Chapter XI: Introduction: By L. H. Bailey (4)

To use the net in water, sweep the water plants as quickly as possible. In running streams, overturn stones, holding the net just below them with the mouth up stream. An old dipper made into a sieve by perforating the bottom with an awl is a good utensil for collecting water insects.

THE KILLING BOTTLE. FIG. 129.

It is desirable to kill the insects in a humane way, so that they will not suffer by the process; it is also desirable that they should not revive after they are pinned, both for their own sakes as well as for the sake of the feelings of the collector. The best way to secure painless and sure death for the insects is by the means of a "cyanide bottle."

_Materials needed for a killing bottle._

1. A bottle with a wide mouth; a morphine bottle or a small olive or pickle bottle will do. Even a glass fruit-can holding a pint will answer very well, although taking off and putting on the cover consumes more time than is desirable.

2. A cork that will fit the bottle tightly and is long enough to handle easily.

3. Two cents' worth of cyanide of potassium.

4. One cent's worth of plaster of Paris.

These latter materials may be procured from any drug store.

Place the lump of cyanide of potassium in the bottle and pour in enough water to cover it. Add immediately enough plaster of Paris to soak up all the water; leave the bottle open in a shady place for an hour and then wipe the dry plaster of Paris from its sides, put in the cork, and it is ready for use. The plaster of Paris forms a porous cement, which, while it holds the cyanide fast in the bottom, also allows the fumes of the poison to escape and fill the bottle. It should be labelled "poison," for cyanide of potassium is very poisonous. If kept corked when not in use, a killing bottle made like this will last a whole season.

The first rule in using the killing bottle is this: do not kill any more insects than you need for your collection. The second rule is: do not breathe the fumes of the bottle, for they smell badly and are not good for you. When you uncork the bottle to put an insect in it, hold it away from your face and cork it up again as quickly as possible.

Some insects may be caught from flowers, etc., directly into the bottle by holding it uncorked beneath them for a moment; the fumes of the poison soon overcome them and they drop into the bottle. In taking insects from the net, hold the bottle in the right hand and the cork in the left; insert the bottle into the net and place the mouth of it over an insect crawling on the inside of the net, then put the cork on the outside of the net into the mouth of the bottle, net and all, for a moment until the insect falls into the bottom of the bottle; then remove the cork and take the rest of the imprisoned insects in the same way. Insects should be left in the bottle at least an hour, and may be left in there over night without injury to the specimens.

INSECT PINS. FIG. 130.

After the insects are caught they should be pinned so that they may be arranged in the collection in an orderly manner. Common pins are not good for pinning insects; they are too thick and they corrode very soon, covering the specimens with verdigris. Regular insect pins are desirable as they are very slender and do not corrode so quickly. These may be obtained of any dealer in entomological supplies at a cost of fifteen cents per hundred.

Ask for the German insect pins Nos. 1, 3 and 5. If these pins are too expensive you can use the black steel mourning pins. These come in shallow boxes one by two inches square and have round glass heads and the boxes are labelled "Germany;" these may be procured from any dry goods store. However, insects pinned with any beside regular insect pins cannot be sold or exchanged.

All insects except beetles should be pinned through that part of the body just back of the head, as shown in Figs. 137, 139, 140, 141. Beetles should be pinned through the right wing-cover, as shown in Fig. 138. About one-fourth of the pin should project above the back of the insect. Very small insects may be gummed to a narrow strip of card board and the pin put through the card board.

LABELLING SPECIMENS.

Specimens should be labelled with the date of capture and the locality. Thus the butterfly, Fig. 141, would be labelled thus:

Ithaca, N. Y.
Aug. 12, 1896.

The paper on which this label is written should be slipped upon the pin with which the butterfly is pinned and placed just below the insect. Labels should be as small as possible and be neatly cut.

INSECT BOXES.

For the beginner nothing is more convenient than an empty cigar box, which may be obtained at any store where cigars are sold. (Fig. 131.) The bottom of the box should be covered with some soft, firm material into which pins may be pushed without bending them. There are many such materials. Sheet cork or pressed peat may be obtained of dealers in entomological supplies. Some ingenious boys use regular bottle corks, cut into cross sections about 1/4 inch thick. Others take the pith of dried corn-stalks divided in half lengthwise. The cheapest and most easily procurable of the purchasable materials is cork linoleum. This is for sale in most carpet stores. Get the quality that is about 1/4 inch thick, which costs about $1 per yard; put it into the box cork-side up. Any of these materials can be fastened to the bottom of the box with glue or with tacks. In all cases they should be covered neatly with white paper, for the insects appear better against a white background.

For permanent collections, wooden boxes with glass tops are much safer; and as the insects may be seen through the glass these boxes are more practical for school collections. This kind of a box is shown in Fig. 132. Its sides are 18 by 16 inches and its height is three inches outside measure. The upper edge of the sides of the bottom part of the box is made with a tongue which fits into a groove made in the lower edge of the sides of the cover. This is done so that the top and bottom parts of the box shall fit very closely together in order that museum pests cannot get in and destroy the specimens.

