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[Illustration: The Toad may be rough and warty in appearance but worth
its weight in gold as a destroyer of insect pests. Note the expression
of satisfaction after a successful night of foraging for cutworms and
June-beetles.]
AN ELEMENTARY
STUDY OF
INSECTS
_By_
LEONARD HASEMAN
_Professor of Entomology in the University of Missouri_
Columbia, Missouri
MISSOURI BOOK COMPANY
1923
CONTENTS.
INTRODUCTION
CHAPTER I INSECTS:
(1) What they are.
(2) Their principal characteristics.
(3) Their methods of developing.
(4) The principal orders.
(5) Their habits.
(6) Their role in agriculture.
CHAPTER II COLLECTING INSECTS:
(1) Directions for collecting.
(2) Pinning and preserving a collection.
(3) Rearing and observing them while alive.
CHAPTER III THE GRASSHOPPER:
(1) Brief discussion of the grasshopper.
(2) Field studies.
(3) Breeding cage observations.
(4) Study of specimen.
CHAPTER IV THE HOUSE FLY OR TYPHOID FLY:
(1) Discussion of the life cycle of the fly, its habits, danger
from it and how it can be stamped out.
(2) Study of the fly and its work.
CHAPTER V THE MOSQUITO:
(1) Brief discussion of the life habits and stages of the mosquito.
(2) Observations and study.
CHAPTER VI THE CABBAGE MILLER:
(1) Brief discussion of the caterpillar, the chrysalis, the
butterfly, and its work.
(2) Observations and study.
(3) Breeding work.
CHAPTER VII THE APPLE WORM:
(1) Brief discussion of the different stages of the pest, its work
and remedies for its control.
(2) Observations and breeding work.
CHAPTER VIII THE TOMATO OR TOBACCO WORM:
(1) Brief discussion of stages, work and habits.
(2) Study and observation.
CHAPTER IX THE FIREFLY:
(1) Brief discussion of the insect.
(2) Observations and studies.
CHAPTER X THE WHITE GRUB OR JUNE-BUG:
(1) Discussion of the insect as a pest and its habits and stages.
(2) Observations and studies.
CHAPTER XI THE COLORADO POTATO BEETLE:
(1) Brief discussion of the pest.
(2) Observations and studies.
CHAPTER XII THE LADY-BEETLE:
(1) Brief discussion of habits and appearance of the lady-beetles,
and their value as friends.
(2) Observations and studies.
CHAPTER XIII THE DRAGON-FLY:
(1) Discussion of life and habits of insect.
(2) Observations and field studies.
CHAPTER XIV THE SQUASH BUG:
(1) Discussion of habits, injury and control of pest.
(2) Observations and field studies.
CHAPTER XV THE PLANT-LOUSE:
(1) Discussion of habits, injury and control of pest.
(2) Observations and field studies.
CHAPTER XVI THE HONEY BEE:
(1) Discussion of the honey bee as to habits in its home and
outdoors, its value to man and the colony as a village.
(2) Observations and studies.
CHAPTER XVII THE ANT:
(1) Discussion of ant life and behavior, the colony as a unit, its
work and remarkable instincts.
(2) Studies and observations.
INTRODUCTION
In the preparation of a book of this nature, to be used in the grade
schools, we realize that the one fundamental thing to keep in mind is
the economic importance of the insect, be it good or bad. The child
wants to know what is good and what is bad and how he can make use of
the good and how he can get rid of the bad. And yet there is something
more associated with the life, work and development of each tiny insect.
There is a story--a story of growth, not unlike that of the developing
child, a story of courage, strife and ultimate success or failure, which
is as interesting and of greater value to the child than many of the
stories of adventure and of historical facts. Snatches of these stories
will appear in the following chapters along with the studies on insects
and their economic importance.
In the development of our grade school system, especially in the rural
districts, there is a growing demand for some practical work along with
the regular cultural studies. To the child in the rural schools,
practical knowledge naturally tends toward agriculture. Many of these
boys and girls do not have a chance to pursue studies beyond the grades
and it therefore becomes necessary to introduce some elementary
agriculture into the grades to supply the natural craving of this vast
assemblage of children in the rural schools of our land.
In the search for a study which will give unlimited scope for
independent thought and observation and which will lead the child to
understand better the forces of nature that affect agriculture, nothing
is so readily available and attractive to the child as nature study, an
elementary study of the natural sciences. In fact agriculture is
primarily a course in nature study where we study how plants and animals
struggle for existence.
