastened
together with silk by a little cater-
pillar living within. Most of this is
done by the leaf-rollers, which are
the most characteristic of the family
Tortriddae, though by no means all
leaf-rollers belong to this group. The
oblique-banded leaf -roller {Archips
rosaceana) is found commonly on
roses and various fruit trees, occa-
sionally becoming injurious, while its

It

Fig. 2S9. The oblique-banded leaf-
roller (.-:/;r///^j- rosaceana). (Slightly
enlarged)

a, egg-mass ; b, larva ; c, pupa; d, female
moth : e, male moth

THE BUTTERFLIES AND MOTHS

187

near relative, the cherry-tree leaf-roller {A. ccrasivorana), festoons
the branches of the wild and cultivated cherries with its large nests
of leaves fastened together with silk, in which a whole brood of
the yellow larvae live and transform. Another
group of this family includes the well-known
codling moth {Cydia pomonclla), the worst pest
of the apple grower, and the eye-spotted bud
moth ( Tinctoccra ocellana), which bores in the
young buds
of the apple,
as well as nu-
merous other
larvae which
bore in the
buds, termi-
nal twigs,
fruits, and
seeds of va-
rious trees
and plants.

The pyralids. The third family, Pyralidac,
includes some half dozen families of quite di-
verse appearance and habits, among which are
the larger "micros," some of the largest having
a wing expanse of one and one half inches and
being larger than the smaller forms of the
macrolepidoptera. Many of the caterpillars be-
longing to this group attack low-growing vegeta-
tion, the garden ^
web-worm {Lo-
xostcgc siinila-
lis) being one
which now and
then becomes a
pest in various
parts of the country, attacking gar-
den crops, sugar beets and young

Fig. 291. The codling moth. (Enlarged)
(.\fter Slingerland)

Fig. 290. Web and
empty pupal skins
of the cherry leaf-
roller (.4;r////'j' cerasi-
i'oraiia). (Reduced)

(Photograph by Weed)

cotton, and corn.

The full-grown

Fig. 292. Codling-moth larva in its

winter cocoon under a bit of bark

(Enlarged and natural size)

1 88

ELEMENTARY ENTOMOLOGY

caterpillars are slightly over an inch long, yellowish or yellowish-
green, marked with numerous shining black tubercles or warts,

and may be recog-
nized by the fine
web which they spin
over the food. The
moths are of a
yellowish-buff color,
with darker mark-
ings (see Fig. 293).
The melon caterpil-
lar and the pickle-
\^"orm ( DiapJiania
hyalinata and iiiti-
dalis) are serious crop
pests in the Gulf
States, though they
occur farther north and in the West. The caterpillars are about
an inch long, yellowish or greenish-yellow, and feed on the foliage,
flowers, and fruit. Among the typical pyralids is the clover-hay

F16. 293. The garden web-worm {Loxoategc similalis)

a, male moth : b, larva, lateral view ; <r, larva, dorsal view ; d,
anal segment ; e, abdominal segment, lateral view ; /, pupa ;
g, cremaster. n,l>.c,f, somewhat enlarged; d,e,g, more en-
larged. (After Riley and Chittenden, United States Depart-
ment of Agriculture)

Fig. 294. The meal snout-moth [Pyralii farinalis Linn.). (Twice natural size)

a, adult moth ; b, larva ; c, pupa in cocoon. (After Chittenden, United States Department

of Agriculture)

worm {Pyralis cos talis), which is abundant in stacks or mows of old
clover hay, upon which it feeds and which is spoiled by being cov-
ered with its silken webs and excrement. The moth is of a lilac

THE BUTTERFLIES AND MOTHS

189

color, with golden bands and fringes, and expands four fifths of
an inch. The meal snout-moth [Py rails farina I is) also sometimes
feeds on clover ha\-, though it is more commonly a pest of meal and
flour, in which it spins silken tubes wherever it feeds. A thorough

Fic;. 295. The Indian-meal moth [Plodia iniei-piinctclla). (Enlarged)

(7, moth: /', pupa: c,f, caterpillar: </, head; c, first abdominal segment of same. (After
Chittenden, United States Department of Agriculture)

cleaning out of barns and grain rooms will usually prevent trouble
from both of these pests.

The subfamily PJiycitinac includes another pair of pests of grain
products, — the Indian-meal moth (Plodia iitterpunctcUd), whose
white larvae spin
silken tubes in
meal, dried fruits,
and other stores
which they infest,
and the Mediter-
ranean flour-moth,
which has similar
habits and has be-

FiG. 296.

The Mediteranean flour-moth {Epheslia
kiiehniella)

a, l>, moth ; c, larva ; </, pupa (enlarged) : e, abdominal segment

of larva (more enlarged). (After Chittenden, United States

Department of Agriculture)

come a xQvy serious

pest of flour mills,

clogging up the

machinery with its

strong silken webs and necessitating frequent fumigation. The only

common representative of another family is the bee-moth, whose

lar\-ae feed upon the wax of honeycombs, in which the)' make

I90

ELEMENTARY ENTOMOLOGY

silk-lined galleries, destroying the combs. They attack weak colo-
nies of bees, which they frequently destroy, and are one of the
worst enemies of the apiary. The moth has purplish-brown fore-
wings and brown
or faded yellow
hind-wings.

The close-wings
{Cranibinac) are
so called because
their winsrs are

Fig. 297. yV crambid moth [C/aiiilius inilgiva^eihis)

a, larva ; /', overground, and c, underground, tube and cocoon ;

d, e, f- moths with wings open and at rest ; g, egg much enlarged.

(After Riley)

wrapped closely
about them when
at rest. They are
also called snout-
moths. They are
the small brown-
ish or silvery-
white moths which
fly up before us
in pastures and

are scarcely distinguishable from the grass stems on which they
alight. The larvae feed on the roots and stalks of grasses, living
in little tubes constructed of bits of earth and vegetation fastened
together with silk. Several spe-

cies are sometimes quite injurious
to young corn planted on land
where they have been abundant,
the most common being known
as the corn-root web-worm.

Two other families of this group
are known as plume-moths {Ptcro-
phoridae and Orncodidae), as the
wings are split into parts looking
like a small fan of feathers. The
larvae of one species occasionally
webs up the terminals of young grape shoots, and another species
is sometimes common on sweet-potato vines, but they are rarely
of economic importance.

Fig.

29S. A California
moth. (Natural size)

(After Kellogg)

plume-

<fr ^"^

THE BUTTERFLIES AND MOTHS

191

MACRO LEPinOPTERA

Among the largjer moths are two famihes whose larvae bore into
soHd wood, though they are by no means nearly related.

The carpenter-moths (Cossidae) are medium-sized to large moths
with spindle-shaped bodies and strong, narrow wings, thus closely

^

4 *\
• •••

Fig. 299. The leopard moth. (Natural size)

17, female moth; i, male moth; c, larva in burrow; cf, pupal skin from which moth has
emerged. (From /used Life, United States Department of Agriculture)

resembling the sphinx moths. The caterpillars are all wood borers,
living from two to four years in the roots or trunks of trees. When
full grown they are from two to three inches long, usually whitish,
more or less black-spotted, with black heads bearing strong jaws.
The female moth of a common species, which lives in the locust,
has a wing expanse of three inches and is of a pepper-and-salt
color. A recently imported European species is the leopard moth

192

ELEMENTARY ENTOMOLOGY

{Ze?tac7'a pyrijid), which is seriously damaging the shade trees
of Eastern cities to which it has spread. It is white, spotted with
numerous black' spots.

The clear-winged moths (Sesiidae). The caterpillars of the clear-
winged moths also bore into the trunks and roots of trees and the
stalks of smaller plants. The wings of the moths are quite narrow
and are free from scales except along the margins and over the

Fig. 300. Peach-tree-borer moths. (Natural size)
The upper one and one at right are females, the other two are males. (After Slingerland)

veins, leaving them quite transparent. The antennae are long, and
the body is long and slender, the abdomen being commonly banded
with yellow and terminating in a tuft of scales. Unlike most moths
they are found frequenting flowers in the daytime, and may very
readily be mistaken for wasps, which they seem to mimic. The
best-known example of the family is the peach-tree-borer {Saiini-
noidea exitiosa), whose white larvae bore into the lower trunks and
roots, being probably the worst insect enemy of the peach tree.
The males are black with narrow yellow bands on the abdomen,

THE BUTTERFLIES AND MOTHS

193

and with quite transparent wings, while the females are much
larger, having fore-wings of a blackish brown and entirely covered
with scales, and a black abdomen with a broad orange band about
the middle. Other injurious species of clearwings, smaller and
more wasplike than the peach-borer, are the currant-borer {Scsia
tipjiliformis), the raspberry root-borer {Bcmbecia marginata), and
the well-known squash-vine borer {HTclittia ceto) whose whitish
larvae bore through the vines of squash and other cucurbits, often
ruining the crops. Not all clear-winged moths belong to this family,

Fig. 301. The squash-borer {Melittia satyrinifo7'mis Hbn.)- (Enlarged

one third)

(7, male moth ; ^, female with wings closed ; <-, eggs on squash stem ; d, larva ;
c, pupa ; f, cocoon

for a few of the sphinx moths (which, however, are much larger)
and one or two other families have species with wings almost
wholly free from scales.

The prominents (Notodontidae) are dull-colored, medium-sized
moths, with a wing expanse of from one and one fourth to two
inches, many of whose larvae bear strong humps or prominences
which may have given rise to the common name of the family.
The moths quite closely resemble the owlet moths, from which they
can be distinguished only by an examination of the wing venation.
The handmaid moths are of a reddish-brown color, with the fore-
wings crossed with several darker brown lines, whose larvae have
the peculiar habit of raising the head and tail and standing quite

194

ELEMENTARY ENTOMOLOGY

motionless when disturbed, as shown in the illustration (Fig. 302)

of the common yellow-necked apple caterpillar {Datana miuistra),

the specific name of which has
given the group the common
name of "handmaids." It is
common on apple trees in late
summer, the colonies of cater-
pillars stripping the foliage
back from the tips of the twigs,
and may be readily recognized
by the black head, yellow neck,
and black-and-yellow striped
body. Nearly related species
of blackish caterpillars covered
with gray hairs often defoliate
the hickory. The red-humped
apple caterpillar {Schi::2ira con-
cinna) is associated with the
above species on the apple
and has very similar habits. It
is of a yellowish-brown color,
pale along the sides, which

are marked with fine black lines ; the head is red, the fourth

segment bears a prominent red hump, and along the back there

are many short

spines. Several of

the caterpillars of

this family have

irregular humps and

prominences along

the back and are

of a green color, so

that as they feed

on the edge of a

leaf they are not

easily distinguished

from the ragged

leaf edge. Most of

Fii;. 30 J. The yellow-necked apple cater-
pillar {Dataiia ?ninistra). (Larvas natural
size and moth slightly enlarged)

Fig. 303. The red-humped apple caterpillar feeding in
characteristic position. (Natural size)

(After Britton)

THE BUTFERFLIKS ANU MOTHS

195

Fig. 304. Antlered maple worms {Ilctcro-

campa gittivitta), showing variation in

color markings. (Slightly enlarged)

our commonest species feed
on shade and forest trees, but
rarely do widespread damage.
An exception to this is the case
of the antlered maple worm
{Hcterocampa gutivitta), which
stripped thousands of acres of
maple and beech along the
mountain sides from central
Maine southwest totheAdiron-
dacks in the summers of 1908
and 1909. These caterpillars
are bright green with a saddle-
shaped mark of purple, and when just hatched from the eggs have
small, branched antlers just back of
the head. The eggs of this family
are laid on the foliage of the food
plant, and the larvae descend to the
ground to pupate, the pupae usually
remaining in the soil over winter.

The measuring-worms (family
Geometridae) are the caterpillars of a
large family ; they have but one or
two pairs of abdominal prolegs, so
that as the middle of the body is
unsupported they are unable to walk
like ordinary caterpillars, but loop
along in a characteristic fashion, which has given them the com-
mon name of " inch-worms " or
" measuring worms." Many of
them will stand with the body
stretched out stiff and motion-
less, so that they are readily
mistaken for broken twigs and
are probably passed over by
T7 /-nvTuri. J,- J birds seeking food. Although

Fig. 306. Moth of the red-humped ° . . ^

oak caterpillar there are no absolutely distmc-

(AfterWeed) tivc characters by which the

¥iG. 305. Red-humped oak cater-
pillars {Sym/fwr/s/a alhifrotis) on
oak leaf. (Reduced)

Fig. 307. Caterpillar of A'erice biJeiitata feeding on leaf, showing resemblance
of contour to edge of leaf

(After Packard)

Fig. 308. The chain-dotted geometer feeding on sweet-fern. (Slightly reduced)

THE BUTTERFLIES AND MOTHS

197

moths may be readily recognized, their slender bodies, small heads,
and broad wings, which are usually noticeably thin and frail, give
them a characteristic appearance. They frequent forests and edges
of woodlands, and though a few are orchard pests, and others
affect the bush fruits,
nearly all of the cater-
pillars feed upon the
foliage of forest or
shade trees, and but
few frequent low-grow-
ing vegetation. The
moths vary from less
than an inch to over
two inches in wing
expanse, but are mostly
of medium size. The
wings remain spread
when at rest. Possibly
the best-known exam-
ples are the canker-
worms, which attack
the foliage of fruit and
shade trees in early
spring and drop down
from the trees on their
silken threads. The
females of the canker-
worms and some nearl)'
related species are wing-
less and look much
more like fat spiders
than moths. The chain-
dotted geometer {Cin-
gilia catenaria) is a snow-white moth marked with zigzag lines
and dots of black. Its larv^ae feed on various low-growing shrubs
and trees and sometimes appear in great numbers, as was the case
in New Hampshire in 1906, when many acres of sweet fern and
scrub birches were stripped. The larvae are of a bright straw yellow,

Fig. 309. The chain-dotted geometer (Chigilia

catenaria) ; larva ; larva spinning cocoon ; pupa in

cocoon; moth. (Slightly enlarged)

z --

J- o

O N

THE BL irKRlLlES AM) MUTILS

marked witli six black lines
and with a l^lack dot on the
side of each segment. The
currant span-worm {Diastictis
rilnaria) is a yellow, black-
spotted looper, which often
appears in such numbers on cur-
rant and gooseberry bushes as
to defoliate them very quickly.

The moths are pale yellow,
marked with irregular, dusk)-
spots. Most of the moths of
the subfamily Gcomctrinac are
of a green color with the wings
barred more or less distinctly
with whitish lines. The larvae
of one of these, the raspberry
geometer {SyncJilora glan-
carid), feeds on the fruit and
foliage of the raspberry, cover-
ing itself with bits of vegetable
matter, thus masking itself
beneath what is apparently a
little heap of rubbish.

The owlet-moths {Noctuidae)
are by far the largest family of
the order, including some
twent}'-one hundred species,
" three times as many as there
are North American species of
birds," and form the great bulk
of the moths commonly taken
by collectors. As their name
indicates, they fiy by night (as do all other moths,
for that matter) and are frequently attracted to lights,
being the common " millers " of popular parlance.
They are not readily distinguished from nearly

199

Fig. 3

moth and egg

winged male of

Adult female
mass and
the fall
cankenvorm. (Natural size)

(After r.ritton)

N

r '

r

related families, nor are the species recognizable

F"iG.3i2. Canker-
worms in charac-
teristic attitudes.
(Natural size)

(After Bailey)

200

ELEMENTARY ENTOMOLOGY

Fig. 313. Drastena erechtea, female

except by an expert, though many
of their caterpillars are the worst
pests of the farm and garden and
are well known as such to the
farmer. The moths are mostly
somber gray or brown, with a
wing expanse of from one to
three inches (averaging about one
and one half' inches), and with
stout bodies. The fore-wings are

Fig. 314 a. Moth of the army-worm
{Leucatiia itnipiincta). (Natural size)

(.\fter Riley)

rather narrow, short, and stout, crossed by darker or lighter wavy
lines, and with one or two darker or lighter spots toward the
center. The hind-wings are usually plain, and when at rest are
concealed by the fore-wings, which
cover them, either fiat on the back
or slightly roof -shaped. Some of
the caterpillars are hairy like the
" woolly bears," but most of them
are smooth, dull-colored '" worms,"
obscurely striped, as are the com-
mon cutworms. Almost all of the
larvae feed on low-growing vegeta-
tion and pupate in the ground.
Among the moths most often observed are those of the northern
grass worm {^Dnxstcria erechtea). They are the common moths
with drab-gray fore-wings, crossed with two dark bands, which fly
up as one crosses a meadow or pasture. The larvae are green,

narrowly striped, and
are semiloopers, some-
what resembling the
measuring worms in
their gait. They feed on
clover, but rarely become
injurious. The common
cutworms which attack
garden and field crops
Fig. 314^. Army-worms. (Natural size) throughout the country

(After Weed) are the larvae of numerous

Fig. 315. The cotton bollvvorm, or corn-ear worm {Helioihis ohsoleia).
(Natural size)

fl, adult moth ; b, dark full-grown larva ; r, light full-grown lar\a ; </, pupa. (.After Howard,
United States Department of Agriculture)

Fig. 316. The cotton-boll cutworm {P7-odenia oriiilhogalli Guen.). (Enlarged)

<7, dark form of male moth ; b, pale form of female moth ; r, pale form of larA'a ; d^ dark

form of same ; f, lateral view of abdominal segments of dark form ; /, of pale form. (After

Chittenden, United States Department of Agriculture)

201

202

ELEMENTARY ENTOMOLOGY

Fig. 317. The dark-sided cutworm

[Agivlis i/iessoria)

(After Riley)

species of moths of this family, be-'
longing to several genera. The
army-worm {Leucajiia iinipiinctd)
is another caterpillar which or-
dinarily feeds unnoticed on rank
grasses, but occasionally becomes
very numerous and advances in
armies, destroying all crops in its
line of march. The fall army- worm
{LapJiygnia frngipci-da) has very
similar habits, but is more common
in the South and West. Two
of the most serious cotton pests are
the leaf worm {Alctia argillacia)
and the bollworm {Hcliothis obso-
leta), although the latter also attacks the ears of corn, tobacco, and
green tomatoes throughout the Middle States. A common pest of

cabbage and lettuce is
the cabbage looper {A n-
tograpJia bras si c a c), a
bright green worm with
whitish lines, which
bores into cabbages
much like the common
caterpillars of the cab-
bage butterfly. It is
known as a looper on
account of the way in
which it "humps"
along, much like a
measuring worm, be-
cause two pairs of
the usual abdominal
prolegs are lacking.

Fig. 7 1 8. The cabbage looper „ r 1 1

Some of the larger

(7, male moth ; b, egg shown from above and from side ; . r j.-l, ■ r M

r, full-grown larva in natural position, feeding ; </, pupa in SpCClCS ()I iniS Idinuy,

cocoon. (7, c, d, one third larger than natural size ; b^ more with a wino" eXpanSC

enlarged. (After Howard and Chittenden, United States . . .

Department of Agriculture) Of trom tWO tO three

THE BUTTERFLIES AND MOTHS

20'

inches, of the genus Catocala, have mottled gray fore-wings which
ver\' closely resemble the bark of trees, upon which they rest during

the day. The hind-

wings are black, bril-
liantly banded with red
or yellow. They are
much fancied by col-
lectors and are taken
by luring them with
sugar water or similar
lures, smeared on the
trees.

The tussock-moths
(Liparidae). The cater-
pillars of the tussock-
moths are strikingly
clothed with tufts of bright-colored hairs, or tussocks, which has
given them their popular name. The moths are medium sized,
usually of a dull brown or gra}- color. The males have feathered

Fig. 319. Ciitociihi ultronia and its larva
(After J. B. Smith)

Fig. 320. The white-marked tussock-moth. (Natural size)
a, wingless females depositing eggs on cocoons ; b, male moths ; c, full-grown female larva

204

FXEMENTARY ENTOMOLOGY

antennae. The females of our common species, of which the
white-marked tussock-moth {Hcmci'ocarnpa Icucostigma) is a good
example, are wingless and look more like hair)^ grubs or fat
spiders than moths. These wingless females pair as soon as they
emerge from the cocoons, and then lay their eggs upon them and
die. The eggs of this species are usually found on the trunks of
trees, and are covered with a white substance looking like frosting.

The caterpillar is
about one and one

^^^^. \ /* .^^flU ^^^^ inches long, with

^^^^^^^jJ^^^^^^V a pair of black pencils

^I^^^HH^^^^Hf of hairs

^^^^HHI^^^^B half inch forward on

^IjjHjp' V^I^^Br either side of the head,

W and a single pencil of

similar length extend-
ing from the tip of
the abdomen. The
head and a small
glandular dot on the
center of the sixth
and seventh abdom-
inal segments are
bright red, the body
is yellow banded with
black, and the first
four abdominal seg-
ments bear brushlike
tufts of white hairs.
This species often becomes a serious pest of shade and fruit trees,
while nearly related species are common but not so injurious. To this
family belong the gypsy moth {PortJictria dispar) and the brown-
tail moth {Eiiproctis chrysorrhoea), both of which have been
imported from Europe into New England, where they have done
enormous damage to trees of all kinds. The male gypsy moth is
tawny brown, with black markings, while the female is much larger,
and is white, with wavy blackish lines across the wings. The
female is unable to use her wings for flight, and lays her eggs on

Fig. 321.

Male and female gypsy moths,
size)

(After Forbush and Fernald)

(Natural

THE BUTTERFLIES AND MOTHS

205

Fig. 322. Gypsy-moth caterpillars. (Natural size)
(After Britton)

the bark near the cocoon. The caterpillar is two and one half
inches long when full grown, of a dark, sooty color, somewhat
hairy, and with a double row of five
pairs of blue and six pairs of red tuber-
cles down the middle of the back,
which distinguish it from all other com-
mon caterpillars. The brown-tail moths
are pure white, with a brown tuft of
hairs at the tip of the abdomen, more
prominent in the female. Both sexes
are strong flyers and are carried readil\-
by the wind. The eggs are laid in a
mass on the foliage and are covered
with brown hairs from the tip of the
female's abdomen. They hatch early
in August, and after feeding two or
three weeks the little caterpillars draw p,G. 3,3. The brown-tail moth,

the leaves together at the tips of the male and female. (Natural size)

206

ELEMENTARY ENTOMOLOGY

Fig. 324. The brown-tail-moth caterpillar,
from side and back. (Natural size)

branches with strands of silk and in them spin httle silken cells,
the whole forming a strong web, within which they pass the winter

and emerge to complete their
growth in the spring. The
caterpillars defoliate fruit and
shade trees, but never attack
conifers, as do the partly grown
gypsy-moth caterpillars. They
are one and one half inches
long, of a dark brown color
marked with patches of orange,
and covered with numerous
long, barbed hairs. On the
side of each segment is a
characteristic white dash, and the little red spots characteristic of
this family are found on the center of the sixth and seventh abdom-
inal segments. The tubercles along the back and sides are thickly
covered with short brown hairs, the •

masses having a velvety appearance.
These are the nettling hairs, which,
when they alight on the skin, produce
an eruption very similar to that caused
by poison ivy, and which is so painful
and annoying that, where the cater-
pillars become abundant, they render
life miserable for the inhabitants dur-
ing early summer. As the nests of
this pest have been imported on pear
seedlings by nurserymen in almost
every state during the past two years,
it will be remarkable if it is not soon
found outside of New England, and
should be constantly watched for, so
that it may be brought under control at
once before it spreads. This family is
a small one, and has almost no species

. . . . , . P'iG. 325. Winter web of the

of economic importance in this country brown-tail-moth caterpillars
other than those mentioned. (Reduced)

THE BUTTERFLIES AND MOTHS

207

Fig. 326. The salt-marsh caterpillar [Estigincne acraea), one of the
" woolly bears "

The tiger-moths (Arctiidae) are well named, for many of them
are conspicuousl)- striped or spotted with orange, red, or black.
Among the lar\'as are the well-
known hairy "woolly bears,"
which crawl across the walks
in late fall and early spring,
faithful harbingers of winter
and summer. The moths are
frequently attracted to lights,
when their brilliant colors al-
ways command attention. On
some of the larvae the hairs
are massed into brushes much
like those of the tussock-moths,
as is the case with the com-
mon harlequin milkweed cater-
pillar {Cycnia eglc), which is

Fig. 327. The hickory tiger-moth {IldL-
sidota ca7yae) and its larva

clothed with tufts of orange, black,
and white hairs, and is the most

Fig. 328. The common red-and-black , .,, , .,,

caterpillar of the Isabella tiger-moth COmmon caterpillar on the milk-
(PyiT/iarctia isabella) WCCd. Our mOSt COmmon SpCcicS

(After comstock) is possibly the Isabella tiger-moth

208

ELEMENTARY ENTOMOLOGY

{PyrrJiarctia isabclla), whose hairy larva is reddish-brown in the
middle and black at either end. It does but little harm, but is the

species commonly
seen on walks in
fall and spring, so
that it is well
known. The fall
web-worm is the
common caterpil-
lar which covers
our fruit trees
with its unsightly
webs in late sum-
mer. The moths
are pure white or
spotted with black.
The caterpillars
\3xy from yellow-
ish to blackish,
with darker lines
and spots, and are
covered with long
hairs. Most of
the caterpillars of
this family feed on
low-growing vege-
tation and weeds ;
several now and
then become over-
abundant and at-
tack garden crops.

Fig. 329. The fall web-worm. (All slightly enlarged)

a, light form of full grown larva; /', dark form of same ; c, pupa ;
if, spotted form of moth, (.\fter Howard, United States Depart-
ment of Agriculture)

The hawk-moths (Sphingidae) are sometimes called humming-
bird moths, for the larger species are fully as large as a humming
bird, with three to five inches wing expanse, and are frequently
found hovering over petunias and similar flowers on warm summer
evenings. They are easily recognized from their long, spindle-
shaped bodies, strong, narrow wings, and thick, prismatic antennae,
which are often curved back at the tip, forming a slight hook. The

thf: butterflies and moths

209

proboscis is very long, in some species being twice as long as the
body, and is coiled up under the head like a watch spring. Many
of the caterpillars are known as hornworms, from the strong horn
on top of the last segment, which is quite characteristic of the
family, though in some cases it is replaced by a bright, glassy
eyespot. "When at rest," says Dr. J. B, Smith, "some of them
have the habit of elevating the front part of the body and curling
the head under a little, giving them a fancied resemblance to a

sphinx, and from
this the scientific
name has been
derived." A well-
known example
of this family is
the large green
tobacco or toma-
to worm {Phlcge-
thontuis qiiinqtie-
niacidatd), which
rags the foliage
of these plants,
and is the tobac-
co grower's worst
enemy. It has
slanting white
stripes along its
sides, and, when
fully grown, is

about three inches long ; then it goes underground and transforms
to a mahogany brown pupa from one and one half inches to two
inches long, bearing a peculiar handlelike process bent back from
the head, which has given it the names of " jug-handle grub " and
" hornblower." The pupae remain in the soil over winter, and the
moths emerge the next spring, there being tw'o broods a season in
the North and three or four in the South. The adults are among
our most handsome moths, the wings expanding from three to five
inches, ashen-gra)' in color, the fore-wings crossed by irregular
darker lines with a w'hite spot near the center, and the hind-vvings

Fig. 330. Larv^ of achemon sphinx

Above, young larva with head extended and with caudal horn (en-
larged); below, full-grown larva with head partly drawn in (natural size)

Fig. 331. Typical sphinx moths (De/lep/iila lineata Fab. above and Phohis

ackemoft below)

(After Lugger)

Fig. 332. Southern tobacco-worm moth. (Natural size)
(After Britton)

THE BUTTERFLIES AND MOTHS

21 I

banded with black and white, while along the sides of the abdomen
are five large yellow spots. The grapevine hog caterpillar {Ani-
pelophaga viyroji) is typical of a series of species in which the
caudal horn of the larva is lost and replaced by an eyespot ; the
first two thoracic segments are much smaller and, with the head.

Fig. T)T)^. Southern tobacco-worm. (Natural size)
(After Britton)

are retracted into the metathorax. This has given some one the
idea that they resemble fat porkers, — hence the name " hog cater-
pillars." This larva is common on the grape and woodbine and is
about two inches long, with a row of seven reddish or lilac spots set
on a yellow background along the middle of the back, and a white

stripe down each side, below
which are seven oblique stripes.
It is quite variable in color
and is very commonly infested
with braconid parasites (see
page 251), whose cocoons are
frequently found covering the
caterpillars. Some of the
smaller moths of this family
have the wings nearly bare
of scales, like the clear-winged
moths, and, like them, fly around flowers during the day. The larger
ones are often called humming-bird hawk-moths, while the smaller

Fig. 334. A clear-winged sphinx moth, or
bee-moth {Hemaris tkysbe)

212

ELEMENTARY ENTOMOLOGY

ones look quite like large bumblebees. They are readily recognized as
belonging to this family by the form of the body, wings, and antennae.
The saturnians (superfamily Satumoided) include some forty-two
species of our largest silkworm moths, divided into four families,
which need not here be distinguished. The large, brilliantly colored
larvae are readily reared, and from the cocoons are secured the
handsome moths which are the pride of every collector. The males
of this group are easily distinguished from the females by their
broadly feathered antennae. The most important economic species

~'^.

^, . ^ ~ i -

4^J^^--^

Fig. 335. Life history of silk moth (ZiVw/m'-v ;«t?;-/) : adult; caterpillars of different
ages; silken cocoons ; pupa; eggs. (Natural size)

(After Jordan and Heath)

of the group is the silkworm {Bojnbyx inori), which is reared in
Europe and Asia for its silk, furnishing all the silk of the world.
It has been frequently introduced into this country, but, although it
can be grown here, its commercial culture has never proved suc-
cessful. It is one of the smaller moths of the group, expanding one
and one half inches, the wings being of a cream color, with two
or three brownish lines across the fore-wings. The larvae are of a
creamy white color and feed on the leaves of the mulberry. Another
small species which often defoliates our maples is the green-striped
maple- worm {Atiisota riibiainda). The caterpillars are one and one
half inches long, yellowish-green, striped with eight lighter lines

THE BUTTERFLIES AND MOTHS

213

'Z

::5^

€

M

i!

\\\

^2

ir

' '\

\

' 'I

alternating with seven darker, almost blackish
lines, with two prominent black horns on the
thorax and a double row of short, thick spines
along either side of the body. The moths are
pale yellow banded with rose color, and are fre-
quently taken at lights. Nearly related species,
whose larvae are brownish with orange markings
and similar black spines, attack the oak foliage.
The lo moth {Autonicris to) is one of the larger
forms, with a wing expanse of nearly three
inches, the fore-wings of the males being a
brilliant yellow color and those of the female a
dark purplish, both having a large eyespot on the

center of the hind-wings.

The full-grown larva

Fig. 336. The green-
striped maple-worm
(Aiiisota riibiLiinda)

is about two inches long, yellowish-green, with a
broad brown or reddish stripe, edged with white,
along either side, thickly covered with black-
tipped, branched spines which are decidedly
poisonous. The polyphemus moth {Telea poly-
pJicintis) is one of our largest and handsomest
species, expanding from four to five inches.

It is of a yellowish or brownish color, with a dusky band,

edged without with pink along the margins of both wings, and

with a prominent eyespot at the middle of each wing, those on

the hind-wings

being bordered

by a large bluish

patch. The lar-
vae feed on oak

and various fruit

and shade trees ;

they are three

inches or more

in length, of

a bright green

color, with an

oblique yellow Fig. 337. The lo moth, female. (Natural size)

line on the side (After Lugger)

Fig. 338. lo moth caterpillar

Fig. 339. Telea polyphemiLs caterpillar

Fig. 340. Telea polyphem7ts moth and cocoon. (Reduced)

(After Lugger)
214

THE BUTTERFLIES AND MOTHS

215

of each abdominal segment, and with numerous small orange-
colored tubercles with metallic reflections. The cocoon is oval,

usually wrapped in a leaf,
and is attached to the
twigs of trees and shrubs.
The luna moth (Actia
luna) is a brilliant green
species with long tails pro-
jecting from the hind-
wings ; it is frequently
attracted to lights on warm
evenings of early summer.
Each wing bears a small
eyespot, and the anterior
margin of the fore-wings
is purplish. The larvas
feed on the leaves of wal-
nut, hickor)', and forest
trees. Possibly our most
common species is the
cecropia moth {Samia
cccropia) whose long
brown cocoons are fre-
quently found on fruit and
shade trees. The moths
are a dusky, reddish brown,
and may be readily recog-
nized from Fig. 34 1 . The
caterpillar is three or four
inches long, of a bright
green color, with six prom-
inent tubercles on the
thoracic segments, — the
first four coral-red and
the hinder two yellow, —
and with smaller, similar yellow tubercles on the back of the abdom-
inal segments. They feed commonly on fruit and shade trees, but
are never numerous enouo^h to do much damage. The cocoons of a

Fig. 341. The cecropia moth (Samia cectvpia),
lan^a, cocoon, and moth at rest. (All reduced)

(Photograph by \\'eed)

2l6

ELEMENTARY ENTOMOLOGY

Fig. 342. The promethea moth {CallosaDiia promethia)
(Reduced)

(Photograph from life by \\'eed)

Fig. 343. Pendent
cocoons of prome-
thea moth. (Greatly
reduced)

nearly related species {CallosaDiia pronictJiia) hang pendent from
the twigs of vvild-cheny, ash, willow, and other trees. Although
many attempts have
been made to manu-
facture the silk in
the cocoons of these
native species, they
have so far been un-
successful.

Our common tent
caterpillar, which i.s
fully described on
page 57, is a repre-
sentative of a family
of this group {Lasi-
ocainpidac), though
much smaller in size
than the preceding,
having a wing ex- <, '%

panse of one and Fig. 344. Luna moth {Actia luiia). (Reduced)

one half inches. (Photograph from hfe by Weed)

THE BUTTERPXIES AND MOTHS 217

Fig. 345. Caterpillar of the imperial moth {Basilona iiiiperialis). (Natural size)

Summary of the I.fpidoptera

Butterflies. Day flyers. Antennae clubbed. Wings held vertically.
Skippers {Hesperi/ia). Antennae hooked.
True butterflies i^Papilioniiia).

Swallowtail butterflies {Papilionidae).

White and yellow butterflies {Pieridae).

Gossamer-winged butterflies {^Lycaenidae).

Four-footed butterflies {AympJialidae).
Moths. Night flyers. Antenna; not clubbed. Wings held flat.
M icrolepidoptera.

Family {Tineidae). Leaf-miners, clothes moths, 'etc.

Family {Tortricidae). Leaf -rollers, bud-borers, etc.

Family {Pyraiidae). Leaf-folders, meal-worms, close-wings, bee-moth,
etc.
Macrolepidoptera (in part).

Carpenter-moths (Cossidae). Larvas wood borers.

Clear-winged moths (Sesiidae). Larvae wood borers.