In Fig. 133 is a cross section through one side of the box, showing how it should be made and giving measurements. In the drawing the glass is fitted into a groove in the inner side of the cover. This glass might be puttied in like a window pane if it is found difficult to make the groove. The corners of the box may be mitred and dove-tailed, or mitred and nailed; the latter is more easily done. Any carpenter or cabinet maker can make this box. Great care must be taken to use only thoroughly seasoned wood in its construction; otherwise the bottom will be sure to warp and shrink and leave cracks through which the museum pests will enter.

The cost of such a box will vary from $0.75 to $1. Basswood should be used for its construction; pine is not at all suitable on account of the resin in it. Screw eyes may be put into these boxes and they may be hung on the walls of the schoolroom like pictures.

MUSEUM PESTS.

These are small beetles which find their way through the narrowest crevice into the insect boxes and lay their eggs on the pinned insects.

The larvæ when they hatch work within the specimens at first but after a time destroy the bodies entirely. The presence of these little rascals may be detected by dust on the bottom of the box just below the infested insect. As soon as this dust is observed, pour into one corner of the box a tablespoonful of carbon bisulfide, or benzine, and close the box quickly. The teacher or parent should put the substances into the boxes, as the first is a poison and both are very inflammable. As a method of preventing the beetles from attacking the collection it is well to fasten a "moth ball" into one corner of the box. These may be obtained at a drug store.

SPREADING-BOARD. FIG. 134.

Butterflies and moths look much better in a collection when their wings are extended at right angles to the length of the body. To arrange them thus we have to use what is termed a spreading-board.

_Materials needed for a medium sized spreading-board._

1. Two strips of pine or other soft wood 18 inches long, 1-1/2 inches wide and 1/2 inch thick.

2. One strip of wood 18 inches long, 3-1/4 inches wide and 1/2 inch thick.

3. Two cleats 3-1/4 inches wide, 3/4 inch high and 1/2 inch thick; and two cleats 1 inch wide and as high and thick as the others.

4. A strip of cork or linoleum 17 inches long and a little less than an inch wide.

To construct the spreading-board, take the two narrow strips of wood, place them one-fourth inch apart and on the under side fasten them across the ends of the longer cleats. Then on the same side as the cleats tack the piece of cork or linoleum over the space between the strips of board, and as the cleats are one-half inch wide the linoleum should cover all the space left. Then midway the boards fasten the two smaller cleats. Fig. 135 shows a cross-section of the spreading-board just in front of these two middle cleats. Now it is ready for the bottom board which will fit exactly if directions are followed, and this completes it. The space between the two upper boards is wide enough to take in the body of the moth or butterfly. The cork or linoleum below the space will hold firmly the pin on which the butterfly is impaled. The cleats hold the top and bottom boards apart and so protect the points of the pins. Spreading-boards may be made much smaller or much larger to suit moths of different sizes; the space between the top boards must always be large enough to admit the body of the insect.

To use the spreading-board: Insert the pin with the butterfly on it into the linoleum just far enough so that the body of the insect will be in the space between the boards up to the wings, Fig. 135. Place the wings out flat on the board and fasten them there with narrow strips of paper pinned across them, Fig. 134, _a_. While held down by these strips of paper arrange them so that the hind margins of the front wings shall cover the front margins of the hind wings and shall be in a line at right angles to the body; then pin larger pieces of paper over the rest of the wings, Fig. 134, _b_. Sometimes isinglass is used instead of paper to hold the wings down, Fig. 134, _c_. The insects should be left on the spreading-board at least three days; and when the board has insects on it, it should be kept in a box where the museum pests and mice cannot get at it.

Sometimes when the moths are not spread soon after being killed, they become so stiff that the wings cannot be moved without breaking them. In such cases the insects should be put on paper in a jar which has some wet sand in the bottom and which can be covered tightly. The air in such a can is so moist that in two or three days the insect will become limber and may be spread with ease.

WHERE TO COLLECT INSECTS.

The border of a piece of woods where many shrubs and weeds are growing is an especially good place for collecting many kinds of insects. Any place where there is a great variety of plants and flowers will give a variety of insects. Banks of streams and underneath stones in the fields are good places for collecting.

WHEN TO COLLECT INSECTS.

The best time of the year is during the summer months. The best time of day is in the forenoon after eight o'clock, and in the twilight at evening.

At night many moths may be caught by making a paste of sugar and water (unrefined sugar is best) and painting it upon tree trunks with a brush after sunset. The paste should cover a space two inches wide and several inches long. After dark seek these places cautiously with a lantern and moths will be found sucking the paste; these may be caught with the killing bottle if you move carefully so as not to frighten them; they do not seem to mind the light of the lantern.

Electric street-lights attract many insects which may be caught in the net. A lamp set in an open window is also a very good lure on warm nights in the spring and summer.

ARRANGING THE INSECTS IN BOXES.

After collecting insects comes the desire to arrange them properly, putting together in neat rows those that resemble each other. To classify insects correctly requires much study. The scope of this leaflet admits of only a few suggestions about the most common insects.