There is a period in the life of every child when he is especially
susceptible to the "call of the fields;" when he roams through woods or
by shady brooks gathering flowers, fishing for mud-cats and cleaning out
bumble-bees' nests. It is often compared with the life of the savage and
is merely the outward expression of an inward craving for a closer
relation with nature and her creatures. If one can reach a child while
at that age he has a ready listener and an apt pupil. That is the time
to guide and instruct the child along the line of nature study.
The most important questions confronting the average teacher in the
grade schools are: "What material shall I use and how shall I proceed to
direct the child along this line?" First of all use that material which
is most readily available, which is most familiar to the child and
which will attract and hold his attention. There is nothing so readily
available and so generally interesting to both boys and girls as are the
thousands of fluttering, buzzing, hopping and creeping forms of insects.
They are present everywhere, in all seasons and are known to every child
of the city or farm. They are easily observed in the field and can be
kept in confinement for study. Many of them are of the greatest
importance to man; a study of them becomes of special value.
In pursuing a study of nature and her creatures one should go into the
woods and fields as much as possible and study them where they are
found. In this way one can determine how they live together, what they
feed on and the various other questions which the inquisitive mind of a
healthy child will ask. When field work is not possible, gather the
insects and keep them alive in jars where they can be fed and observed.
Some forms cannot be kept in confinement and in such cases samples
should be killed and pinned, thereby forming a collection for study.
Most of the forms which are included in the following chapters can be
kept in confinement in glass jars or studies out doors. The studies have
been made so general that in case the particular form mentioned is not
available any closely related form can be used. Each child should make a
small collection of living and pinned insects for study and should be
encouraged to observe insects and their work in the field. The
collections and many of the observations could be made to good advantage
during the summer vacation when the insects are most abundant and
active.
Pupils should not be encouraged merely to make observations, but they
should be required to record them as well. Brief descriptions of the
appearance and development of insects, the injury they do, and remedies
for the same, will help fix in mind facts which otherwise might soon be
forgotten. Drawings, whenever possible, should also be required. The
pupil who can record observations accurately with drawings will not soon
forget them. The teacher should therefore require each pupil to provide
himself with a note-book for keeping brief, but accurate notes and
careful drawings. The drawings should be made with a hard lead pencil on
un-ruled paper, the size of the note-book, and the pupils should be
encouraged to be neat and accurate.
The author wishes to take this opportunity of expressing his deep
appreciation for the many helpful suggestions and other assistance which
Mr. R. H. Emberson, superintendent of Boys and Girls Club Work in
Missouri, has given. It was his life-long devotion to the boys and girls
of the grade schools and his keen appreciation of their needs that lead
him first to suggest to the author the importance of preparing this
little book for their use.
LEONARD HASEMAN
University of Missouri.
* * * * *
"_The study of entomology is one of the most fascinating of
pursuits. It takes its votaries into the treasure-houses of Nature,
and explains some of the wonderful series of links which form the
great chain of creation. It lays open before us another world, of
which we have been hitherto unconscious, and shows us that the
tiniest insect, so small perhaps that the unaided eye can scarcely
see it, has its work to do in the world, and does it._"
--REV. J. G. WOOD.
CHAPTER I
INSECTS
"_There is a difference between a grub and a butterfly; yet your
butterfly was a grub._"
--SHAKESPEARE.
In undertaking a study of insects it is well first of all to know
something about what they are, their general nature, appearance, habits
and development. The insects comprise the largest group of animals on
the globe. There are about four times as many different kinds of insects
as all other kinds of animals combined. Insects vary greatly in size.
Some are as large as small birds, while others are so small that a
thousand placed in one pile would not equal the size of a pea.
Insects are commonly spoken of as "bugs." This term, however, is
properly used only when referring to the one order of insects which
includes the sap and blood-sucking insects such as the chinch bug,
bed-bug, squash bug, and the like. Then too, there are many so-called
"bugs" which are not insects at all. Spiders, thousand-legs, crawfishes
and even earth-worms are often spoken of as bugs.
_What They Are_
[Illustration: Side view of grasshopper with wings and legs partly
removed. Note the division of the body into head, thorax, composed of
prothorax, mesothorax and metathorax, and abdomen consisting of
ring-like segments.]