Prominen ts (^Notodoiitidae).

Measuring-worms (family Geoiiiciridac).

Owlet-moths (Noctuidae).

Tussock-moths {Llparidae).

Tiger-moths {Arcfiidae).

Hawk-moths {Sp/ii/ti^idat').

Saturnians (superfamily Satiinioidea). Silkworm moths. Tent-
caterpillar moths.

yw

CHAPTER XIV

FLIES, MOSQUITOES, AND MIDGES {DIPTERA)

Characteristics. Insects with one pair of wings borne by the mesothorax;
the hind-wings represented by a pair of knobbed threads, called halteres ;
mouth-parts, suctorial ; metamorphosis, complete.

Ordinarily all sorts of small insects with membranous wings are
indiscriminately called t^/Vj-, and the term " fly " has been used to
form part of a compound name for insects of several different

orders, such as May-
fly, sawfly, gallfly,
butterfly, etc., but,
considered from the
entomological stand-
point, a fly is a two-
winged insect of the
order Diptcra. With
this in mind, it is al-
ways easy to distin-
guish flies, as no
other order has a
single pair of wings
(except the male scale insects), and the name of the order becomes
significant, being derived from dis (two) and pteron (wing). The
hind-wings are replaced by a pair of odd, club-shaped organs,
called balancers, or halteres, which seem to be concerned with main-
taining the equilibrium of the insect and are, of course, peculiar
to this order. A few of the parasitic families are wingless. The
mouth-parts have already been referred to (see page i8) and
are fitted for sucking the juices of plants and animals, though in
some there are strong, lancelike mouth-parts fitted for piercing,
while in others a large, fleshy proboscis, fitted for rasping and
lapping, is developed.

218

Fig. 346. The house-fly. (I*Lnlarged)

a, larva, or maggot ; /', puparium : c, adult. (After Howard,
United States Department of Agriculture)

FLIES, MOSQUITOES, AND MIDGES

219

The transformations are always complete. The most common
lar\'ae are termed "maggots," and are headless and footless, white, or
light-colored, tapering to a point at the head, usually with a horny,
rasplike feeding organ retruded within the head, though many
absorb nutriment from the surrounding food through the skin. In
other larvae the head and mouth-parts are well developed, while
some, like the mosquito wrigglers, lead a most active life. The
pupae are usually
naked or inclosed in
the last larval skin,
though a few make
cocoons. Instead of
being molted, the
last larval skin of
most common flies
becomes hard and
distended, and the
pupa separates with-
in it, so that the lar-
val skin practically
forms a cocoon for
the pupa and is
known as a pupa-
rium, which looks
much like a large
brown or black seed.

The Diptera is
one of the largest
orders, with over
five thousand species in this country (a great majority of which
mav be classed as injurious), and includes many serious crop pests
and most of the insects which cany disease. The different fami-
lies are distinguished by the structure of the antennas and of the
wing veins, and are divided into two suborders, the typical Dip-
tera {Diptera genuina), including all the common families, and
the Pupipara, including three small families of parasitic species,
mostly wingless.

Fig. 347. A crane-fly {Tipiila hebes Loew)

a, larva, or meadow-maggot ; /', pupa ; f, adult male fly.
(After Weed)

220

ELEMENTARY ENTOMOLOGY

I. Typical Diptera {Diptera genuina)

Disregarding characters of the puparium which are not readily
observable, the typical Diptera are divided into two series of fami-
lies, based upon the length of the antennae, known as the Long-
horned Diptera, which have
more than five antennal
segments, and the Short-
horned Diptera, having not
more than five segments.

jm

LONG-HORNED DIPTERA

{NEMATOCERA)

The crane-flies {Tipulidae)

are easily recognized by
their long, slender bodies,
narrow wings, and exceed-
ingly long, fragile legs,
which characteristics have
given them the name
" granddaddy-long-legs," a
name more correctly ap-
plied to the harvestmen,
which are round-bodied
spiders with very long legs.
The maggots of crane-flies,
sometimes called leather-
jackets, or meadow-mag-
gots, are dirty white, with
a tough skin, and feed
upon the roots of plants,
decaying vegetable matter,
and fungi. They are fre-
quently found in the decay-
ing wood and mold in the
crotch of an old tree or in
a stump, while several species which feed on their roots sometimes
become abundant enough to do considerable damage to grasses and
grains. The adults are among our largest flies, the common species

Fig. 348. Life history of a mosquito
(Ciilex sp.). (Mucli enlarged)

On the surface of the water, a small raft of eggs ;

in the water, several long, slender larvae (wrigglers)

and one large-headed pupa (tumbler) ; above the

water, an adult. (From life, after Kellogg)

FLIES, MOSQUITOES, AND MIDGES »

221

having a wing expanse of from one and one half to two inches.
The giant crane-fly {Holoriisia mbiginosd), of California, is the

Fig. 349. Anopheles mosquito and malaria

(7, larva; /', pupa; c, adult; d^ the blast introduced into the blood by the mosquito ; e to j,
stages through which the plasmodium passes in the red blood corpuscle ; k, the spores
which enter new blood corpuscles ; /, m, the microgamete ; /;, 0, the macrogamete ; /,
flagellse forming ; q, union of a flagellum with macrogamete ; r, fusion of nuclei ; s, the
vermicule ; t to ;', formation of the zygote in the mosquito stomach, the fully developed
zygote, ;', rupturing to produce blasts. (After J. B. Smith)

largest species of the order, being two inches long and the legs
spreading some four inches. What advantage the crane-flies derive
from their size is a question, as they are very awkward and fragile.

222

ELEMENTARY ENTOMOLOGY

The mosquitoes (Culicidae) are so well known as to need no
description, but there are many mosquitolike flies which might

easily be confused with
them. They have the
mouth-parts developed
into a strong proboscis
fitted for piercing, and
the antennae of the males
are strongly plumose (see
Fig. 5 3) ; but the most
distinctive character consists of a fringe of scales along the margin
of the wing and also along the wing-veins, which can be readily
seen with a lens. The eggs are laid in small masses on the surface

FRt. 350. Resting positions of Anopheles and
Ciilex mosquitoes. (Slightly enlarged)

(After Grass!)

Fig. 351. The yellow-fever mosquito {Stegomyia calopiis). (Enlarged)
(After Howard, United States Department of Agriculture)

of quiet or slow-moving water, and hatch in from one to four days.
The larvae are the well-known wrigglers of ponds and ditches, with
their characteristic long, squirming bodies, thick head end, and

FLIES, MOSQUITOES, AND MIDGES

223

forked abdomen. They breathe through the respiratory tube pro-
jecting upward from the abdomen, which is thrust through the
surface of the water as the wriggler rests at the surface. The
wrigglers feed on bits of organic matter and microorganisms.
The pupa has the head and thorax very remarkably enlarged, and
there are two breathing tubes which project from the back of the

Fig. 352. Wing of a mosquito {Maiiscnia titillaiis Walk.) enlarged, showing
scales on veins, and a portion of same further enlarged

(After Felt)

thorax. The pupa stage lasts from one to three days, the whole life
from Qgg to adult requiring from eight days to two or three weeks.
Not only are mosquitoes exceedingly annoying, rendering some
sections almost uninhabitable, but it has been shown that malarial
fever is transmitted only by mosquitoes of the genus Anop/iclcs,
and that the dreaded yellow fever is similarly carried only by species
of the genus Stcgomyia, which has resulted in an entire change in
the methods of controlling these diseases. Very much can be

224

ELEMENTARY ENTOMOLOGY

done toward the riddance of mosquitoes in thickly settled com-
munities by destroying their breeding places by draining or filling
the pools and by oiling the surface of small ponds, rain barrels, etc.
True midges (Chironomidae). Many of these look much like
mosquitoes, the males having the plumose antennae and being of
about the same size, but the wing-veins are simpler and fewer in

Fig. 353. A midge {Chiroiiovms sp.). (Greatly enlarged)
a, adult male ; /', pupa ; c, larva. (After Felt)

number, and lack the scales. Most of the larvae are aquatic, being of
very long, threadlike worms which live in the slime and decaying
vegetation at the bottom of pools and streams, where they feed on
vegetable matter. Many are a bright red in color and have been
called blood-worms. The minute punkies, or " no-see-ums," are
among the worst enemies of the hunter and fisherman, and one
must have a thick skin to withstand their bloodthirsty attacks.

Fig. 354. A punkie, or "no-see-um" (CVra/^^/^'^^w ^/«/^d'««/.r). (Greatly enlarged)

a, adult ; b, head of sanje ; c, larva ; d, head of same ; e, pupa. (After Pratt, United States
Department of Agriculture)

Fig. 355. a, a net-winged midge {Bih-
liocephala elegantitlns), female (two
and one half times natural length); b,c,
upper and under sides of larva of B.
coinstockii (five times natural length)

(After Kellogg)

225

226

ELEMENTARY ENTOMOLOGY

They are grayish-black, not over one twenty-fifth of an inch long,

and the larvae develop in the water in stumps and logs and under

damp, dead bark.

The net-winged midges (Blepharoceridae) are so called on account

of the peculiar network of small veins crossing the main wing-
veins around the margin of
the wing, which are peculiar to
this family. The small, black
larvae live in masses on the
rocks in swift-running moun-
tain streams, and seem to have
but seven segments strongly
constricted at each joint.

The Dixa-midges (Dixidae)
include but a single genus,
whose larvae are also aquatic.
Both of the last families com-
prise only a few uncommon
species, and lack the whorls
of hairs of the male antennae.

Fig. 356. A black fly [Simuliiim venitsUitii)
(Four times natural size)

(7, larva ; b, pupa ; c, adult. (After Weed)

The black-flies {Simuliidae). Another pest of mountain lovers is
the black fly, the females of which are most bloodthirsty and often

Fig. 357. The fickle midge [Sciara tncoiistaiis), a fungus-gnat sometimes trouble-
some in greenhouses. (Much enlarged)

a, male ; b, genital organs of same ; c, female ; (/, enlarged antennal segments of same ;

f, maxillary palpus of same ; /, tip of abdomen of same from side ; g, pupa ; h, lar\'a. (After

Chittenden, United States Department of Agriculture)

FLIES, MOSQUITOES, AND MIDGES

227

appear in immense numbers. The larvae are found attaclied to
rocks in shallow, swift-flowing streams, where they feed on various
minute plants and bits of vegetation. The adult flies are about one
fifth of an inch long, stout-bodied, blackish, with short legs and an-
tennae, though the antennae have many distinct segments. Recent
experiments made in the White Mountains indicate that it may be
possible to eradicate the larvae in mountain resort regions by oiling
the streams with Phinotas oil. The southern buffalo gnat is a
serious pest of domestic animals in the South, such immense
swarms sometimes appearing as to cause their death.

Fig. 35S. The pine-cone willow gall caused by a cecidomyiid, cut open at
right to show maggots within

(After Washburn)

Fungus-gnats. Wherever there is decaying vegetable matter
or damp fungi, as in decaying wood, under damp bark, in decom-
posing leaves, etc., there are found small, white or pink maggots,
which develop into the graceful little fungus-gnats {JMycetopJiilidac).
The larvae often stick together in large patches, and sometimes
form long processions of wriggling maggots. One species feeds on
injured apples, while another has been shown to cause a form of
potato scab, and one is a serious pest of mushrooms, but most of the
larvae are entirely harmless. The flies are mosquitolike in general
form, but the antennas are bare and the coxae are unusually long.

228

ELEMENTARY ENTOMOLOGY

Fig. 359. Pear midge {Di-
plosis pyrivora). ( Enlarged)

(After Riley)

Gall-gnats. The smallest and most deli-
cate of the gnatlike flies are the gall-gnats
(Cecidomyiidae). The adults are rarely
over one eighth of an inch long, with long
antennae clothed with short hairs, and with
the wing-veins greatly reduced in number.
They will be rarely noticed by the begin-
ner, but the work of the larvae is often
much in evidence, owing to their feeding
within the stems and leaves of plants and
giving rise to galls. Frequently a green,
cone-shaped gall is found on the tips of
willow twigs, known as the pine-cone
willow-gall, which is caused by one of
these larvae {Cccidoviyia strobiloides).
The larvae of the clover-seed midge live in
the heads of clover and destroy the seed
so that in many sections it is often impossible to mature it. The
best-known exam-
ple of the family,
andourworstwheat
pest, isthe Hessian
fly, so called be-
cause it was sup-
posedly introduced
in straw brought
over to Long Is-
land by the Hes-
sian troops during
the Revolutionary
War. The mag-
gots bore into the
crown and stalks
of wheat, weaken-
ing the plant and
seriously curtailing
production where
they are abundant.

Fig. 360. The Hessian fly, adult male. (Much enlarged)
(After Marlatt, United States Department of Agriculture)

FLIES, MOSQUITOES, AND MIDGES

229

Fig. 361. Horse-fly (Talmmts u/nrfi/s)
a, lan'a; b, pupa; c, adult. (,\fter Riley)

.SirORT-IIORNEI) FLIES [BA'AC// VCEA'A)

In this section the antennae are composed of from three to five
segments, the famihes being divided into three groups according

to the structure of the
antennae, and being fur-
ther . distinguished by
the wing- venation.

In the first group the
third segment of the an-
tenna is clearly ringed,
showing that it is made
up of several segments
grown together.

Horse-flies. The best-
known family of this
group is that of the
horse-flies {Tabanidac).
They are well-known
pests of live stock and often become annoying to man. The adults
have short, broad heads, large eyes, thick bodies, short, oval abdo-
mens, and strong, powerful wings, which enable them to outstrip the
swiftest horse. They
are often most trouble-
some along wooded
roads, where they will
attack a horse in
swarms and, with their
loud buzzing, render
the animal frantic.
The larvas are long,
pointed maggots which
live mostly in water in
swampy places and
along the edges of
streams and ponds,
and are carnivorous. In the swamp lands of southern Texas and
Louisiana the large horse-flies appear in such swarms as to make
life for cattle almost impossible, and along our coasts wherever

Fig. 362. A "green-head" {Tabamis Ihieola Fab.).
(Much enlarged)

(After Lugger)

2^0

ELEMENTARY ENTOMOLOGY

there is marshland the well-known green heads annoy bathers as
well as animals. Our largest horse-fly is an inch long, with a
two-inch wing expanse, and of a dull black color, while other
common, smaller species are brown, with the wings banded with
black. Only the females are bloodsuckers, the males feeding on
the pollen of flowers.

The soldier-flies {Stratiomyidae) somewhat resemble the smaller
horse-flies, and are so named on account of the bright yellow or green
stripes across the abdomen. The antennas are somewhat longer

Fig. 363. St7-atiomyia iliscalis. (Greatly enlarged)
(After Lugger)

and the wing venation is quite characteristic. The adults are found
on flowers near water, and the larvae are carnivorous or feed on
decaying vegetable matter, living in water, earth, or decaying wood.

In the second group are found two families having four or five
distinct antennal segments, — the robber-flies (Asilidac) and the
nearly related Midas-flies {Midaidac), which have very similar
habits.

The robber-flies (Asilidae). They are well named, being large,
hairy, ferocious-looking flies, which are strong, swift flyers. They
may often be seen resting quietly on a dead twig, which they closely
resemble in color ; suddenly they will dart off and in mid-air will
snatch a fly or any insect which they can overpower, in much the

FLIKS, MOSQUITOKS, AND MllKlKS

Fie. 364. A robber-fly {Stetwpogon iinjiiiiiatiis), and

another [Dasylis soceata) resembling a bumble-bee.

(Natural size)

(After Kellogg)

same manner as does a dragon-fly. The most common species are
of a sober gray color, marked with white, yellow, or black, with a
long, tapering abdomen, long, narrow wings, large, keen eyes, and
a strong proboscis, with which they suck the juices of their prey.

Other species are
thickly clothed
with black and
yellow hairs, so
that they closely
resemble bumble-
bees. The larvae
are mostly pre-
dacious and live
in the ground or
indecayingwood,
where they feed
on the larvae of
beetles and on

decaying vegetable matter. The robber-flies can hardly be con-
sidered beneficial, as they rarely feed on noxious insects to any
extent, and often destroy bees.

In the third group is a considerable series of important families,
in which the first two segments of the antennae are small and the
third is large and clublike and bears a single,
conspicuous bristle, called an arista.

The bee-flies (Bombyliidae) are medium-sized,
oval-shaped flies, with a thick covering of
yellow hairs, giving them a resemblance to
bees which is increased by their habit of hover-
ing over flowers, upon the nectar of which the
flies feed by means of their long tongues.
Some of them frequent orchards and aid in
carrying the pollen from flower to flower by
means of the body hairs, to which it adheres.
The larvae live in the ground and are very beneficial, being para-
sitic upon cutworms, army-worms, and grasshopper eggs.

The long-legged flies (Dolichopodidae) should be mentioned, for
they are of such a striking metallic green, or blue, as to attract

Fig. 365. A bee-fly
(Bombyliiis sp.)- (En-
larged)

(After Weed)

232

ELEMENTARY ENTOMOLOGY

attention as they flit over rank-growing foliage in damp places. The
adults feed on small flies, and the larvae live underground, being

either predacious or feeding on
decaying vegetable matter.

The wasp-flies (Conopidae)
should also be mentioned, on
account of their close resem-
blance to wasps, with which
they may readily be confused at
first glance, and which they
undoubtedly mimic. They are
narrow-waisted, the tip of the
abdomen is like that of a wasp,
and they are often banded and
colored to heighten the likeness.
The head is robust, which has
given them the common name
of "thick-headed flies." The
bodies of

Fig. 366.

A long-legged fly {Psilopo-
d hi Its sipho)

(After Lugger)

larvae are parasitic within the

wasps, bumble-bees, and grasshoppers, on

which the eggs are laid. The adults feed on

nectar and pollen of flowers, over which they

may be found hovering.

The flower-flies (Syrphidae) are medium-
to-large-sized, bright-colored flies which feed

upon nectar and pollen of flowers, over
which they may be seen
to hover, almost motion-
less, for several seconds
and then to dart off and
as quickly return. These

flies may be readily recognized by a thicken-
ing which looks like a vein extending across
the middle of the wing. Our more common
species of the genus Sy7-pJuis have the abdo-
men marked with alternate bands of black and
yellow, and have greenish, bronze, or yellowish
bodies. They lay their small, oval, white eggs

Fig. 367. A wasplike

fly {Physocephala affiiiis).

(One and one half times

natural size)

(After Kellogg)

Fig. 36S. The bee-
fly (E>-i stalls ienax).
(Natural size)

FLIES, MOSQUITOES, AND MIDGES

233

Fig. 369. Rat-tailed maggot, larva of

a syrphid fly similar to Fig. 368. (Twice

natural size)

(After Kellogg)

among colonies of plant-lice, around which the flies may be seen
hovering, and the maggots devour the aphides greedily, being
among their most important natural enemies. Some of the larger
species are thickly covered with yellow and black hairs, thus closely
resembling bumble-bees, in whose nests their larvae reside. A

common species which is
often found on windows in
fall is known as the drone-fly,
from its close resemblance
to a honey-bee drone. Its lar-
va lives in foul water and
excrement, and is typical of
a group which is often found
in privies and similar filth.
The larva is maggotlike in
shape but has a long, extensile tube, through which it breathes,
projecting from the tip of the abdomen to the surface of the food-
material, which has given it the name of " rat-tailed maggot."
None of the family seems to be injurious, and those larvae which
feed on plant-lice are exceed-
ingly beneficial.

Bot-flies (Oestridae) . Another
family in which the flies are well
covered with hairs, so as to
closely resemble bees, is that of
the bot-flies, whose maggots are
among the worst insect parasites
of domestic animals. The adults
have xev)' rudimentary mouth-
parts, so that they probably take
no food. The eggs are usually
laid on the hair of various animals, from which they are licked off
and pass into the alimentary tract, though others lay them upon
the lips or in the nostrils of the host. Among the more common
are the horse bot-fly, which gives rise to the bots in the stomach
of the horse, the ox-warble fly, whose maggots pass from the
stomach through the tissues of cattle and finally emerge through
holes in the skin, causing " grubby " hides, and the sheep bot-fly,

Fig. 370. A syrphus-fly ( J'olucella erecta)
which resembles a bumble-tee and is an
inquiline in bumble-bees' nests (after
S. J. Hunter); and a typical syrphus-fly
(Syrphits rihesii)

2 34

l-XEMENTARY ENTOMOLOGY

whose maggots work in the nasal sinuses of sheep, causing " grub-
in-the-head, " which often results in fatal vertigo, or "staggers."

Other species affect various wild
mammals, one inhabiting rabbits
being particularly common in the
South. When full grown, the bots
pass out with the excreta, or drop
to the ground, in which they
pupate.

The muscids. The last group
of the typical flies is much the
largest and is now held by most
students of this order to represent
from twenty to thirty families, so
that it may be considered as a
superfamily. They are all com-
monly called muscids (superfamily
Mjiscmd) and the house-fly is the
best-known example. No attempt
will be made to give the technical
distinctions by which the different families or subfamilies may be
distinguished, for the knowledge of an expert is required for their
recognition ; but the different groups will be considered according

Fig. 37 1 . The ox bot-fly {Hypodernia
li II eat a)

(After Marlatt, United States Department
of Agriculture)

Fig. 372. The horse bot-fly {Gastrophiliis f(/;//),_male ; abdomen of female at left :
egg attached to hair at right. (Much enlarged)

(After Lugger)

FLIES, MOSQUITOES, AND MIDGES

235

Fig. 373. Bots in stomach of a horse ; some removed to show point of attachment
(After Osbom, United States Department of Agriculture)

to their habits. All are alike in having three-segmented antennas
bearing a strong bristle near the base, the modifications of which aid
in distinguishing the groups. The larv^ are typical white or light-
colored maggots
livingwithin their
food, and the pu-
paria are usually
formed on or in
the soil.

The discovery
in recent years
that the common
house-fly and also
many of its near
relatives are re-
sponsible for the
spread of typhoid
fever, intestinal
diseases of in-
fants, and possibly other infectious diseases has given new interest
to the study of the common flies heretofore considered mere

F"iG. 374. Stable-fly {Sto/?ioxys ctik/tfaiis). adult, larva, and
puparium. (Enlarged)

(After Howard, United States Department of Agriculture)

236

ELEMENTARY ENTOMOLOGY

nuisances. Very similar and almost indistinguishable from the
house-fly is the common stable-fly, so annoying to cattle. The mouth-
parts of the females are fitted for piercing. Just before a storm
these flies frequently come into houses and annoy us, from which
comes the saying that flies bite before a storm. Like those of the
housefly, the larvae live in fresh horse manure. The little horn-flies
often annoy cattle by assembling on their flanks and clustering at
the base of the horns. The maggots develop in cow manure.

The flesh-flies (Sarcophagidae) are so called because many of them
lay their eggs on the bodies of dead animals or in open wounds.

Fifi. 375. The horn-fly. (Enlarged)
a, egg ; b, ^y \ c and d, head and mouth-parts. (After J. B. Smith)

though some of the larvae live in dung and decaying vegetable
matter. The common flesh-fly (SarcopJiaga sarracoiia) looks like
a very large house-fly and gives birth to live maggots (the eggs
hatching in the body of the female), which are deposited on fresh
meat or in open wounds. The blow-flies and blue-bottle flies are
about the size of house-flies, with the abdomen steely-blue or green-
ish, and lay their eggs on meat, cheese, or other provisions, which
are said to be " blown." The eggs hatch in a day ; the maggots feed
on the juices of decaying meat and become full grown in a few
days. The common blue-bottle or green-bottle fly {LiLcilia caesai-)
also lays its eggs on cow dung. The screw- worm fly (Chrysomyia
fnaccllaria) is a bright, metallic green, about one third of an inch

FLIES, MOSQUITOES, AND MIDGES

237

long, with four black stripes on the thorax. It li one of the most
serious pests of cattle in the South and West, laying its eggs in
wounds or sores in which the maggots develop, causing very serious
festering sores. Sometimes it oviposits in human nostrils, the
work of the larvae not infrequently resulting fatally.

Fig. 376. The screw-worm fly {Litcilia maccllaria)
a, b, c, larva and details of same ; (if', pupa ; c, adult ; /. head from side. (After J. B. Smith)

The tachina-flies (Tachinidae) are found frequenting flowers ; they
somewhat resemble the last group, but are commonly recognized
by the numerous stout bristles and hairs with which they are clothed.
The adults are mostly of a modest gray color, with thorax streaked
with blackish-brown or gray, though some have yellow-banded or
red abdomens. The eggs are
laid on the bodies of caterpillars
or on foliage on which they are
feeding, and the maggots are
parasitic within them. Any one
who has tried rearing moths
from their caterpillars will have
encountered these flies, for often
a score or more will inhabit a
large caterpillar. When full

grown the puparia are formed within the caterpillar or pupa, which
never transforms. Some European species which are parasitic on
the gypsy moth have been imported into Massachusetts with the
hope that they may aid in controlling that pest in this country.

Fig. 377. A parasitic tachina-fly
and its puparium

(After Weed)

2 3S

ELEMENTARY ENTOMOLOGY

The tachina-flies are among our most beneficial insects, their white
eggs being commonly found on the necks of caterpillars and

grasshoppers, the flies
appearing in large num-
bers whenever there is
an outbreak of such
caterpillars as the army-
worm.

Root-maggot flies
{Anthomyiidae) are an-
other group of trouble-
some flies belonging to
this series, many of whose
larvae are serious pests
of the roots of vegeta-
bles. The flies somewhat
resemble house-flies, but
are smaller and slighter
The cabbage-

FlG. 378. The cabbage-maggot. (Enlarged)

i7, larva ; l>, pupa ; c, adult ; d, head ; c, antenna.
(After Riley)

in build.

maggot and onion-maggot are well-known examples of these inju-
rious larvce, and wherever small flies are seen hovering around
these or other root crops, such as radishes, turnips, beets, etc.,

Fig. 379. The apple-maggot

a, adult ; b, larva, or maggot ; r, funnel of spiracle on head ; d, puparium ; c, portion of

apple showing injury by maggots, {a, t>, d, enlarged ; ^, reduced.) (After Quaintance, United

States Department of Agriculture)

FLIES, MOSQUrrOKS, AND MIDOKS

239

they may well be regarded with suspicion. One species occasionally
attacks the roots of corn, and another, the beet leaf-miner, makes
tortuous mines in beet leaves.

The fruit-flies (Trypetidae) burrow in the flesh of fruits and in
the stems of plants. The common round gall on the golden-rod is
caused by the maggot of one of this group, most of which are
medium-sized flies, often metallic in color and usually with strik-
ingly banded or mottled wings. In New England the common
apple-maggot {RJiagolctis povioucUa), or "railroad worm," which

Fig. 3S0. A pomace-fly [Divsophila anipelophila). (Enlarged)

(7, adult ; b, antenna of same ; c, base of tibia and first tarsal segment ; d^ c, puparium

from side and above; /, larva; g, anal spiracles of same. (After Howard, United States

Department of Agriculture)

bores through the flesh of the apples, is a well-known example, the
adult being black and white with black-banded wings. In Mexico
a similar species infests the orange and is occasionally imported
into this country. The little pomace-flies {Drosophila sp.), small,
yellowish flies about one eighth of an inch long, are common about
cider mills and wherever there is decaying fruit, in which their
maggots develop.

II. PUPIPARA

This suborder includes three parasitic families, with but few
species, so named on account of the peculiar mode of reproduction.
The eggs and larvae are developed within the body of the female
and are given birth when mature and all ready to pupate.

240

ELEMENTARY ENTOMOLOGY

Some of the louse-flies {Hippoboscidac) are winged, though some
of them cast off or bite off their wings, and are frequently found
on birds of prey, while others are common on various birds and

mammals. The bodies are
very much flattened, the
head is joined to the thorax
broadly, the antennae con-
sist of 'a single segment,
and the wing-venation is
very simple. The best-
known example of the
wingless forms is the com-
mon sheep-tick {Mclopha-
gus ovinus), which should

Fig. 381. A louse-fly (C^^rj/fl sp.). (Enlarged)

be carefully distinguished from the true ticks
(belonging to the Arachnida), and which is the
only troublesome member of the family.

A nearly related family {Nycteribiidac), look-
ing like small spiders, are known as bat-ticks
and are even more degenerate in structure. The
third family {Braulidae) consists of a single spe-
cies, the bee-louse, a minute insect about one six-
teenth of an inch long, which is found clinging

to the thorax of queen and drone bees

Fig. 382. Sheep-tick

{Melaphagiis ovinus)

Fleas (Siphonaptera)

The fleas may be considered in con-
nection with the flies, for they were
formerly thought to be wingless Dip-
tera, but are now classed as a distinct
order. The name of the order is de-
rived from two Greek words, siphon (a
tube) and aptcivs (wingless), referring
to the tubelike mouth-parts and the
lack of wings. The fleas have an oval
body which is very strongly compressed laterally, enabling them to
pass through narrow cracks. They are usually of a brown color,
with small heads bearing sucking or piercing mouth-parts, and

Fig. 383. Bee-louse [Braula

caeca) and its larva. (Greatly

enlarged)

FLIES, MOSQUITOES, AND MIDGES

241

have the merest rudiments of wing-pads. The posterior legs are
strongly developed, so that they are able to jump a considerable
distance. In the adult stage they live upon various warm-blooded
animals, sucking their blood. The eggs are scattered about in the
sleeping places of domestic animals and in the cracks of floors.
The larvae are vvormlike creatures, with a distinct head, but without
legs. They have biting mouth-parts, and feed upon particles of
decaying animal and vegetable matter always abundant in the
places in which they live. The full-grown larva spins a cocoon in
which the pupal stage is passed. In view of these habits, in addition
to cleansing domestic animals it is also necessary to thoroughly
clean the sleeping places of cats and dogs, to scrub the floors,
and to treat large cracks, in which rubbish may accumulate, with
gasoline, kerosene, or a similar contact insecticide. In temperate
climates the common species which lives upon dogs and cats is
the only one often troublesome to human beings ; in the tropics
fleas are much more abundant, and attack man as well as the
domestic animals.

Fig. 3S4. Cat and dog flea (Cienocepkalus cants). (Much enlarged)

"> egg ; b, larva in cocoon ; c, pupa ; d, adult ; e, mouth-parts from side ; /, antenna ; g,
labium from below, (.\fter Howard, United States Department of Agriculture)

242 ELEMENTARY ENTOMOLOGY

Summary of the Dipteka

Suborder I. Typical Diptera (D/pfera ^e^iui/ia).

Section i. Antennae with over five /Segments. Long-horned Diptera

Aquatic larvae.

Families. Mosquitoes {Culicidae).

Midges (Chiroiioniidae, etc.).
Black-flies (Siniuliidae).
Nonaquatic larvae.

Families. Crane-flies {Tipulidae).

Fungus-gnats {Myceiophilidae).
Gall-gnats {Cecidomyiidac).
Section 2. Antennas with five or less segments. Short-horned Diptera
(BracJiycerd).
Third antennal segment ringed.
Families. Horse-flies {Tabanidae).

Soldier-flies {Stratioiiiyidae).
Antennae with four or five segments.
Families. Robber-flies [Asilidae).
Midas-flies {Midaidae).
Antennae with three segments ; with an arista on third segment.
Families. Bee-flies {Bombyliidae).
Flower-flies (Syrphidae).
Wasp-flies (Conopidae).
Bot-flies {Oestridae). '. '
Superfamily. Muscids [Muscind). ,

House-flies, etc. {Muscidae).
Flesh-flies {Sarcophagidae). ' -^
Root-maggot flies {AniJioniyiidae).
Tachina-flies ( TacJiiiiidae).
Fruit-flies ( Trypetidae).
Suborder \\. Pupipara.

Families. Louse-flies [Hippoboscidae).
Bat-ticks {Nycteribildae).
Bee-lice {Braulidae).

CHAPTER XV

THE SAW-FLIES, ICHNEUMONS, WASPS, BEES, AND ANTS
{HYMENOPTERA)

Characteristics. Insects with four membranous wings, with few cross-veins,
the hind-wings smaller than the fore-wings ; mouth-parts, formed for both biting
and sucking, or lapping ; abdomen of the females, usually bearing an ovipositor
or sting ; metamorphosis, complete.

The insects of this order are mostly beneficial, though a few
families are injurious to crops. Probably no other invertebrate ani-
mals, and very few vertebrates, have as highly developed instincts
as many of the insects of this order, the social ants, bees, and
wasps having always been the objects of the greatest popular and
biological interest on account of their high intelligence, if it may
be so termed.

The wings are membranous, with but few veins, are frequently
clothed with short hairs, and are held together by a row of hooks
on the anterior margin of the hind-wings, which grasp a fold of
the hind-margin of the fore-wings, so that the two wings move to-
gether as one. The name of the order is derived from hyuicii (a
membrane) and ptcnvi (a wing). The mandibles are always well
developed and used for biting. In the ants, bees, and wasps the
maxillae are more or less developed as a sheath surrounding the
labium, which is prolonged into a tongue, so that these mouth-
parts are adapted for sucking or lapping the liquid food.

Most of the larvae are footless and maggotlike, living within the
food, where the eggs are placed by the adults, but the larvae of the
first two families bear both true legs and several pairs of abdominal
prolegs, and resemble caterpillars in both form and habits. Many
species spin a cocoon before pupating, and the newly formed pupae
are white, with the legs, wings, and antennae pressed close to the
body.

The different families fall into several natural groups recogniz-
able by their structure and habits.

243

244

ELEMENTARY ENTOMOLOGY

Suborder I. The Boring Hymenoptera (Terebrantia)

In the first suborder the females bear a well-developed ovipositor,
with which the eggs are inserted into the food plant or host insect,
and the trochanters of the hind-le^s consist of two segments.

1. PLANT-EATING HYMENOPTERA

The first two families are distinguishable by the base of the ab-
domen being broadly joined to the thorax, with no constriction at
this point.

The saw-flies {Tenfhredinidae) are so called on account of the saw-
like ovipositor. It is toothed at the tip, having a structure which
enables the females to insert their eggs beneath the surface of leaves

Fig. 385. The American rose-slug [Endelomyia rosae)

a, adult saw-fly ; b, mature larva ; c, work of larva on rose leaf ; d, piece of rose leaf showing
location of egg near margin : c, egg. {a, b, c, and e enlarged, d, natural size.) (After Chitten-
den, United States Department of Agriculture)

or in the stems of plants. They are medium-sized insects from one
fourth to one half of an inch long, usually blackish or yellow-and-
black in color, with the wings folded over the back when at rest.
The larvae resemble small caterpillars, but usually have a larger

HYMENOPTERA

245

Fig. 386. The pear-slug

(7, adult saw-fly, female ;
c, same in normal state

number of prolegs on the abdomen, and lack the hard shield usually-
found on the prothorax
of lepidopterous cater-
pillars. Most of them
feed on foliage, and many
are quite injurious. Sev-
eral species are soft-
bodied and covered with
a viscid, slimy matter,
which has given them
the name of " slugs."
Among the more com-
mon species are the
yellow-and-green currant
worms (jVema/us ribe-
sii), which devour the
foliage of currants and
gooseberries, the rose-
slug {Moiiostcgia rosae),
which strips off the sur-
face of rose leaves, leaving them brown as if scorched, and the

pear-slug {Eriocampa cc-

rasi), which injures pear

and cherr}' foliage in the

same manner. Other spe-
cies often defoliate straw-
berry and raspberry bushes,

and there are numerous

species which may be

found on various shade

and forest trees, one of

the most injurious being

the larch saw-flly (Ly-

gaconcviatns cricJisoiiii) ,

which has defoliated and

thus destro}'ed large areas

of larch in New England

and Canada.

