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قراءة كتاب An Elementary Study of Insects

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An Elementary Study of Insects

An Elementary Study of Insects

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دار النشر: Project Gutenberg
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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

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

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.
Mouth parts of grasshopper shown in relative position; lbr., labrum; md., mandibles; hyp., hypopharynx; max., maxillae; lab., labium.

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

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