_Dragon Flies._--There are many kinds of these, but they all have four wings, finely netted and transparent, the hind wings being as large or larger than the front wings. These are perfectly harmless insects.

_Grasshoppers, Crickets and Katydids._--These are known to all, Fig. 136. There are two families of grasshoppers: those with long horns or antennæ and those with short antennæ. Katydids, crickets, cockroaches and walking-sticks are near relatives to the grasshoppers.

_Bugs._--These insects have the front pair of wings thick and heavy at the base and thin and transparent at the tips, Fig. 137, _b_. The squash-bug, the chinch-bug, and the electric-light bug are examples of these. Some bugs have the front wings entirely thin and transparent and sloping like a steep roof over the back of the insect, like the cicada, Fig. 137, _a_; and the Brownie bug, Fig. 137, _c_, _d_.

_Beetles._--These have hard wing-covers which meet in a straight line down the back and have a pair of thin wings folded under them, Fig. 138. The "June bug" or "May beetle" and the potato beetle are good examples of beetles.

_Flies._--These have only two wings, usually transparent. Behind each of these wings a short thread with a knob on it extends out on each side of the body instead of hind wings, Fig. 139. House-flies, horse-flies and mosquitoes are examples of flies.

_Bees, Wasps and Ants._--Bees, wasps and the winged form of ants have four transparent wings, Fig. 140. Some flies resemble bees and wasps, but if examined it will be found that they have only two wings instead of four.

_Butterflies and Moths._--Butterflies and moths may be told apart by the following character: The antennæ or horns of the butterflies are always threadlike and knobbed at the tip, Figs. 141, 142, while the antennæ of moths are in various shapes, but never bear knobs at the tips, Figs. 143, 144, 145, 146.

DEALERS IN ENTOMOLOGICAL SUPPLIES.

The following is a list of the dealers in entomological supplies that have advertisements in the current American entomological journals:

A. Smith & Sons, 269 Pearl Street, New York, N. Y.

John Akhurst, 78 Ashland Place, Brooklyn, N. Y.

M. Abbott Frazar, 93 Sudbury Street, Boston, Mass.

Entomological Society of Ontario, Victoria Hall, London, Ont.

Queen & Co., 1010 Chestnut Street, Philadelphia, Pa.

The Bausch & Lomb Optical Company, 515-543 N. St. Paul Street, Rochester, N. Y.

LEAFLET XIX.

SOME TENT-MAKERS.[24]

BY ANNA BOTSFORD COMSTOCK.

[24] Teachers' Leaflet No. 5, June, 1897.

It is unfortunate that there is, throughout the country, a prevailing dislike for the small creatures called "worms." This dislike is, in most instances, the result of wrong training, and is by no means a natural instinct. As evidence of this, witness the joy with which the small boy or even the small girl, handles "bait" when preparing to go fishing; although of all common "worms" surely the angle-worm is least attractive from any point of view. A still more striking example is the hardihood with which young fishermen catch the dobson to use as a lure for bass--for the dobson is not only very ugly in appearance but is also vicious, often pinching severely the careless fingers of its captors. Thus the dislike for insects being the result of the point of view, it should be the first duty of the teacher to remove this repulsion. In the lesson which follows there is no occasion for teacher or pupils to touch the insects unless they choose to do so; but an attempt is made to arouse an interest in the habits and ways of insect life. If we can succeed in arousing the child's interest in the actions of a caterpillar, he will soon forget his dislike for the "little brothers" which live upon foliage and which experience miraculous changes of form during their short lives.

In selecting the Apple-tree Tent Caterpillar for this lesson we have been guided by the following facts: First, it is to be found in early spring; second, its life-history from egg to cocoon is accomplished within the limits of the spring term of our schools; third, it is common everywhere; fourth, it is an important insect from an economic point of view, and the children may be taught how to keep it out of the orchards, thus making the lesson of practical use.

In this lesson the teacher is encouraged to use her own methods and originate new ones to make the work interesting. The Leaflet is meant for the exclusive use of the teacher and the text should not be shown to the pupils. The pictures on page 235 are to be shown to the pupils at the teacher's discretion. When answers are herein given to the questions asked, they are meant to aid the teacher in drawing out the correct replies from the children.

MATERIALS NEEDED.

1. A pocket lens or a tripod lens is desirable, but not a necessity. These lenses may be bought from or ordered through any jeweler or bookseller. They cost from twenty-five cents to one dollar each. It is worth while for any teacher to possess one of these magnifiers as a means of interesting her pupils in many things.

2. A bottle, a broad-bottomed one being preferable so that it will not tip over easily. This bottle is to be filled with water in which a small branch of the apple tree may be placed to keep it fresh. A common ink bottle will do to begin with. Fig. 147.

3. A wooden or pasteboard box, twelve or fourteen inches square,--a soap box or hat box will do. In place of a cover, nail or paste mosquito netting or cheese cloth over the top; remove the bottom so that the box may be placed over the bottle and the branch of apple in it. This is called a "breeding-cage," and its use is to keep the insects from straying about the schoolroom.