Insects are variously formed, but as a rule the mature ones have three
and only three pairs of legs, one pair of feelers, one pair of large
eyes, and one or two pairs of wings. The body is divided into a head,
thorax and abdomen. The head bears the eyes, feelers and mouth, the
thorax bears the legs and wings, and the abdomen is made up of a number
of segments. The presence of wings at once decides whether or not it is
an insect, for, aside from bats and birds, insects alone have true
wings. These are the distinguishing characters of the full grown insect,
but, like birds, they hatch from eggs and while young do not always look
like their parents. When young they may take on various shapes as
caterpillars, borers, maggots, grubs, hoppers, and the like. Young
insects are often difficult to distinguish from true worms, centipedes,
snails, and such forms, but after one has collected and reared some of
the young and watched them pass through the different stages and emerge
with wings they are much more easily recognized.
_Their Principal Characteristics_
[Illustration: Face of grasshopper enlarged showing parts; ant.,
antenna; eye, compound eye; oc., ocellus or simple eye; cl., clypeus;
lbr., labrum or upper lip; mx. p., maxillary palpus; lb. p., labial
palpus; lab., labium or lower lip.]
Young insects as a rule are soft like caterpillars and maggots, while
the old ones usually have a hard body wall, similar to the beetles and
wasps. The wings are usually thin and transparent though in some cases
they are leathery or hard as in case of beetles or covered with scales
as in the butterflies. The three pairs of legs are jointed and used for
running, climbing, jumping, swimming, digging or grasping. The feelers
or antennae are usually threadlike, clubbed, or resemble a feather and
extend forward or sidewise from the head. The large eyes are compound,
being made up of many great small units which, when magnified, resemble
honey-comb. In some cases two or three small bead-like eyes may be
present besides the two large eyes. The mouth parts of insects may be
formed for chewing, as in the grasshopper, or for sucking up liquids, as
in the mosquito. The mouth of an insect is built on an entirely
different plan from our own. Chewing insects have an upper and lower lip
and between these there are two pairs of grinding jaws. These jaws are
hinged at the side of the face and when chewing they come together from
either side so as to meet in the middle of the mouth. They therefore
work sidewise rather than up and down. The mouth parts of the sucking
insects are drawn out to form a sucking tube or proboscis as in case of
the butterfly or mosquito.
[Illustration: Mouth parts of grasshopper shown in relative position;
lbr., labrum; md., mandibles; hyp., hypopharynx; max., maxillae; lab.,
labium.]
[Illustration: Leg of grasshopper showing segmentation. The basal
segment c, is the coxa, the next t, the trochanter, the large segment f,
the femur, the long slender one ti, the tibia, and the three jointed
tarsus ta, with claws at the tip.]
The internal organs of insects are similar to those of other animals.
The digestive tube consists of oesophagus, gizzard, or stomach, and
intestines. The nervous system is well developed as shown by the extreme
sensitiveness of insects to touch. The brain is comparatively small
except in the bees and ants. The circulatory system consists simply of a
long tube heart, the blood vessels being absent. In this way the
internal organs of the insect are simply bathed in the blood. The
system of respiration is most complicated. The air is taken in through
pores usually along the side of the body and is then carried through
fine tracheal tubes to all parts of the body. You cannot drown an insect
by putting its head under water, since it does not breathe through its
mouth. The muscular system is similar to that of other animals which
have the skeleton on the outside.
[Illustration: The internal organs of the honey bee. Note the strong
wing muscles in the thorax. The tube-like heart begins in the head and
extends back through the thorax and follows the curve of the abdomen.
Below the heart is the digestive tube consisting of the slender
oesophagus which extends back to the expanded honey stomach, in which
the bee carries the nectar it collects from flowers, then the curled
true stomach, the small intestine and expanded large intestine. Below
this is the nervous system consisting of the brain and a chain of
connected enlargements or ganglia extending back into the abdomen in the
lower part of the body. The respiratory system in part appears just
above the honey stomach, and the black circular or oval spots are cross
sections of connecting air tubes, which run all through the body. Also
note the sting with the poison gland and sack which are pulled out with
the sting; also the sucking tube for getting honey from flowers, and the
structures on the legs for gathering and carrying pollen; the pollen
basket is on the back side of the hind leg.]