/', larva with slime removed ;
d, leaves with larva (natural
size), (a, b, c, much enlarged.) (After Marlatt, United
States Department of Agriculture)

Fig. 387. Pear-slug, illustrating method of ovi-
position and emergence of larva. (Enlarged)

a, cutting of cell beneath epidermis of leaf, showing
the tip of the ovipositor ; b, the cell after the egg
has been deposited ; c^ same after the escape of the
larva. (After Marlatt, United States Department of
Agriculture)

246

ELEMENTARY ENTOMOLOGY

Horn-tails {Siricidae). The ovipositor of the horn-tails is cyhn-
drical, more like a borer, and, as it projects from the abdomen, has
given the family its name. The eggs are laid within the stems of
grasses and various plants, such as berry canes and alder, while
some of the larger species deposit them in the solid wood of various
shade and forest trees, usually when the tree is beginning to die.

Fig. 388. The pigeon tremex, or horn-tail [Tremex coliimba)

a, larva with young larva of Thakssa fastened to its side ; b, its head ; t, d^ female and male
pupae ; r, female. (After Riley)

The larvae feed within these plants, tunneling out burrows, and
are difficult to combat. Fortunately but few are of considerable
economic importance.

2. GALL-INHABITING HYMENOPTERA

Gall-flies {Cynipidae). The gall-flies lay their eggs in the leaves
and stems of plants, and the injury done by the developing larvae
causes the formation of a characteristic gall by the plant tissues
surrounding them. The adults are small insects resembling wasps,

HYMENOPTERA

247

and the abdomen is joined to the thorax by a slender petiole, or

stalk, as in the fam-
ilies named below,
from which they
are distinguished by
lacking the dark
spot, or stigma,
toward the end of
the anterior margin
of the fore-wings.
They have short,
thick bodies, and
the abdomen is com-
monly compressed,
so that the segments
appear to be more
or less telescoped.
The mossy rose-gall
{Rhoditcs rosae),
which forms a large,

Fig. 389. Mossy rose-gall [RJio,liics rosac]
(After Comstock)

mosslike gall on the stems of roses, and the
spongy oak-apple {AinpJiibolips spongificd),
which looks like a puff-ball on the leaves and
stems of oaks, are well-known examples. The
adult flies may be easily reared by removing
the galls from the plants when fully matured
and placing them in any suitable receptacles.
Only a few species are of economic importance
on cultivated crops, among which may be men-
tioned the pithy blackberry-gall {Diastrophus
iicbidosiis), an irregular swelling two to three
inches long on blackberry stems, inside which
will be found numerous larvae.

3. PARASITIC HYMENOPTERA

Fig. 390. Spongy oak-
Most of the small, slender, wasplike hymen- apple {AmphiboUps

optera, which are distinguishable from the true spongifica)

wasps by the two-segmented trochanters of the (Photograph by Weed)

248

ELEMENTARY ENTOMOLOGY

hind legs, are parasitic upon the eggs or larvae of other insects,

and belong to a group of families which are the most important

,— . of parasitic insects. The technical differences

between the more common families are based

Fig. 391. A gall-fly (C)'-
7iips (jiteraissailratix),
which produces the
jumping galls formed
on oak leaves. (Much
enlarged)

(After Kellogg)

Fig. 392. Long-tailed ophion {Ophion
macrii-nim). (Much enlarged)

(After Riley)

upon the wing-venation, and need not be discussed, but the gen-
eral habits are somewhat similar. The female lays her eggs either

Fig. 393. Pimpla conqnisitoi: (Twice natural size)
a, female ; b, female in act of ovipositing in cocoon of tent caterpillar. (After Fiske)

HYMENOPTERA

249

upon or within a larva or an egg, the larger forms laying but a
single egg on a larva, while the smaller species may deposit a con-
siderable number within a large caterpillar. The young larva at
once enters the body of the host and feeds upon its blood, not
interfering with the principal tis-
sues and organs, so that the host
goes on growing and furnishing
food to the parasite. Finally,
however, the parasite so depletes
the vitality of the host that it
dies, though often not until it
has transformed to a pupa. The
parasitic larva then spins its co-
coon, usually either within or upon
the dead host, and in due time
the adult parasite emerges and
continues the good work. To a

Fig. 394. Long-tailed ichneumon-fly (T/ialessa liiiiator). (Natural size)

The parts of the long ovipositor normally lie together as a single organ ; the figure at the left
shows the manner of inserting the ovipositor in wood. (After Comstock)

certain extent many parasites are peculiar to certain host insects,
though many of them attack various larvae or caterpillars having
similar habits. Frequently many of our worst insect pests are
brought under control by the beneficent work of these little parasites,

250

ELEMENTARY ENTOMOLOGY

and we are just commencing to learn how to utilize them in com-
bating imported insects. Thus the state of Massachusetts and
the United States Bureau of Entomolog)' are now carrying on ex-
tensive experiments in the importation of the parasites of the
gypsy and brown-tail moths, which are very largely effective in
holding those insects in control in Europe. The various parasites
which attack the eggs and caterpillars at different stages of growth
have been imported; they are reared in this country until suf-
ficiently numerous, and are then liberated in sections badly affected
by the caterpillars, with the hope that they will ultimately become
numerous enough to hold their hosts in check.

Ichneumon-flies (Ichneumonidae). Any one who has attempted to
rear any of our large moths, such as the cecropia or polyphemus

moths (see page 215), will have be-
come acquainted with the Ophion flies,
which commonly parasitize them.
They are light brown or golden in
color, about three fourths of an inch
long, and the abdomen is compressed
laterally, so that the back is ridged.
A single ^g^ is laid on the caterpillar,
which lives to pupate. The Ophion
larva spins a tough brown cocoon
within the pupal shell and emerges
from it the next spring. They belong
to the large family of ichneumon-flies,
which includes most of the larger par-
asites, though some of this family are
quite small. The Pinipla flies are nearly the same size, but are
black in color and have the abdomen more broadly joined to the
thorax. They are effective parasites of many of our most common
caterpillars, such as the tent caterpillar, tussock-moth caterpillars,
the cotton-worm, and others.

Braconid-flies (Braconidae). Wherever plant-lice are abundant
there will be found some empty brown skins, globular in form and
with a small round hole in each. Other individuals will be brown,
swollen, and dying as a result of the parasitism of little braconid,
flies which are developing within them. When mature the parasite

Fig. 395. Limneria fiigitiva, a

parasite of the tent caterpillar.

(Twice natural size)

(After Fiske)

HYMENOPTERA

251

leaves the swollen skin of the aphis through a round hole. Often
whole colonies of aphides will be found to have been thus parasi-
tized. One little species {Lysiphlcbns tritici) has been principally
responsible for subjugating the green-bug, or southern grain aphis,

Fig. 396. Lystphlebus tritici, male, the wasplike parasite
of the green-bug. (Very much enlarged)

(After S. J. Hunter)

which has been so destructive to grain in the southwest ; this par-
asite also attacks many other commonly injurious aphides. Larvae of
the large green tobacco or tomato worm (PhlegetJwnthis qtiinqiie-
maculata (Fig. 333)
are frequently found
covered with what
appear to be small
silken eggs. These
are the cocoons of
little braconids of
the genus Apantcles

which have devel- y\g. 397. Lysiphlebus parasite in act of depositing
oped within the cat- eggs in the body of a grain aphis. (Much enlarged)
erpillar's body. Not (After Webster, United States Department of Agriculture)

2$2

ELEMENTARY ENTOMOLOGY

infrequently such caterpillars are ruthlessly destroyed on the sup-
position that these are the eggs of the caterpillars, whereas they
are its worst enemies and should always be protected. The bra-

conids are small, wasplike flies, from one
sixteenth to one eighth of an inch long,
of brown or yellow-and-black colors.

Fig. 398. Dead green-
bugs, showing holes from
which parasites emerge.
(Much enlarged)

The upper figure shows the lid
still attached, and the lower
shows the parasite emerging.
(After Webster, United States
Department of Agriculture)

Fig. 399. Wheat-louse parasite [Aphiditis
granariaphis Cook) and parasitized aphid
from which a parasite has emerged. (Much
enlarged)

(Copied from J. B. Smith)

Fig. 400. Sphinx caterpillar with cocoons of braconid parasites

HYMENOPTERA

253

The chalcis-flies (Chalcididae) are even smaller, and are usually
blackish with strongly metallic reflections of bronze or green, and
are readily recognized by the stout bodies and the almost entire ab-
sence of wing veins. Some of them are parasitic on various cater-
pillars. One species {Pteronuihts piipannn) attacks the common

Fig. 401. rteromahis fupanim, a chalcis-fly which parasitizes the cabbage-worm
and many other injurious insects. ((Greatly enlarged, hair Hne shows natural size)

(?, male : />, female. (After Chittenden, United States Department of Agriculture)

cabbage-butterfl}' caterpillars, from one of whose chrysalids several
hundred of the parasitic flies may often be reared, and in some sec-
tions entirely prevents the increase of this troublesome garden pest.
Many of the species are parasitic in the eggs of insects, while others
are the most effective parasites of scale insects. Unfortunately one
or two species are injurious to crops, the best-known example being
the joint- worm of wheat
[Isosonia tritici), whose
larva works in the lower
stems, causing gall-like
swellings of the joints
and weakening them so
that the grain is blown
over, much the same as
when affected by the Hes-
sian fly.

Smallest of all the par-
asites are the little proc-

tOtrypids {Pmctotrypidae), ym^. 402. A chakis parasite {Chiropachys colon)
the largest of which are of the fruit-tree bark beetle

254

ELEMENTARY ENTOMOLOGY

not over one twenty-fifth of an inch long, and the smallest not
over one fifth that size. Most of them inhabit the eggs of insects,
though some are secondary parasites ; that is, they are parasitic
on larger parasites, and to this degree are sometimes injurious.

Fig. 403. The fig insect {Blastophaga grossorioji), whose introduction has made
Smyrna fig culture possible in California. (Enlarged)

a, adult female ; /', head of same from below ; c, from side ; (/, male fertilizing female ; e,
female issuing from gall ; /, adult male. (After Westwood, from Howard)

Suborder IL The Stinging Hymenoptera {Aculeata)

In the second suborder the female bears a well-developed sting
at the tip of the abdomen, which is effectively used as an organ of
offense. The trochanters of the hind-legs have but a single seg-
ment in all of the ants, wasps, and bees which form this suborder.

1. THE ANTS [FOKMICINA)

A long chapter might well be devoted to these well-known in-
sects, for many interesting volumes have been written by some of
our greatest naturalists concerning their remarkable intelligence
and the highly developed organization of their society.^ Every one
recognizes an ant, but the so-called white ants, or termites {Terini-
tidac, order Platyptcra), and the velvet ants {Miitillidac) may be
distinguished from them by the fact that the first segment of the

^ See the most interesting monograph of Dr. W. M. Wheeler, "Ants," Colum-
bia Biological Series.

HYMENOPTERA

255

Fig. 404. Wheat straw-worm, spring genera-
tion. (Much enlarged)

a, b, larvae ; /, female. (After Riley, United States
Department of Agriculture)

abdomen of true ants forms a sort of knot or tooth between the

thorax and abdomen. The males and females are winged and mate

in their nuptial flight,
which may often be ob-
served on a warm summer
day, when the air will be
filled with them. After
this the males soon die,
but the females bite off
their wings and either
found a new colony or are
taken in by some workers.
The workers, or neuters,
are wingless, undeveloped
females. They may upon
necessity lay eggs, but
these give rise to males
only. The workers do all

the work of the colony, caring for the eggs and larvas, which they

feed and bring up with all the nicety

of the best-ordered nurser)-. The true

females, or so-called queens, merely

lay the eggs, having no control over

the colony, which is managed on the

most socialistic lines by the workers.

There are frequently many different

sizes and forms of workers, each of

which has a particular sort of work.

Thus the large-headed, strong-jawed

individuals are naturally the soldiers,

while others look after the larvae and

eggs. Ants feed on various animal

substances, being very fond of dead

insects and sweets of all kinds. It is

the latter taste which leads many

species to take such care of the little „ , ,. , . ,

^ Pig. 405. Ants attending aphids.

green plant-lice (see page 127), which (Slightly enlarged)

give off the sweet honey-dew of which (Photograph by Weed)

256

ELEMENTARY ENTOMOLOGY

they are so fond. Wherever aphides which produce honey-dew
are abundant, the ants will be found watching over them, warding
off parasites and often transporting them from plant to plant when
food becomes scarce. Now and then an ant may be seen to tap
an aphis with its antennae, when a drop of the honey-dew will be
exuded and greedily lapped up. So well do they herd them that
the aphides have been aptly called the ants' little green cattle. The
relation of some ants to plant-lice is most remarkable, as in the
cas.e of the little brown ant {Lasins niger ainericamis) which cares
for the eggs of the corn root-aphis in its
9 I ] f nest over winter and then carries the

aphides to the roots of weeds and grasses
and then to corn roots in the spring. It is
this relation of the ants to aphides which
makes many species of decided economic
importance to the farmer and necessitates
his destroying them as far as possible.
There are several families of ants, but
most of our common forms are included
in two large families.

The typical ants {Camponotidae) have but
one segment to the petiole of the abdomen,
and have no sting. The large, black car-
penter-ant {Caniponotns pennsylvaniciis),
which tunnels out dead or dying trees,
logs, and timbers, is a well-known example
of one of our larger species, and the little
brown ants of the genus Lasiiis make their
nests along roadways and in pastures and meadows, and include the
species which care for the corn root-aphis and other injurious
plant-lice. Some of the species make large mounds for their
homes, and others are slaveholders, capturing the ants of other
colonies and maintaining them in servitude.

Stinging ants. In the Mynnicidae the petiole of the abdomen
is composed of two segments, and most of the females bear a sting.
The little red ant {Monoinoriiim pharaonis) which often infests our
pantries is well known, but fortunately has no sting. The so-called
agricultural-ants of the southwest belong to this group. Their

Fig. 406. Lateral aspects
of abdomens of three fam-
ilies of ants

/, Camponotidae ; 2, Poneri-
dae ; j, My)tn'iddac ; a, tho-
rax ; b, first abdominal seg-
ment ; c, second abdominal
segment ; d, third abdominal
segment. (After Kellogg)

Fig. 407. The red ant iyMonotnoriinii phai-aonis). (Enlarged)
rt, female ; /', worker. (After Riley)

Fig. 40S. The little black ant (Mo>ioi>iorhnn iiihnitui/i). (Much enlarged)

a, female, or queen ; b, same with wings ; c, male ; d, workers ; r, pupa ; /, larv'a ; g, egg of
worker. (After Marlatt, United States Department of Agriculture)

257

Fig. 409. The Argentine ant [Iridomyrniex huinilis Mayr.
<^?, worker; 1^, fertile queen. (After Newell)

Fig. 410. Mound nest of western agricultural-ant {Pogonomymiex occidentalis
Cress.), showing entrance hole in mound, and cleared space around it

(After Headlee and Dean)

HYMENOPTERA

259

nests are made underground, and around the entrance all vegeta-
tion is cleared off and regular runways radiate out

Fig. 411. Western agricultural-ant,
or mound-building prairie ant {Pc\i^o-
iiomynnex cccideiitalis). (Enlarged)

«, worker; b, queen. (After Headlee
and Dean)

among the neighboring grasses, the seeds
the nest and furnish food, A few years ago
into New Orleans from Argentina, known as
the Argentine ant {Iridomyrnicx /uiniilis),
and has now spread over Louisiana and
neighboring states, becoming a very serious
household pest as well as attacking vegeta-
tion. Another common species of this fam-
ily {Solenopsis
gcniinata) is
one of the
most impor-
tant enemies
of the larvae of
the cotton-boll
weevil. It will
thus be seen
that our com-
mon ants are
of very diverse
habits and of

of which are stored in
a species was imported

Fig. 412. Solenopsis gemiiiata
Fab., a native ant which is a val-
uable enemy of the cotton-boll
weevil. (Much enlarged)

(After Hunter and Hinds, United
States Department of Agriculture)

varymg eco-
nomic impor-
tance. They
are much more
abundant in

Fig. 413. Work of the

black carpenter-ant [Cam-

po)!oti(s petin sylvan icits) in

black spruce

The injury to the living tree
allowed the ants to enter, so
that the heartwood was com-
pletely destroyed by them and
the tree fell. (After Hopkins)

26o

ELEMENTARY ENTOMOLOGY

the South, and in the tropics become veritable pests. Various arti-
ficial nests have been devised whereby colonies may be maintained
indoors for study, for which no insects are of more interest.^

2. WASPS

Every small boy soon makes the acquaintance of the bees and
wasps, which he naturally classes together from their ability to sting
most painfully. The males, however, are entirely harmless, but

Fig. 414. A digger-wasp {Amviophila sp.). (Natural size)

rt, wasp putting an inch-worm into its nest burrow ; b, the nest burrow with food for the

young, paralyzed inch-worms in bottom and burrow nearly filled ; r, wasp bringing a bit of

material to put over the filled nest burrow. (From life, after Kellogg)

unfortunately we have no means of recognizing them in the field.
The wasps may be distinguished from the bees by the first seg-
inent of the hind tarsus being cylindrical and naked, and the body
hairs being simple and unbranched.

Digger-wasps (Sphecina). Several families of wasps are grouped
together under this name, which is due to their habit of digging

1 See Kellogg's "American Insects," p. 548.

HYMENOPTERA

261

holes in the ground or in wood, in which their nests are made.
They are distinguished from the true wasps ( [ ^espina) by the wings
lying flat on the body when at rest. They are solitary forms, each
female making her own nest in which the eggs are laid, and pro-
visioning it with spiders, caterpillars, or other insects, upon which
the larvae feed. The food is stored alive in a remarkable manner.
The female seizes the spider or insect and stings it in the nerve
ganglia of the thorax, thus paralyzing it so that it remains alive
but helpless. The prey thus para-
lyzed is placed in the burrow, the
egg is laid with it, and the tube is
then sealed up, several compart-
ments usually being made, one after
another. When the egg hatches,
the young larva finds an abundant
supply of well-preserved food for
its nourishment. Many of the nests
are made in burrows in sandy banks,
others in the pith of plants, such as
the sumac and elder, while others
make mud nests or tubes, as do the
common mud daubers.

Velvet-ants (MutiUidae). In the
warmer parts of the country one
will often see large, antlike insects
thickly covered with black, red, or
yellow hair, which has given them
this name. The males are winged,
but the females are wingless and can sting severely. One of the
largest species is bright scarlet and black, two thirds of an inch
long, and provisions its burrows, made in beaten paths, with flies
and other insects, though it is known to enter beehives and
kill bees.

The spider-wasps (Psammocharidae) are slender, long-legged,
blackish wasps with reddish or black wings, the body often marked
with red or orange ; they provision their nests with spiders. They
are mostly medium-sized wasps, though the tarantula hawk {Pcpsis
formosa), which preys upon the tarantulas of the southwest, is

Fig. 415. A velvet-ant {Sphaero-

phthalnia similima), female. (Four

times natural size)

(After Lugger)

262

ELEMENTARY ENTOMOLOGY

the largest species of the order, being nearly two inches long
and having a wing expanse of over three inches. Not infrequently
it is overpowered and destroyed by its formidable prey.

Fig. 416. The tarantula-killer (Pepsis formosa). (Natural size)

The thread-waisted wasps (Sphecidae) are readily recognized by
the very long, threadlike petiole of the abdomen, and include our
common mud-daubers, which make their nests under the eaves of

buildings and in barns, attics, etc.

^^^ ^

Fig. 417. A mud-dauber {Pelopacm
cemefiiarius)

(After S. J. Hunter)

The nests are composed of sev-
eral tubes placed side by side,
each of which is provisioned
with spiders. They may be seen
around pools, collecting mud for
their nests, and jerking their
wings from side to side ■ in a
nervous manner.

A nearly related family {Bem-
becidac), which burrows in the
sand and provisions its nests with
flies and similar insects, includes
the large cicada-killer. This is

HYMENOPTERA

263

one of our largest wasps, one and one fourth inches long, black
or rusty in color, with the abdomen banded with yellow, which
pounces upon a cicada and carries it off to its burrow in the ground
as food for the larva. Other nearly related families of digger-wasps
make their nests in the pith of plants or bore into more solid

i : i

Fig. 418. Mud-dauber wasp {Pelopaens sp.) and nest. (Natural size)
(After Linville and Kelly)

wood, or often use the deserted burrow of some other insect (such
as some of the bees which have similar habits), provisioning them
with flies, spiders, and various insects.

The true wasps (Vespina) may be distinguished from the digger-
wasps by having the wings folded on the back like a fan when at
rest, and the legs are not adapted to burrowing, being free from
spines and bristles. The solitary- wasps {Enmenidae) resemble the

264

ELEMENTARY ENTOMOLOGY

digger-wasps in their habits, making burrows in the earth or in
wood, or forming their nests of mud and provisioning them with

insects. One of our common
species {Eunienes fraternns)
makes a little mud nest on
the twigs of bushes and trees,
which looks like a miniature
water-jug. The young are fed
on caterpillars, and enjoy
cankerworms when these are
available. Other species of
this family look like small yel-
low-jackets. The Social-wasps

Fig. 419. Female Sphechis speciosiis carry-
ing cicada to her burrow. (Natural size)

(After Riley, United States Department of
Agriculture)

{Vcspidae) live in colonies and, be-
sides males and females, have a
form of undeveloped females known
as workers, all of which are winged.
They build their nests either in the
ground or attached to bushes, trees,
or buildings, and construct them of
paper made from bits of wood chewed
up and formed into a paste, for they
discovered the possibility of making
paper from wood pulp long before
man thought of it. They are very
jealous of their homes and enforce
a wholesome respect for them upon
whoever even accidentally disturbs
them, as every one who has attacked
a nest of yellow-jackets or hornets is

Fig. 420. The fraternal potter

wasp {Eiiinenes fraternns) and its

earthen nest

(Photograph by Weed)

Fig. 421. Pollutes aiiuular-is and its nest. (Two thirds natural size)
(After Quaintance and Brues, United States Department of Agriculture)

Fig. 422. Nest of yellow-jacket {I'espa sp.) ; at right, nest opened to show combs

(Photograph by Weed)

265

266

ELEMENTARY ENTOMOLOGY

Fig. 423. White-faced wasp
(J'espa /iiaciiiahj)

well aware. The adults are predacious and feed their young on

insects which have been masticated. Not infrequently, where an

outbreak of caterpillars occurs, wasps
will be seen carrying them off to their
nests in considerable numbers ; we
have observed them at work on the
cotton boll-worm and leaf-worms in
the South. But two genera are com-
mon in the East. Polistes are black
ringed with yellow, or are brownish,
and have long, spindle-shaped abdo-
mens. Their nests are composed of a

single comb and are attached by a short stem. The genus l^espa

includes the hornets and yellow-jackets, which are black, spotted

or banded with yellow, or yellowish-white,

with a short, stout body, and the abdomen

attached by a very short peduncle. Their

nests are formed of several layers of combs,

all of which are covered with a waterproof

covering of paper, made from weatherworn

wood of stumps, trees, fences, and buildings.

The nests are gradually enlarged, new combs

being added and the

outer envelope being

enlarged to cover

them. The males and

workers die in the fall,

and the females hiber-
nate over winter and

start a new colony in

the spring.

3. BEES {APINA)

Most of our com-
mon bees are readily
distinguished as such
by the general shape
and hairy clothing of

Fig. 424. a, mouth-parts of a short-tongued bee
(P/vsopis fubescens) (note short, broad, flapHke
tongue, or glossa) ; b, mouth-parts of a long-tongued
bee {A)ithophora pilipes) (note greatly extended
tongue). (Much enlarged)

(After Sharpe, from Kellogg)

HYMENOPTERA

267

the body. Some of them, however, may be confused with some of
the wasps, from which they may be separated by the structure of the
first segment of the hind tarsus (which is dilated, flattened, and
usually provided with numerous hairs __

to aid in carrying pollen) and also by
the fact that the body hairs are covered
with short branches instead of being
simple, as in wasps. They are quite
variable in habit : some are solitary, —
that is, each female makes a nest for her
young, as do the solitary wasps ; others
lay their eggs in the nests of other bees ;
while others, of which the honey-bee is
the best example, live in colonies. The
nests may always be recognized, how-
ever, by their being stored with pollen
and honey and never with insects. Two
families are recognized, which are dis-
tinguished by the length of the tip of
the labium, or glossa.

In the Short-tongued bees {AndTe-
iiidac) the tip of the labium is shorter
than the base, while in the Long-tongued
bees (Apidae) it is much longer and en-
ables them to secure the nectar from
deeper flowers. All of the bees are of
great economic importance, for as they
go from flower to flower the pollen be-
comes attached to the hairs of the body
as well as to the special structures on the
legs, by which they transport it, and is
brushed off on the stigma of the next
flower visited. Thus the bees are the
most important agents in the cross-fer-
tilization of flowers, without which many plants will not set their seed
or fruit. For this reason those who grow cucumbers and tomatoes
under glass always have a hive of bees to fertilize the flowers, and
where bees are scarce, many of our common fruits set but sparingly.

Fig. 425. Nest of Audreiia,
the mining bee

(After Packard)

268

ELEMENTARY ENTOMOLOGY

Fig. 426. A common

short-tongued bee {A//-

drena sp.). (Slightly

enlarged)

None of the short-tongued bees Hve in colonies, and many of

them make their nests in the ground, which has given them the
name of "mining bees." Their tunnels are
usually branched, each branch terminating in
a single cell, which is lined with a sort of
glazing. After this cell is filled with nectar
and pollen, the Q.gg is laid and the cell is then
sealed up. Quite commonly, large numbers
of these tunnels will be found near together,
forming large villages. Some of the smaller

forms mine into the sides of sand banks and

cliffs, their numerous holes making the surface

appear as if it had received a charge from a

shotgun. These little females of the genus

HalictJis have the interesting habit of making

a common burrow into a bank and then each

making a side passage to her own cells, so

that, as Professor Comstock aptl)' remarks,

"While Andrcna builds villages composed of individual homes,

Halictus makes cities composed of apartment houses."

Fig. 427. A mining-
bee {Halictus lerouxii
var. 7-iibontm Ckll.).
(Slightly enlarged)

Fig. 428. The leaf-cutter bee and a leaf-covered cell removed from its burrow.

(Natural size)

(After Linville and Kelly)

HYMENOPTERA

269

The majority of the Long-tongued bees {Apidac) are solitary and

have most diverse nesting habits : some make their cells in the
ground, as do the miners ; others are potters, and
fashion nests of mud, which are attached to the
stems of plants ; some are carpenters, boring holes
in wood ; while some go so far as to upholster
their nests with neatly cut pieces of leaves, with
which the cells are lined and covered. The leaf-
cutter bees are peculiarly interesting forms, though
of no particular economic importance. They bore
a hole in soft or decaying" wood, in the bottom of
which is deftly fitted a piece of a leaf, rose leaves
being commonly used, so as to make a thimblelike
cup. In this the pollen and nectar are placed and
an ^gg is laid, and then a circular-shaped piece of
leaf is jammed down so as to make a tight wad
over the cell, and another similar cell is made
above it. The circular areas cut from rose leaves
b)' these bees may frequently be noticed. Others
are known as carpenter-bees, making their nests
in wood. The smaller carpenter-bee {Ceratina
dupla) inhabits the dead stems of sumac or the
hollow stems of other plants, which are cleaned
out and used over again by the young. Several
cells are made and separated by little chips. When

the tunnel is full, the female waits for her children to grow up.

" The lower one hatches first," says Professor Comstock, "" 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 y\g. 430. <?, carpenter-bee (Xylocopa Carolina Linn.) ;
leads forth her full- b, first segment of hind tarsus ; c, same of bumble-bee

fledged famih' in a (After Waish)

Fig. 429. Nest

of carpenter-bee.

(Reduced)

(.-Vfter Jordan and
Kellogg)

270

ELEMENTARY ENTOMOLOGY

flight into the sunshine." The larger carpenter-bee {Xylocopa
virginicd) closely resembles a bumble-bee, being fully as large,
yellow and black in color, with a metallic blue reflection on the
abdomen. It excavates its nests in solid
wood, often boring for a foot or more.

Many of the long-tongued bees are known
as guest-bees, from their habit of laying
their eggs in the cells of other bees, which
rear the larvae of the intruders as they do
their own. The largest of these {PsytJiirus)
so closely resemble bumble-bees that it is
difficult to distinguish them from the males,
though the females are readily recognized
from their lacking the pollen-basket borne
by the hind-legs of the bumble-bees. Just
why they are tolerated is a mystery, for the
bumble-bees allow them to go in and out
of their nests with the greatest freedom.
The social bees include our
common bumble-bee and the
domesticated honey-bees. The
bumble-bees are of considerable
importance to the farmer, for
they are the only ones whose
tongues are long enough to feed
on red-clover blossoms, so that
they are entirely responsible for
its pollination, and where they
are scarce it is difficult to secure
a crop of clover seed. It is
hardly necessary to describe the nest of a bumble-bee, for what
country boy does not look back upon the stirring experiences in-
cident to the robbing of their nests, or of accidentally disturbing
one while mowing, and being given good reason to remember the
fact. The queens are larger than the males or workers, and are
the only forms which live over winter. In the spring the queen
finds some deserted mouse nest and within it places a ball of pol-
len and her eggs. The larvae feed on the pollen and, when full

Fig. 431. Nest of bumble-bee (Bombus

sp.), showing opening at the surface of

the ground and also brood cells in the

cavity beneath

(Adapted from McCook by Kellogg)

HYMENOPTERA

271

a, worker ; /',

a

Fig. 432. ]>umble-bees

queen, or fertile female,
and Kellogg)

(After Jordan

grown, make strong, brown, silken cocoons, in which they change
to pupae. These cocoons are strengthened with wax by the queens,

and are used for storing
honey, after the young
emerge. The first broods
are all workers, and af-
ter their appearance the
queen has nothing more
to do but lay her eggs.
Later in the season the
males and other queens
appear, all living together
in the same nest. In the
fall the young queens
crawl away to a suitable
hibernating place, and in
the spring start new colonies, in the manner previously described.
Honey-bees. Probably no other insect is of quite as much human
interest as the honey-bee. Apiculture is a well-developed art, its
literature is extensive, and its devotees have well-organized associ-
ations. The honey-bee was
brought from Europe by
the early settlers of this
country, and swarms have
escaped, which have become
the wild bees now found in
hollow trees. There are
three forms in every hive,
— the queen, the drones, or
males, and the workers,
which are imperfectly devel-
oped females. The workers
are the common forms with
which we are familiar, and which do all the work of the colony. The
drones are larger than the workers, are reared in larger cells, and are
blunter and broader in shape. They are relatively few in number,
and occur only in the early summer, during the swarming season,
after which they are expelled from the nest or killed by the workers.

Fig. 433. The honey-bee {Ap/s mcllifica)
4, queen ; B, drone ; C, worker. (After Kellogg)

272

ELEMENTARY ENTOMOLOGY

The queen bee
is much larger
than the work-
er, and has a
long, pointed
body. She is
developed in a
special cell sev-
eral times the
size of an or-
dinary cell and
readily distin-
guishable, as it
extends at a

right angle to

Fig. 434. Queen cells of the honey-bee, and worker brood in , , ,.

various stages

(After Benton, United States Department of Agriculture)

all fed by the
workers, who provide honey and bee-bread, composed of pollen and
nectar, for the ordinary cells which are to develop workers and

Fig. 435. Honey-bees building comb (side of hive removed)
(After Benton, United States Department of Agriculture)

HYMENOPTERA

273

drones, but for the queen cell a
the mouths of the workers and
may be developed into a queen
at the desire of the workers
by enlarging the cell and feed-
ing the larva with this royal
jelly. In the spring new
queens appear in the colony,
which are defended from the
old queen by the workers,
when the old queen, with
many of her subjects, forms
a new swarm and goes off
to start a new colony, thus
insuring the multiplication
and continuance of the spe-
cies. The comb is made of
wax, and is constructed in
thin, hexagonal cells so as
to use as little material as
possible, for it takes twenty-
one pounds of honey to make
one pound of wax. To secure
the wax, some of the workers
gorge themselves with honey
and hang in a curtainlike mass
in the hive. In a day or so the
wax commences to exude
from the wax plates on the
underside of the abdomen
and is scraped off and used
by other workers in construct-
ing the comb. From the buds
of various trees, particularly
the poplar, they collect a
sort of resin, called propolis,
which is used for cementing
crevices in the hive. The

royal jelly, which is excreted from
is very nutritious. Any worker egg

Fig. 436. Legs of the honey-bee

.-/, left front leg of worker (anterior view), show-
ing position of notch (M) of antenna cleaner
on base of first tarsal joint (/ Tar) and of clos-
ing spine (cc) on end of tibia (Ti) ; B, left
hind-leg of worker (anterior view), showing the
pollen-basket {C/>) on outer surface of tibia
(Td) ; C, inner view of first tarsal joint of hind-
leg of worker, showing rows of pollen-gather-
ing hairs and the so-called "wax shears."
(After Snodgrass, United States Department
of Agriculture)

2 74 ELEMENTARY ENTOMOLOGY

bee-bread on which the larvae are fed is made from the pollen of
flowers and is carried to the nest on the hind-legs, which have a
hair-encircled area, called the pollen-basket, for transporting it.
The honey is stored for food during the winter, and is made from
the nectar of flowers, which is taken into the honey-stomach, where
it is changed to honey, and is then regurgitated into the cells of
the comb.

Summary of the Hymenoptera

Suborder I. Boring Hymenoptera {Terebrantia). With ovipositor and two-
segmented trochanters.
Section i. Plant-eating Hymenoptera. Abdomen not constricted.
Family. Saw-flies {Tenthredinidae).
Horn-tails (Siricidae).
Section 2. Gall-inhabiting Hymenoptera {Cy)iipidae).
Section 3. Parasitic Hymenoptera. Abdomen petiolate.
Family. Ichneumon-flies (IcJiiieiononidae).
Braconid-flies {Braconidae).
Chalcis-flies ( Chalcididae).
Proctotrypid-flies {Proctotiypidae).