4. A twig bearing the egg-mass of the tent caterpillar. These are easily found before the leaves appear on the apple tree or the wild cherry tree.

METHODS OF USING THE LEAFLET.

The teacher should give the pupils a preliminary talk on tents. Speak of the tents used by Indians, by armies, by circuses, by campers, and describe them each in turn. The teacher should use all the facts at her disposal, and all her ingenuity to get the children interested in this subject. Spend a little time for two or three days in discussing tents, and get the pupils to tell orally or in essays all they know about tents. When sufficient interest is thus aroused, tell them this: "The reason we have talked about tents is that we are going to study some little folks who make tents and live in them. Their tents are not made of bark like the Indian's or of canvas like the soldier's, but are made of the finest silk, which is spun and woven by the tenters themselves. These silken tents are not pitched upon the ground and fastened down by ropes and pegs, for these folk, like the Swiss Family Robinson, live in trees. Many people live in one of these tree tents, and they are all brothers and sisters. Now, just where these tents are made, and how they are made, and what sort of little people make them are things which we shall find out if we watch carefully and patiently."

LESSON I.--THE EGGS. FIG. 149, _a_.

The teacher, having found the egg-mass, should show it to the pupils and let them, during play hours, collect some for themselves. Say that they are eggs, but explain no further. Get the children to examine the egg-masses; ask the following questions:

On what part of the trees are these egg-masses found?

What is the shape of the egg-mass? (Bring out the fact that they look like a portion of the twig swollen or budded.)

What is the color of the egg-mass?

Is there much difference in color between the egg-mass and the branch?

Has this similarity in color any use? (Develop the idea that the shape and the color of the egg-mass make it resemble the twig so closely as to hide it from birds or any animal that would be likely to eat the eggs.)

Does the egg-mass shine?

Why does it shine? _Answer._ Because there is a coat of varnish around the eggs.

Why was varnish put around the eggs? (Get the answer by asking why varnish is put on wood. Varnish is put around the eggs to preserve them and to keep them dry during the rains and snows of autumn and winter.)

If the eggs are near the hatching period the varnish will have scaled off, revealing the tiny white eggs; if not, let the teacher remove the varnish with a knife or pin, thus exposing the eggs. If the teacher has a lens the children should view the eggs through it. Exhibit the picture Fig. 149, b, which represents the eggs greatly enlarged showing the net-work of cement which holds them in place. Ask the children to compare the shape of these eggs with that of bird's eggs, and bring out the fact that these are thimble-shaped. Then ask the pupils to guess what sort of mother laid these eggs, cemented them fast with a network, and then covered them with a coat of waterproof varnish. After sufficient interest is aroused on this point, explain to them: "One day last July a little moth or miller was flitting about the tree from which these twigs were taken. If we could have been there and caught her we should have found her a pretty little creature with four wings covered with down and a soft fuzzy body. In color she was a pale rosy-brown, and had two bands of pale yellow across each front wing." (Call attention to the picture of the moth, Fig. 149, e.[25])

[25] If a specimen of the moth could be obtained, it would be much more interesting to the children than the picture. The teacher can collect or breed the moths in July to use the next spring to illustrate the lesson.

"This is the little mother which laid her eggs in a ring around the twig and covered them with a waterproof coat to keep them safe and sound until this spring, when they will hatch."

What will come out of these eggs when they hatch? The teacher should not answer this question, but let the pupils watch the eggs and discover the answer for themselves.

Place the twig with the egg-mass upon it in the bottle of water (Fig. 147). It will be best if this twig is a part of a forked branch, so that the caterpillars may make their web upon it (Fig. 148). As soon as the eggs hatch ask the following questions:

What sort of young ones hatch out of the eggs?

Are they like their mother?

What color are they?

Why are their heads so large? _Answer._ So that they can gnaw the lid off the egg and thus get out.

Why should the young ones of a pretty moth be little black caterpillars?

(Leave this answer for future investigation.)

After the caterpillars hatch it will be necessary to bring in each day fresh apple twigs with buds and leaves on them so as to feed the little prisoners. It is very desirable that they be kept alive until they have begun their web and have molted at least twice. If they show a disposition to wander off, put the breeding cage over the bottle and branch and so keep them confined with their food.

To supplement the study of the imprisoned caterpillars, study should be made at the same time of the insects out of doors and under natural conditions. If none appear upon an apple or wild cherry tree near the school-house, the teacher should transfer a colony to such a tree (Fig. 148). This may be done by fastening a twig with an egg-mass upon it to a branch of the tree. If too late to get the unhatched eggs, get a nest with the small worms in it and tie that to the convenient branch instead. This study of the insects out of doors is very necessary in discovering their normal habits.

LESSON II. THE CATERPILLARS. FIG. 149, _c_.

If the eggs hatch before the leaves appear, upon what do the caterpillars feed?

How long is it after hatching before the caterpillars commence to make their tent?

Where is the tent always formed?

_Answer._ In the fork of the branches.

Why is this so?