_Their Methods of Developing_
In most cases the parent insect deposits small eggs which hatch later
into the young insects. In some cases, as with the blow-flies, the
maggot may hatch from the egg while yet in the parent's body, when the
active larva is born alive. Whether the egg hatches before or after it
is deposited, the young insect continues to develop in one of three
ways. It may resemble the parent and simply grow as does a kitten, or it
may look somewhat like its parent though smaller and without wings, as
the young grasshopper, or it may bear no resemblance whatever to the
parent, as the caterpillar which feeds and grows and finally spins a
cocoon in which it passes to the resting chrysalis stage and later
emerges with wings. The development of insects is therefore extremely
complicated.
[Illustration: The chinch bug showing development with incomplete
metamorphosis; a, egg; b, first nymph; c, second nymph; d, third nymph;
e, fourth nymph; f, adult winged bug; g, chinch bugs extracting sap from
corn plant. To control this pest burn over all winter harboring places
and use chemical or dust barriers following wheat harvest.]
_The Principal Orders_
In order to study a group of animals which includes so many thousand
different kinds it is necessary to divide them into a number of sharply
defined divisions or orders. All animal life is naturally grouped into
such divisions and subdivisions. Among the insects we at once detect
seven large, sharply defined divisions or orders, and ten or more
smaller ones. Of these we have first, the two-winged true flies; second,
the four-winged butterflies and moths; third, the hard-backed beetles;
fourth, the stinging four-winged wasps and bees; fifth, the variously
formed sucking insects or true bugs, as chinch bugs and bed-bugs; sixth,
the rapid-flying four-winged snake doctors or dragon-flies and, seventh,
the hopping forms, the grasshoppers. Besides these we have the various
smaller orders of water-loving insects, fleas, etc. The seven groups
mentioned above include the majority of our common forms and in the
studies to follow we will include only representatives from these
orders.
[Illustration: The Hessian fly showing development with complete
metamorphosis; a, egg; b, larva or maggot; c, flax-seed stage; d, pupa;
e, adult winged fly; f, wheat stubble with flax-seed stages near base
taken after harvest. To control this pest, plow under stubble after
harvest; keep down all volunteer wheat and sow wheat after fly-free date
in the fall.]
_Their Habits_
The habits of insects are as varied as their forms and adaptations. Some
live in the water all their life, others spend a part of their life
under water, others live the care-free life of the open air, others
enjoy feeding upon and living in the foulest of filth, others associate
themselves with certain definite crops or animals thereby doing untold
injury, while others produce food and other materials which are to be
used by man for his comfort. Every imaginable nook and crook, from the
depths of lakes to the tops of mountains, from the warm, sunny south to
the cold frigid north, from the foul damp swamps to the heart of our
desert lands, offers a home for some small insect.
The most striking habits and developments among insects is found in the
more highly advanced families of bees and ants where definite insect
societies are formed, resembling in many respects human societies and
human activities. Among these villages are established, homes built,
battles fought, slaves made, herds kept by shepherds, and even fields
cultivated. In these groups we have the nearest approach to human
intelligence.
_Their Role in Agriculture_
Some insects may be very destructive to crops, others are beneficial,
while the majority of insects are of no importance to man or
agriculture. The various forms of pests such as the chinch bug, potato
beetles, and others do an enormous amount of damage each year. They
destroy hundreds of millions of dollars worth of crops annually in the
United States alone. They devour enough to pay for the entire cost of
running the school system of our country and nearly enough to meet all
the expenses of our government. In view of these facts it is the duty of
each and every farmer, young or old, to acquaint himself with these
destructive pests and prepare himself for combating them. With a
knowledge of the methods of controlling these pests much of this
enormous loss can be prevented.
While some insects are extremely injurious, others are very helpful. The
products of the honey bee in the United States alone amount to several
million dollars a year, to say nothing of its value to the farmer in
pollinating fruits. The annual output of silk, all of which is spun by
the silkworm, is worth millions of dollars. Many other forms are of
value to man by producing material of commercial value such as lac,
shellack, dyes, medicines, etc. Of all the beneficial insects those
which are of greatest value to man are the parasites and similar forms
which help to keep in check many of the severest pests of the farm.
Insects are not all bad fellows by any means. One must acquaint himself
with those which are good and those which are bad before he can hope to
deal with them intelligently.
* * * * *
"_And with childlike credulous affection
We behold those tender wings expand,
Emblems of our own great resurrection,
Emblems of the bright and better land._"
--LONGFELLOW.