Suborder H. Stinging Hymenoptera {Aciileafa). Females bearing a sting;
simple trochanters.
Section i. Ants (superfamily Fonnicina).
Family. Common ants (Cainponotidae).
Stinging ants {Mynnicidae).
Section 2. Wasps. First segment of metatarsi cylindrical ; hairs simple.

A, Digger-wasps (superfamily Sphecind).

Family. Velvet-ants [Mutillidae).

Spider-wasps {Psafii/nocharidae).
Thread-waisted wasps {SpJiecidae).
Bembecids {Beinbecidae),
and others.

B. True wasps (superfamily Vespina). Wings folded fanlike on

back when at rest.
Family. Solitary wasps (Eiunenidae).
Social wasps {Vcspidae),
Section 3. Bees (superfamily Apia a). First segment of metatarsi,
broad, flattened, hairy ; body hairs, plumose.

Family. Short-tongued bees {Andretiidae).
Long-tongued bees (Apidae).

Solitary bees, guest-bees, social bees.

PART III. LABORATORY EXERCISES

CHAPTER XVI

THE EXTERNAL ANATOMY OF THE LOCUST

Note. Beyond a doubt, one of the most difficult problems every instructor in
the biological laboratory has to meet is to determine the amount of assistance
which shall be given individual students. In advanced work, probably the best
plan is to train students to rely on their own resources and to solve their own
problems. In elementary classes, however, far too much time is often wasted in
the laboratory because the instructor does not happen to be at hand to aid and
direct the student. For this reason the following instructions are given, more or
less in detail, with the hope that the students may intelligently carry on their
work without the constant attention of the instructor.

In order to derive the most benefit from the laboratory work, it is essential
that the students should verify every detail of structure herein given before pro-
ceeding with the drawings, the latter being considered simply as a means to an
end. In fact, the amount of good derived by the student from the laboratory work
is largely dependent upon the energy of the individual. For this reason the lab-
oratory work should not be judged entirely by the drawings, and, if possible, the
actual amount of information obtained by the student in the laboratory should be
determined by examinations similar to those given in lecture or recitation work.

For details concerning laboratory methods and equipment, see Chapter XXIII.

Section I. External Anatomy of the Grasshopper (Type
OF Class Insecta)

Material. The red-legged locust {RIelanoplus fefuur-rubruin) has been
selected as the type of the class Insecta, partly on account of its abundance
and the ease with which it may be collected, and partly on account of its
simplicity of structure. Specimens for class work should be collected in the
late summer or early fall, and preserved in 85 per cent alcohol for three or four
days. After this time has elapsed, they should be transferred to 80 per cent
alcohol, to which 10 per cent of pure glycerin has been added. If soaked in
warm water a short time before using, the specimens will be rendered soft and
pliable. The students should verify the following points :

1. Body covering. Carefully examine with a hand lens the body
covering of the specimen, and note that it is made up of a series

275

276 ELEMENTARY ENTOMOLOGY

of hardened plates. These plates are known as sclerites, and the
depression between two plates is called a suture. The hardness
of the plates is due to the deposition of a horny substance called
chitin.

2. General divisions of the body. Typically the bodies of all
insects are divided into a series of rings, or segments. In many
places two or more of these rings have grown together, or are fused.
Again, in certain regions of the body, parts of the segments may be
lost. Regardless of the amount of variation in this respect, however,
we find that the segments are always grouped into three regions,
known as head, thorax, and abdomen.

a. TJic head. The head is made up of a number of segments,
which are fused together, forming a boxlike structure. On the
head are found the eyes, mouth-parts, and antennae.

b. The thorax. This is the second division of the body, and
consists of three segments, known as the prothorax (division nearest
the head), mesothorax, and metathorax. Each of these segments
bears a pair of walking appendages, and in addition the meso-
thorax and metathorax are provided with wings.

c. The abdomen. This is the third division of the body, and is
made up of eleven segments. The posterior segments, however,
are not complete, showing modifications.

Exercise 1. Pin the specimen to the bottom of a dissecting dish, spread the
wings and wing-covers of one side, and make an enlarged drawing (dorsal view)
of the entire insect, showing the above-named divisions.

3. Detailed study of the head. As already noted, the head of the
locust is made up of a number of segments which have been firmly
fused together. The following divisions should be noticed :

a. The epicraninm. This is a boxlike piece which surrounds the
eyes and forms the basis of attachment for the movable parts of
the head. It extends down the front of the head, between the eyes,
to the transverse suture, and down the sides of the head to the
base of the mouth-parts. The sides of the epicranium below the
compound eyes are known as the genae, or cheeks, while the front
of the head between the compound eyes is called the frons.

b. The compound eyes. These are situated upon the upper por-
tion of the sides of the head, and are large, brown, oval areas with

THE EXTERNAL ANATOMY OF THE LOCUST 277

smooth, highly pohshed surfaces. If examined with a lens, the
surface will be seen to be made up of a number of hexagonal
areas, which are known as facets.

c. The ocelli. These are sometimes called the simple eyes, and
consist of three very small, almost transparent oval areas. One of
the ocelli is situated on the front of the head just below the lowest
margin of the compound eyes ; the other two are placed in the
top of the impression which contains the bases of the antennae-,
and in contact with the upper portion of the compound eyes.

d. The antemi(E. These are two long, threadlike processes situ-
ated median to the compound eyes. Each consists of about twenty-
six segments. Each antenna arises from an oval depression known
as the antennary fossa, and is attached by a thin membrane which
admits of motion in all directions.

e. TJic clypcus. This is a short, rectangular piece attached to
the lower straight edge of the epicranium.

f . TJie mouth-parts. These consist of a number of separate parts
attached to the ventral region of the epicranium, and will be
studied in detail later.

Exercise 2. Make an enlarged drawing of the front of the head, showing
the above parts.

Exercise 3. Make an enlarged drawing of the side of the head, showing all
the parts.

Exercise 4. Remove the head and notice the occipital foramen, or the
large opening by which the cavity of the head communicates with that of the
neck and thorax.

Section H. Mouth-Parts of Locusts

Material. In order to effectively study the mouth-parts of the locust each
student should be provided with prepared slides as well as with the alcoholic
specimens. As the parts are removed for study they should be mounted on
glass slides in a glycerin solution, and may then be compared with the pre-
pared mounts. The parts may be removed by grasping them at their attachment
with a pair of atout forceps and pulling them back at right angles to their
attachment.

1. Labrum. The labrum, or upper lip, is a flaplike piece at-
tached to the lower edge of the clypeus. The free edge is deeply
notched on the median line.

278 ELEMENTARY ENTOMOLOGY

2. Mandibles. These lie directly beneath the labrum and con-
sist of a pair of short, thick pieces. The inner edge is somewhat
flattened and provided with a number of toothlike projections
which form the grinding surface of the mandibles.

3. Maxillae. These are the second pair of jaws ; they lie directly
beneath the mandibles and are much more complicated in struc-
ture. After they have been removed and mounted in glycerin,
the following parts can be distinguished :

a. The cardo. This forms the attachment or basal piece of the
maxilla, and is triangular in shape.

b. TJie stipes. This is a quadrangular-shaped segment forming
the central part of the maxilla. One side is attached to the cardo,
and two of the other sides form the attachment for the remaining
structures.

c. TJic lacinia. This is attached to the inner edge of the
stipes, and is a long, curved piece terminating in a row of sharp
teeth.

d. The galea. This portion of the maxilla articulates with the
stipes on its outer edge, just below the attachment of the lacinia.
It closely resembles this latter structure, except that the end is
rounded instead of being toothed.

e. The maxillary palp (2. These arise from a basal portion
known as the palpifer, which articulates with the stipes between
the attachment of the galea and the cardo. The palpae consist of
five long, slender segments, and, like the antennas, are sensory in
function.

4. Labium. The labium, or under lip, forms the under part of
the mouth and, together with the upper lip, almost incloses the
mandibles and maxillas. The labium is a complicated structure
made up of the following parts :

a. The suhnientum. This forms the attachment to the epicra-
nium and is a crescent-shaped piece. It is also joined to the
membrane which connects the head with the thorax.

b. The mentjun. This is the central portion of the labium, and
is joined to the distal margin of the submentum.

c. The ligula. The ligula consists of two large, movable flaps
attached to the distal, or outer, edge of the mentum, and forms
the terminal, central portion of the labium.

THE EXTERNAL ANATOMY OE THE LOCUST 279

d. The labial palpcc. These resemble the maxillary palpae, but
consist of only four segments, which are attached to the palpifers.
These are located on either side of the mentum, below the attach-
ment of the ligula.

5. Hypopharynx. The hypopharynx, or tongue, is located on
the floor of the mouth, between the maxillae. It is diamond-shaped
when viewed from above, and is covered with numerous small
taste setae.

Exercise 5. Make a careful drawing of the mouth-parts, showing all of the
above-named structures.

Section III. The Thorax

Material. Each student should be provided with both alcoholic and dry speci-
mens, and should remove the wings and legs from one side of the body only.

1. Divisions of the thorax. As has already been noted, the
thorax is divided into three segments, known as the prothorax,
mesothorax, and metathorax.

2. Prothorax. This is the segment to which the head is attached,
and may be divided into two regions, — a dorsal region known as
the pronotum, and a ventral region known as the sternum.

a. TJic proiiotuni. This is a bonnetlike piece extending over
the dorsal and lateral region of the prothorax. It is made up of
a fusion of four plates, which are indicated by the transverse sutures.
Anteriorly there is an opening corresponding to the occipital fora-
men of the epicranium.

b. The sternum. The ventral side, or sternum, of the prothorax
is also made up of separate plates, or sclerites. The anterior sclerite
bears a spine on the median line.

c. The prothoracic legs. These arise from the ventral, lateral
region of the prothorax. Their structure will be noted later.

3. Mesothorax and metathorax. The sclerites of these two
segments are very intimately associated, and their structure will be
discussed together. The mesothorax is joined to the prothorax by
a membrane which permits of more or less movement. Posteriorly
the metathorax is joined immovably with the first abdominal seg-
ment. The mesothorax and metathorax form a strong, boxlike struc-
ture for the support of the wing and leg muscles. Like the prothorax

28o ELEMENTARY ENTOMOLOGY

these segments are made up of separate plates, held together by
a tough, connecting membrane. These plates may, however, be
divided into three groups : the tergum, or dorsal region ; the
sternum, or ventral region ; and the pleuron, or lateral region. On
the dorsal and ventral regions of the body the sutures separating the
mesothorax from the metathorax are not very distinct. On the sides
of the body, however, there is a very distinct line, or suture, running
from the posterior border of the attachment of the second pair
of legs toward the dorsal part of the body. This suture divides
the mesothorax from the metathorax. The pleura of each of the
posterior thoracic segments are again divided by transverse sutures,
so that each pleuron consists of two sclerites.

a. TJic legs. The mesothoracic and metathoracic legs arise from
the lower posterior border of the pleura of their respective seg-
ments, and are joined to the thorax by a tough, elastic membrane.

b. The wings. The wings have a more anterior origin in respect
to their thoracic segments than do the legs. Each pair arises at
the union of the pleura and tergum.

c. The spiracles. The spiracles, or openings of the respiratory
system, consist of two pair of liplike structures situated on either
side of the body on the anterior margin of the pleural plates. The
mesothoracic spiracle is concealed by the posterior edge of the
pronotum. The metathoracic spiracle is located just dorsal to
the mesothoracic leg, near the suture separating the two segments.
There is another spiracle just dorsal to the attachment of the meta-
thoracic leg, but this belongs to the first abdominal segment.

Exercise 6. Make a full-page drawing of a side view of the thorax of a
locust with the wings and legs removed, showing all of the parts noted above.

Section IV. The Thoracic Appendages

Material. With a pair of fine-pointed scissors remove the legs from one
side of the body of the locust and arrange them on a piece of white paper in
their regular order. Also remove the wing and wing-cover (mesothoracic wing)
from one side and pin to a thin sheet of cork, spreading the wing to its full
dimension.

1. Legs. Make a comparative study of the legs, which will be
found to consist of the following segments :

THE EXTERNAL ANATOMY OE THE LOCUST 28 1

a. TJic coxa. This is the first segment, and is attached to the
thorax by a tough, elastic membrane. It; is short, ahnost globular,
and is more distinct on the prothoracic legs than on the other two.

b. The t roc limit cr. This is the second segment, and is consid-
erably shorter than the coxa, and partially or entirely fused with the
next segment. It is hard to distinguish except in the first pair
of legs.

c. TJic fcviiir. This is the third and largest segment of the leg,
and in the case of the metathoracic leg contains the muscles used
in jumping.

d. TJic tibia. This is the fourth segment, and is much more
slender than the femur, although about equaling it in length.

e. TJic tarsus. This is the last division, and is made up of three
short segments freely articulating with each other. These seg-
ments bear a series of pads, which terminate on the last one in a
large, suckerlike disk known as the pulvillus. On each side of the
pulvillus is a pair of claws, the ungues.

Exercise 7. Make drawings of the first and third thoracic legs, showing all
the parts.

2. Wing-covers. The wing-covers are leathery in texture and
do not fold fanlike over the abdomen, as do the two wings. They
are strengthened by numerous veins and cross veins.

Exercise 8. Make an enlarged drawing of a wing-cover, noting the arrange-
ment and number of the veins and cross veins ; also note the attachment to
the mesothorax.

3. Wings. These are sometimes called the second, or meta-
thoracic, wings. They are membranous in texture and fold fanlike
when not in use. They are also strengthened by numerous veins
and cross veins, as are the wing-covers.

Exercise 9. Make an enlarged drawing of a wing, showing the arrangement
of the veins, method of folding, attachment, etc.

282 ELEMENTARY ENTOMOLOGY

Section V, The Abdomen

Material. Each student should be provided with one alcoholic specimen
each of the male and the female locust. The remains of the specimens used in
previous sections will be sufficient.

1. Abdomen of the male. The abdomen of the male locust con-
sists of eleven segments ; only seven of these, however, are complete,

a. The first abdoviinal segment. This is made up of a curved,
dorsal shield, the tergum, which terminates just above the attach-
ment of the third pair of legs. This piece partially surrounds the
tympanic membrane, or ear, which is a large, crescent-shaped area
covered with a semitransparent membrane. Between the ear and
the attachment of the legs are the spiracles, which have already
been noted. The ventral part of the first segment, the sternum,
is not attached to the tergum, owing to the large size of the attach-
ment of the legs. The pleura are entirely absent.

b. TJie second to eighth abdominal segments. These are all quite
similar, consisting of a dorsal tergum, which extends laterally to
near the ventral part of the body, where it joins the sternum.
The pleura, or side pieces, noted in connection with the thorax,
have been inseparably fused to the tergum. One pair of spiracles
is located at the anterior margin of each segment near the union
of the sternum and tergum.

c. Segments nine and ten. The terga of these two segments
are partially fused together, the union of the two being indicated
by the presence of a transverse suture. The sterna of these two
segments are entirely fused and much modified, forming a broad,
platelike piece.

d. Segment eleven. This is represented only by the tergum,
which forms the terminal, dorsal, shield-shaped piece.

e. The ccrci. These are a pair of plates attached to the lateral,
posterior border of the tenth segment, and extend back past the
end of the eleventh tergum.

f. The sjibgenital plate. This is attached to the ninth sternum
and forms the most posterior ventral plate of the body.

g. The podical plates. These lie directly beneath the cerci and
ventral to the eleventh tergum. The anus opens between these
plates, and the genital chamber lies directly below them.

THE EXTERNAL ANATOMY OF THE LOCUST 283

Exercise 10. Make an enlarged drawing of the side view of the abdomen of
the male locust, showing all of the above parts.

2. Abdomen of the female. The abdomen of the female from the
first to the seventh segment is nearly the same as in the male.

a. Segment eight. This segment resembles the other segments,
except that the sternum is nearly twice as long, and is known as
the subgenital plate.

b. Segments nine, ten, and eleven. These are essentially like
those of the male, the tergiim of nine and ten being partially fused,
and tergum eleven forming the terminal, dorsal shield.

c. The eerei and podieal plates. These plates are similar to
those in the male, except that the podieal plates are much more
prominent.

d. The ovipositor. The ovipositor consists of three pairs of
movable plates. The dorsal pair lie just ventral to the eleventh
tergimi and are long, lance-shaped pieces with hard, pointed tips.
The ventral pair arises just dorsal to the eighth sternum and
resembles the dorsal pair. When these four pieces are brought
together, their points are in contact, forming a sharp organ b)-
means of which the female bores the holes in the ground in which
to deposit her eggs. The third set of plates are known as the egg
guides. These are much smaller and are located median to the
plates of the true ovipositor.

Exercise 11. Make a drawing of the side view of the last five segments of
the female locust.

CHAPTER XVII

A COMPARISON OF THE DIFFERENT TYPES OF ARTHROPODA

Section VI. Comparison of Insfxts and Crustaceans
(Types, Locust and Crayfish)

Material. Alcoholic specimens of both crayfish and locusts should be pro-
vided, although the student by this time should be familiar with the structure
of the locust. The lobster is much larger and easier to work than the crayfish,
and instructions here given will apply to either. Both the lobster and the crayfish
may be obtained from any of the natural-history supply companies. Crayfish
may be collected in many sections of the country from streams and ponds,
and should be preserved in the same manner as recommended for the locust.
Material for Exercise 17 (the sow-bug) can be obtained in abundance under
boards and stones and in other damp locations. It may be preserved in
alcohol.

Exercise 12. Comparison of the anatomy of the crayfish and the locust.
With the two specimens at hand, write out a careful comparison of the following
points :

1. Nature of the body covering.

2. General divisions of the body. (A fusion of the head and thorax is known
as the cephalothorax.)

Exercise 13. The head and head appendages. Remove the appendages
from one side of the crayfish, beginning with the first appendage anterior to
the first walking leg. These may be removed by grasping them near their
attachment with a pair of strong forceps, and pulling them backwards toward
the posterior end of the body. As each one is removed, it should be laid on a
piece of wet blotting paper in regular order. The appendages of the crayfish
are numbered from the anterior to the posterior end of the body. The head
appendages are as follows :

1 . The antennule, consisting of a basal piece and two long, slender filaments.

2. The antenna, consisting of a basal piece, one long, slender filament,
known as the endopodite, and a short, platelike projection, known as the
exopodite.

3. The mandibles.

4. 5. The first and second maxillae. The above include all the head append-
ages. Write out a careful comparison of these appendages and corresponding
appendages in the locust. Also with a hand lens make a comparative study
of the eyes.

284

THE DIFFERENT TYPES OF ARTHROPODA 285

Exercise 14. .7 coiiiparisoji of the iJioracic appendages. Appendages 6, 7,
and 8 of the thorax are known as the first, second, and third maxillipeds, and
the appendages from 9-13 are the walking appendages. Write out a comparison
of the thoracic appendages, noting the number, segmentation, etc.

Exercise 15. A compaj-ative study of the abdomens of the crayfisJi and
locust. Appendages 14-20 of the crayfish are known as the swimmerets.
Compare these with the more anterior appendages of the crayfish. Also write
out a careful comparison of the segmentation of the abdomens of the crayfish
and locust.

Exercise 16. Make a drawing of the side view of the crayfish, naming the
different appendages and divisions of the body.

Exercise 17. Make drawings of appendages 2, 10, and 16.

Exercise 18. Comparison of the locust and soiv-bug. Write out a careful
comparison of these two forms, noting :

1. The nature of the body covering.

2. The general divisions and segmentation of the body.

3. The nature of the appendages.

4. The number and position of the appendages.

Exercise 19. Make a drawing of the ventral view of the sow-bug, showing
the number, position, and arrangement of the appendages.

Section VII. Comparison of Insects and Myriapoda
(Types, Locust and Centipede)

Material. Centipedes are flattened, wormlike animals living under logs, stones,
and other damp localities. They are quite common in most places, and may be
collected and preserved in ']^ per cent alcohol. Large specimens may usually
be supplied by most of the natural-history supply house's.

Exercise 20. Write out a detailed comparison of a centipede and locust, noting
the following points :

1 . The general divisions of the body.

2. The nature of body covering.

3. The segmentation of the body.

4. The eyes and antennae.

5. The mouth-parts.

6. The legs, number of their segments, etc.
Exercise 21. Make a drawing of the dorsal view of the head.
Exercise 22. Make a drawing of a ventral view of the head.

286 ELEMENTARY ENTOMOLOGY

Section VIII. Comparison of Insects and Arachnida
(Types, Spider {Argiopc) and Locust)

Material. When possible, the ladder-spider should be collected for this work,
as it is large, brilliantly colored, and can usually be collected in large numbers
in the fall.

Exercise 23. Write out a careful comparison of the following parts:

1 . The covering of the body and segmentation.

2. The general divisions of the body.

3. The eyes (located on the anterior portion of the cephalothorax), their
number, arrangement, etc.

4. The mouth-parts, consisting of the mandibles, with terminal fang, maxillae,
hypopharynx, and a rudimentary labium.

5. The legs, number, number of segments, etc.

6. The abdomen, including the following structures :

a. The opening of the book-lungs, which lie on either side of the me-

dian line at the anterior end of the abdomen and are respiratory
in function.

b. The genital opening, situated in the female on a prominent median

tubercle located between the book-lungs.

c. The spinnerets, consisting of six papillae at the posterior end of the

body.
Exercise 24. Make a drawing of a dorsal view of the spider.
Exercise 25. Make a drawing of the mandibles and maxillae of the spider.

CHAPTER XVIII

A COMPARISON OF DIFFERENT TYPES OF INSECTS; STRUCTURE
OF THE BEE, FLY, AND BEETLE

Section IX. Anatomy of the Honey-Bee (Second Type of
THE Class Insecta)

Material. The ordinary honey-bee can be easily collected for this work, and
should be in as fresh a condition as possible. While alcoholic specimens will
do, it is much better to furnish the students with fresh material, or to dry the
specimens and place them in a moist chamber about two hours before using.
It is almost imperative that the students be supplied with prepared slides of
the legs to supplement the dry material. As this section's work will not deal
with the mouth-parts, prepared slides of these will not be needed until later.

1. General anatomy of the honey-bee. The bee furnishes an ex-
cellent example of the specialization of insects, all of the parts being
modified for a special purpose. This laboratory section's work is
intended to give the student an idea of these modifications, with
the exception of the mouth-parts, which will be studied later. The
plan of structure does not differ much from that of the locust ; the
student, however, should notice the following points :

Exercise 26. Write out a careful comparison of the bee and locust as follows :

1. The nature of the body covering.

2. The segmentation of the body.

3. The divisions of the body.

4. The number and position of the appendages.

5. The structure of the head (except the mouth-parts). Note the compound
eyes, ocelli, and antenna3.

2. Modifications of the prothoracic leg. Carefully remove the
prothoracic legs and mount in the glycerin solution. Compare
with the prepared slides and notice the following points (the gen-
eral divisions of the leg are the same as those of the locust) :

a. The coxa. This basal piece is a rather large, triangular seg-
ment attached to the prothorax.

287

288 ELEMENTARY ENTOMOLOGY

b. Tlic trochanter. This is proportionally larger than in the
locust ; aside from this it shows no special modifications.

c. TJie fcnuir. This is a large, club-shaped joint covered with
long hairs.

d. The tibia. This segment is smaller than the preceding and
is provided with a spine at the lower end.

e. The tarsus. The tarsus consists of five segments, the first
being nearly as large as the tibia. It is provided with a notch, near
its attachment to the tibia, which, together with the spine on the
latter segment, forms the antenna cleaner.

Notice also the bilobed claws on the end of the tarsus, together
with the median, flaplike structure known as the empodium. This
secretes a sticky substance, which enables the bee to walk on a
smooth surface.

Exercise 27. Make an enlarged drawing of a prothoracic leg, showing the
segmentation, antenna cleaner, claws, etc.

3. Mesothoracic leg. The mesothoracic leg differs but slightly
from the prothoracic leg, except that the antenna cleaner is absent
and that on the inner side of the tibia there is a spur used in loosen-
ing the pollen from flowers.

Exercise 28. Make drawing of the inner side of the tibia and tarsus of the
mesothoracic leg, showing the spine.

4. Metathoracic leg. This resembles the prothoracic leg, with
the following modifications :

a. The pollen-basket. The outer surface of the tibia of the third
thoracic leg is smooth and surrounded with a row of long, incurved
hairs. This is known as the pollen-basket, and is used in carrying
the pollen to the hive.

b. TJic wax pincers. Between the end of the tibia and the tarsus
is a pincerlike structure consisting of a row of thick, flattened spines
on the edge of the tibia, which come in contact with the smooth
edge of the tarsus. These wax pincers are supposed to be used in re-
moving the plates of wax from the abdomen, where they are secreted.

c. The pollen comb. This structure is located on the inner sur-
face of the flat, basal segment of the tarsus, and consists of nine
parallel rows of bristles, which are used in combing the pollen from
the body, where it collects while the bee is gathering nectar.

COMPARISON OF DIFFERENT INSECTS 289

Exercise 29. Make a drawing of the inner surface of the third thoracic leg.

Exercise 30. Make a drawing of the outer surface of the third thoracic leg.

Exercise 31. Examine the wings of the bee under the compound micro-
scope and make a drawing showing the fine hooks and groove by means of
which the wings arp locked together during flight. Also notice the arrangement
of the veins.

Section X. Comparison of the Fly with the Locust and Bee

Material. Probably the best material for the study of the anatomy of the
Diptera is some of the large horse-flies, like Tabanus afrafiis, although these
may be hard to secure in sufficient numbers. If these cannot be secured, any
of the smaller, more abundant species will suffice. The material may be pre-
served in 75 per cent alcohol, or dried, the latter method probably being pref-
erable for a study of the external parts ; the specimens should, however, be
placed in a moist chamber at least twenty-four hours before they are wanted
for use.

Exercise 32. Write out a careful comparative description of the external
anatomy of the fly, comparing it with the locust and the bee, and noting the
following points of structure :

1. The divisions of the body, the body covering, and the segmentation.

2. The head and its appendages, with the exception of the mouth-parts.

3. The thorax and thoracic appendages.

4. The abdomen and its segmentation.

Exercise 33. Make a drawing of the wing of a fly, comparing it with the text
figure.

Section XI. Comparison of a Beetle with the Locust

AND Bee

Material. Almost any of the larger beetles will serve for this work, although
the May-beetle will probably be the easiest to secure. These should be pre-
served in the alcohol-glycerin solution.

Exercise 34. Write out a comparison of the beetle with the locust and bee,
noting :

1 . The nature of the body covering, the segmentation, and the divisions of
the body.

2. The head, including the eyes and antennas.

"(If time permits, the mouth-parts of the beetle might profitably be dissected
and compared with those of the locust.)

3. The thorax, including the wings and wing-covers, especially noting the
modification of the wing-covers.

4. The abdomen, the number of segments, etc.

Exercise 35. Make a drawing of the antennae, wings, and wing-covers of
the beetle.

CHAPTER XIX
THE INTERNAL ANATOMY OF THE LOCUST

Section XII

MateriaL Fresh material will be found the most satisfactory for this work,
the specimens being placed in 85 per cent alcohol for about an hour before
being used. If fresh material is not available, alcoholic specimens that have been
previously soaked in warm water for a short time will work very satisfactorily.
After removing the wings and legs from the right side of the locust, make a
longitudinal, dorsal incision to the right of the median, dorsal line, and the
entire length of the body. Make a similar longitudinal ventral incision to the
right of the midventral line. Remove carefully the right side of the chitinous
covering, exposing all of the internal organs, of which the following systems
should be studied :

1. Digestive system. The digestive system occupies the greater
part of the thoracic and the ventral part of the abdominal cavity.
It is essentially a continuous tube, divided into the following re-
gions, each with a particular function to perform.

a. The esophagus. This is a cylindrical tube, with tough, mus-
cular walls. It runs from the mouth, opening dorsally to a point
opposite the foramenal aperture, where it bends at right angles
and enters the thorax.

b. The crop. This is an enlargement of the esophagus and, be-
ginning in the mesothorax, runs to the abdomen, almost filling the
mesothoracic and metathoracic cavities.

c. TJie gizzard {proventriaihis). This is the next division (not
found in the genus Acridium). The walls are thick and muscular,
and on the inside are lined with a series of chitinous plates which
are used in completing the mastication of the food.

d. The stomach {ventricidus). This division is separated from
the gizzard by a slight constriction. It is approximately the same
diameter as the gizzard and extends from the first to the seventh
segment of the abdomen.

e. TJie large intestine. This is of somewhat smaller diameter
than the stomach and runs from the seventh to the tenth segment.

290

THE INTERNAL ANATOMY OF THE LOCUST

291

f . TJic small i)itcstinc. The small intestine is a short, muscular
tube mnning from the end of the large intestine toward the dorsal
part of the body and ending in segment eleven.

g. The rcctimi. The rectum is a short, muscular enlargement
in segment eleven and ends in the anal opening.

2. Accessory organs of digestion. In connection with the ali-
mentary tract are a certain number of glands or glandular structures
which either aid in the digestion of the food or assist in eliminating
the waste products.

a. TJie salivary glands. These are small, white glands located
on either side of the esophagus in the thorax. They open out into
two main ducts which lead to the mouth.

b. TJlc gastric ccBca. The gastric caeca consist of a set of eight
double, cone-shaped pouches which open at the union of the crop
and stomach. They form a complete belt around the alimentary
tract at this point and secrete a fluid which aids in digestion.

c. TJie MalpigJiian tnbiilcs. The Malpighian tubules are a sys-
tem of very fine, hairlike tubes which arise from the most anterior
end of the large intestine. Their function is excretory, similar to
that of the kidneys.

3. Reproductive system. The ease with which the organs of
this system may be distinguished depends considerably on the sex
and the time of year at which the specimens were collected.

a. Female reproductive organs. In the fall, just before the eggs
are deposited, the entire abdomen of the female is filled with a
yellow, coarsely granular organ known as the ovary. There are a
pair of these, one located on either side of the body. Running
from the posterior end of the ovary are two small tubes called the
oviducts, which unite near the posterior end of the body to form
the vagina. This opens externally upon the upper surface of the
subgenital plate, between the ovipositor. On a median line slightly
dorsal to the egg guides there is a second opening, which communi-
cates with a long, slender tube ending in an enlarged pouch known
as the spermatheca. This entire structure is very difficult to locate.

b. Male 7-eproductive organs. The general arrangement of the
male reproductive organs is quite similar to that of the female, only
much smaller. The two pair of testes (corresponding to the ovaries)
lie on the dorsal side of the stomach and are inclosed in a saclike

292

ELEMENTARY ENTOMOLOGY

membrane. Leading from the testes are two very fine, hairlike
tubes known as the vas deferens. These pass down to the ventral
side of the body on either side of the alimentary tract and unite,
forming the ejaculatory duct, which opens dorsally to the subgenital
plate. Just before the union of the vas deferens they are joined
on either side by a number of fine tubules known as the seminal
vesicles, the function of which is to store up the products of the
reproductive glands.

Exercise 36. Make a careful drawing of the side view of a locust, showing
the alimentary tract, accessory organs of digestion, and either the male or the
female reproductive system.

4. Nervous system. With a pair of fine scissors cut the alimen-
tary tract through the esophagus and small intestine, and carefully
remove, together with the reproductive organs. Great care must be
taken to not injure or displace any of the other organs. Also care-
fully remove the right side of the chitinous portion of the head.

The nervous system consists principally of a supra-esophageal
ganglion, or brain, which lies dorsal to the esophagus. This is a large,
whitish mass of nervous tissue and, if carefully dissected, can be
seen to be directly connected with the compound eyes. Running
on either side of the esophagus is a small, white nerve cord that
unites on the ventral side, forming the sub-esophageal ganglion.
Running from this ganglion toward the posterior end of the body
is the ventral nerve cord. If carefully examined, this will be found
to consist of two parallel white cords that are occasionally united
by the ventral ganglia, from which arise numerous lateral nerves.
These ventral ganglia occur in the following segments, — the
prothorax, mesothorax, metathorax, and abdominal segments two,
three, five, six, and seven.

5. Muscular system. In elementary work of this sort no attempt
will be made to trace out the different sets of muscles, but the
general relation of the different muscles to the segments should be
noted. In the mesothorax and metathorax notice the large wing mus-
cles ; also in the abdomen notice the longitudinal and ventral bands.

6. Respiratory system. The respiratory system is made up of
tubes known as trachea. These open out along either side of the
body ; the openings, which have already been noted, are termed the

THE INTERNAL ANATOMY OF THE LOCUST

293

spiracles. Soon after entering the body the trachea unite to form
two large lateral trunks. From these, dorsal branches are given off,
which unite, forming two parallel dorsal trunks. Running off from
both the dorsal and lateral trunks are smaller branches, which
separate into extremely minute tubes and ramify through all the
tissues.

Exercise 37. If fresh specimens are at hand, mount in water some of the
fatty tissue surrounding the alimentary tract, and examine under the compound
microscope. The trachea will be seen as much-branched silver-colored tubes.
Make a careful drawing.

Exercise 38. Make a drawing of the side view of the locust, with the alimen-
tary tract and reproductive organs removed, showing the general arrangement
of the muscular, tracheal, and nervous systems.

7. Circulatory system. The circulatory system consists of a
dorsal, median, tubular heart. This can be seen in fresh specimens
by removing the dorsal body wall.

Exercise 39. In order to observe the rhythmic contraction of the heart,
obtain living larvae of mosquitoes, dragon-flies, or May-flies. Place them in
water on a slide and examine under the microscope. Draw.

CHAPTER XX

MOUTH-PARTS OF INSECTS

The type of biting mouth-parts has already been considered
in Chapter XVI, the forms here considered being more highly
specialized.

Section XIII. Sucking Mouth-Parts (Type, Squash-Bug)

Material. Students should be provided with prepared slides of the mouth-
parts of the squash-bug. They should also have alcoholic specimens, as the
arrangement of the parts cannot be easily distinguished on the prepared slides.
Before studying the prepared slides the students should dissect out the mouth-
parts of an alcoholic specimen. With a pair of sharp-pointed scissors cut off
the ventral part of the head and place it in a thick glycerin solution, consist-
ing of equal parts of glycerin and alcohol. Then, under the lens of a dissect-
ing microscope, pull the long proboscis apart, noting the order of arrangement
of the different pieces.

The mouth-parts of the squash-bug consist of a long, jointed beak in which
are found four long, threadlike setae. They should be compared with the
mouth-parts of the locust.

1. Labrum. The labrum, or upper lip, is a long, triangular,
sharply pointed piece, with slightly serrated edge, and fits over
the groove of the lower lip.

2. Mandibles. The mandibles are a. pair of long, hairlike setae
with sharp-toothed points. They adhere very closely together, and
are used in cutting into the tissues of plants in order to induce
a flow of sap.