_Answer._ The forking branches offer a convenient support upon which to stretch the tent: and when, as in the case out of doors, the tent is spread in a fork of the larger limbs, these limbs afford two branching roads for the caterpillars to follow in searching for food.

Let the pupils make drawings of the tent as soon as it is large enough to be seen well.

What is the color of the caterpillars when they are a week old?

Upon what do they feed?

At what time of day do they feed?

When on a tree, how far from their tent do they go for food?

Are the paths over which the caterpillars travel when searching for food marked in any way?

_Answer._ This caterpillar spins a silken thread wherever it goes and therefore leaves a trail of silk behind it.

Of what is the tent made?

Compare the tent with a spider's web and note the differences.

Where does the silk come from, of which the tent is made?

_Answer._ The silk glands of the caterpillar are situated near the mouth, while those of the spider are on the rear end of the body.

LESSON III. HOW THE INSECTS GROW.

The caterpillars shed their skins about five times. The first molt occurs about three days after they hatch; the second molt about four days later; and the third molt about six days after the second. After each molt, the color and markings of the caterpillars are somewhat changed. During some of the molts the pupils should watch a caterpillar change his skin. After the class has seen this operation the teacher may give the following lesson:

Where is your skeleton?

What is it made of?

What is it for? Bring out the fact that the skeleton is a support for the muscles and organs of the body.

Where is an insect's skeleton? Get as many answers to this question as possible, then explain:

The insect's skeleton is on the outside of its body instead of a skin, and the flesh and muscles are supported by it on the inside instead of on the outside like our own. As this skeleton is hard it cannot stretch; as the insect grows and gets too large the shell bursts open and the insect walks out of it. Now underneath this old hard skeleton a new one is formed, which is soft and flexible at first, and so stretches to accommodate the growing insect. After a little time this new skeleton also hardens and has to be shed when it is too small to suit its owner.

Notes should be made by the pupil upon the change of color and markings after the different molts, and the process of molting should be described.

LESSON IV. THE PUPA. FIG. 149, _d_.

In ordinary seasons, about the middle of May, the caterpillars get their growth. If those in the breeding cage have died or have not thrived, bring in a few full-grown caterpillars from the orchard and put them on some branches in the breeding cage. Give them fresh food each day as long as they will eat; also place some sticks and chips on the bottom of the breeding cage for the worms to "spin up" on. Then have the children observe the following things:

How do the caterpillars begin their cocoons?

Where are the cocoons made?

How are they made?

Draw a picture of a cocoon.

About a week after a cocoon is made, open it carefully with a pair of scissors so as not to hurt the inmate, and let the pupil see the change that has come over the caterpillar.

Have the pupils describe the pupa.

Let the pupils make drawings of the pupa.

The moths will hardly emerge from the cocoons until after the close of the school term. The children should be encouraged to gather the cocoons from the fences around the orchards and from the sticks and the branches on the ground and to carry them home. The cocoons may be placed in pasteboard boxes and kept until the moths emerge, about the middle of July.

LESSON V. DESTROYING THE CATERPILLARS.

After the caterpillars are fully grown and all the processes of growth have been observed by the pupils, the teacher should give a lesson upon the injury which they do to trees and the necessity of keeping the orchards free from these pests. This lesson should be given guardedly so as not to encourage the children to cruelty in killing insects. The teacher should always try to inculcate in the child reverence for life, that wonderful force, which we can so easily take from a creature but which we can never give back. It is better to appeal to the child's sense of justice in giving this lesson. The teacher may vary it to suit her own ideas, but in substance it might be given somewhat as follows:

"All life is sacred; the smallest worm has as good a right to live in the sight of God as you or any child has. Life should never be taken except when necessary. However, no one has the right to interfere with the rights of another. Neither the child nor the worm has any right to trespass upon the property of any one else."

"Let us see whether these caterpillars are trespassers or not. The farmer works hard to earn the money to buy the land upon which the orchard is planted; he works hard to earn the money with which to buy the young trees; he works hard to set out the trees and cultivate the orchard; therefore the orchard and the fruit of it are his property, and he has a right to drive away all thieves. If men or children steal the fruit, he has a right to appeal to the law and have them fined or imprisoned. If worms come and injure the tree by eating up the foliage, he has a right to keep them out if he can. The leaves are necessary to the tree, for if they are destroyed the tree cannot get the air it needs to keep it vigorous and enable it to mature its fruit. We have seen that these caterpillars destroy the leaves, and thus do great injury to the apple crop. We therefore have a right to destroy these little robbers, as that is the only way we can keep them out of our orchards."

How can the caterpillars be destroyed?

The egg-masses can be collected in winter and early spring from young orchards, and burned.

Tie bits of suet or fresh fat pork to the branches of the trees and thus induce chickadees, nuthatches, and woodpeckers to visit the orchard in winter. These birds will destroy eggs and cocoons of the tent caterpillar, and of other insect pests also.

In large, old trees, we must wait until later. Ask the pupils the following questions:

At what times did we find the worms in their tents? _Answer._ Early morning; late afternoons; and during cold, dark days.

