The weevil is commonly found among seeds

The weevil is commonly found among seeds

The weevil is commonly found among seeds

The Weevil. The weevil is commonly found among seeds. Its attacks are serious, but the insect may easily be destroyed.

Treatment. Put the infected seeds in an air-tight box or bin, placing on the top of the pile a dish containing carbon disulphide, a tablespoonful to a bushel of seeds. The fumes of this substance are heavy and will pass through the mass of seeds below and kill all the weevils and other animals there. The bin should be closely covered with canvas or heavy cloth to prevent the fumes from being carried away by the air. Let the seeds remain thus from two to five days. Repeat the treatment if any weevils are found alive. Fumigate when the temperature is 70° Fahrenheit or above. In cold weather or in a loose bin the treatment is not successful. Caution: Do not approach the bin with a light, since the fumes of the chemical used are highly inflammable.

Fig. 169. The Hessian Fly

The flea-beetle inflicts much damage on the potato

The flea-beetle inflicts much damage on the potato

The flea-beetle inflicts much damage on the potato

The Flea-Beetle. The flea-beetle inflicts much damage on the potato, tomato, eggplant, and other garden plants. The accompanying figure shows the common striped flea-beetle which lives on the tomato. The larva of this beetle lives inside of the leaves, mining its way through the leaf in a real tunnel. Any substance disagreeable to the beetle, such as plaster, soot, ashes, or tobacco, will repel its attacks on the garden crops.

About the only practicable remedy is to pick these insects by hand

About the only practicable remedy is to pick these insects by hand

About the only practicable remedy is to pick these insects by hand

Treatment. About the only practicable remedy is to pick these insects by hand. We can, however, protect our young plants by small nettings and thus tide them over the most dangerous period of their lives. These bugs greatly prefer the squash as food. You can therefore diminish their attack on your melons, cucumbers, etc. by planting among the melons an occasional squash plant as a "trap plant." Hand picking will be easier on a few trap plants than over the whole field. A small board or large leaf laid beside the young plant often furnishes night shelter for the bugs. The bugs collected under the board may easily be killed every morning.

Fig. 168. Flea-Beetle and Larva
a, larva; b, adult.
Lines on sides show
real length of insects

The squash bug does its greatest damage to young plants

The squash bug does its greatest damage to young plants

The squash bug does its greatest damage to young plants

The Squash Bug. The squash bug does its greatest damage to young plants. To such its attack is often fatal. On larger plants single leaves may die. This insect is a serious enemy to a crop and is particularly difficult to get rid of, since it belongs to the class of sucking insects, not to the biting insects. For this reason poisons are useless.

Poisons therefore do not avail

Poisons therefore do not avail

Poisons therefore do not avail

Treatment. These are sucking insects. Poisons therefore do not avail. They may be killed by spraying with kerosene emulsion or a strong soap solution or with tobacco water. Lice on cabbages are easily killed by a mixture of one pound of lye soap in four gallons of warm water.

Fig. 167. A Squash Bug

This is really a method of milking

This is really a method of milking

This is really a method of milking

The plant louse gives off a sweetish fluid of which some ants are very fond. You may often see the ants stroking these lice to induce them to give off a freer flow of the "honey dew." This is really a method of milking. However friendly and useful these "cows" may be to the ant, they are enemies to man in destroying so many of his plants.

Fig. 166. A Cheap Spraying Outfit

But it multiplies with very great rapidity

But it multiplies with very great rapidity

But it multiplies with very great rapidity

The Plant Louse. The plant louse is very small, but it multiplies with very great rapidity. During the summer the young are born alive, and it is only toward fall that eggs are laid. The individuals that hatch from eggs are generally wingless females, and their young, born alive, are both winged and wingless. The winged forms fly to other plants and start new colonies. Plant lice mature in from eight to fourteen days.