3. Maxillae. These closely resemble the mandibles and, like
them, lock together, forming a lancelike structure. They are used
in piercing plants, the same as the mandibles.

4. Labium. The labium, or under lip, is formed into a long,
partially closed tube, in which lie the mandibles and maxillae. It is
made up of four segments of about equal length.

Exercise 40. Make a careful drawing of the mouth-parts of the squash-bug,
showing the above details.

294

MOUTH-PARTS OF INSECTS 295

Section XIV, Specialized Piercing Mouth-Parts
(Type, Horse-fly)

MateriaL Specimens of any of the common horse-flies (Tabamis) will do
for this work, though only female flies can be used, as the mandibles are lack-
ing in the males. The two sexes may be distinguished by the position of the
eyes. In the male the eyes touch for a greater or less distance, while in the
female there is a narrow space between the eyfes. The mouth-parts are quite
conspicuous and should be removed and mounted as in the previous section.
Students should also be provided with prepared slides. A comparison should
be made with the mouth-parts already studied. The mouth-parts of the fly are
more highly specialized than those of the squash-bug, and consist of a number
of stylets, or flat, pointed pieces, more or less completely inclosed in the fleshy
under lip. They consist of the following parts :

1. Labrum. The labrum, or upper lip, is the uppermost stylet,
and consists of a flat, unpaired piece, bluntly tipped. It is broader
than any of the remaining stylets.

2. Mandibles. These consist of a pair of flat, smooth, sharply
pointed pieces adapted for piercing.

3. Maxillae. These are the second pair of stylets and are under-
neath the mandibles, which they very closely resemble. The max-
illae are narrower than the mandibles, are less strongly chitinized,
and are provided with palps, which are attached to the base of each
maxilla. The palps consist of two segments and are thick, clublike
structures covered with very fine hairs.

4. Hypopharynx. The hypopharynx, or tongue, is a slender,
unpaired piece resembling very much the labrum, but is narrower
and more sharply pointed. It lies directly underneath the maxillas.

5. Labium. This is a conspicuous, proboscislike structure,
which partially incloses the other mouth-parts. At the end of the
labium is a large, fleshy, disklike piece called the labella. It con-
sists of two lobes, which fit closely around the stylets when they
are being used.

Exercise 41. Make careful drawings of the above mouth-parts.

296 ELEMENTARY ENTOMOLOGY

Section XV. Sucking Mouth-Parts
(Type, Butterfly)

Material. The commonest type, and one of the best for this work, is the
monarch butterfly {A/iosia plexippus). These may be collected and dried and
the scales carefully removed from the head with a stiff camel's-hair brush.
Part of the specimens should be boiled in caustic potash (KOH) and the head
mounted in balsam. The remainder of the specimens should be placed in the
hioist chamber for a day or so before they are wanted. The mouth-parts of the
Lepidoptera are greatly modified, and only careful study reveals the relation
between them and the biting mouth-parts of the locust.

1. Labium. This is a very short, quadrangular piece, almost or
entirely indistinguishable in some species, as it is immovably joined
to the clypeus.

2. Mandibles. The mandibles are almost entirely wanting in the
monarch butterfly, although they are represented in some forms
by two triangular pieces which are of little or no use to the insect.
In some of the moths they are more highly developed.

3. Maxillae. The maxillae are the most conspicuous part of the
mouth, the two together forming a long, coiled sucking tube used
in drawing up nectar. Each maxilla is deeply grooved on the
inner side, the two fitting together, forming a complete tube. The
maxillary palps are wanting in this form, although present in some
of the lower forms.

4. Labium. The labium consists of a small, triangular flap
almost completely fused with the base of the maxilla. Extending
out from either side of the labium are the large labial palps, which
form two prominent, plumelike projections from either side of the
head. They are three-jointed and covered with scales.

Exercise 42. Make a drawing of the mouth-parts of the monarch butterfly,
showing the above in detail.

Section XVI. Sucking and Biting Moutii-Parts
(Type, Honey-bee)

Material. The honey-bees for this section's work may be preserved in 75
per cent alcohol. It may be found advantageous to substitute the bumble-bee,
as the mouth-parts are larger and more easily dissected. In either case it is
desirable that the students be provided with prepared slides. The mouth-parts

MOUTH-PARTS OF INSECTS 297

of the honey-bee are made up of the typical number of parts, but arc adapted
both for biting and sucking. The student should refer to the other types of
mouth-parts already studied.

1. Labrum. This consists of a small, rectangular piece attached
to the clypeus, and resembles closely the labrum of the locust.

2. Mandibles. These are hard, well-developed structures, more
elongated than in the locust, and are devoid of teeth.

3. Maxillae. The maxillae are complicated structures and, as in.
the locust, consist of the following parts :

a. The cardo. This serves as the attachment to the epicranium
and is an elongated piece.

b. TJic stipes. These are rather thick, club-shaped pieces strongly
chitinized.

c. The niaxillary palps. These are short and almost atrophied,
located at the distal, outer edge of the stipes.

d. The lacinia galea. These two structures are fused together
in the bee and form a pair of elongated pieces deeply grooved on the
inner edge. When fitted together, they form a partially closed tube
more or less completely surrounding the parts of the labium,

4. Labium. The labium, or under lip, is even more modified
than the maxillae, and consists of the following parts :

a. TJie subinetitnni. This is a triangular, basal piece, running off
from which are two small, rodlike pieces known as the lora.

b. The vientum. This is a large, pear-shaped piece attached to
the submentum.

c. TJie labial palps. The labial palps are greatly modified, form-
ing two long, four-jointed structures grooved on the inner edge.
When these are fitted together, they form a tube which in turn is
inclosed by the lacinia galea of the maxillae.

d. TJie paraglossa. This is a sheathlike arrangement which
incloses the base of the tongue, lies median to the palps, and is
attached to the mentum.

5. Tongue. The tongue is a long, flexible rod, densely covered
with hairs. Along the ventral side there is a deep groove, forming
almost a complete tube, and at the end is a flaplike structure known
as the flabellum.

Exercise 43. Make a careful drawing of the mouth-parts of the honey-bee,
showing the above structures in detail.

CHAPTER XXI

THE LIFE HISTORY OF INSECTS

Section XVII. Life History of a Plant-Louse
(Family Aphididae)

Material. The family Aphididae probably furnishes some of the best ex-
amples for the study of incomplete metamorphosis of insects. It does not
matter much what particular species is selected for this work, as any of the
ordinary aphids attacking greenhouse plants will be found quite satisfactory.
Among the forms most easily managed may be mentioned the lettuce aphis and
the rose aphis. These may almost always be secured at any time of year. For
work on the lettuce aphis each student should be provided with a flowerpot
in which is growing one small lettuce plant. The instructor should keep on
hand a supply of aphids. These should be grown on lettuce under a large bell
jar, to prevent the escape of the winged forms. Each student should be given
one wingless, viviparous female just before the insect reaches maturity.

It will be recalled that the life history of t\\Q,Ap/iididae may vary
considerably with the different species. Nearly all of them, how-
ever, have two forms of reproduction, known as viviparous repro-
duction (in which the living young are brought forth without the
fertilization of the female by the male) and oviparous reproduction
(in which eggs are deposited by fertilized females). The sexual
forms are usually brought forth in the fall by a viviparous female,
and after mating, the oviparous female deposits eggs which are not
hatched until the next spring. P"rom these eggs are hatched the
viviparous females, this form of reproduction continuing throughout
the summer. It will also be recalled that of the viviparous forms
part may be winged and part wingless.

Exercise 44. Watch the viviparous female carefully and write up a detailed
set of notes, including the following observations :

1 . Date of birth of first young, giving the hour when the observation was made.

2. Date of birth of subsequent young, giving the number of young, the day,
and the hour when observed. Be sure that only one viviparous female is present
on each culture, and keep careful track of all the offspring.

298

THE LIFE HISTORY OF INSECTS 299

3. Number the offspring consecutively, according to age, and note which
developed into winged and which into wingless forms.

4. Note the age at which each of these individuals begins reproduction. It
might be suggested that when the first of this generation begins reproducing,
it is best to remove the young in order to prevent confusion of the generations.

Exercise 45. Make a chart from your above notes, giving the number of the
individual, whether winged or wingless, date of birth, date of maturity (when
first young is produced).

Exercise 46. Notes on the rapidity of growth. Isolate some newly born
individuals, noting the date and hour of birth. Watch these carefully, and note
the date and the hour that molting occurs. The cast skin will usually be found
near the young aphids, which begin feeding soon after molting. Those indi-
viduals just having molted will be found to be the lightest in color, but the cast
skin should be taken as the only proof that the insect has molted. As soon as
these individuals begin to reproduce, tabulate your above notes, giving the
number of hours between each molt for each individual.

Exercise 47. Write up a detailed set of notes describing one wingless in-
dividual after each molt, up to and including the adult form, noting all the
changes which may occur.

Exercise 48. Write up a detailed set of notes, similar to the above, for the
winged form.

Exercise 49. Mount a wingless individual in the alcohol-glycerin solution
and make a drawing of the dorsal view. (The aphids should first be dipped in 95
per cent alcohol, and may then be mounted directly in the glycerin solution.)

Exercise 50. ]Mount a winged individual in the alcohol-glycerin solution
and make a drawing of the dorsal view.

Section XVIII. Life History of the Dr agon-Fly

Material. It will be quite impractical for a class in elementary entomology
to try to trace the complete life history of the dragon-fly, but this form will
give the student a good idea of the habits and structure of aquatic nymphs.
The dragon-flies deposit their eggs on water plants, and as soon as these hatch,
the young nymphs settle to the bottom of the pond and may be found, at almost
any time of the year, crawling about in decaying vegetation or other sediment.
The easiest way to secure them is to rake out the sediment from the quiet pools
of a stream, or from the edge of ponds, with an ordinary garden rake. The
nymphs, together with a small amount of sediment, should be placed in an
aquarium until ready for observation. This applies especially to material collected
in the fall, as it will be difficult for each individual student to provide food and
suitable conditions for the nymphs that he may have under his observation.

When this work is undertaken by a class, each student should be provided
with a glass dish containing three or four of the largest-sized nymphs. As it is
necessary to feed the nymphs on other aquatic insects, it might be better not
to collect the material until early spring.

300 ELEMENTARY ENTOMOLOGY

Exercise 51. Observations on tJie structure of t lie nymphs. Write up a
careful description of the nymphs, noting the details of structure. In the
description, refer to and use the terms with which you have already become
familiar in your description of other forms.

Exercise 52. Habits of the nymphs. Make as many notes as possible on
the general habits of the nymphs, noting their methods of feeding, locomotion,
secreting themselves, etc. (see page 98).

Exercise 53. Observations on the transformation of nymphs. Note care-
fully whether or not the nymph molts, or sheds its skin, and, if observed, how
the act is performed. Toward spring the nymphs should be placed in the sun-
light as much as possible. Each dish should also be provided with a number
of sticks, up which the nymphs may crawl when they are ready to transform to
the adult stage. If possible, observe this transformation and write up a com-
plete set of notes on the subject.

Section XIX. Complete Metamorphosis. Life History of
THE Cabbage Butterfly {Pontia rapae)

Material. The following instructions have been prepared especially for the
study of the cabbage butterfly, though the life history of any of the other Lepi-
doptera may be studied in the same manner, substituting, of course, the proper
food plants. Each student should be provided with a flowerpot in which is grow-
ing a young cabbage plant. If this work may be begun by the middle of Septem-
ber, cabbage butterflies should be collected and one pair placed in each of a
number of breeding cages (see Chapter XXIII). The pots containing the young
plants can be placed in the cages, and daily observations made for the presence
of eggs. After the eggs hatch, a large lantern globe, the top of which has been
covered with cheesecloth, should be placed over each plant, to prevent the
escape of the larvae.

Exercise 54. Egg deposition. The student should, if possible, determine
and make notes of the following points :

1 . On what part of the leaf are the eggs deposited 1

2. Are they deposited in clusters or singly?

3. The number of eggs deposited by one female.

4. The period of incubation.

5. Describe and make drawings of the eggs.

Exercise 55. Observations on the larvce. Determine and make notes of the
number of molts, describing each of the larval stages.

Exercise 56. Observations on the pnpce. If possible, observe the transfor-
mation of the larvae to the pupal form. Note the locality selected for pupation,
the attachment of the pupa, and length of time in the pupal stage. Also draw
and describe. (After pupation the pupae should be removed to a cool, dark
place and left until spring, or, if wanted for more immediate use, they should
be placed in a light, warm room, where they will probably emerge in a short

THE LIFE HISTORY OF INSECTS 30 1

time. Low temperatures are not injurious, but too much moisture must be
avoided. The latter part of March the pupae may be brought out and again
placed under observation.)

Exercise 57. The emergence of tJie adult. Note the date and the method
of emergence, and write a brief description of the adult.

Section XX, Complete Metamorphosis. Life History of
THE Fruit-Fly {Drosophila sp.)

Material. Material for this work may be secured by placing decaying
bananas in the sunlight for a few days. The material should then be cov-
ered with a bell jar and used as a stock culture. Each student should be pro-
vided with a glass tumbler containing about one fourth of an inch of decayed
banana. Cut a piece of black paper the size of the tumbler and lay on top of
the banana, and cover the tumbler securely with a glass plate. The student
should then place three or four adult fruit-flies in the tumbler.

Exercise 58. Write up a careful set of notes on the following points :

1. Describe, and make a drawing of egg, which will be deposited on the
black paper.

2. Note the length of time of incubation.

3. Describe, and make a drawing of a larva.

4. If possible, determine the length of the larval stage.

5. Describe, and make a drawing of a pupa.

6. Determine the length of the pupal stage.

7. Describe the adult, and determine the distinguishing characters of the
sexes.

CHAPTER XXII

CLASSIFICATION OF INSECTS

Section XXI. Classification of the Orders of Insects

Material. One of two methods may be employed for this work : (a) Each
student should be required to make a collection of insects containing repre-
sentatives of at least eight of the principal orders, {b) Provide each student
with a representative collection of twenty-five insects. These should be num-
bered from one to twenty-five, and should contain as nearly representative
forms as possible.

Exercise 59. On a sheet of paper place the numbers one to twenty-five.
After each number write the order (to be determined by the key) to which the
corresponding insect belongs.

Section XXII. Classification of Families

Material. Give each student a collection representing as nearly as possible
the different families of insects treated in the key. It will be found convenient
to place twenty-five insects on a block, each block containing only the insects
of one order, thus obviating the necessity of classifying every insect to its
order before placing it in the family. The insects should be distributed as
follows : One block containing representatives of the lower orders (Neuroptera
and Neuropteroid insects) ; one block of Hemiptera ; two of Coleoptera ; two
of Lepidoptera ; one of Hymenoptera ; and one of Diptera.

Exercise 60. Classification of the families of the lower orders.

On a sheet of paper place the numbers one to twenty-five. After each
number write the family (to be determined by the key) to which the corre-
sponding insect belongs. If possible, by referring to the text or by compari-
son with a named collection, identify common forms to genus and species.

Exercise 61. Classification of the families of Hemiptera.

Exercise 62. Classification of the families of Coleoptera.

Exercise 63. Classification of the families of Coleoptera.

Exercise 64. Classification of the families of Lepidoptera.

Exercise 65. Classification of the families of Lepidoptera.

Exercise 66. Classification of the families of Hymenoptera.

Exercise 67. Classification of the families of Diptera.

302

/

CLASSIFICATION OF INSECTS 303

KEY TO THE ORDERS OF INSECTS

The principles underlying the classification of insects have already
been discussed in the text. In arranging this key an attempt has
been made to eliminate all useless characters and to include only
those families commonly encountered. Possibly this elimination has
been carried too far for some of the extreme forms of the different
orders ; however, in an elementary textbook it is not deemed prac-
tical to include material that would be of use only to the specialist.

Several families are included in the key which are not mentioned
in the text. This becomes necessary for the complete arrangement
of the key, and may be of use in aiding students to determine the
more uncommon families which they may collect. In giving out
specimens for determination the teacher should, if possible, use
only those families described in the text.

The following key is intended only for the identification of typical
adult forms. An attempt has been made to produce a usable key in
preference to a strictly natural one. An ideal key should, of course,
combine these two characteristics, but it has been found necessary
many times to sacrifice the natural arrangement for clearness.

In the production of these keys the authors are indebted to all
previous workers in entomology. Due credit is given in every case
where a key has been adapted from another author's work,

KEY TO THE ORDERS

A. Mouth-parts adapted for biting.
^ B. Without wings, or rudiments of wings. ^

p C. Mouth-parts retracted within the head. (Page 73) . . Aptera
7 CC. Mouth-parts not retracted within the head.

;. D. Abdomen joined to thorax by slender petiole. Ants. (Page

243) Hymenoptera

DD. Abdomen broadly joined to thorax.

E. Insects small, body antlike or louselike in form. Bird-lice ;

book-lice; white ants. (Page 103) . . . Platyptera

EE. Insects of medium or large size. Body not antlike or

louselike in form.

E. Head prolonged into beak, at the end of which are

the biting mouth-parts. Scorpion-flies. (Page 93)

Mecoptera
EE. Head not prolonged into beak.

304 ELEMENTARY ENTOMOLOGY

G. Antennas filiform. Cockroaches ; grasshoppers ;
walking sticks. (Page 76) . . . Orthoptera
GG. Antennas serrated, or of various types, but not fili-
form. Fireflies, etc. (Page 136). . Coleoptera
^,^ BB. Winged insects, ^r .

, C. First pair of wings horny, meeting in a straight line down the back,
y D. Abdomen with forceplike appendages. Earwigs. (Page 87)

EUPLEXOPTERA

DD. Abdomen without forceplike appendages. (Page 136)

Coleoptera
'-f CC. First pair of wings leathery or membranous.

^, • D. Wings membranous ; the second pair, if present, not folded in
plaits under first.
E. Head prolonged into beak, at the extremity of which are
the biting mouth-parts. Scorpion-flies. (Page 93)

Mecoptera
£E. Head not prolonged into beak. /
y E. Wings with but few cross veins. (Page 243)
•^ Hymenoptera

7 EE Wings net-veined ; abdomen broadly joined to thorax.
G. Abdomen provided with two or three long, many-
jointed filaments. (Page 95) . . Ephemerida
CG. Abdomen without jointed filaments.

//. Antennae short, awl-shaped, and inconspicuous ;
wings of equal size, held horizontal, vertical, or
parallel to the body; not rooflike. Dragon-flies.

(Page 98) Odonata

////. Antennas not awl-shaped, more or less prom-
inent.
/. Wings folded flat on body. Body compact,
antlike, and flattened or louselike in form.

Platvptera
//. Wings rooflike over body; body linear. (Page

90) Neuroptera

DD. First pair of wings more or less leathery, with second pair
folded under first.
E. Wings clothed with hairs. Caddis-flies. (Page 93)

Trichoptera
EE. Wings not clothed with hairs.

E. First pair of wings leathery, second membranous. Not

alike in structure. (Page 76) . . . Orthoptera

EE. Wings alike in structure, both more or less leathery.

C. Tarsi 5-jointed. (Page 90) . . . Neuroptera

GG. Tarsi less than 5-jointed. Stone-flies. (Page 97)

Plecoptera

CLASSIFICATION OF INSECTS

305

I A A. Mouth-parts adapted for sucking.

, B. Mouth-parts not adapted for piercing.

C. Body covered with scales, wings usually broad. Butterflies and

moths. (Page 172) Lepidoptera

^ , CC. Body not covered with scales, wings comparatively narrow.
' D. Mandibles, if present, not fitted for biting.

E. Two pair of wings, fringed with hair. Thrips. Physopoda
EE. One pair of wings usually naked, or with microscopic hairs.

Flies. (Page 218) Diptera

DD. Mandibles normally developed Hymenoptera

BB. Mouth-parts adapted for piercing.

C. Mouth-parts consisting of a jointed tube containing the bristlelike
mandibles and maxillae. Bugs. (Page 107) . . . Hemiptera
CC. Mouth-parts consisting of a fleshy tube containing usually bristle-
like mandibles and maxillae.
D. Wingless insects ; body laterally compressed. Fleas. (Page 240)

Siphonaptera
DD. Winged or wingless insects, body not laterally compressed.
E. Tarsus provided with single strong, hooklike claw. Wing-
less parasitic lice of mammals. (Page 107). Hemiptera
EE. Tarsus normal. Winged or wingless insects. (Page 218)

Diptera

KEY TO THE FAMILIES OF APTERA 1

A. Abdomen elongate, composed of at least ten segments; antennae many-
jointed ; abdomen usually provided with a pair of two-or-more-jointed, fila-
mentous, or forceplike appendages. (Page 74) Suborder I, Thysanura

B. Body covered with scales Lepismidae

BB. Body not covered with scales.

C. Abdomen without caudal appendages . . . Anisophaeridae
CC. Abdomen with caudal appendages.

D. Caudal appendages sickle-shaped Japygidae

DD. Caudal appendages consisting of many-jointed filaments.

Campodeidae
AA. Abdomen composed of not more than six segments; antennae of not
more than eight segments ; ventral spring usually present, but no ter-
minal abdominal appendages. Springtails. (Page 74)

Suborder II, Collembola
B. Ventral spring present.

C. Ventral spring attached on penultimate abdominal segment.
D. Abdomen globular, only slightly longer than broad.

Sminthuridae
DD. Abdomen cylindrical, longer than broad. Entomobryidae

1 Revised from Dr. K. W. v. Dalla Torie's " Die Gattungen und Arten der
Apterygogenea."

/

306 ELEMENTARY ENTOMOLOGY

CC. Ventral spring attached to antepenultimate abdominal segment.

PODURIDAE

BB. Ventral spring absent Aphoruridae

THE EPHEMERIDA

This order includes only a single family, the members of which have deli-
cate membranous wings with a fine network of veins. The fore-wings are
large, and the hind-wings much smaller or wanting. Mouth-parts rudimentary.
May-fiies. (Page 95) Ephemeridae

KEY TO THE FAMILIES OF ODONATAi

A. Front and hind wings similar in outline, distinctly narrow at base, held
vertically over the back when at rest. Damsel-flies. (Page 98) Sub-
order Zygoptera
B. Wings with not less than five antecubital cross veins. Calopterygidae
^ BB. Wings with not more than three, usually two, antecubital cross veins.

Agrionidae
A A. Front and hind wings dissimilar, the hind-wings being much wider at the

base ; wings held horizontally when at rest. Dragon-flies. (Page 98) s^

Suborder Anisoptera
J B. Antecubital cross veins of first and second rows usually meeting each

other Libellulidae

3 BB. Antecubital cross veins of first and second rows not meeting each other. '"/
C. Eyes meeting above in median line of head ; abdomen with lateral

ridges Aeschnidae

CC. Eyes separate, or nearly so ; abdomen without lateral ridges.
/^ D. Eyes touching at a single point, or barely apart.

CoRDULEGASTERI DAE

DD. Eyes distinctly separated Gomphidae

THE PLECOPTERA

This order includes only a single family, having four membranous wings,
the hind-wings being folded plaitlike under the fore-wings. The mouth-parts
are biting, but slightly developed. Stone-flies. (Page 97) . . . Perlidae

KEY TO THE FAMILIES OF NEUROPTERA

A. Hind-wings broad at base, the inner margin folded in plaits. Dobsons.

(Page 90) Sialidae

AA. Hind-wings narrow at base, not folded in plaits.
B. Prothorax gready prolonged into necklike stalk.

1 Revised from Kellogg's " American Insects."

i

CLASSIFICATION OF INSECTS 307

C. Prothoracic legs normal Rai'HIdiidae

CC. Prothoracic legs fitted for grasping Mantispidae

BB. Prothorax normal.

C. Wings clear, densely net-veined.

D. Antennae filiform, without terminal knob. Lace wings.

(Page 92) Chrvsopidae

DD. Antennae filiform, with terminal knob. Ant-lions. (Page 93 )

MVR.MELEONIDAE

CC. Wings more or less opaque, with many longitudinal but few cross
veins Hemerobiidae

THE MECOPTERA

This order includes only one family, having four membranous wings, fur-
nished with numerous veins. The head is prolonged into a beak, at the end
of which are the biting mouth-parts. Scorpion-flies. (Page 93) Panorpidae

THE TRICHOPTERA

This order includes but one family, having four membranous wings, fur-
nished with numerous longitudinal but few cross veins ; wings more or less
densely covered with hair ; rudimentary biting mouth-parts. Caddis-flies.
(Page 93) Phryganeidae

KEY TO THE PLATYPTERA

A. Body cylindrical, social insects with white, antlike bodies. White ants.

(Page 103) Termitidae

A A. Body depressed, if cylindrical, not andike. Nonsocial, louselike insects.
B. Antennae of not more than five segments. Bird-lice. (Page 106)

Suborder Mallophaga
C. Antennae exposed, consisting of three or five segments.

D. With three-segmented antennae : tarsi with one claw ; infesting

mammals only Trichodectidae

DD. With five-segmented antennas ; tarsi with two claws ; infesting

birds only Philopteridae

CC. Antennas concealed in shallow cavities on underside of head, con-
sisting of four segments.
D. Tarsi with one claw ; infesting mammals only . Gyropidae
DD. Tarsi with two claws ; infestmg birds only . . Liotheidae
BB. Filiform antennas of more than five segments.

Suborder Corrodextia
C. Wings well developed ; ocelli present in addition to the compound

eyes. Bark-lice. (Page 105) Psocidae

CC. Wings and ocelli wanting. Book-lice. (Page 105) . Atropidae

3o8 ELEMENTARY ENTOMOLOGY

THE EUPLEXOPTERA

This order includes a single family the members of which have four wings :
the first pair are leathery or horny, meeting in a straight line down the middle
of ihe back ; the second pair are membranous, with numerous radiating veins
folded lengthwise like a fan and then crosswise under the first pair. Earwigs.

(Page 87) FORFICULIDAE

KEY TO THE FAMILIES OF ORTHOPTERA

A. Third pair of legs not adapted for leaping.

B. Body oval, dorsoventrally compressed. Cockroaches. (Page 77)

Blattidae
BB. Body elongate, not dorsoventrally compressed.

C. First pair of legs fitted for grasping and holding their prey ; prono-
tum longer than any of the other body segments. Praying mantis.

(Page 78) Maxtidae

CC. First pair of legs not fitted for grasping and holding prey ; prono-

tum short. Walking-sticks. (Page 80) Phasmidae

A A. Third pair of legs adapted for leaping.

B. Antennae shorter than body. Locusts. (Page 81). . . Acrididae
BB. Antennae longer than body.

C. Tarsi consisting of four segments. Long-horned grasshoppers.

(Page 83) LocusTiDAE

CC. Tarsi consisting of three segments. Crickets. (Page 85)

Grvllidae

THE THVSANOPTERA

This order includes but a single family of very small .insects with long,
narrow, membranous wings, having but few or no veins and bordered by a
fringe of long hair ; the tarsi swollen, bladderlike, with or without claws.

Phvsopodae

KEY TO THE FAMILIES OF HEMIPTERAi

A. Wingless insects with fleshy unjointed beak; parasitic on mammals.
(Suborder Parasitica.) Suctorial Hce. (Page 121) . . Pediculidae
AA. Winged or wingless insects, with a jointed beak.

B. First pair of wings leathery at the base, membranous at the tip, the
tips overlapping on the back ; beak arising from front part of head.

Suborder Heteroptera
C. Antennae shorter than head. Aquatic or shore insects.

D. With two ocelli. Toad-bugs Galcjulidae

DD. Without ocelli.

1 Adapted from Kellogg's "American Insects."

CLASSIFICATION OF INSECTS 309

E. Hind tarsus without claws.

F. Pronotum overlapping head above. Back-swimmers.

(Page 108) NOTONECTIDAE

FF. Head overlapping prothorax above. Water-boatman.

(Page 108) CoRisiDAE

EE. Hind tarsus with claws.

F. Caudal end of abdomen furnished with a respiratory
tube. Water-scorpions. (Page 109) . . . Nepidae
FF. Caudal end of abdomen without respiratory tube.

G. Hind legs flattened, adapted for swimming. Giant
water-bug. (Page 109) . . . Belosto.matidae
GG. Hind legs slender, not adapted for swimming.

Naucoridae
CC. Antennae at least as long as head.

D. Head as long as entire thorax Limnobatidae

DD. Head shorter than thorax.

E. Last segment of tarsus more or less split, with claws
inserted before apex.
F. Body elongated ; beak four-jointed. Water-striders.

(Page 109) Hydrobatidae

FF. Body usually stout and oval ; beak three-jointed.

Velidae
EE. Last segment of tarsus entire, and with claws inserted at
apex.
F. Antennas of three or four segments.
G. Beak three-jointed.

H. Body very long and slender . . Emesidae
HH. Body not long and slender.

/. Front legs with greatly thickened femora.

Ambush-bugs. (Page 114) . Phvmatidae

//. Front legs with normal femora, or at least not

unusually wide.

J. Antennasof three segments. Assassin-bugs.

(Page 112) Reduviidae

JJ. Antennae of four segments.

K. Tarsus of two segments ; body very
flat. Flat-bugs .... Aradidae
KK. Tarsus of three segments.

L. Dorsal portion of body more or less
rounded ; beak long, reaching to or
beyond second coxa. Shore-bugs.
Saldidae
LL. Dorsal part of body flat ; beak not
reaching beyond second coxa. Bed-
bugs. (Page I 14) ACANTHIDAE

3IO

ELEMENTARY ENTOMOLOGY

GG. Beak four-jointed.
H. Ocelli absent.

/. Membrane of front wings with two large cells
at the base, from which arise about eight
branching veins. Red-bugs. Pyrrhocoridae
//. Membrane of front wings with one or two
closed cells at the base, and with no longitudi-
nal veins. Leaf-bugs. (Page 1 1 7) Capsidae
HH. Ocelli present.

/. Front legs fitted for grasping prey, the tibia
being armed with spines and capable of being
closed tightly on the femora, which are unusu-
ally stout. Damsel-bugs . . . Nabidae
//. Front legs not differing from the others.
J. Body and legs very long and slender.

Stilt-bugs Berytidae

JJ. Body not unusually slender.

A'. Tarsus two-jointed; wing-covers resem-
bling lace network. Lace-bugs. (Page

117) Tingitidae

KK. Tarsus three-jointed.

L. Membrane with four or five
simple veins arising from its base.
Chinch-bug family. (Page 120)

LVGAEIDAE

LL. Membrane with many forked veins
springing from a transverse basal
vein. Squash-bugs. (Page 121)

COREIDAE

FF. Antennae of five segments.
G. Dorsal portion of body flat.

H. Tibia with few or no spines. Stink-bugs. (Page

115) Pextatomidae

HH. Tibia armed with rows of spines . Cydxidae
GG. Dorsal portion of body strongly convex.

H. Prothorax rounded in front, nearly straight be-
hind ; lateral margin of scutellum with a furrow
in which the edges of the wing-covers fit when
closed. Negro-bugs . . . Thyreocoridae
HH. Prothorax not as above ; lateral margin of
scutellum without furrow. Shield-backed bugs.

Scutelleridae
BB. Wings membranous or sometimes leathery throughout; beak arising
from the hinder parts of the lower side of the head.

Suborder Homoptera

CLASSIFICATION OF INSECTS 311

C. Beak evidently arising from head ; tarsi three-jointed ; antennae
minute, bristlelike.
D. With three ocelli ; males with musical organs. Cicadas. (Page

122) CiCADIDAE

DD. With two ocelli or none ; males without musical organs.
E. Antennas inserted on sides of cheek beneath the eyes.

FULGORIDAE

EE. Antennae inserted in front of and between the eyes.

E. Pronotum prolonged posteriorly over the abdomen or
at least over the scutellum. Tree-hoppers. (Page 124)

Membracidae
EE. Pronotum not prolonged above abdomen.

G. Hind tibia armed with one or two stout teeth and
with short, stout spines at tip. Spittle-insects. (Page

124) Cercopidae

GG. Hind tibia with two rows of spines. Leaf -hoppers.

(Page 125) Jassidae

CC. Beak apparently arising from between the front coxae, or absent ;
tarsi one- or two-jointed.
D. Hind femora fitted for leaping; antennae of nine or ten seg-
ments with two bristles on apex. Jumping plant-lice. (Page

127) PSYLLIDAE

DD. Hind femora normal ; antennas usually with less than ten
segments.
E. Legs long and slender ; wings transparent. Plant-lice.

(Page 127) Aphididae

EE. Legs short ; wings usually opaque.

E. Tarsus consisting of two joints ; body covered with a
whitish powder, male and female each with four wings.

Aleyrodidae

EE. Tarsus consisting of one joint ; adult male with two

wings ; female wingless, with the body scale-like or

gall-like in form. Scale insects. (Page 129) Coccidae

KEY TO THE FAMILIES OF COLEOPTERA

A. Head not prolonged into beak. {Coleopfera ge/iui/ia.)

B. First and second tarsus consisting of five segments ; third tarsus con-
sisting of four segments Section Heteromera

C. Head without distinct neck ; narrower than thorax and more or
less inserted in it; body wall hard. Darkling-beetles. (Page 165)

Texebrionidae
CC. Head with distinct neck and as wide as prothorax ; body soft and

elytra flexible. Blister-beetles Meloidae

BB. First, second, and third tarsi of same number of segments.

312

ELEMENTARY ENTOMOLOGY

Tarsi consisting of five segments . . . Section Pentamera
D. Antennae filiform, with distinct cylindrical segments.

Tribe Adephaga
E. Legs adapted for swimming, aquatic in habits.

F. Eyes divided laterally, making apparently four compound
eyes. Whirligig-beetles. (Page 140) . . Gyrinidae
FF. Eyes not divided. Predacious diving-beetles. Dytiscidae
EE. Legs adapted for running ; terrestrial in habit.

F. Antennas inserted on front of head above base of man-
dibles. Tiger beetles. (Page 137) . Cicixdelidae
FF. Antennas inserted on sides of head between base of
mandibles and eyes. Predacious ground-beetles. (Page

138) Carabidae

DD. Antennae not filiform.

E. Antennas capitate or clavate . . . Tribe Clavicornia
F. Aquatic, legs fitted for swimming. Water-scavenger

beetles. (Page 141) Hvdrophilidae

FF. Terrestrial, legs not fitted for swimming.

G. Antennae moniliform, the segments gradually en-
larging toward the end ; elytra covering only basal
half of abdomen. Rove-beetles . Staphylinidae
GG. Antennae of various forms (clavate or capitate) ;
elytra covering most of abdomen.
H. Abdomen with six or more ventral segments ; an-
terior coxae conical ; antennas gradually thickened
or clavate. Carrion-beetles. (Page 142)

SiLPHIDAE

HH. Abdomen with five ventral segments ; anterior
coxae conical and projecting from the coxal cavi-
ties ; last three segments of the antennae forming
a large club. Larder-beetles, etc. Dermestidae
EE. Antennae serrate or lamellate.