If we should destroy the tents in the middle of a warm, sunny day, what would happen? _Answer._ The caterpillars, being out feeding on the leaves, would not be hurt, and as soon as they came back would make another tent.

If the tent is destroyed in the early morning or late afternoon or on a cold, dark day, what would happen? _Answer._ The caterpillars, all being in the tent, would be destroyed.

How may the tents be destroyed? _Answer._ By wiping them out with a long pole on one end of which is wound a rag saturated with kerosene. Or by burning them out with a torch.

Is it best to destroy the caterpillars early in the season, while they are still small, or to wait until they are large and are about ready to pupate.

If the trees were sprayed with Paris green in the early spring, what would happen? _Answer._ The caterpillars would be killed as soon as they began to eat, when they were first hatched.

When these caterpillars feed on the leaves of wild cherry they are doing no damage to an orchard. Therefore, when the tents appear on wild cherry trees have we any right to destroy them? _Answer._ The wise and careful farmer does not allow wild cherry trees to grow along his fences if they will become breeding places for insect enemies which will next year attack his orchards.

LEAFLET XX.

MOSQUITOES.[26]

BY MARY ROGERS MILLER.

"Nature-Study is learning those things in nature that are best
worth knowing, to the end of doing those things that make life
most worth living."

--PROFESSOR HODGE in _Nature-Study and Life_.

[26] Home Nature-Study Course, Vol. IV, No. 23, May, 1902.

Spite of all the efforts of scientists and nature-students to popularize the mosquito, its reputation as a public nuisance is as well sustained as ever, and it seems destined to remain as unpopular as were its ancestors. There is no doubt that these creatures "abound" and that "they are great annoyances to both man and animals," as Dr. Howard tells us in "The Insect Book;" but he has laid a new and even more deadly sin at their door in stating, as he does in no uncertain terms, that "they are active agents in the transfer of disease."

There seems to be no escape from the attention of these persistent "imps o' evil." Though we travel to far Alaska or to icy Greenland we cannot be free. Since we are doomed to existence in the same world with the mosquito it behooves us to discover, if possible, some way to turn the creature to account for our entertainment or instruction. Forget for the moment that you despise mosquitoes, and let us study their ways. By making its life history the subject of some of our lessons we may at least learn how the mosquito lives and develops; and later we can turn this knowledge to practical account. Since for many generations these creatures have made the human race the subject of insistent study, it is no more than fair that the tables should be turned!

You are not good nature-students until you have recognized and overcome your prejudices. You read the life history of the rabbit and you think you hate its enemies. You watch a family of foxes with their cunning ways, and the mother's care for her young and you cannot help sympathizing with them in their struggle for existence. Every creature in its turn becomes interesting to you when you find yourself wondering about how it makes its home, rears its young, and gets its food. As you get nearer to nature you will cease to feel any pride in the fact that you "hate" snakes, mosquitoes, and all such "varmints." Indeed that hatred, born of ignorance, will have given place to sympathy and interest. You have a new point of view.

One of the first questions asked of the returning animals in early spring is, "How have you spent the winter?" The bluebird and the robin show no signs of weariness after their long flight from the South. The "woolly bear" caterpillars look just as they did in October. The early butterflies are a trifle worn and shabby after their hibernation. But who has thought to inquire where and how the mosquito has spent the cold season? "Who cares," one may say, "so long as they don't stay around where we are as they did last summer?"

Suppose we make it our business from now on to care about such things, and to inquire into the ways our plant and animal neighbors have of living and of getting a living. Are you quite sure that the mosquitoes have not spent their winter under your protection? If in April you had had occasion to frequent either garret or cellar there you might have found them. By dozens and scores they were waiting for the return of warm weather to free them. Many of them winter not as eggs, larvæ, or pupæ, but as winged adults, as _mosquitoes_. This rather interferes with the prevalent notion that mosquitoes live but for a day. Would that this were true, and might that day be short!

THE LIFE HISTORY OF THE MOSQUITO.

The life history of a mosquito is in four chapters, some of which are exceedingly short, others long. The length of each may be varied by the weather and the season. Moisture and warmth are particularly advantageous to the rapid development of these creatures. Ten days in hot weather may be sufficient time for the growth of a generation of them, from egg to adult. There are many generations in a year.

The larvæ of mosquitoes are aquatic. They live in stagnant water everywhere, in ponds, swamps, ditches, puddles, rain-water barrels, and horse-troughs. In early spring the female mosquito that has wintered in your garret will probably go to the nearest rain-water barrel or water-tank. She finds her way by instinct, before the sun is up. When you go to replenish your pitcher you will find a little flat cluster of eggs like a tiny raft floating on the surface (Fig. 151). It is dark-colored and the chances are you will not see it unless it gets into your pitcher. By two o'clock in the afternoon there may be from two to four hundred lively little wigglers in the water. Possibly they will wait until the following day. They all hatched from the eggs of one mosquito. They hitch and twitch about in the water, coming often to the surface and hanging there for a moment (Fig. 152). You call them "wigglers." But did you ever wonder why they wiggle, why they come so often to the surface, and why they thrust up the little tube which projects from near the end of the body? Did you ever ask what they find to eat in the water, and how they eat it?

