A Guide for the Study of Animals. Worrallo Whitney
upon a plant. Why are plant lice a very serious pest?
6 If any plant lice have ants associated with them, study the behavior of the ants in this curious relationship. What advantages result from this relationship of ant and aphis to either or both insects?
Scale Bugs
Materials.
Twigs of trees, leaves, fruit, ferns, etc., infested with these bugs. If possible, have samples of San José scales, maple scales, and oyster scales.
Observations.
1 What is the general size and appearance of the various scale bugs in your collection? How do they differ in form and size and color?
2 Remove a scale and study it carefully with a lens. What is under the scale? Of what is the scale composed? What do you discover about these bugs to indicate that they are really insects?
3 What can be said about the number of scale bugs? Why are they difficult to exterminate? How can they be distributed from one place to another, as from orchard to orchard, since only the males have wings?
Drawings suggested.
1 A single aphis as seen with hand lens.
2 Various scale bugs as seen with a hand lens.
3 Twigs showing the distribution and numbers of scale bugs.
WATER BUGS AND BEETLES
Water Bugs
Materials.
Water bugs and beetles of several species in small aquaria covered with a wire net.
Observations.
1 With what legs does the bug swim? Describe their appearance and tell how used and how fitted for this use. Which legs are not used in swimming?
2 Remove the bug from the water for a moment to test other methods of locomotion, as jumping, crawling, flying. What do you discover?
3 Watch the bug as it gets a fresh supply of air, and describe the process. Where is the air stored for use when under water? Does the bug sink or rise when it stops swimming? Why?
4 Identify the bug's mouth parts. What is their appearance and probable manner of use? How are the forelegs fitted for grasping food?
5 What is the shape of the body? What is the position of the wings? Do the two cover (fore) wings meet in a straight line or do they cross at their tips? Are they smooth throughout and sheath-like, or are they thick at the base and thin at the tips?
Summary.
Summarize your study of the bug by enumerating the various ways the bug is adapted for life in the water.
Water Beetles
Use the same questions for the study of water beetles as for water bugs. In addition answer the following:—
1 Identify the eyes of the whirligig beetle and note their peculiar construction. How can you explain this peculiar form of the eyes on the basis of use? Why are the antennæ of both water bugs and beetles so small?
Suggested drawings.
1 The dorsal view of both bug and beetle.
2 Ventral view of the bug's head to show the beak and first pair of legs.
GETTING ACQUAINTED WITH THE LIBRARY
Directions.
The books in a zoölogical library may be roughly divided into three groups:—
1 Reference books.Advanced textbooks.Elementary textbooks.Natural histories.Books for classifying or naming animals.
2 Descriptive books.Life histories and habits of animals. Adventures with animals—popular accounts of animals seen on walks and travels.
3 Economic zoölogy.Books on harmful animals and methods of destroying them.Books on useful nondomesticated animals and their products.Books on domestic animals.Books of a general nature not included in the above.
Examine as many of the books in your library as you can and record for each one in your notebook:—
1 Title of the book; author's name; publisher; date of publication.
2 The kind of book as classified above.
3 What it includes or what animals or topics are covered by the book.
4 Whether the style is popular or technical, i.e. whether it is easy for you to read.
5 The general character of its illustrations and whether they appear to be especially helpful.
6 Comments on the value or interest of the book as it appears to you.
7 Select a book which interests you, for future reading.
CHAPTER II
STUDIES OF INSECTS
The effect of great numbers upon the structure and habits of animals. The use of keys in finding the names of animals.
1. FIELD STUDIES
Materials.
1. Boxes for carrying insects. 2. A net. This may be homemade, using mosquito netting or fish net and a stout wire. If it is to be used for a dragnet for water insects, the wire must be stout and the netting strong. Make the net twice as long as wide. 3. A cyanide jar for killing insects. 4. A few paper triangles for carrying butterflies. 5. A notebook.
Note.—Your instructor will give directions for obtaining the material called for in 3, 4, and 5.
Directions.
Look carefully and quietly in the various situations noted below. Do not be in a hurry. Weedy meadows or vacant lots and neglected roadsides are good places for your first trips. Note concerning each insect found: (a) its name or something by which to identify it, (b) where you found it, (c) what it was doing, (d) its probable food. Record these observations in your notebook. Make a special study of such insects as your instructor may designate.
Where to look for Various Insects
Grasshoppers, locusts, katydids.Look along roadsides, waste places, gardens, especially weedy ones, weedy lots, and grassy meadows and pastures.Crickets.Under old boards, along the edges of board or stone walks, along fences.Beetles.Same locations as for crickets, and also on flowering plants, under loose bark of trees and stumps, in rotten logs, etc. For water beetles drag edges of ponds and streams.Dragon flies.Along water-courses, ponds, and swamps. Drag ponds and ditches for larvæ.Bees.On flowering plants, especially on large patches of wild asters, golden-rods, and thistles.Wasps.Sandy stretches—especially along the water—among flowering plants, under the eaves and roofs of outbuildings. Nests may be found in these latter places.Butterflies and moths.In fields where there are many flowering plants; look carefully on the leaves of plants for caterpillars, and for eggs. Also look very carefully on the under side of leaves, on twigs, and on the bark of trees for chrysalids of butterflies and cocoons of moths.Bugs.In same locations as for bees and grasshoppers and water beetles. Also