F. Antennae serrated. Saw-horned beedes. (Page 144)

Tribe Serricornia

G. Head inserted in thorax, which extends as far as

compound eyes ; body elongated or elliptical.

H. First two abdominal segments fused together on

ventral side. Metallic wood-borers. (Page 146)

BUPRESTIDAE

HH. First two abdominal segments not fused. Click-
beetles. (Page 144) .... ElatEridae
GG. Head not inserted in thorax as far as compound eyes.

H. Head bent nearly at right angles to thorax, which
protrudes over it. Size usually less than one
fourth of an inch Ptinidae

CLASSIFICATION OF INSECTS

313

HH. Head normal, but partially or nearly covered by
thin anterior margin of thorax.
/. Wing-covers flexible ; body elongated and
flattened ; antennae not enlarged at tip. Fire-
flies. (Page 147) .... Lampyridae
//. Wing-covers firm ; body not much flattened ;
antennse often enlarged at tip. Checkered-
beetles Cleridae

FF. Antennas lamellate, composed of a stemlike portion
on the end of which are a number of flat, bladelike

segments Tribe Lamellicornia

6^. Antennas elbowed ; terminal lamella consisting of
fixed transverse plates. Stag-beetles. (Page 148)

LUCANIDAE

CG. Antennas not elbowed ; terminal lamella consisting

of flat plates which fold together. Leaf chafers and

scavenger-beetles. (Page 149) . Scarabaeidae

CC. Tarsus less than five segments.

D. Tarsus consisting of four segments. (Page 153)

Section Tetramera
F. Body short and more or less oval ; antennae short.

F. Front of head not prolonged as a short, broad beak ;
elytra usually covering tip of abdomen ; larvas and adults
leaf feeders. Leaf-beetles. (Page 153)

Chrysomelidae
FF. Front of head prolonged as a short, quadrate beak ;
elytra short, exposing tip of abdomen. Pea- and bean-
weevils. (Page 1 58) Bruchidae

EE. Body long and cylindrical; antennae long. (Page 158)

Cerambycidae

DD. Tarsus consisting of three segments ; comparatively small

beetles with semispherical bodies. Ladybird beetles. (Page

161) (Section Trimera) Coccixellidae

A A. Head prolonged into a beaklike structure at the end of which are biting

mouth-parts.

B. The dorsum of the last segment of the male divided transversely so

that, when viewed dorsally, this sex appears to have one more body

segment than the female.

C. Mandibles with a scar of the anterior aspect . Otiorhynchidae

CC. Mandibles without scar on anterior aspect. Curculios. (Page 167)

CURCULIOXIDAE

BB. Dorsum of last segment of both sexes undivided.

C. Tibia not serrated. Bill-bugs and granary-weevils. (Page 169)

Calandridae
CC. Tibia serrated. Bark-beetles. (Page 1 70) . . . Scolytidae

CLXizir^

Fig. 437. Diagram of wings of

Hepialus gracilis, showing jugum

(/) and similarity of venation of

fore- and hind-wings

(After Comstock, from Kellogg)

" fl fl

Fig. 438. Venation of a tortricid
moth [Cacoecia ce7-asivora}ia)

(After Comstock, from Kellogg)

ririXsr-f

a^ — ^

Fig. 439. Venation of a pyralid moth
( Fy ra lis faTina lis )

cs, costal vein ; sc, subcostal vein ; r, radial
vein ; m, medial vein ; c, cubital vein ; a,
anal vein. Note the hairlike projection, the
frasnulum, at the base of the hind-wing.
This fits into a little pocket on the fore-
wing. (After Comstock, from Kellogg)

Fig. 440. Venation of a saturniid
{Bombyx mori)

(After Comstock, from Kellogg)

314

a a a

Fig. 441. Venation of a cossid
{Prioiioxystus robinae)

(After Comstock, from Kellogg)

Fig. 442. Venation of a hes-
perid {Epargyreiis iityms)

(After Comstock, from Kellogg)

Fig. 443. Venation of a notodontid
{iVotodoiita simgtila)

(After Comstock, from Kellogg)

Fig. 444. Venation of a geome-
trid {Dyspepteris abortivaria)

(After Comstock, from Kellogg)

315

Fig. 445. Venation of a noctuid
(Agrotis ypsiloit )

(After Comstock, from Kellogg)

Fig. 446. Venation of a lasio-
campid (Malacasoma americaiia)

(After Comstock, from Kellogg)

r4*^

Fig. 447. Venation of a zygaenid
[Ciemicha virginica)

(After Comstock, from Kellogg)

Fig. 448. Venation of a lycaenid

{Chiysoj-hanus ihoe)

(After Comstock, from Kellogg)

316

Fig. 449. Venation of a papilionid
{Papilio polyxeues)

(After Comstock, from Kellogg)

Fig. 450. Venation of an arctiid

[Halesidota tessellata)

(After Comstock, from Kellogg)

C£ a

Fig. 451. Venation of a nymphalid
{Basila)rhia astyaiiax)

(After Comstock, from Kellogg)

cs-{-

FiG. 452. Venation of a pierid
(Foiitia protodice) . (Enlarged)

(After Comstock, from Kellogg)

1>^1

3l8 ELEMENTARY ENTOMOLOGY

KEY TO THE FAMILIES OF LEPIDOPTERAi

A. Lepidoptera with slender antennae, the tips of which are expanded or
dilated. Mostly diurnal in habits. Butterflies and skippers.
B. Dilation of antennas terminated by recurved hook. Wing venation

as in Fig. 26 [. Skippers. (Page 174) Hesperidae

BB. Dilation of antennae not terminated by recurved hook.
C. First pair of legs normal, or simply reduced in size.

D. First pair of legs reduced in size. Wing venation as in Fig. 448.

(Page 178) LVCAENIDAE

DD. First pair of legs normally developed.

E. Front tibia without pads ; claws toothed ; cubital of fore-
wing three-branched. Fig. 452. (Page 178) . Pieridae
EE. Front tibia with pads ; claws not toothed ; cubital of fore-
wing four-branched. Fig. 449. Swallowtails. (Page 175)

Papilioxidae
CC. First pair of legs atrophied, without claws ; wing venation as in

Fig. 451. (Page 179) Nvmphalidae

AA. Lepidoptera with antennae of various forms but never enlarged at tip.
Mostly nocturnal in habits. Moths.
B. Hind-wings with not over two complete anal veins.

C. Second and third median veins arising together ; /;/- not arising
from center of discal cell.
D. Humeral vein present in hind-wing, arising at base of costal.
Frsenulum absent. Fig. 446. (Page 216) . Lasiocampidae
DD. Humeral vein absent ; fraenulum present.

E. Subcosta and radius of hind-wing fused to near apex of
discal cell ; ocelli present. Tiger moths. Fig. 450. (Page

207) Arctiidae

EE. Subcosta and radius of hind-wing distinct, or but slightly

fused.

E. Diurnal moths with simple antennae and contrasting

coloration. Wood nymphs .... Agaristidae

EE. Nocturnal moths with simple or pectinate antennae and

without contrasting coloration.

G. Ocelli absent ; antennas pectinate. Tussock-moth.

(Page 203) Liparidae

GG. Ocelli present ; antennas usually simple. Owlet
moths. Fig. 445. (Page 199) . . . NocTUiDAE
CC. Second and third median vein not arising together, arising from
center of discal vein.
D. Fraenulum present.

E. Subcosta and radius of hind-wing connected near base by
crossbar. Hawk moths. (Page 208) . . . Sphingidae

1 This key has been adapted from keys of Holland, Smith, Bunter, and others.

CLASSIFICATION OF INSECTS

319

EE. Subcosta and radius of hind-wing not connected by crossbar.
F. Moths with heavy abdomens and narrow, strong fore-
wings. Prominents. Fig. 443. (Page 193)

NOTODOXTIDAE

FF. Moths with narrow, slender abdomens, and broad, deli-
cate wings. Fig. 444. (Page 195) . (iEOMEXRiDAE
DD. Frasnulum absent.

E. Tongue absent ; tibia without spurs. Fig. 440. (Page 212)

Superfamily Saturxoidea ^
' EE. Tongue present ; tibia with spurs. Royal moths.

Ceratocampidae
BB. Hind-wing with three complete anal veins.

C. Wings transparent, free from scales. Fore-wings narrow. Clear-
winged moths. (Page 192) Sesiidae

CC. Wings covered with scales.

D. Hind-wings with subcosta fused with or approximate to radius.

Fig. 439. (Page 187) Pyralidae

DD. Hind-wings with subcosta and radius far apart.

E. Small moths with fringe on inner angle of hind-wing
unusually long.
/•"■. Second anal vein of hind-wing forked at base. Leaf-
rollers. Fig. 438. (Page 1 86) . . . Tortricidae^
FF. Second anal vein of hind-wing not forked at base. Leaf-
miners. (Page 184) TixEiDAE

EE. Large or medium-sized moths, without unusual fringe on
hind-wing.
F. Anal veins of fore-wing partially fused. Bag-worm

moths PSVCHIDAE

FF. Anal veins of fore-wing not fused. Carpenter moths.
(Page 191) CossiDAE

KEY TO THE FAMILIES OF HYMENOPTERA3

A. Posterior trochanter consisting of two segments ; ovipositor modified into
a saw, or borer.
B. Abdomen broadly joined to thorax.

C. Tibia of forelegs with two terminal spurs ; female with sawlike

ovipositor. Saw-flies. (Page 244) .... Texthredinidae

CC. Tibia of foreleg with one terminal spur ; female with ovipositor

fitted for boring. Horn-tails. (Page 246) .... SiRiclDAE

BB. Abdomen joined to thorax by slender petiole.

1 Includes families Bombycidae, Saturniidae.

2 Includes families Grapholithidae, Conchylidae, and Tortricidae.
^ Modified from Cresson.

320 ELEMENTARY ENTOMOLOGY

C. Fore-wings with few or no cross veins ; if a few cross veins are
present, the abdomen is not compressed. Very small parasitic
Hymenoptera.
D. Ovipositor issuing before apex of abdomen . Chalcididae
DD. Ovipositor issuing from apex of abdomen. (Page 253)

Proctotrypidae
CC. Fore-wings with one or more closed cells.

D. Fore-wings without a stigma, or costal vein. Gall-flies. (Page

246) Cvnipidae

DD. Fore-wings with a stigma.

E. Fore-wing with two recurvent veins . Ichneumonidae
EE. Fore-wing with one recurvent vein . . Braconidae
A A. Posterior trochanter consisting of a single segment.
B. Fore-wings with no closed submarginal cells.

C. Abdomen long and slender ; antennae long and filiform.

Pelecinidae
CC. Abdomen short, but little longer than the head and thorax together ;
antennas short and elbowed. Cuckoo-flies . . . Chrysididae
BB. Fore-wings with at least one closed submarginal cell.

C. First abdominal segment, and sometimes the second, forming a
knot, or node, on the upper side of the petiole. Ants. (Page 254)

Superfamily FoRMiciNA
D. First segment of the abdomen forming the petiole.

E. Abdomen somewhat constricted between the second and

third segments ; sting present Poneridae

EE. Abdomen not constricted between the second and third

segments ; sting absent Camponotidae

DD. Petiole consisting of the first and second segments of abdomen ;

sting present Myrmicidae

CC. Petiole normal, without scales or nodes.

D. First segment of tarsus of hind-leg cylindrical, and naked, or
with little hair.
E. Wings folded longitudinally when at rest. True wasps.

(Page 263) Superfamily Vespina

E. Antennae clavate or knobbed at tip . . Masaridae
EE. Antennae filiform or nearly so.

G. Tibia of second pair of legs with a single terminal

spur Eumenidae

GG. Tibia of second pair of legs with two terminal
spurs. Tarsal claws simple. (Page 264)

Vespidae
EE. Wings not folded longitudinally when at rest. Digger-
wasps. (Page 260) Superfamily Sphecina

E. Sides of the pronotum extending back to the base of
the wings.

CLASSIFICATION OF INSECTS 32 1

G. First abdominal segment distinctly separated from
the second on the ventral side by a constriction.
H. Tibia of second pair of legs with two terminal
spurs ; females wingless. Velvet ants. ( Page

261) MUTILLIDAE

HH. Tibia of second pair of legs with single terminal

spur SCOLIIDAE

GG. First and second segment of abdomen not separated
on ventral side by constriction. (Page 261)

PSAMMOCHARIDAE

FF. Prothorax forming a narrow collar, not reaching to base
of wing.
G. Base of abdomen with a long, slender petiole. (Page

262) Sphecidae

GG. Base of abdomen without long, slender petiole.

Bemhecidae
DD. First segment of tarsus of hind-leg expanded and flattened,
furnished with numerous hairs, often poorly developed in para-
sitic bees. Bees. (Page 266) .... Superfamily Apina
F. Glossa short and flat, no longer than the mentum. Short-

tongued bees. (Page 267) Axdrenidae

EE. Glossa long and slender, not flattened. Long-tongued bees.
(Page 267) Apidae

KEY TO THE MORE IMPORTANT FAMILIES OF DIPTERAi

Adults nonparasitic upon the warm-blooded vertebrates ; habits variable.
Abdomen distinctly segmented. Rarely viviparous.
B. Anal cell rarely narrowed at the margin ; antennae consisting of more
than 5 joints, usually elongate, filiform, and verticellate, rarely pecti-
nate or with a differentiated style or arista . . . Nematocera
C. \'eins of the wings covered with hairs, the usual cross veins want-
ing. Small mothlike flies Psvchodidae

CC. Veins and margin of the wings fringed with scales. Mosquitoes.
(Fig. 455) ' CULICIDAE

D. Thorax with a distinct V-shaped suture ; wings variable. Crane-
flies. (Fig. 453) TiPULIDAE

DD. Thorax without the distinct V-shaped suture.

E. Discal cell present. False crane-flies . . . Rhvphidae
EE. Discal cell wanting.

F. Wings with few longitudinal veins ; tibiae without spurs.

Gall-gnats. (Fig. 458) Cecidomyiidae

FF. Tibiae with spurs ; coxae elongate. Fungus-gnats.
(Fig. 459) Mycetophilidae

1 By C. W. Johnson, Curator Boston Society of Natural History.

-'« CU3 CU' '"'

Fig. 453. Venation of a tipulid {Protoplasa fitchii)
(After Comstock)

Fig. 454. Venation of Blepharocera sp.
(After Comstock)

-fi'tS

Fig. 455. Venation of a mosquito (Ciilex sp.)
(After Comstock)

r' r^*3

}-4*5

Fig. 456. Venation of a Chironoimts sp.
(After Comstock)

.so r'r^'^ r-*

Fig. 457. Venation of a soldier-fly {Stratiomyia sp.)

(After Comstock)

322

CLASSIFICATION OF INSECTS 323

G. Abdomen slender ; wings narrow ; antennae plumose

in the males. Midges. (Fig. 456) Chironomidae

GG. Abdomen short and thick ; antennae shorter than the

thorax, nonplumose.

H. Wings very broad, anterior v^ins stout, the other

weak. The black-flies . . . . Simuliidae

HH. Wings large but more normal in character ; legs

strong, front femora often thickened.

BiBIONIDAE

BB. Anal closed or distinctly narrowed, second vein never fucate ; antennas
usually with three joints, the third joint sometimes complex and com-
posed of numerous annuli Brachvcera

C. Third joint of the antennas with from 4- to 8-segmented annuli.
D. Squamas rather large ; third joint of the antennae without a

style or arista. Horse-flies Tabaxidae

DD. Squamae small or vestigial.

E. Costal vein does not extend beyond the tip of the wing,
longitudinal veins covered anteriorly ; posterior veins often
weak; tibiae without spurs. Soldier-flies. (Fig. 457)

Stratiomyidae

EE. Costal vein encompasses the wing ; posterior veins strong ;

middle tibis at least with distinct spurs ; antennae extremely

variable Leptidae

CC. Third joint of antennae simple, not composed of numerous annuli.
D. Antennae long, clavate, apparently 4-jointed ; palpi small or

wanting. Mydas-flies Mydaidae

DD. Antennae 3-jointed, often with a variable style or arista ; palpi

always present, usually prominent. Robber-flies . Asilidae

E. Antennae apparendy 2-jointed ; anterior veins stout, the

others weak and extending obliquely across the wing.

Small hunch-backed flies Phoridae

EE. Antennae 2- or 3-jointed ; head small ; squamas very large ;
abdomen inflated. Parasitic on spiders . . Cyrtidae
E. Third antennal joint usually with a terminal style, pro-
boscis often prominent; body frequently covered with
long, delicate hairs. Bee-flies. (Fig. 460) Bombyliidae
EE. Third antennal joint without terminal style : fourth vein
terminates at or before the tip of the wing. Window-
flies SCENOPINIDAE

G. Small, for the most part bright-colored green or blue ;
second boscal cell confluent with the discal cell ; arista
dorsal or terminal. Predacious. Dolichopodidae
GG. Small, not brighdy colored ; head small, eyes some-
times contiguous ; proboscis rigid. Predacious.

Empididae

cu- ' Cll'

Fig. 458. Venation of a cecidomyiid gall-gnat
(After Comstock)

Fig. 459. Venation of a fungus-gnat {Mycetophilidae)
(After Winnertz, adapted from Comstock)

H^

la cu^ m3+cu'

Fig. 460. Venation of a bombyliid (Pentarbes capita)

(After Comstock)

~cu^* la

Fig. 461. Venation of a bot-fly [Gastrophilus sp.)
(After Comstock)
324

CLASSIFICATION OF INSECTS 325

H. Third joint almost always with a dorsal arista ; a

spurious longitudinal vein between the third and

fourth longitudinal veins ; first posterior cell al-

waysclosed. Flower-flies. (Fig. 463) Svrphidae

HH. No spurious longitudinal veins.

/. Small ; hind tarsi enlarged and often orna-
mented in the male arista terminal. Flat-
footed flies Platypezidae

//. Small ; head large, composed chiefly of eyes ;
arista dorsal. Big-eyed flies. Pipunculidae
/. Squamae small or vestigial ; eyes never con-
tiguous ; the front in both sexes of equal
width ; thorax without complete transverse

suture ACALVPTERAE

K. Auxiliary vein distinct, the first vein
ends near or beyond the middle of the
wings ; a distinct bristle on each side
of the face; oval vibrissas present ; front
usually with well-developed bristles and

hairs Cokdvluridae

KK. Front never bristly near the antennae ;
abdomen cylindrical, contracted near
*the base. Small shining black flies.
Cheese-maggot, etc. . . - Sepsidae
L. No oral vibrissae ; abdomen elon-
gate, often narrowly constricted ,
proboscis long and folded near the
middle. (Fig. 462) . CONOPIDAE
LL. Upper fronto-orbital bristles only
present; preapical tibial bristle rarely
present ; arista rarely plumose ; ovi-
positor horny ; wings usually pic-
tured Ortalidae

M. Fronto-orbital bristles present
or absent ; second joint of the
antennae often elongate ; arista
plumose ; preapical tibial bristle
present; ovipositor not horny;
wings often pictured. Meadow-
flies . . . SCIOMYZIDAE
MM. One or two fronto-orbital bris-
tles ; third joint of the antennae
more or less elongate ; preapical
bristle absent or present. All
small species. Sapromyzidae

cu*ia

Fig. 462. Venation of a conopid ( Coiops affinis)
(After Comstock)

sc r^ r2-^3 y4+5

Fig. 463. Venation of a syrphid {Eristalis sp.
(After Comstock)

la cu^ '-'^

Fig. 464. Venation of a dixa midge {Dixa sp.)
(After Comstock)

Y**S

Fig. 465. Venation of an empidid [Rhamphomyia sp.)

(After Comstock)
326

CLASSIFICATION OF INSECTS 327

N. Auxiliary vein absent or in-
complete; first vein usually
ends in the costa before the
middle of the wing; head
produced on each side into
a lateral process for the
eyes . . . Diopsidae

JVN. Hind metatarsi incrassated
and usually shorter than the
second joint ; oval vibrissae
present. Small flies about
excrement near water.

BORBORIDAE

O. Discal and basal cells
united, anal cell absent;
front bare or at most
bristly above. Small,
usually light-colored

flies . . OSCINIDAE

00. Front often bristly,
face often very convex,
mouth cavity usually
large ; no oval vibrissas.
Small dark-colored flies
about water.

Ephydridae
P. Anal cell complete ;
oral vibrissas pres-
ent ; aristae long, plu-
mose, or pectinate
above. Vinegar or
pomace flies.

Drosphilidae
PP. Arista bare or pubes-
cent ; front bristly
at least as far as
the middle. Very
small flies, compris-
ing most of the leaf-
miners.

Agromyzidae
Q. Oval vibrissa ab-
sent ; anal cell an-
gular ; no preapi-
cal tibial bristle;

328

ELEMENTARY ENTOMOLOGY

ovipositor long
and jointed ;
wings usually
pictured. Fruit-
flies.

Trypetidae
QQ. Anal cell not pro-
duced ; antennae
usually elongated
and decumbent.
Rather small
elongate flies.

PSILIDAE

//. Squamae large ; front of male narrowed or

eyes contiguous ; thorax with complete

transverse suture . . . Calvpterae

A". Oval opening small ; the mouth-parts

small or vestigial. Larvae parasitic upon

mammals. Bot-flies. (Fig. 461)

Oestridae
A'A'. Oval opening of usual size, not vestigial ;
hypopleurae with a tuft of bristles ; first
posterior cell narrowed or closed ; arista
bare or somewhat pubescent. Larva
parasitic upon the early stages of other

insects Tachinidae

L. Arista bare on the outer half ; dor-
sum of the abdomen rarely bristly
on the anterior part. Larva usually
feeds on decaying animal matter.
Flesh-flies . . Sarcophagi dae
LL. Arista entirely plumose ; dorsum of
the abdomen usually bristly on the
anterior part ; legs long. Larva para-
sitic on other insects . Dexiidae
M, Arista plumose; abdominal seg-
ments without bristles except
near the tip ; first posterior cell
narrowed or closed. House-fly,

etc Muscidae

MM. Arista plumose, pubescent, or
bare ; first posterior cell very
slightly or not at all narrowed
at the margin. Larva are vege-
table feeders. Anthomyiidae

CLASSIFICATION OF INSECTS 329

^^. Adults usually ectoparasitic upon warm-blooded vertebrates; abdomen

indistinctly segmented. Larvae born when about to pupate. Pupipara

B. Winged or wingless flies; eyes faceted; palpi forming a sheath for

the proboscis ; veins of the wing, when present, crowded anteriorly, the

weaker veins running obliquely across the wing. Parasitic upon birds

and mammals. House-flies Hippoboscidae

BB. Winged or wingless ; when present the wings are pubescent, with

parallel veins and outer cross-veins ; eyes usually unfaceted ; ocelli

wanting ; antennae 2-jointed ; palpi broad, not forming a sheath for

the proboscis. Usually parasitic upon bats .... Streblidae

C. Wingless ; halteres present ; eyes vestigial ; head folding back on

the dorsum of the thorax. Small, spiderlike flies ; parasitic upon

bats. Bat-ticks Nvcteribiidae

CC. Wingless ; halteres absent ; eyes vestigial ; last joint of the tarsi
with a pair of comblike appendages. Parasitic upon the honey-
bee. Bee-louse Braulidae

CHAPTER XXIII

METHODS OF COLLECTING INSECTS

The following instructions on the methods and equipment for
collecting and preserving insects have been compiled to give as
concise information on the subject as possible. Most of the methods
and equipment have been tried and tested out either by the author
or under his observation. There are a number of accessible bulletins
and papers on this subject, one of the best of which is United States
National Museum Bulletin No. 6y, " Directions for Collecting and
Preserving Insects," by Nathan Banks.^

Field kit. In order to secure a collection that is at all valuable,
it is necessary to make special trips after insects, and to be provided
with special equipment. Therefore, among the first requirements
is a means of carrying the outfit so that every article will be
accessible.

The have7-saek. This is one of the most common means of
carrying collecting outfits, and if constructed of the proper material,
will be found very handy. The size will depend somewhat on the
length of the trip taken, but for ordinary purposes a sack twelve
by fourteen by four inches will be found most convenient. It should
be provided with a good flap, to fasten by means of a buckle or snap,
as well as with shoulder straps and loops for the belt. These latter
are very important, as they prevent the sack from flopping about
while collecting. Canvas or khaki makes very serviceable sacks, but
they are not waterproof. Some of the numerous imitation leathers
or heavy oilcloth will wear nearly as long and be much more
serviceable. The haversack should have at least three separate
compartments, and if manufactured at home, with a little ingenuity
one can provide a place for each article of the outfit.

Colleeting eoat. Any comfortable, loose-fitting coat may, with a
little alteration, be converted into an entomologist's collecting coat.
The requirements are a sufficient number of pockets to hold the

1 See also the bottom of page 359.
330

METHODS OF COLLECTING INSECTS 331

field outfit. The ordinary khaki or duck's-back hunting coat will
be found very convenient, having, as it does, an abundance of
room for accommodating cyanide bottles, folding nets, and other
necessary articles.

Collecting belt (Fig. 466). For short, half-day excursions a loose-
fitted, woven belt, about three or four inches wide, provided with
pockets to hold cyanide bottles, forceps, storage boxes, etc., is \ery

Fig. 466. A collecting belt
(After Banks)

serviceable. The objection to this affair, however, is the unavoid-
able width of the belt. These belts may be obtained, with a complete
collecting outfit, from any of the entomological supply companies.
Insect nets. Of first importance to the entomologist is the insect
net. In its simplest form the net consists of a ring, or hoop, firmly
attached to a handle two or three feet in length. Attached to the
hoop is a net about eighteen inches in depth. A very serviceable net
may be constructed by bending a stout wire into a circle (Fig. 467),
then bending the ends back at right angles and lashing them

132

ELEMENTARY ENTOMOLOGY

firmly to the stick with stout binding wire. The ring will be held
much more firmly if the ends of the wire are sharpened and again
bent at right angles and driven into the stick. Also, a groove cut in
either side of the stick for the reception of the wire w'ill make it
much stouter. There are numerous other ways of constructing net
frames, but most of them are too complicated for practical use.
Many folding frames of various types may be obtained of entomo-
logical supply companies, but none of these are equal to the spring-
steel, folding landing nets sold by dealers in fish tackle. These

may be obtained with a three-foot, jointed
handle, are nearly as light, and will
stand much more wear than any of the
regular insect-net frames on the market.
The simplest and lightest net ring is that
of the simplex net (see Appendix) ; this
consists of a thin steel band which is
easily coiled up and carried in the pocket,
and readily attached to the handle.
Numerous materials are used in the
construction of the net itself. Mosquito
bar is sometimes used, but this lasts but
a short time and is too coarse to catch
small insects. A fine bobbinet is far
superior to the mosquito bar, as is also
cheesecloth. With any of these mate-
rials a hem of stout cotton cloth should
first be sewed to the net, through which
to run the net frame. The net should be about eighteen inches in
depth, tapering nearly to a point.

The net above described is to be used for all ordinaiy purposes,
such as catching butterflies, dragon flies, etc., but is scarcely suitable
for certain kinds of collecting.

The siueeping net. This type of net is very similar to the one
just described, except that the frame is much heavier and the net
of stronger material, such as denim or canvas. It is used by sweep-
ing it back and forth rapidly over the tops of the bushes, through
long grass, weed patches, etc. After sweeping back and forth a
number of times, the net is given a half turn, which prevents the

Fig. 467. A wire net frame

METHODS OF COLLECTING INSECTS 333

insects from escaping. An improved form of this net consists of an
outer sack with square in place of tapering bottom, the sack to be
made out of cheesecloth, cotton cloth, or some such material. On
the inside of this is fitted a short, funnel-shaped net made out of
bobbinet or light cheesecloth. This net has an opening of about
two inches at the bottom. In sweeping, the insects pass down
through this opening between the two nets and are unable to es-
cape. In this way great numbers of grass insects may be collected
without stopping to remove them from the net. The insects may
be stupefied by placing the entire net in a pail together with a piece
of cotton saturated with ether.

For aquatic collecting certain other types of nets are desirable,
although the ordinary insect net may sometimes be used to
advantage.

Wato- dip net (Fig. 468). The frame of this type of net is usu-
ally flattened on one side so as to allow the net to be manipulated

Fig. 46S. A water dip net Fig. 469. A small dip net

(After Packard) (After Howard)

closer to the bottom. The net itself should be made of fine brass-
wire netting, about twelve inches in diameter and of about the same
depth. Fig. 469 shows a dip net with a flange, or lip, of tin or
sheet iron, which is useful in dislodging aquatic larvae or insects
from around stones, thick weeds, etc.

TJie sag net (Fig. 470). This form of aquatic net is described
by Professor James G. Needham, who is probably our best authority
on aquatic insects, as follows :

It consists of a ring of stout spring wire three to four feet in diameter, to
which is attached a very shallow bag of bobbinet, and at one side is a handle
only long enough to be held readily. It is intended to catch insects adrift in
the stream, and is accompanied by an instrument for dislodging them. Such
an instrument is figured below the net. It consists of a handle three or

334

ELEMENTARY ENTOMOLOGY

four feet long, with a double hook at one side and a brush at the other side
at its distal end. To illustrate the use of this apparatus, suppose we wish to

collect the insects from the stones
obstructing a brook. We place the
net directly below the obstruction
and in the current, and adjust it to
the bottom by downward pressure
on the handle with one hand, while
with the other we rapidly overturn
the stone and with a brush sweep
free the clinging insects. These are
driven by the current into the net,
when it is then lifted and emptied.

Fig. 470.

Sag net, hook and brush for col-
lecting in rapids

(After Needham)

An aquatic sieve net (Fig. 471). This net is intended to be used
in stagnant water or on sandy bottoms where there is but httle
vegetation. The frame consists of a Hght steel rod, sides of heavy
tin or galvanized iron, and a bottom of fine brass or galvanized

Fig. 471. An aquatic sieve net
(After Needham)

wire netting. When provided with a long handle, this net may
be used from the shore, and is particularly recommended for
burrowing nymphs of aquatic insects.

Rake net. The rake net consists of an ordinary garden rake,
with a stiff semicircle of wire fastened on the upper side of the
rake above the teeth. This should be braced to the handle with
another piece of wire. A net is then attached to the upper part of
the rake and around the semicircle of wire. This is very useful in
slightly weedy water, or where there is a large amount of debris
on the bottom. When the bottom of a pond or stream is raked,
the insects, nymphs, and small crustaceans are either entangled in
the debris and brought to shore, or, in trying to escape the rake
teeth, swim back into the net. The debris should be carefully

METHODS OF COLLF-CTING INSECTS

searched for any nymphs or larvae that may be entangled in it.

This form of net is particularly useful in' collecting dragon-fly
nymphs, and is much superior to the ordinary
garden rake, which has often been recommended
for this purpose.

Cyanide bottle (Figs. 472 and 473). These
bottles should be provided in at least three sizes,
the largest with a di-
ameter of two and one
half inches or more,
a smaller, straight-
necked bottle with a
diameter of an inch
and a half, and an-
other much smaller
straight-necked bot-
tle with a diameter
of about half an inch.
Before much collect-
ing is done, the stu-
dent will probably
find it necessary to
provide himself with
two complete sets of
these bottles, with

possibly one or two extra of the smaller

sizes. Cyanide bottles are made in

the following manner : Place a few

good-sized pieces of potassium cya-
nide (a most deadly poison) in the

bottom of each bottle, and cover the

cyanide with dry plaster of Paris.

(As the fumes of potassium cyanide

are very poisonous, it should be

handled with extreme care.) Then

mix up a thick paste of plaster of

Paris and water, and pour over the dry plaster in the bottles.

Leave standing open for a few hours, until the water has evaporated

Fig. 472. A cya-
nide bottle for the
pocket. (One half
actual size)

Fig. 473. A larger cyanide bottle
with paper strips to give sup-
port to the insects

(After Banks)

336

ELEMENTARY ENTOMOLOGY

and the plaster of Paris set. After this the bottle should always be
kept corked, so as to retain the strength of the cyanide. The ad-
vantage in putting the dry plaster of Paris in first is that it absorbs
the moisture and will keep the bottle dry longer than if the wet
plaster is poured directly over the cyanide. It will also be found
advantageous to place a few strips of dry blotting paper in each
cyanide bottle, as this serves the double purpose of helping to
absorb the moisture and preventing the insects from shaking about.
After the insects are caught in the net, they
should be transferred to the cyanide bottle,
which, if properly constructed, will stupefy
them in a few seconds. Insects, especially
beetles, should not be removed from the
bottle for an hour, although Hymenoptera
and Diptera will be killed within ten minutes.
If the cyanide is too dry, it does not act so
rapidly, and a few drops of soda water will
greatly increase its efficiency. Very small
cyanide bottles may be made by placing a
piece of cyanide in the bottom, covered with
cotton or blotting paper.

If possible, only insects of the same size
should be placed together in the cyanide bot-
tles. Fragile insects, or those with scaly wings,
should not be put in with the general collection.
Chloroform bottle (Pig. 474). While not an
absolute essential to the collecting of insects,
the chloroform bottle will be found one of the
most valuable assets, especially to the collector of Lepidoptera.
One of the most convenient forms consists of a small-mouthed
bottle, into the cork of which has been inserted a camel 's-hair
brush. These will be found most useful in collecting very small
insects or butterflies. In collecting very small insects, touching them
with a brush moistened in chloroform is sufficient to kill them, and
at the same time the insects will adhere to the brush and may
thus be transferred to the storage botde or box. In collecting
Lepidoptera the sides of the thorax should be moistened with the
chloroform before placing them in the cyanide bottle.

Fig. 474. Chloroform

bottle with a brush

stopper

(After Banks)

METHODS OP^ COLLKCTING INSECTS t^2>7

Another form of chloroform bottle suitable for stupefying large
Lepidoptera is made by inserting a fine-pointed medicine dropper
through the cork of the bottle. A few drops of chloroform can then
be applied directly to the specimens, through the net, before they
are removed. This will also be found convenient in collecting some
of the larger Hymenoptera. Since the chloroform has a tendency
to harden the specimens, only a sufficient amount should be used
to stupefy the insects, which should immediately be placed in the
cyanide bottle.

Alcohol. This is another accessory that should be used in the
field onl\- in collecting very small insects, such as Thysanura, very
small larvae, Aphididae, etc. The alcohol outfit should consist of
a number of small, straight-necked vials, fitted with cork stoppers,
about half filled with 75 per cent alcohol. In addition to these
vials the collector should have a larger bottle and brush, similar to
the chloroform bottle described above. This bottle should contain
95 per cent of alcohol and 5 per cent of glycerin. The speci-
mens are killed by touching them with the brush moistened in the
95 per cent alcohol, after which they are washed off into the bottle
containing the weaker alcohol. The reason of this combination of
two grades of alcohol is that many insects are protected with a
waxy secretion which the weaker alcohol will not penetrate. Of
course, specimens should not be collected in this way unless they
are to be preserved permanently in some liquid medium. In collect-
ing some Thysanura it may be found necessary to dispense with
the glycerin, although it has a tendency to retain the color better
than the alcohol alone.