The larval stage lasts about ten days in hot summer weather, but longer when the days are cool. Then comes a change in form into the pupa (Fig. 153). The creature is still active and aquatic, though no food is taken. It does not stay long away from the surface while in this stage. Finally, after two or more days as a pupa, the full-grown mosquito emerges and takes wing, leaving its pupa case floating on the top of the water like a forlorn little derelict.

ENEMIES OF THE MOSQUITO.

Besides man, the mosquito has many natural enemies. In the water especially they fall easy victims to the thousand-and-one insect ogres. The nymphs of dragon-flies are especially fond of wigglers, and there has been much said and written about raising dragon-flies as a safeguard against mosquitoes. Most of the predaceous insects which live in still water feed on young mosquitoes, while the adults often fall prey to their more swiftly flying insect neighbors.

HOW TO STUDY THE MOSQUITO.

Over and around the tumbler place a piece of close-woven mosquito netting to confine the adult insects. A glass tumbler two-thirds full of rain-water, a little cluster of eggs, or a half dozen wigglers, a keen observer, and you have a nature-study opportunity not to be surpassed in the finest laboratory. If you have already seen a part of the life history, do not be satisfied until you have completed your chain of observations. Get the eggs; watch the hatching, the molting, the transformations. See every stage. Learn something new every time you look at the wiggler or the mature mosquito. It is not at all necessary that you let these insects escape into the school-room and cause trouble.

Those who wish more minute description, with many illustrations of mosquitoes of different kinds, should obtain from the Division of Publications, Department of Agriculture, the published results of Dr. L. O. Howard's studies of mosquitoes. In this pamphlet, from which the drawings in this lesson are copied, the subject of the transfer of disease germs by mosquitoes is very thoroughly discussed, with pictures which distinguish between the common mosquito and those which transfer malaria and other diseases.

Those scientists who had to do with the naming of the many species of mosquitoes had certainly a sense of humor. One would think they named the creatures according to the mildness or malignity of their bite. A few of the names are as follows:

Culex excitans
Culex pungens
Culex irritans
Culex stimulans
Culex perturbans
Culex excrucians

THE CRUSADE AGAINST MOSQUITOES.

BY M. V. SLINGERLAND.

There is now a world-wide crusade against mosquitoes, extending from the wilds of Africa through the noted malarial districts of Italy to America. In America a National Mosquito Extermination Society has been formed. This extensive crusade is due to the practical demonstration that some kinds of mosquitoes may transmit malaria, yellow fever and probably other diseases of human beings.

All mosquitoes must have water in which to develop, and the warfare against them consists largely in destroying their watery breeding grounds. This is being done on a large scale, either by draining or by filling in marshes, pools, and similar places which often swarm with the "wigglers." Large areas of such mosquito-breeding waste lands in New Jersey and on Long Island are thus being reclaimed and the mosquito nuisance largely abated.

Aquaria, rain barrels, tanks, small ponds and similar places can be kept free from the "wigglers" by introducing small fish, as gold fish or silver fish, sunfish, "killies," roaches or minnows. An interesting and instructive object lesson could be given by putting a few minnows from a near-by brook into the school aquarium or into a specially prepared glass dish well stocked with the "wigglers."

One can easily prevent mosquitoes from breeding in rain barrels or tanks by covering them with mosquito netting.

Another practicable and successful method is to pour or sprinkle kerosene oil every two or three weeks in a thin film over the surface of cesspools, rain barrels, tanks, ponds or any other body of sluggish water where the "wigglers" are found. This oil film kills the "wigglers" (both larvæ and pupæ) by preventing them from getting to the surface to breathe, and it also prevents the mother mosquito from laying her eggs on the water. There are patent preparations or oils which penetrate all through the water, killing the "wigglers" but spoiling the water for general use, so that such oils are usually applied only to infested cesspools, sewer basins, or manure pits.

By a little concerted effort of local officials, individuals, or by the school children in applying whichever of the above methods is most practicable, much interesting and valuable work could be accomplished and the pestiferous mosquito largely eliminated in many localities.

LEAFLET XXI.

THE WAYS OF THE ANT.[27]

BY ANNA BOTSFORD COMSTOCK.

[27] Home Nature-Study Course, Vol. V, No. 1. October, 1903.

For many years ants have been recognized as among the most interesting of the little animals that people our fields. However, not until recently have we begun to understand, even in a small measure, their economic importance and the part they play in maintaining the balance in insect life. Therefore, we shall give a few studies of ants and their ways, and as a knowledge of their habits is necessary to begin with, we will take up the ant-nest first.

AN ANT-NEST.

Two panes of glass laid flat one on the other with a space between of one-eighth of an inch or less, these panes covered with a piece of dark paper or wood to keep out the light and then placed on something that will allow them to be surrounded by water; a bit of blotting paper two inches square, dampened and placed at one end of the glass chamber--these are all the materials and the art necessary for the construction of a perfectly equipped ant-nest.