But we can diminish it somewhat by good clean agriculture

But we can diminish it somewhat by good clean agriculture

But we can diminish it somewhat by good clean agriculture

Treatment. Unfortunately we cannot prevent all of the damage done by chinch bugs, but we can diminish it somewhat by good clean agriculture. Destroy the winter homes of the insect by burning dry grass, leaves, and rubbish in fields and fence rows. Although the insect has wings, it seldom or never uses them, usually traveling on foot; therefore a deep furrow around the field to be protected will hinder or stop the progress of an invasion. The bugs fall into the bottom of the furrow, and may there be killed by dragging a log up and down the furrow. Write to the Division of Entomology, Washington, for bulletins on the chinch bug. Other methods of prevention are to be found in these bulletins.

Fig. 165. A Plant Louse Colony

Birds aid in the destruction of this pest

Birds aid in the destruction of this pest

Birds aid in the destruction of this pest

Treatment. Birds aid in the destruction of this pest. Paris green mixed with air-slaked lime will also kill many larvæ. After the cabbage has headed, it is very difficult to destroy the worm, but pyrethrum insect powder used freely is helpful.

The Chinch Bug. The chinch bug, attacking as it does such important crops as wheat, corn, and grasses, is a well-known pest. It probably causes more money loss than any other garden or field enemy. In Orange county, North Carolina, farmers were once obliged to suspend wheat-growing for two years on account of the chinch bug. In one year in the state of Illinois this bug caused a loss of four million dollars.

Fig. 164. Cabbage Worms and Butterflies

Garden And Field Insects

Garden And Field Insects

THE TROUBLESOME CHINCH BUG (ENLARGED)
1, bugs on plant; 2, eggs; 3, young bug; 4 and 5, older bugs;
6, long-winged bug; 7 and 8, short-winged bug

The Cabbage Worm. The cabbage worm of the early spring garden is a familiar object, but you may not know that the innocent-looking little white butterflies hovering about the cabbage patch are laying eggs which are soon to hatch and make the dreaded cabbage worms. In Fig. 164 a and b show the common cabbage butterfly, c shows several examples of the caterpillar, and d shows the pupa case. In the pupa stage the insects pass the winter among the remains of old plants or in near-by fences or in weeds or bushes. Cleaning up and burning all trash will destroy many pupæ and thus prevent many cabbage worms. In Fig. 164 e and f show the moth and zebra caterpillar; g represents a moth which is the parent of the small green worm shown at h. This worm is a common foe of the cabbage plant.

Fig. 163. The Dreaded
Chinch Bug

Watch the curculio lay her eggs in the plums

Watch the curculio lay her eggs in the plums

Watch the curculio lay her eggs in the plums

Watch the curculio lay her eggs in the plums, peaches, or cherries. What per cent of fruit is thus injured? Estimate the damage. Let the school offer a prize for the greatest number of tent-caterpillar eggs. Watch such trees as the apple, the wild and the cultivated cherry, the oak, and many others.

Make a collection of insects injurious to orchard fruits, showing in each case the whole life history of the insect, that is, eggs, larva, pupa, and the mature insects.

EXERCISE

EXERCISE

EXERCISE

EXERCISE

How many apples per hundred do you find injured by the codling moth? Collect some cocoons from a pear or an apple tree in winter, place in a breeding-cage, and watch for the moths that come out. Do you ever see the woodpecker hunting for these same cocoons? Can you find cocoons that have been emptied by this bird? Estimate how many he considers a day's ration. How many apples does he thus save?

Fig. 162. Peach-Tree Borers, Male and Female
Female with broad yellow band across abdomen

If there are only a few trees in the orchard

If there are only a few trees in the orchard

If there are only a few trees in the orchard

Treatment. If there are only a few trees in the orchard, digging the worms out with a knife is the best way of destroying them. You can know of the borer's presence by the exuding gum often seen on the tree-trunk. If you pile earth around the roots early in the spring and remove it in the late fall, the winter freezing and thawing will kill many of the larvæ.