Collecting forceps. Wliile these are not absolutely essential to
the field kit, it will be found convenient to have a pair of stout,
broad-pointed forceps for handling stinging Hymenoptera, some
beetles, and other insects that are liable to injure the collector.
Fine-pointed forceps should also be taken along to handle very
small insects, although a moistened camel's-hair brush will serve
the same purpose.

Hatchet and chisel. These tools will be found very useful in
collecting wood-boring insects and their larvae. The marble safety
ax stands in a class by itself, being far superior to anything else on
the market for this purpose. Even in general collecting this ax will

338

ELEMENTARY ExNTOMOLOGY

be found very useful for numerous purposes. In addition to the
ax, many collectors always carry a chisel, but this will be found of
but little advantage except in collecting wood-boring larvae.

Receptacles for carrying insects. For general collecting, one
should always carry a number of receptacles in which to place the
insects as soon as they have been killed in the cyanide bottle. For

Fig. 475. The paper envelope for Lepidoptera, and method of folding it
/, first fold ; 2, second fold. (After Banks)

METHODS OF COLLECTING INSECTS 339

this purpose ordinary pill boxes of various sizes are most conven-
ient. Each box should be partly filled with crushed tissue paper,
to prevent the insects from shaking about. Care should be taken
not to place too many insects together. If the insects cannot be
mounted at once, the date of collecting, the locality, and other
notes may be written on the outside of the box. For very small
insects gelatin capsules will prove more useful than the pill
boxes. Large-sized capsules especially adapted to this purpose
may be obtained of entomological supply companies or large drug
houses. Glass bottles should never be used for this purpose, as
the moisture from the bodies of the insects soon causes them to
deteriorate, or otherwise injures the more delicate specimens.
Also, cotton should not be used in the pill boxes or capsules, as
the claws and delicate hairs of the insects become entangled and
often broken off. Small paper envelopes will be found very useful
in carrying Lepidoptera, but they should be packed in a tin or
wooden box to prevent crushing.

Collecting larvae. The method of collecting larvae depends
somewhat upon the manner in which they are to be preserved.
Small larvae, to be preserved in alcohol or mounted on slides, may
be placed directly in the alcohol-glycerin solution, as indicated
above. The larger forms, which are to be blown (see page 353),
should be placed in tin boxes, together with a small amount of
their food plant. Aquatic forms which it is desirous to keep alive
must be packed in damp moss or damp paper, or else carried in
a large, open receptacle filled with water. If placed in a bottle or
tightly closed receptacle, they will soon die. One danger of carry-
ing aquatic larvae or nymphs in water is that the larger forms will
often destroy the smaller ones, especially if dragon-fly nymphs
have been collected. There is much less liability of this occurring
if the nymphs are packed in wet moss or paper.

Insect traps. Many insects can be collected much more easily by
means of traps than in any other way. These traps may consist
of some form of light for attracting insects, some attractive food
from which the insects may be collected as they come to it, or
a trap that the insects will fall into.

TJie funnel trap. The ordinary glass or tin funnel is fre-
quently employed in trapping insects. One of the simplest ways

340

ELEMENTARY ENTOMOLOGY

of using this is to fit a cyanide or alcohol bottle over the lower
end of the funnel, and sink the bottle and funnel in the ground
level with the surface. This is particularly useful along the coast
or in sandy localities where ground beetles are numerous. This will
prove more effective for carrion beetles if a dead fish, mouse, or
piece of meat is strung on a wire and laid across the funnel. The
funnel is also used in collecting very small insects, like Thysanura.
The simplest method is to take an ordinary glass funnel, from
twelve to twenty-four inches in diameter, and place a cork stopper
in the lower end of the neck. The neck is
to be partly filled with alcohol. The funnel
should then be placed in a basin with
straight sides, which is partly filled with
water. The basin may be of tin or granite
ware, of slightly smaller diameter than
the top of the funnel, but deep enough so
that the neck of the funnel does not rest
on the bottom. If the funnel is not heavy
enough to prevent floating, it may be held
in position by strips of lead laid across the
top. This apparatus should then be placed
over a gas flame or some other even heat,
and the temperature of the water raised
to between sixty and one hundred degrees.
Since alcohol evaporates so rapidly, it
should not be placed in the funnel until
the apparatus is ready for use. The mate-
rial containing the insects, such as leaves,
decayed wood, etc., is next placed in a sieve, the diameter of which
is slightly smaller than that of the funnel. The sieve is then
placed over the top of the funnel, and the insects, attracted by the
heat, rapidly work their way through the material and drop down
into the funnel. The insects are removed from the funnel by taking
out the cork stopper and allowing the alcohol to run out into a bottle.
A very convenient time to collect these small insects is during the
early fall or winter. Cotton-cloth bags may be used to gather up
the decaying leaves, wood, etc., which are then brought to the
laboratory and the insects sorted out.

Fig.

476. A simple
lantern

trap

METHODS OF COLLECTING INSEC^TS

541

Many insects can be secured in the fall by providing suitable
places in which they may hibernate, such as boards, old gunny
sacks, etc. placed on the ground. Another method is to place
strips of cloth or gimny sacks around the trunks of trees, and
examine them frequently for insects.

Light traps. Numerous forms of traps have been constructed,
to take advantage of the habit of some insects of flying toward the
light. One of the simplest of these
traps (Fig. 476) is made by placing
an ordinary lantern in a shallow
pan eighteen or twenty inches in
diameter and four inches deep.
This apparatus is then placed on
a stump, fence post, or other con-
spicuous locality. The lantern is
then lighted, and an inch or two
of water, covered with a film of
kerosene, is placed in the pan.
Leave the trap overnight (the
darker the better) and in the morn-
ing remove the insects and place
them in gasoline or benzine for a
short time, to remove the kero-
sene. They can then be laid on
blotting paper, dried, and mounted
in the usual way.

Another method of using the
trap lantern is to suspend a lantern
above a large tin funnel with a
diameter of twenty or twenty-four
inches. At the bottom of the funnel is placed a cyanide bottle.
The insects, particularly beetles, fly against the light and fall into
the funnel and, the sides being smooth, roll down into the cyanide
bottle. Other more elaborate arrangements may be fitted up, but
either of the above forms will do for most cases.

Baiting insects. This form of collecting is used principally
in capturing moths and other insects that have a fondness for
sweets. As usually practiced, the entomologist goes out just at

SXTVS.

Fig. 477. The Gillette trap light

A lantern is hung over the mouth of the
funnel

34^

ELEMENTARY ENTOMOLOGY

twilight with a mixture of sugar and rum, sugar and vinegar, or
some such substance, which is painted on the trunks of trees. After
an hour or so the trees are visited by the entomologist, who is armed
with a dark lantern or a bicycle lantern. The moths are caught
either by means of a net or by carefully approaching the tree and
placing a large-mouthed cyanide bottle over the insects as they feed.
Warm, cloudy nights are best for this work, although one is not
always assured of success.

If pieces of decaying fish, meat, or other animal matter are
placed in a convenient locality and examined from time to time,
large numbers of beetles may be collected.

CHAPTER XXIV

METHODS OF PRESERVING AND STUDYING INSECTS

The work of the entomologist is only just begun when the insects
are collected. They must then be pinned, dried, and labeled, the
latter including the identification, which in itself is no little matter.

Mounting insects. Insects should be mounted as soon as pos-
sible after being killed. When it is impossible to mount them
immediately, put the insects in shallow pill boxes packed in tis-
sue paper, and set in a warm place to dry. When ready to mount,
remove the lid and place the box in a tight glass jar, together with
a sponge dipped in camphor water. The insects should be left in
this chamber for from 24 to 48 hours, when they can be mounted
as usual.

Insects should be mounted on insect pins. These are made
especially for the purpose, are about an inch and a half in length,
and range in size from No. 000, the most slender, up to No. 8,
which is the largest. Nos. i, 2, and 3, however, will do for nearly

Fig. 47S. Pinning forceps

all purposes, with a few of No. 5 for the larger moths. No. 3 is
large enough for almost all larger insects, and insects too small for
No. I should be mounted on points. The pins may be obtained
in either the black japanned or the plain white metal ; the latter,
however, should be used only in mounting insects on points, as a
green verdigris is produced near the insect, which corrodes the pin.
The collector should be careful to have all the insects at the
same distance from the head of the pin ; this not only makes the

343

344

ELEMENTARY ENTOMOLOGY

collection look better, but also makes it much easier to handle and
study. The general rule followed by entomologists is that one fourth
of the pin shall project above the insect. For this purpose a pinning
block is almost indispensable, t'^e construction of which will be
readily understood by referring to t ig. 479. The lower hole should
be one fourth the length of the pin in depth, the second, one half
the length, and the third, three fourths the length. After the pin
has been pushed through the insect, the head is inserted in the
lower hole and the insect pushed down until the back touches the
block. The second hole is for evening up the labels, and the third
one for placing points on the pins.

A great deal of skill is required in pinning insects properly.
The specimen should be grasped by the thumb and forefinger

Fig. 479. A pinning block

and held very lightly in the groove formed between the tips of the
thumb and forefinger while the pin is inserted in the proper place.
Another method is to place the insects on some soft substance, as
a folded handkerchief, and turning the insect ventral side down,
insert the pin, finishing the operation on the pinning block.

Since the different groups of insects present certain structural
peculiarities, the following system of pinning the members of
different orders has gradually been formed. (The directions for
mounting on points and slides are given below.)

Thysanura and Collembola. All of the smaller species are
mounted on microscope slides ; the larger forms are pinned through
the metathorax, A very fine wire is run entirely through the body,
to serve as a support. In the case of the Thysanura, this should
be inserted just underneath the long, median setae and run forward
well into the thorax. If the end is left projecting, it may be made
to serve as a support for the posterior setae.

PRESERVING AND STUDYING INSECTS

345

May-flies, dragon-flies, and stone-flies. The pin is inserted in
the metathorax, and a fine wire run from the end of the body
into the thorax. In the case of the May-flies this wire should be
left projecting to serve as a s' )ort for the posterior setae, which
should be attached to the wire. The wings of both the May-flies
and dragon-flies should be spread. This is done by means of a
spreading board.

Spreading boards. Fig. 480 shows the construction of a simple
spreading board. Two soft-pine boards are placed parallel on short
crosspieces, the boards being
at a slight angle to each other.
The edges of the board should
be from one sixteenth to one
half an inch apart, depending
on the size of the insects to be
mounted, A thin sheet of cork
is glued to the underside of
the boards. When the spread-
ing board is used, the insect
is pinned in the ordinary man-
ner and the pin is then forced
through the sheet of cork until
the dorsal portion of the insect
is nearly level with the upper
surface of the boards. The
spreading board, of course,
must be selected with a groove
wide enough to accommodate the body of the insect. After being
placed on the spreading board, the wings of the insect are brought
forward and held in position by narrow strips of paper or tracing
cloth, as shown in the illustration. Glass-headed pins are handy
for pinning the strips. The spreading board is then set away until
the insect is thoroughly dry.

In the case of the May-flies the front margins of the first pair of
wings are brought forward until they are at right angles with the
body. In the case of the dragon-flies the hind margins of the first
pair of wings should be at right angles to the body. In pinning
stone-flies, usually only the wings of the right side are spread,

Fig. 4S0. Board showing method of
spreading Lepidoptera. (Reduced)

346

ELEMENTARY ENTOMOLOGY

Fig. 481. Showing method of pinning
Orthoptera

(After Washburn)

although some entomologists spread the wings on both sides. The
front margins of the hind pair of wings should be at right angles
to the body, the front pair being brought forward until they just
touch the hind pair.

Platyptera. White ants are usually mounted in alcohol, or on
microscope slides, although the winged forms may be pinned
through the metathorax. The wings are seldom spread. Book-
lice are mounted either on points
or on microscope slides, while
bird-lice are invariably mounted
on microscope slides. Earwigs
are mounted on points, or, in the
larger forms, the pin is inserted
through the anterior portion of
the right wing-cover.

Orthoptera (Fig. 481). In the
ordinary grasshopper, and in
those forms having the prono-
tum well developed, the pin is
usually inserted through the posterior margin of the pronotum.
In forms in which the pronotum is not well developed the pin is
run through the metathorax. The wings may or may not be
spread, but the usual method is to spread the wings on the right
side of the body. Care should be taken to arrange the legs and
antennae, the latter being laid back over the body,
if possible. The legs may be held in position by
running the pin through a square of stiff paper,
which is brought up to the proper distance and
the legs kept in a natural position until dry.

Hemiptera (Fig. 482). All of the larger He-
miptera are pinned through the metathorax ; the
smaller forms, with the exception of the Aphididae
and scale insects, are mounted on points. The two
latter groups require special methods of mounting.
The Aphididae are frequently mounted by plac-
ing them on a glass slide and covering them with a drop of Canada
balsam dissolved in xylol. They are allowed to stand for twenty-
four hours, when a small amount of fresh balsam is applied, and

Fig. 482. Showing

method of pinning

Hemiptera

(After Washburn)

PRESERVING AND STUDYING INSECTS 347

the specimens covered with a cover glass. This method is far
from satisfactory, as the balsam soon clouds, but at present it is
the only thing that can be recommended as a permanent mount.

Two methods are employed in mounting scale insects. The
entire scales are mounted by taking a thin strip of bark on which
is found a colony of scales, and after leaving it in the cyanide
bottle for twenty-four hours, it is placed between two pieces of
celluloid. The two plates of celluloid are held apart by a cell cut
out of cardboard, and the entire mount sealed with passe-partout
tape. The thickness of the cell depends upon the thickness of the
piece of bark to be mounted. It will be found very convenient to
have these cells cut the size of an ordinary microscope slide. This
form of mounting will do only for very superficial study, and some
of the scales must be cleared and mounted in balsam. This is
done bv removing the scales from the bark and, in the case of the
armored or flat scales, removing the insects from under the scales
and placing them in a small test tube with caustic potash solution.
These should be boiled until clear, the length of time depending
upon the thickness of the scales. They are then washed in water
by sedimentation ; that is, the test tube is filled with water and
held in a vertical position until the scales have settled to the bot-
tom. The water is then nearly all drawn off with a pipette, and the
process is repeated. After all of the caustic potash has been re-
moved, they are washed in 95 per cent alcohol and cleared in
xylol. They should then be removed to a glass slide by means of
a camel's-hair brush, and mounted in balsam. Since the last seg-
ment of the abdomen, the pygidium, is the only part of the insect
used in classification, this is all that it is necessary to mount.

Neuroptera, Mecoptera, and Tricoptera. These forms are all
pinned through the metathorax ; the wings may or may not be
spread, but it is usually best to spread the wings at least on one
side of the body, the hind borders of the front pair of wings being
brought fonvard at right angles to the body.

Lepidoptera (Fig. 480). In mounting Lepidoptera the pin is run
through tli,e mesothorax or metathorax ; the wings are always spread,
the front pair being brought forward until the hind margins are at
right angles to the body. This rule is invariably followed both
with the moths and butterflies. The smaller forms are usually

348

ELEMENTARY ENTOMOLOGY

Fig. 483. Showing

method of pinning

Coleoptera

(After Washburn)

mounted on elbow pins, or on bits of fine silver wire {mimitien-
nadclji), which are stuck through bits of cork or pith and pinned
like a cardboard point.

Diptera. In the Diptera the pin is run through the central part
of the thorax, and the wings, if not spread, should be extended.
In the long-legged flies, as the crane-fly, the
legs should be supported until the specimen
is dry. In fact, it is not a bad idea to place a
permanent piece of cardboard on the pins hold-
ing such specimens. The smaller Diptera are
usually mounted on wire or cardboard points.

Coleoptera (Fig. 483). All of the larger Cole-
optera are pinned through the anterior inner
portion of the right wing-cover.
The wings are never spread,
and but little attention need be
given the specimens after pin-
ning, as the legs usually adjust
themselves. The smaller forms
are mounted on cardboard points and should be
glued on the side to reveal the undersurface.

Hymenoptera (Fig. 484). These are pinned
through the metathorax ; the wings may or may
not be spread. Some of the more slender forms,
as the Ichneumon-flies, require a support until
they are dry. Many of the parasitic Hymenoptera
are mounted on slides in Canada balsam, but the usual way is to

mount on points,
either cardboard or
wire.

Mounting insects
on points. General
directions have al-
ready been given
for mounting insects on points. It may be well, however, to men-
tion some of the different types of points used in mounting insects-.
Micro-pins (Fig. 486, d) are largely used for mounting Lepidoptera,
Neuroptera, and Diptera. These micro-pins {miniiticii-^iadehi)

Fig. 4S4. Showing

method of pinning

Hymenoptera

(After Washburn)

Fig. 485. Point punch

PRESERVING AND STUDYING INSECTS

549

consist of very fine pieces of steel wire, and may be run through
narrow strips of cork, pieces of paper, or small squares of cork, as
shown in Fig. 486, b, d, and c. Elbow pins (Fig. 486, c) present
a neater appearance than the micro-pins, and may be obtained of
entomological supply companies.

^

^fE2^

f

Fig. 486. Method of mounting insects on points

rt, with a cardboard point ; b, micro-pin in corlv ; c\ elbow pin ; i/, micro-pin in paper ;
e, micro-pin in side ; /, double point. (After Banks)

Most small Hemiptera and Coleoptera (Fig. 487) are mounted
on small, triangular points cut from light Bristol board. Punches
(Fig. 485) may be secured to cut these points accurately.

In mounting, the point is first placed on the pin at the required
height. The end of the point is next dipped in gum shellac dis-
solved in alcohol and then touched to the ventral side of the insect.
The insect will adhere to the point, and
should be arranged in position with fine
needles and forceps. The insect is mounted
so that when the point is directed to the
left, the head of the insect is away from
the person. For insects having long bodies
a double point should be used, as shown
in Fig. 486,/.

Whether micro-pins or points are used,
care should be taken not to obscure more
of the insect than is absolutely necessary.

Labeling. All specimens should be labeled as soon as possible
after pinning. The label should consist of the name of the town
and state, on the first line, and the date of collecting, on the

Fig. 487. Method of glu-
ing beetle on paper point

(After Banks)

350 ELEMENTARY ENTOMOLOGY

second line ; some entomologists have the name of the collector
on the third line. These labels should be printed in diamond type
on the best paper procurable, and may be had for from twenty-five
to thirty cents a thousand. In having labels printed, the space for
the date should be left blank, to be filled in later. Only the best
India ink and very fine crow-quill pens should be used. Below
the locality label should be the accession number, the collection
being numbered serially and each insect given a separate number,
unless two or more of the same species were collected under
the same conditions. The accession number should refer to the
collector's notes, in which everything known about the insect is
recorded. The date and place of collecting should again be re-
corded and the food plant or nature of the locality where the
insect was found, etc.

Arrangement of insects. For the permanent storage of insect
collections two general types of box are used. One consists of
large glass-top drawers, about fifteen by eighteen inches, which fit
into cabinets. The other type consists of separate boxes, with cork
bottoms. For the beginner the latter type is probably the better.
Numerous boxes are on the market, made from both cardboard
and wood, the latter, of course, being far superior to the cardboard.

In selecting insect boxes care must be taken to obtain those
having tight-fitting lids. This is absolutely essential in order to
keep out certain Dermestid beetles, which, if they gain access to the
collection, will quickly destroy it. Further precaution against these
insects should be taken by placing flake naphthalene in the boxes.
By far the best on the market is the Schmitt box (Fig. 488).
This comes in two sizes, twelve by fifteen inches and eight and
one half by fifteen inches, and is lined with pressed cork. In using
the drawers, the insect pins are stuck into small blocks of wood,
or into a lining of sheet cork, by means of pinning forceps (Fig.
478). The blocks^ are cut to a uniform length and are made in
multiple width. The width of the blocks used depends on the size
of the insects and the number of specimens of each species. The
advantage of this system is that it allows an indefinite amount of
expansion of a collection, without necessitating the transfer of each
individual insect.

1 See Comstock's "Insect Life."

PRESERVING AND STUDYING INSECTS

151

Whether the boxes or drawers are used, all of the specimens
of one species should be kept together, which plan should be
followed out in genera, families, and orders.

■S^Sm^SSSBSSSSSSSSSSSSSS

Fig. 48S. A Schmitt insect box, opened to show arrangement of insects
(After Banks)

Mounting insects on slides. Directions have already been given
for the mounting of aphides and scale insects. The directions
given for mounting scale insects may be used for mounting legs

352

ELEMENTARY ENTOMOLOGY

or other hard parts of insects, where nothing but the chitinous
portion is desired. For most purposes, however, such as mount-
ing the legs of bees for laboratory use, or mounting small,
hard-bodied insects, the following method will be found more
desirable.

The insect or part of the insect to be mounted should first be
placed in 85 per cent alcohol. This rule applies to mounting both
fresh specimens and material previously preserved in alcohol or
glycerin. After the insect has become thoroughly saturated, it
should be transferred to 95 per cent alcohol and left for an hour
or longer. The specimens should then be transferred to xylol and
left until the alcohol is entirely replaced. The insect should then
be placed in the center of the slide, the excess of xylol removed
with a piece of blotting paper, and a drop of Canada balsam placed
over the insect. The balsam should then be warmed slightly over
an alcohol lamp, and a cover glass placed over it. Care must be
taken not to get on more balsam than is necessary to cover the
insect and fill out the space under the cover glass. For the be-
ginner there is less liability of having air bubbles in the mount if
the balsam is first placed on the slide and the insect laid on after-
wards. However, it is much more difficult to arrange the wings
and legs of the insect if mounted in this way.

Preserving material in liquids. Directions have already been
given for collecting small, soft-bodied insects in liquid. When this
material is first brought into the laboratory, it should be thoroughly
washed in 50 per cent alcohol and then transferred to 85 per cent
alcohol. If the specimens are large, soft-bodied larvae, or insects
of considerable size, the alcohol should be changed at least ^nce
before permanently storing the specimens. For permanently
storing alcoholic material small, straight-necked vials will be found
the most convenient. These should be of one-, two-, and four-
dram sizes and fitted with the best cork stoppers procurable. The
bottles should be numbered and labeled as in pinned insects, the
labels being written on strips of good linen paper in India ink,
which must be absolutely waterproof. These should be placed
inside the bottles with the specimens. Numerous trays have been
devised for holding alcoholic material, the one shown in Fig. 489
being very satisfactory. An improvement of this tray consists in

PRESERVING AND STUDYING INSECTS

353

having either end extend up above the top of the bottles. This
allows the trays to be stacked one above another without injuring
the bottles.

Numerous substitutes for alcohol have been employed, of which
a 4 per cent solution of formaldehyde is probably the best, as it
is cheaper, tends to preserve the color, and does not harden the

Fig. 4S9. The Marx tray for specimens in liquid

specimens. This, however, is not much superior to alcohol, and
in many cases shrinks the specimens more than alcohol would.

Material intended for dissection may be treated as above, but
if alcohol is used, should be permanently preserved in 70 to 85
per cent alcohol, to which 10 percent of glycerin has been added.

Inflating insect larvae. The larvae of most of the Diptera,
Coleoptera, and Hymenoptera are preserved in alcohol, as noted
above. It has been found, however,
that lepidopterous larvae may be
preser\^ed much better by inflating
them, the method of which is as
follows :

The lan^ae are brought to the
laboratory alive, and when ready to
be inflated are killed or stupefied in
a cyanide bottle. This method will
be found much better than killing
the lar\'ae in the field, as they should
be blown as soon as possible after
they are killed. Remove the larva from the cyanide bottle and
place it on a piece of blotting paper. A glass tube or pencil is
next rolled over the body from the head toward the tip of the
abdomen. This causes the alimentary tract to protrude, which is
then snipped off at the anus by a pair of sharp-pointed scissors.

Fig. 490. Homemade apparatus
for inflating larvae

(After Washburn)

354

ELEMENTARY ENTOMOLOGY

Fig. 491. Method of mounting inflated larvae
(After Washburn)

The rolling is then continued until the entire contents of the body
have been forced out through the posterior end. A straw or a
glass tube which has been drawn out to a fine point is next in-
serted through the open-
ing. This may in turn be
attached to a rubber tube
and bulb, or the larva
may be inflated by blow-
ing gently through the
tube. In order to keep
the specimen on the end
of the tube, it should be
allowed to dry for a few
minutes. To thoroughly dry the skin it is kept distended inside a
glass lamp chimney, which rests in a pan of sand over a gas or
alcohol flame, as shown in Fig. 490. When the skin is thor-
oughly dried, it is removed from the glass tube and may then be
mounted on an elbow pin by bending the point of the elbow into
a loop, which is dipped into glue and inserted into the opening in
the abdomen. Another method is shown in Fig. 491.

Dissecting instruments. The number of
different instmments required for the study of
the anatomy of insects is not great. However,
owing to the small size of the specimens
studied, the instruments should be of the very
best material.

Forceps. Forceps should be of two kinds,
curved-pointed and straight-pointed (Fig. 492).
Both pairs should have very fine points which
are slightly roughened.

Scissors. Curved scissors will be found very
useful in carrying on minute dissecting work,
the difficulty being to secure a pair that will
cut entirely to the point. In using the fine-
pointed scissors, care must be exercised not
to strain them by cutting too thick objects, ^^

Scalpels. These are of less importance in JJr''veSpoinL''d'lnd
entomological work than in most other forms straight-pointed

PRESERVING AND STUDYING INSECTS 355

of dissecting, but two or three scalpels of various shapes will
be found useful. The short, curved, sickle-shaped scalpel will be
used in general dissection more than any other.

A^ccdles. These are really of more importance than the scalpel.
They may be made by forcing the eye of an ordinary needle into
a small stick about the size of a lead pencil. Much more satisfac-
tory needle handles may be secured of the supply companies, with
arrangements for removing and exchanging the needle. One should
be -provided with three of four of these needle holders and a num-
ber of needles bent into various shapes, — hooks of different
sizes, and curved and straight needles.

Brus/ics. An assortment of camel's-hair brushes will be found
useful on the dissecting table.

J^iJis. For holding the dissected specimens in position ordinary
insect pins will be found most convenient. The larger sizes,
Nos. 4, 6, and 8, are well adapted for minute dissection. A few
large pins with black glass heads will also be found useful for
heavier work.

Microscopes and lenses. Every collector should be provided with
at least one good pocket lens. For most work a half-inch lens,
procurable of any microscope supply company, will be found suf-
ficient. For very small insects, however, a one-fourth-inch lens
will be found much better.

Dissecting microscopes are almost an essential if careful work in
insect anatomy is to be done. V'arious types of these are sold by
all optical companies. Compound microscopes are essential for very
minute work, but for studying the general anatomy of insects they
can be more easily dispensed with than the dissecting microscope.

Dissecting trays. Dissecting trays, as found on the market, con-
sist of shallow tin or porcelain trays ranging in size from four by five
to twelve by fifteen inches, with a depth of from one to three inches.
The bottoms of these trays are usually covered with paraffin or bees-
wax, so that the specimens may be pinned out under water. Home-
made trays may be constructed by obtaining tin pans of the proper
size, and having two or three short pieces of wire soldered to the
bottom. The ends of the wire should be left projecting, so that
when hot paraffin or beeswax is poured into the pan, the wire will
hold it firmly in place and prevent it from floating when in use.

356

ELEMENTARY ENTOMOLOGY

This sort of dissecting tray works very well for rough dissection,
where nothing more than a hand lens is required. It has the
objection, however, of the projecting sides, which frequently pre-
vent one from manipulating the dissecting instruments as desired.
By far the most successful dissecting tray for insect work that we
have used is made as follows : A glass plate four by five inches is
thoroughly washed in alcohol in order to remove all traces of dirt.
This is then placed in a shallow pan which has been previously
coated with vaseline or oil. A mixture of four parts paraffin and

one part beeswax is next

poured over the glass
plate to a depth of about
one inch. After this is
thoroughly cool, it is re-
moved from the pan and
the paraffin trimmed off
to the edge of the glass
plate. A trough is scraped
out in the center of the
plate to accommodate the
body of the insect to be
dissected. After a little
experience one can very
quickly regulate the size
and shape of this trough
to the best advantage. A
sufficient amount of par-
affin should be left be-
neath the insect to permit
of its being firmly pinned
in position. The work
will also be greatly facilitated if glycerin, to which an excess of
chloral hydrate has been added, is used as a dissecting medium in
place of water. This form of tray has a number of distinct advan-
tages. In the first place, the work can be carried on entirely with
the dissecting microscope, or even a low power of the compound
microscope. There are no projecting sides to interfere with the
manipulation of the instruments, and if the dissection is not

Fig. 493. The Riley breeding cage

PRESERVING AND STUDYING INSECTS

;57

completed, it may be temporarily sealed by covering with a glass
plate which is firmly pressed in position. The glycerin has many
distinct advantages over water, its density
holding the more delicate structures in
position, and at the same time it has a
higher index of refraction. Plates of vari-
ous sizes and depths may be easily con-
structed to meet different requirements.

Rearing insects. If one wishes to study
the life history of insects, or if desirous of
procuring especially fine specimens, by far
the best method is to rear them under
artificial conditions. In this work an at-
tempt must always be made to simulate
natural conditions as closely as possible.
There is less liability of the larvae being
parasitized if they are placed in a breed-
ing cage when quite small. Numerous
breeding cages have been constructed for
the purpose of rearing larvae. Of these,
one of the best is shown in Fig. 493.
This consists of a frame with a glass door
on one side, the other three sides being
covered with cheesecloth. If possible, the
food plant is placed in a flowerpot inside
the breeding cage. If this is impracticable, twigs and branches
can be placed in the cage in bottles of water, the top of the bottle
being stuffed full of cotton to prevent the lar-
vae from drowning. Another simple breed-
ing cage for smaller insects is made b}-
placing a lantern globe or lamp chimney,
the top of which is covered with a square of
cheesecloth, over the food plant (Fig. 494)
in a flowerpot. The food material should be
changed frequently, so that it may be kept
fresh and sufficient.

For rearing large quantities of larvae an
open tray three by five feet is most convenient. (After washbum)

Fig. 494. A lamp-chimney
breeding cage

(After Banks)

Fig. 495. A simple aqua-
rium for aquatic larvae

358

ELEMENTARY ENTOMOLOGY

.The sides of the tray are made of Hght six-inch boards, and the
bottom is formed by a piece of cheesecloth. Four-inch strips are
next tacked to the top of the tray, so that they project inward
around it. The inside of the projecting ledge formed by the four-
inch strips is coated with tanglefoot. The food and the larvae are
placed in the tray on the cheesecloth. The larvae are easily ob-
served all the time, and the food material may be quickly changed,
while the tanglefoot prevents the escape of the larvae. The larvae,
however, are not protected from parasites, and the pupae must be

removed and placed in
tight cages before the
adults emerge.

Aquatic larvae and
nymphs may be reared
in any suitable aquarium
{Fig. 495), but only
larvae of the same size
should be kept together,
and care should be taken
to separate those which
are predacious upon one
another.

Numerous cages for the study of special insects have been

devised, as the Comstock root-cage, devices for studying the life

history of ants, the limb cage for rearing insects out of doors in

their natural habitat, and the breeding cage for parasites (Fig. 496).

For further methods, consult the following books :

L. O. Howard, The Insect Book. (Doubleday, Page & Co.)
W. J. Holland, The Moth Book. (Doubleday, Page & Co.)
V. L. Kellogg, American Insects. (Henry Holt and Company)
J. H. and A. B. Comstock, Insect Life. (D. Appleton & Co.)

Fig. 496. Breeding cage for parasites
(After Banks)

APPENDIX

r. DEALERS IN ENTOMOLOGICAL SUPPLIES

The American Entomological Co., 55 Stuyvesant Ave., Brooklyn, N.Y.

The Kny-Scheerer Co., 404 West Twenty-seventh St., New York City

The Entomological Society of Ontario, Guelph, Ontario

M. Abbott Frazer, 93 Sudbury St., Boston, Mass.

A. Smith and Sons, 269 Pearl St., New York City

Charles C. Reidy, 432 Montgomery St., San Francisco, Cal.

The Simplex Net Co., Ithaca, N.Y. (Nets.)

Bausch and Lomb, Rochester, N.Y. (Microscopes, lenses, instruments, etc.)

Queen & Co., 10 10 Chestnut St., Philadelphia, Pa. (Microscopes, lenses, instru-
ments, etc.)

The Spencer Lens Co., Buffalo, N.Y. (Microscopes, lenses, instruments, etc.)

The Wiegner Printery, 2234 North Twenty-ninth St., Philadelphia, Pa.
(Labels.)

C. V. Blackburn, 32 Chestnut St., Stoneham, Mass. (Labels.)

II. ADDRESSES OF STATE AGRICULTURAL EXPERIMENT
STATIONS AND OF STATE ENTOMOLOGISTS

Alabama, Auburn Iowa, Ames

Arizona, Phoenix Kansas, Manhattan

Arkansas, Fayetteville Kentucky, Lexington

California, Berkeley Louisiana, Baton Rouge

Colorado, Fort Collins Maine, Orono

Connecticut, New Haven Maryland, College Park

Delaware, Newark Massachusetts, Amherst

Florida, Gainesville Michigan, East Lansing

Georgia, State Entomologist, Atlanta Minnesota, St. Anthony Park

Hawaii, Honolulu Mississippi, Agricultural College

Idaho, Moscow Missouri, Columbia

Illinois, State Entomologist, LIrbana Montana, Bozeman

Indiana, Lafayette Nebraska, Lincoln

State Entomologist, Indianapolis Nevada, Reno

359

36o ELEMENTARY ENTOMOLOGY

New Hampshire, Durham Pennsylvania, State Zoologist, Harris-
New Jersey, New Brunswick burg

New Mexico South Carolina, Clemson College

New York, Geneva South Ju ta, Brookings

Cornell University Agricultural Ex- Tennessee, Knoxville

periment Station, Ithaca Texas, College Station

State Entomologist, Albany, N.Y. Utah, Logan

North Carolina, West Raleigh Virginia. Blacksburg

State Entomologist, Raleigh Washington, Pullman

North Dakota, Agricultural College West Virginia, Morgantown

Ohio, Wooster Wisconsin, Madison

Oklahoma, Stillwater United States Department of Agri-
Oregon, Corvallis culture, Bureau of Entomology,

Washington, D.C.

in. A LIST OF BOOKS FOR THE REFERENCE LIBRARY
General Extomologv

COMSTOCK, J. H. A Manual for the Study of Insects. (Comstock Publishing
Co., Ithaca, N.Y., 1895.)

Comstock, J. H. and A. B. Insect Life. (D. Appleton & Co., New York
City, 1 90 1.)

FoLSOM, J. W. Entomology, with Special Reference to its Biological and Eco-
nomic Aspects. (J. B. Lippincott and Co., Philadelphia, Pa.. 1906.)