Once we wished to make an ant-nest hurriedly, and this is the way we did it: we chose an agate wash basin (Fig. 154), as this would not rust, and filled it half-full of water; in this we made an island, by placing in it a three-pint agate basin turned bottom side up. We took two discarded negatives, size 4x5 inches, and cleaned off the films; then we placed one of the pieces of glass on the basin-island, took the stumps of four burnt matches and placed one on each side of this glass near its edge; then we placed the other piece of glass on top, letting it rest on the matches to make a chamber just high enough for the ants to live in comfortably. This done, we took the cover of a cigar-box and cut it down to the size of the negatives, put a screw-eye in the center to lift it by and placed it on top of the upper glass to make the chamber below quite dark. Then we took a trowel and fruit-can and went after some inhabitants for our island. We went to an open pasture and turned over stones until we found beneath one a heap of yellowish grain-like pupæ and little translucent whitish bodies, which we knew were larvæ, all being cared for by swarms of worker-ants. One of us pushed the trowel beneath, taking up dirt and all, while the other held the can open, into which the trowel was emptied. We hastened back and as gently as possible, taking care to hurt none of our little captives, placed the contents of the can on the top of the nest.

As the first thought of an ant is never for its own safety, but for the safety of its infant sisters, the little workers began to hunt for a safe and dark place in which to stow away their charges. In running about they soon discovered the space between the two pieces of glass and in a few hours the young ones were moved into the new quarters. Then we cleaned away the earth on top of the nest, and by lifting the cover we were able to see all that was going on within. The water in the wash-basin prevented any of our uneasy captives from escaping, as these little people, so clever in most things, have never yet mastered the art of swimming.

I have an ant-nest on my table as I write, shown in Fig. 156. Instead of matches to keep the two pieces of glass apart I have a narrow strip of canton flannel glued around the edge of the glass floor except for two little doors at the opposite corners; there is also a narrow strip of cloth partitioning the chamber into two rooms with a door at one end. One room I left empty and in the other I placed a bit of blotting paper which I keep damp by occasionally adding a few drops of water. The nest is placed upon a piece of plank 18 inches square. Around the plank near the edge is a groove about an inch deep made with a chisel and kept full of water, so that my ants have a castle with a moat. It was necessary to paint this bit of plank thoroughly, above and below, to keep it from warping.

The ants in my nest I found on a hillside beneath a stone; they are brownish with yellow legs and a little less than a quarter of an inch in length. They were stupid at first and would not discover the chamber prepared for them, but persisted in hiding their young under bits of earth which were brought in with them. So I made a scoop of a sheet of writing paper and with it placed a heap of the young, with a few of the nurses, in the empty chamber, then put on the glass ceiling and cover and left them. In a few hours the whole colony had moved into this chamber, but evidently it was not humid enough for the health of the young, and by the next morning the pupæ and larvæ and eggs were all in the other chamber arranged around the edges of the blotting paper.

What I have seen of interest in this nest on my table would fill a small volume, if written out in detail. Just now a worker approached a pupa, that appears through the lens like a little bag of meal tied at one end with a black string; she examined it carefully with her antennæ and concluded it needed to be moved, and, though it is as large as she, picked it up in her jaws and carried it to a position which she regarded as more favorable. Then she approached a larva which looks like a little crook-neck squash, inquired as to its needs with her antennæ and then cleaned it with her tongue, as a cat licks a kitten, and fed it. Her next duty was to pick up a whole bunch of little white oblong eggs and scurry off with them to get them out of the light. Then she stopped to help another worker to straighten out the soft legs and antennæ of a pale, new sister that was just emerging from the pupa skin. By the time I had seen as much as this I felt it my duty to replace the cover, as the light greatly disturbs the little captives. It is said that if a yellow glass be used for the upper piece, the ants feel that they are in darkness, and their actions may be watched constantly without disturbing them.

For a permanent nest, it is necessary to secure a queen, which lays all the eggs for the colony. She may be recognized by her larger size and may sometimes be found in a nest under the stones. However, it is so difficult to obtain a queen that I more often bring in the young and the workers; the latter will be content as long as they have the babies to feed and bring up; when finally this is accomplished, I usually take my colony back to its nest in the field, where it is made most welcome. This may seem sentimental, but after you have watched these little people working so hard and taking such devoted care of their baby sisters and doing so many wise things in their home, you will be loth to let the tiny creatures die of discouragement because they have nothing else to do, and you will be still more loth to let them loose to scatter, bewildered and helpless, over a strange earth. However, I have to be very careful and mark the nest to which they belong, for if I should put them near another colony, my poor captives would soon die inglorious deaths.

Food which we provide for the ants in captivity should be varied and should be put on the island, rather than in the nest as we may thus be able to better clean away the refuse. Crackers or bread soaked in sweetened water, sponge cake, berry-jam, sugar, bits of raw meat, yolks of hard boiled eggs crushed, freshly killed insects or earth-worms, all may prove acceptable to our little friends. Their food may be soft but should not be in a fluid state.

QUESTIONS ABOUT ANTS.