Howard, L. O. The Insect Book. (Doubleday, Page & Co., New York, 1904.)

Kellogg, V. L. American Insects. (Henry Holt and Co., New York,
1905-1908.)

Packard, A. S. A Text-Book on Entomology. (The Macmillan Company,
New York, 1898.)

Sharp, D. The Cambridge Natural History. Insects. 2 vols. (The Macmillan
Company, London, 1895- 1899.)

(The works of Folsom, Kellogg, and Packard above are especially strong con-
cerning the anatomy of insects.)

Butterflies and Moths {Lepidoptera)

Comstock, J. H. How to Know the Butterflies. (D. Appleton & Co., New
York, 1904.)

French, G. H. The Butterflies of the Eastern United States. (J. B. Lippin-
cott and Co., Philadelphia, 1886.)

APPENDIX 361

Holland, W.J The Butterfly Book. (Doubleday. Page & Co., New York,

1905.)
The Moth Book. (Doubl'^day, Page & Co., New York, 1903.)
Eliot, Ida M., and S<, ...M, Caro G., Caterpillars and their Moths. (The

Century Co., 1902.)
DiCKERSOX, Mary C, Moths and Butterflies. (Ginn and Company, Boston,

1905.)

Economic Entomology

Smith, J. B. Economic Entomology. (J. B. Lippincott and Co., Philadelphia,

1896.)
Sanderson, E. D. Insects Injurious to Staple Crops. (John Wiley and

Sons, New York, 1902.)
Insect Pests of Farm, Garden and Orchard. (John Wiley and Sons, New

York, 191 2.)
Chittenden, F. H. Insects Injurious to \'egetables. (Orange Judd Co.,

New York, 1907.)
Saunders, Wm. Insects Injurious to Fruits. (J. B. Lippincott and Co.,

Philadelphia, Pa., 18S3.)

INDEX

Abdomen, 7, 11, 25, 282; of female,

283 ; of male, 282
Acalypterae, 325
Acanthidae, 114, 135, 309
Accessory organs of digestion, 291
Acrididae, 81, 308
Actia luna, 215
Aculeata, 274
Adalia bipunctata, 162
Adephaga, 137, 171, 312
Adult, 53,- 56
Aeschnidae, 306
Agaristidae, 318
Agrionidae. 306
Agromyzidae, 327
Alaus oculatus, 146
Alcohol, 337
Aletia argillacia, 202
Aleyrodidae, 311
Allorhina nitida, 152
Ambush-bugs, 114, 135, 309
American acridium, 83
Ampelophaga myron, 211
Amphibolips spongifica, 247
Anals, 24

Anasa tristis, 50, 121
Anatomy of insects, internal, 28
Andrenidae, 267, 274, 321
Angumois grain-moth, 186
Anisophaeridae, 305
Anisoptera, 306
Anisota rubicunda, 212
Anopheles, 223
Anosia plexippus, 179
Antennae, 7, 1 1
Anthomyiidae, 238, 242, 328
Anthonomus grandis, 168
Anthonomus signatus, 16S
Anthrenus scrophularia, 143
Antlered maple worm, 195
Ant-lions, 93, 307
Ants, 243, 254, 274, 303, 320 ; habits of,

255; relation of, to aphids, 255
Aorta, :i^
Apanteles, 251
Aphides, 107, 127
Aphididae, 127, 135, 311
Aphis-lions, 92

Aphis maidi-radicis, 129
Aphis pomi, 129
Aphodius, 150
Aphoruridae, 306
Apiculture, 271
Apidae, 267, 269, 274, 321
Apina, 266, 274, 321
Apple leaf-hqpper, 125
Apple-leaf trumpet miner, 185
Apple-maggot, 239
Aptera, 73, 303
Aquatic bugs, 135
Aquatic sieve net, 334
Arachnida, 7
Aradidae, 309
Archips cerasivorana, 187
Archips rosaceana, 186
Arctiidae, 207, 217, 318
Argentine ant, 259
Argynnids, 182
Arilus cristatus, 112
Arista, 231
Armored scales, 132
Army-worm, 202
Arrangement of insects, 350
Arthropoda, 6 ; types of, 284
Articulata, 6
Asilidae, 230, 242, 323
Asparagus beetles, i 53
Assassin-bugs, 112, 135, 309
Atropidae, 307
Australian ladybird, 163
Autographa brassicae, 202
Automeris io, 213

Back-swimmers, 135, 309
Bacteria, 3

Bag-worm moths, 319
Baiting insects, 341
Bark-beetles, 170, 171, 313
Bark-lice, 307
Barnacles, 7
Bat-ticks, 242, 329
Bean-weevils, 313
Bedbugs, 114, 135, 309
Bee-bread, 274
Bee-flies, 231, 242, 323
Bee-lice, 242, 329

364

ELEMENTARY ENTOMOLOGY

Bee-moth, 189, 217
Bees, 5, 243, 266, 274, 321
Beetles, 5, 136; families of, 137
Belostomidae, 109, 135, 309
Bembecia marginata, 193
Bembecidae, 262, 274, 321
Bembecids, 274
Beneficial insects, 2
Berytidae, 120, 135, 310
Bibionidae, 323
Big-eyed flies, 325
Bill-bugs, 169, 171, 313
Bird-lice, 303, 307 ; biting, 106
Blackberry-gall, 247
Black damsel-bug, 114
Black-flies, 226, 242, 323
Blattidae, 77, 308
Blepharoceridae, 226
Blister-beetles, 166, 171, 311
Blond damsel-bug, 114
Blood, :i3
Blood vessels, 32
Blow-flies, 236
Blue-bottle flies, 236
Body covering of locust, 275
Body structure, 10
Boll weevil, 2
Bollworm, 202
Bombyliidae, 231, 242, 323
Bombyx mori, 212
Book-lice, 105, 307
Borboridae, 327
Boring hymenoptera, 244, 274
Bot-flies, 233, 242, 32S
Box-elder bug, 121
Brachycera, 229, 242, 323
Braconidae, 250, 274, 320
Braconid-flies, 250, 274
Brain, 37

Braulidae, 240, 242, 329
Bristletails, 73, 74
Brown ant, 250
Brown-tail moth, 204
Bruchidae, 158, 171, 313
Brushes, 355
Bud-borers, 217
Buffalo-moth, 143
Buffalo tree-hopper, 124
Bumble-bee, 270; flower-beetle, 152
Buprestidae, 146, 171, 312
Burying-beetles, 142
Butterflies, 5, 172, 174, 217 ; four-footed,
179

Cabbage aphis, 129
Cabbage butterfly, 178:

300
Cabbage looper, 202

life history of.

Cabbage-maggot, 238
Caddis-flies, 93, 307
Caecal tubes, 31 •
Calandra granaria, 169
Calandra oryza, 169
Calandridae, 169, 171, 313
Callosamia promethia, 216
Calopterygidas, 306
Calosoma scrutator, 139
Calypterae, 328
Campodeidae, 305
Camponotidae, 256, 274, 320
Camponotus pennsylvanicus, 256
Capsidae, 117, 135, 310
Carabidae, 138, 171, 312
Carnivorous beetles, 137, 171
Carpenter-ant, 256
Carpenter-bee, 269
Carpenter-moths, 191, 217, 319
Carpet-beetle, 143
Carrion-beetles, 142, 171, 312
Catocala, 203

Cecidomyia, strobiloides, 228
Cecidomyiidae, 228, 242, 321
Cecropia moth, 215
Celery caterpillar, 175
Centipedes, 8
Cephalothorax, 7
Cerambycidae, 158, 171, 313
Ceratocampidae, 319
Cerci, 26

Cercopidae, 125, 135, 311
Ceresa bubalus, 124
Chain-dotted geometer, 197
Chalcididae, 253, 274, 320
Chalcis-flies, 253, 274
Checkered-beetles, 313
Cherry-tree leaf-roller, 1S7
Chestnut weevils, 16S
Chilocorus bivulnerus, 162
Chinch-bug, 120, 135, 310
Chironomidae, 224, 242, 323
Chitin, 27, 276
Chloroform bottle, 336
Chrysalis, 48
Chrysididae, 320
Chrysomelidae, 153, 171, 313
Chrysomyia macellaria, 236
Chrysopidae, 92, 307
Cicadas, 122, 135, 311
Cicadidae, 122, 135, 311
Cicindelidae, 137, 171, 312
Cigar case-bearer, 185
Cingilia catenaria, 197
Circulatory system, 32, 293
Classification, 67, 302
Clavicornia, 141, 171, 312
Clear-winged moths, 192, 217, 319

INDEX

365

Cleridae, 313

Click-beetles, 144. 171, 312

Close-wings, 190, 217

Clothes moths, 1S6, 217

Clouded sulphur butterfly, 178

Clover-hay worm, 188

Club-horned beetles, 141, 171 .

Coccidae, 129, 135, 311

Coccinella 9-notata, 162

Coccinellidae, 68, 161, 171, 313

Cockroaches, 77, 308

Cocoon, 48, 60

Codling moth, 1S7

Coleoptera, 136, 304, 311 ; families of,

311; mounting of, 348
Coleoptera genuina, 137, 171
Collecting belt, 331
Collecting coat, 330
Collecting forceps, 337
Collecting insects, methods of, 330
Collecting larvae, 339
Collembola, 74, 305 ; mounting of, 344
Colorado potato-beetle, 153
Complete metamorphosis, 57
Conopidae, 232, 242, 325
Cordulegasteridae, 306
Cordyluridae, 325
Coreidae, 121, 135, 310
Corimelaenidae, 116
Coriscus ferus, 1 14
Coriscus subcoleoptratus, 114
Corisidae, 135, 309
Corn root-aphis, 129
Corrodentia, 307
Corydalus cornuta, 90
Cossidae, 191, 217, 319
Costa, 24

Cotton-boll weevil, 168
Cotton square-borer, 179
Cotton-stainer, 1 19
Cottony maple scale, 132
Coxa, 22
Crabs, 7
Crambinae, 190
Crane-flies, 220, 242, 321
Crayfish, 7

Crickets, 85, 305 ; music of, 86
Crop, 30
Croton bug, 77
Crustacea, 6, 7
Cubitus, 24
Cuckoo-flies, 320
Cucujidae, 143, 171
Cucujus clavipes, 143
Culicidae, 222, 242, 321
Curculionidae, 167, 171, 313
Curculios, 167, 171, 313
Currant-borer, 193

Currant span-worm, 199
Currant worms, 245
Cutworms, 200
Cyanide bottle, 335
Cydia pomonella, 187
Cydnidae, 310
Cynipidae, 246, 247, 320
Cyrtidae, 323

Damsel-bug, 114, 135, 310

Damsel-flies, 98, 306

Darkling-beetles, 165, 171, 311

Datana ministra, 194

Dermestes lardarius, 144

Dermestidae, 144, 171, 312

Dermestid-beetles, 171

Dexidae, 328

Diaphania hyalinata, 1S8

Diaphania nitidalis, 188

Diastictis ribearia, 199

Diastrophus nebulosus, 247

Differential locust, 53, 82 ; habits of, 54

Digestive system, 29, 290

Digger-wasps, 260, 274, 320

Diopsidae, 327

Diptera, 18, 218, 305, 321 ; characteris-
tics of, 218 ; mounting of, 34S ; sum-
mary of, 242

Diptera genuina, 219, 242

Dissecting instruments, 354

Dissecting trays, 335

Diving-beetles, 140

Divisions of body, 276

Dixa-midges, 226

Dixidae, 226

Dobsons, 90, 306

Dog-day harvest-fly, 122

Dolichopodidae, 231, 323

Dragon-flies, 98, 306; mounting of, 345

Dragon-fly, life history of the, 299

Drasteria erechtea, 200

Drosophila, 239

Drosphilidae, 327

Dynastes tityrus, 152

Dysdercus suturellus, 119

Dytiscidae, 140, 171, 312

Earwigs, 87, 307

Echinoderms, 5

Ecology, 2

Egg, 45, 50; laying, 56, 63 ; mass, 58

Elateridae, 144, 171, 312

Elbow pins, 348

Elm leaf-beetle, 1 54

Elytra, 24

Embryology, 1 1

Emesidae, 113, 135, 309

Empididae, 323

366

ELEMENTARY ENTOMOLOGY

Empoasca mali, 125
Empoasca rosae, 125
Empodium, 22
Enchenopa binotata, 124
Engraver-beetles, 170, 171
Entomobryidae, 305
Ephemerida, 95, 304, 306
Ephydridae, 327
Epicauta vittata, 166
Epilachne, 163
Epitrix fuscula, 156
Eriocampa cerasi, 245
Esophagus, 30
Eumenes fraternus, 264
Eumenidae, 263, 274, 320
Euphoria inda, 152
Euplexoptera, 87, 304, 30S
Euproctis chrysorrhoea, 204
Euvanessa antiopa, 63
Eyed elater, 146
Eyes, 12

Eye-spotted bud moth, 187
External anatomy of locust, 275

Facets, 12, 40
Fall army-worm, 202
Fall web-worm, 20S
Families, 71
Feelers, 1 1
Femur, 22
Field kit, 330
Fireflies, 147, 171, 313 .
Flat-bugs. 309
Flat-footed flies, 325
Flat-headed borers, 147
Fleas, 240

Flesh-flies, 236, 242, 328
Flies, 5, 218
Flower-beetles, 152
Flower-bugs, 114
Flower-flies, 232, 242, 325
Forceps, 354
Forficulidae, 308
Formicina, 254, 274, 320
Four-lined leaf-bug, 118
Fritillaries, 182
Frog-hoppers, 125, 135
Fruit-flies, 239, 242
Fruit-fly, life history of, 301
Fruit-tree bark-beetle, 170
Fulgoridae, 31 1
Fungus-gnats, 227, 242, 321
Funnel trap, the, 339

Galea, 14

Galerucella luteola, 154
Galgulidae, 308
Gall-flies, 246, 320

Gall-gnats, 228, 242, 321

Gall-inhabiting Hymenoptera, 274

Ganglia, 28, 37

Garden web-worm, 187

Gastric caeca, 31

Gelechia cerealella, 186

Genus, 68, 71

Geometridae, 195, 217, 319

Geometrinae, 199

Giant crane-fly, 221

Giant water-bugs, 135, 309

Gizzard, 30

Gomphidae, 306

Gossamer-winged butterflies, 178

Granary weevil, 169, 313

Grape leaf-hopper, 125

Grape phylloxera, 129

Grape thrips, 125

Grapevine hog caterpillar, 211

Grasping Orthoptera, 78

Grasshopper, external anatomy of,

275
Green apple aphis, 129
Green bug, 129
Green-fly, 127
Green soldier-bug, 115
Green-striped maple-worm, 212
Green tomato worm, 209
Ground-beetles, 138, 171
Growth, 47, 54
Gryllidae, 85, 308
Guest-bees, 274
Gypsy moth, 204
Gyrinidae, 140, 171, 312
Gyropidae, 307

Halictus, 268

Ilalteres, 24

Handmaids, 194

Harlequin cabbage-bug, 115

Harlequin milkweed caterpillar, 207

Hatchet, 337

Haversack, 330

Hawk-moths, 208, 217

Head, 10, 11 ; study of, 276

Hearing, 42

Heart, 32

Heliothis obsoleta, 202

Hellgramite, 90

Hemerobiidae, 307

Hemerocampa leucostigma, 204

Hemiptera, 17, 107, 135, 305, 308;

mounting of, 346
Ilesperidae, 318
Hesperina, 174, 217
Hessian fly, 228
Heterocampa gutivitta, 195
Heteromera, 163, 171, 311

INDEX

367

Heteroptera. 107, 135. 308

Hexapoda, 8

Hickory-borer. 160

Hippoboscidae. 240, 242. 329

Hog caterpillars, 21 i

Holorusia rubiginosa, 221

Homoptera, 122, 135, 310

Hone\-bees, 270 ; anatomy of, 287 ;
life histor}' of, 271

Hop merchant, 179

Hornblower. 209

Horned passalus, 149

Horn-tails, 246, 274, 319

Hornworms, 209

Horse-flies, 229, 242, 323

House-fly, i, 234, 242, 328

Humming-bird hawk-moths, 211

Hydrobatidae, 135, 309

Hydrophilidae, 141, 171, 312

Hymenoptera, 18, 243, 303, 304, 305,
319; characteristics of, 243; gall-in-
habiting, 246 ; larvae of, 243 ; mount-
ing of, 348 ; parasitic, 247 ; plant-
eating, 244 ; stinging, 254 ; summary
of, 274

Hypophar>'nx, 15, 279, 295

Ichneumon-flies, 250, 274

Ichneumonidae, 250, 274, 320

Ichneumons, 243

Identity of insects, 67

Ileum, 31

Inch-worms, 195

Incomplete metamorphosis, 50, 53

Indian-meal moth, 189

Inflating insect larvae. 353

Injury to crops. 2

Injury to domestic animals, 2

Injury to household and stewed goods, 2

Insecta, 8

Insect nets, 331

Insect pins. 343 ^

Insects, and disease, i ; near relatives
of, 5 ; classes of, 67 ; compared with
Arachnida, 286; compared with Crus-
taceans, 284 ; compared with Myri-
apoda. 2S5; comparison of types of,
2S7; external anatomy of, 10; growth
and transformation of, 45; number
of, 3 ; structure and growth of, 5

Insect traps, 339

Integument, 26

Intestine. 31

Invertebrates, 5, 6

lo moth. 213

Iridomyrmex humilis, 259

Isabella tiger-moth. 207

Isosoma tritici, 253

Japygidae, 305
Jassidae, 125, 135. 31 1
Jug-handle grub, 209
lumping plant-lice, 311
June-bugs, i 51

Labeling, 349
Labium, 14, 278, 294-297
Laboratory exercises, 275.
Labrum, 13, 277, 294-297
Lace-bugs. 117. 135. 310
Lace wings, 307
Lachnosterna, 151
Lacinia, 14

Ladybird-beetles, 161, 171, 313
Lamellicornia, 148, 171, 313
Lampyridae. 147. 171, 313
Laphygma frugiperda. 202
Larder-beetles, 143, 312
Larger carpenter-bee, 270
Larva. 47, 58, 63
Lasiocampidae, 216, 318
Lasius niger americanus, 256
Leaf-beetles, 153, 171, 313
Leaf-bugs, 117, 135, 310
Leaf-chafers, 313
Leaf-cutter bees, 269
Leaf-folders, 217
Leaf-hoppers, 125, 135, 311
Leaf-horned beetles, 14S, 171
Leaf-miners, 217, 319
Leaf-rollers, 186, 217, 319
Leaf worm, 202
Leather-jackets, 220
Lebia grandis, 139
Lecanium, 132
Legs, 21, 2S0
Lenses, 355
Leopard moth, 191

Lepidoptera, 17, 172, 305, 31S; mount-
ing of, 347 ;. summary of, 217
Lepismidae, 305
Leptidae, 323

Leptinotarsa decemlineata, 153
Leptocoris trivittatus, 121
Lesser migratory locust, 81
Leucania unipuncta, 202
Leucocytes, 33
Libellulidae, 306
Lice, 121

Life history of insects, 298
Light traps, 341
Ligula, 15
Limnobatidae, 309
Liotheidae, 307
Liparidae, 203, 217, 318
Lobsters, 7
Locust-beetle, 157

568

ELEMENTARY ENTOMOLOGY

Locust-borer, i6o

Locustidae, 83, 308

Locusts, 81, 308; internal anatomy of,

290 ; preservation of, 275
Long-horned beetles, 158, 171
Long-horned grasshoppers, 83, 308
Long-legged bugs, 135
Long-legged flies, 231
Long-tongued bees, 267, 269, 274,

321
Louse-flies, 240, 242
Loxostege similalis, 187
Lucanidae, 148, 171, 313
Lucilia caesar, 236
Luna moth, 2 1 5
Lycaenidae, 178, 217, 318
Lygaeidae, 120, 135, 310
Lygus pratensis, 1 17
Lysiphlebus tritici, 25^

Machilis, 74

Macrolepidoptera, 191, 217
Maggots, 219

Malacosoma americana, 57
Malarial fever, i, 223
Mallophaga, 106, 307
Malpighian tubes, 31
Mandibles, 13, 27S, 294-297
Mantidae, 78, 308
Mantids, 78
Mantispidae, 307
Mantis religiosa, 79
Marx tray, 353
Masaridae, 320
Maxillae, 14, 278, 294-297
May-beetles, 151

May-flies, 95, 306; mounting of, 345
Meadow-fiies, 325
Meadowmaggots, 220
Meal snout-moth, 189
Meal-worm beetle, 165
Meal-worms, 217
Mealy-bugs, 131
Measuring-worms, 217
Mecoptera, 93, 303, 304, 307 ; mount-
ing of, 347
Media, 24

Mediterranean flour-moth, 189
Melanolestes picipes, 113
Melanoplus atlantis, 81
Melanoplus differentialis, 53, 82
Melanoplus femur-rubrum, 81
Melanoplus spretus, 82
Melittia ceto, 193
Meloidae, 166, 171, 311
Melon aphis, 129
Melon caterpillar, 1S8
Melophagus ovinus, 240

Membracidae, 124, 133, 311

Mesothorax, 20, 279

Metallic wood-borers, 146, 171, 312

Metamorphosis, complete, 46, 47

Metathorax, 20, 279

Milkweed butterfly, 179

Millers, 199

Minutien-nadeln, 348

Mites, 7

Molluscs, 5

Monarch butterfly, 179

Monomorium pharaonis, 256

Monostegia rosae, 245

Mosquitoes, 218, 222, 242, 321

Mossy rose-gall, 247

Moth, 60, 172, 183, 217, 318

Mounting insects, 343

Mounting on points, 348

Mounting on slides, 351

Mouth-parts, 11, 12, 277, 294 ; suctorial

type of, 1 5
Mud-daubers, 262
Murgantia histrionica, 115
Muscidae, 242, 328
Muscids, 234, 242
Muscina, 234, 242
Muscular system, 36, 292
Mutillidae, 261, 274, 321
Mycetophilidae, 227, 242, 321
Mydaidae, 323
Mydas-flies, 323
Myriapoda, 8
Myriapods, 6
Myrmeleonidae, 93, 307
Myrmicidae, 256, 274, 320

Nabidae, 114, 135, 310

Naucoridae, 309

Necrophorus, 142

Needles, 354

Negro-bugs, 116, 310

Nematocera,, ^2_20j,^^, 321

Nematus r^^^esii, 245

Nepidae, 135, 309

Nervous system, 37, 292

Neuroptera, 90, 304, 306 ; mounting of,

347
Nezara hilaris, 115
Nine-spotted ladybird-beetle, 162
Noctuidae, 199, 217, 318
Nodus, 98

Northern grass worm, 200
Notodontidae, 193, 217, 319
Notonectidae, 135, 309
Notum, 21

Nycteribiidae, 240, 242, 329
Nymph, 50, 54
Nymphalidae, 179, 217, 31S

INDEX

369

Oak-apple, 247

Oak-pruncr, 160

Oberea bimaculata, i6i

Oblique-banded leaf-roller, 186

Ocelli, 12, 39

Odonata, 98, 304, 306

Odontota dorsalis, 157

Oestridae, 233, 242, 328

Ommatidium, 40

Onion-maggot, 23S

Ophion flies, 250

Orders, 68, 71

Orneodidae, 190

Ortalidae, 325

Orthoptera, 76, 304, 308 ; mounting of,

346
Oscinidae, 327
Otiorhynchidae, 313
Ovipositors, 26
Owlet-moths, 199, 217, 318
Ox-bot, 2
Oyster-shell bark-louse, 134

Palpus, 14

Panorpidae, 307

Papilionidae, 175, 31S

Papilionina, 174. 217

Papilio polyxenes, 175

Parasita, 121, 135

Parasitic Hymenoptera, 274

Passalus cornutus, 149

Pea aphis, 129

Peach-tree-borer, 192

Pear psylla, 127

Pear-slug, 245

Pea-weevils, 15S, 171, 373

Peddlers, 157

Pediculidae, 30S

Pelecinidae, 320

Pentamera, 137, 171, 312

Pentatoma sayi, 116

Pentatomidae, 114, 310

Pepsis formosa, 261

Periodical cicada, 122

Perlidae, 306

Pharynx, 29

Phasmidae, 80, 308

Philopteridae, 307

Phlegethontius quinquemaculata, 209

Phoridae, 323

Phryganeidae, 307

Phycitinae, 189

Phyla, 6

Phymata wolfii, 1 14

Phymatidae, 114, 135, 309

Physopoda, 305

Physopodae, 308

Phytophaga, 153

Pickle-worm, iSS

Piercing mouth-parts, 295

Pieridae, 178, 217, 318

Pimpla flies, 250

Pinning block, 344

Pins, 343

Pipunculidae, 325

Pissodes strobi, 168

Plant-bugs, 116, 135

Plant-eating Hymenoptera, 274

Plant-hoppers, 124

Plant-lice, 127, 135, 311 ; jumping, 127,

135; life history of, 298
Platypezidae, 325
Platyptera, 103, 303, 304, 307 ; mounting

of, 346
Plecoptera, 97, 304, 306
Pletirum, 21

Plodia interpunctella, 189
Plum curculio, 168
Plume-moth, 190
Podisus spinosus, 115
Poduridae, 306
Poecilocapsus lineatus, 118
Polistes, 266
Pollenization, 2
Polygonia comma, 179
Polyphemus, 213
Pomace-flies, 239, 327
Poneridae, 320
Pontia rapae, 300
Porthetria dispar, 204
Potato flea-beetle, 156
Praying mantis, 308
Predacious bugs, 112, 135
Predacious diving-beetles, 171, 312
Predacious ground-beetles, 312
Preserving, 352
Preserving insects, 343
Prionids, 160

Proctotrypidae, 253, 274, 320
Proctotrypid-flies, 274
Proctotrypids, 253
Productive insects, 2
Prominents, 193, 217, 319
Prothorax, 20, 279
Protozoa, 3
Proventriculus, 30
Psammocharidae, 261, 274, 321
Pseudoneuroptera, 95
Psilidae, 328
Psocidae, 105, 307
Psocids, 106
Psychidae, 319
Psychodidae, 321
Psylla pyricola, 127
Psyllas, 127, 135
Psyllidae, 127, 135, 311

370

ELEMENTARY ENTOMOLOGY

Psythirus, 270

Pteromalus puparum, 253

Pterophoridae, 190

Ptinidae, 312

Puddle butterflies, 178

Pulvillus, 22

Pupa, 47, 60, 63

Pupipara, 219, 220, 239, 242, 329

Pyloric valve, 31

Pyralidae, 187, 217, 319

Pyralids, 1S7

Pyralis costalis, 188

Pyralis farinalis, 189

Pyrrharctia isabella, 20S

Pyrrhocoridae, 119, 135, 310

Radial sector, 24
Radius, 24
Railroad worm, 239
Rake net, 334
Raphidiidae, 307
Raspberry cane-borer, 160
Raspberry geometer, 199
Raspberry root-borer, 193
Rearing nets, 357
Rectum, 31
Red ant, 256
Red-bug, 119, 135, 310
Red-humped apple caterpillar, 194
Red-legged locust, 81
Red milkweed-beetle, 161
Red-necked blackberry-borer, 147
Reduviidae, 112, 135, 309
Reproductive system, 291
Reptiles, 5

Respiratory system, 33
Rhagoletis pomonella, 239
Rhinoceros beetle, i 52
Rhodites rosae, 247
Rhynchophora, 137, 167, 171
Rhyphidae, 321
Rice weevils, 169
Robber-flies, 230, 242, 323
Rocky Mountain locusts, 82
Root-maggot flies, 238, 242
Rose-chafer, 151
Rose leaf-hopper, 125
Rose-slug, 245

Round-headed apple-tree borer, 160
Round-headed borers, 158
Rove-beetles, 143, 171, 312
Royal moths, 319
Running Orthoptera, 77

Sag net, 333
Saldidae, 309
Salivary glands, 29
Samia cecropia, 215

San Jose scale, 134

Sanninoidea exitiosa, 192

Sapromyzidae, 325

Sarcophaga sarracenia, 236

Sarcophagidae, 236, 242, 328

Saturnians, 212, 217

Saturnoidea, 212, 217, 319

Saw-flies, 243, 244, 274, 319

Saw-horned beetles, 144, 171, 312

Saw-toothed grain-beetle, 143, 144

Sawyer beetle, 160

vScale insects, 107, 129, 135, 311

Scalpels, 354

Scarabaeidae, 149, 171, 313

Scarabaeid beetles, 171

Scavenger-beetles, 313

Scenopinidae, 323

Schistocerca americana, 83

Schizura concinna, 194

Schmitt box, 350

Scientific names, 68

Sciomyzidae, 325

Scissors, 354

Sclerites, 21 ; of locust, 276

Scoliidae, 321

Scolytidae, 170, 171, 313

Scolytus rugulosus, 170

Scorpion-flies, 93, 303, 307

Scorpions, 7

Screw worm, 2

Screw-worm fly, 236

Scutelleridae, 310

Searcher, 139

Senses of insects, 39

Sepsidae, 325

Serricornia, 144, 171, 312

Sesia tipuliformis, 193

Sesiidae, 192, 217, 319

Sheep maggot, 2

Sheep-tick, 240

Shield-backed bugs, 310

Shield-shaped bugs, 135

Shore-bugs, 309

Short-horned flies, 229

Short-horned grasshoppers, 81

Short-tongued bees, 267, 274, 321

Shot-hole borers, 170

Shrimps, 7

Sialidae, 306

Sight, 39

Silkworm, 2, 212

Silkworm moths, 217

Silpha, 142

Silphidae, 142, 171, 312

Silvanus surinamensis, 143

Simuliidae, 226, 323

Siphonaptera, 240, 305

Siricidae 246, 274, 319

INDEX

37^

Skippers, 174, 217, 318

Slugs, 245

Smell, 42

Sminthuridae, 305

Snapping beetles, 144

Snout-beetles, 137, 167, 171

Social bees, 270, 274

Social-wasps, 264, 274

Soft scales, 131

Soldier-beetles, 148

Soldier-bugs, 115

Soldier-flies, 230, 242, 323

Solenopsis geminata, 259

Solitary bees, 274

Solitary-wasps, 263, 274

Sow-bugs, 7

Species, 68,70

Sphecidae, 262, 274, 321

Sphecina, 260, 274, 320

Sphingidae, 20S, 217, 318

Spiders, 6

Spider-wasps, 261, 274

Spined soldier-bug, 1 1 5

Spiny elm caterpillar, 179; the life of

the, 63
Spiracles, 34

Spittle-insects, 125, 135, 311
Spreading boards, 345
Springtails, 73, 74
Squash-bug, 50, 121, 135, 310
Squash-vine-borer, 193
Stable-fly, 236
Stag-beetles, 148, 171, 313
Staphylinidae, 143, 171, 312
Stegomyia, 223
Sternum, 21
Stigmata, 34
Stilt-bugs, 120, 135, 310
Stinging ants, 256
Stinging hymenoptera, 274
Stink-bugs, 114, 135, 310
Stomach, 31

Stone-flies, 97, 306; mounting of, 345
Stratiomyidae, 230, 242, 323
Strawberry root-louse, 129
Strawberry weevil, 168
Streblidae, 329
Striped blister-beetle, 166
Striped cucumber-beetle, 156
Subcosta, 24

Sucking mouth-parts, 294, 296
Suctorial lice, 308
Sugar-maple-borer, 160
Suture, 276
Swallowtails, 175, 31S
Sweeping net, 332
Sympathetic system, 38
Synchlora glaucaria, 199

Syrphidae, 232, 242
Syrphus, 232

Tabanidae, 229, 242, 323

Tachina-flies, 237, 242

Tachinidae, 237, 242. 328

Tarantula hawk, 261

Tarnished plant-bug, 117

Tarsus, 22

Taste, 41

Telea polyphemus, 213

Tenebrio molitor, 165

Tenebrionidae, 165, 171, 311

Tent caterpillar, 216; life history of

the, 57
Tent-caterpillar moths, 217
Tenthredinidae, 244. 274, 319
Terebrantia, 244, 274
Tergum, 21
Termes flavipes, 104
Termitidae, 103, 307
Tetramera, 153, 171, 313
Tetraopes tetraophthalmus, 161
Texas fever, 2
Thorax, 7, 11, 20, 279; appendages of,

2S0
Thread-waisted wasps, 262, 274
Thyanta custator, 116
Thyreocoridae, 310
Thysanoptera, 308
Thysanura, 74, 305 ; mounting of,

344
Tibia, 22
Ticks, 2, 7

Tiger beetles, 137, 171,312
Tiger moths, 207, 217, 318
Tineidae, 184, 217, 319
Tineids, 184

Tingitidae, 112, 135, 310
Tipulidae, 220, 242, 321
Tischeria malifoliella, 185
Tmetocera ocellana, 1S7
Toad-bugs, 308
Tobacco-worm, 209, 251
Tongue, 297
Tortoise-beetles, 157
Tortricidae, 186, 217, 319
Touch, 41

Toxoptera graminum, 129
Trachea, ^^
Transformations, 46
Tree-hoppers, 124, 135, 311
Trichodectidae, 307
Trichoptera, 93. 304 ; mounting of, 347
Trimera, 161, 171
Trochanter, 22
Trypetidae, 239, 242, 328
Tumble-bugs, i 50

372

ELEMENTARY ENTOMOLOGY

Tussock-moths, 203, 217, 318
Twelve-spotted Diabrotica, 156
Twice-stabbed ladybird, 162
Two-spotted ladybird, 162
Tympanum, 43
Typhlocyba comes,. 125
Typhoid fever, 2

Uranotes mellinus, 179

Vedalia cardinalis, 163

Veins, of wings, 24

Velidae, 309

Velvet ants, 261, 274, 321

Ventriculus, 31

Vermes, 6

Vertebrates, 5

Vespa, 266

Vespidae, 264, 320

Vespina, 261, 263, 274, 320

Vinegar flies, 327

Walking Orthoptera, 80
Walking-sticks, 80, 308
Warble, 2

Wasp-flies, 232, 242
Wasps, 243, 260, 274
Water-boatman, 135, 309

Water dip net, 333

Water-scavenger beetles, 141, 171, 31;

Water-scorpions, 135, 309

Water-striders, 135, 309

Weevils, 167

Western cricket, 85

Wheel-bug, 112 *

Whirligig-beetles, 140, 171,312

White ants, 103, 307; work of, 105

White grub, 151

White-marked tussock-moth, 204

White-pine weevil, 168

Window-flies, 323

Wing-covers, 281

Wings, 23, 281

Wire-worms, 146

Wood nymphs, 318

Woolly apple aphis, 129

Woolly bears, 207

Worms, 5

Xylocopa virginica, 270

Yellow fever, i
Vellow-necked caterpillar, 194

Zeuzera pyrina, 192
Zygoptera, 306

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