161 you see the effect of the peach-tree borer s activity

161 you see the effect of the peach-tree borer s activity

161 you see the effect of the peach-tree borer s activity

The Peach-Tree Borer. In Fig. 161 you see the effect of the peach-tree borer's activity. These borers often girdle and thereby kill a tree. Fig. 162 shows the adult state of the insect. The eggs are laid on peach or plum trees near the ground. As soon as the larva emerges, it bores into the bark and remains there for months, passing through the pupa stage before it comes out to lay eggs for another generation.

Fig. 161. Borer Signs around Base of Peach Tree

The twig girdler lays her eggs in the twigs of pear

The twig girdler lays her eggs in the twigs of pear

The twig girdler lays her eggs in the twigs of pear

The Twig Girdler. The twig girdler lays her eggs in the twigs of pear, pecan, apple, and other trees. It is necessary that the larvæ develop in dead wood. This the mother provides by girdling the twig so deeply that it will die and fall to the ground.

Treatment. Since the larvæ spend the winter in the dead twigs, burn these twigs in autumn or early spring and thus destroy the pest.

There are three principal methods

There are three principal methods

There are three principal methods

Treatment. There are three principal methods, (1) Destroy the eggs. The egg masses are readily seen in winter and may easily be collected and burned by boys. The chickadee eats great quantities of these eggs. (2) With torches burn the nests at dusk when all the worms are within. You must be very careful in burning or you will harm the young branches with their tender bark. (3) Encourage the residence of birds. Urge your neighbors to make war on the larvæ, too, since the pest spreads rapidly from farm to farm. Regularly sprayed orchards are rarely troubled by this pest.

Encourage the chickadee and all other birds

Encourage the chickadee and all other birds

Encourage the chickadee and all other birds

Encourage the chickadee and all other birds, except the English sparrow, to stay in your orchard. This is easily done by feeding and protecting them in their times of need.

The Apple-Tree Tent Caterpillar. The apple-tree tent caterpillar is a larva so well known that you only need to be told how to guard against it. The mother of this caterpillar is a reddish moth. This insect passes the winter in the egg state securely fastened on the twigs as shown in Fig. 159, a.

Printer s ink will do very well

Printer s ink will do very well

Printer s ink will do very well

Treatment. The inability of the female to fly gives us an easy way to prevent the larval offspring from getting to the foliage of our trees, for we know that the only highway open to her or her larvæ leads up the trunk. We must obstruct this highway so that no crawling creature may pass. This is readily done by smoothing the bark and fitting close to it a band of paper, and making sure that it is tight enough to prevent anything from crawling underneath. Then smear over the paper something so sticky that any moth or larva that attempts to pass will be entangled. Printer's ink will do very well, or you can buy either dendrolene or tanglefoot.

Fig. 159. Apple-Tree Tent Caterpillar
a, eggs; b, cocoon; c, caterpillar

Fig. 160. The Twig
Girdler at its
Destructive Work
a, the girdler;
b, the egg-hole;
c, the groove cut by girdler;
e, the egg

Nearly all the common birds feed freely upon the cankerworm

Nearly all the common birds feed freely upon the cankerworm

Nearly all the common birds feed freely upon the cankerworm

Nearly all the common birds feed freely upon the cankerworm, and benefit the orchard in so doing. The chickadee is perhaps the most useful. A recent writer is very positive that each chickadee will devour on an average thirty female cankerworm moths a day; and that if the average number of eggs laid by each female is one hundred and eighty-five, one chickadee would thus destroy in one day five thousand five hundred and fifty eggs, and, in the twenty-five days in which the cankerworm moths crawl up the tree, would rid the orchard of one hundred and thirty-eight thousand seven hundred and fifty. These birds also eat immense numbers of cankerworm eggs before they hatch into worms.

In early summer the larvæ burrow within the earth and pupate there

In early summer the larvæ burrow within the earth and pupate there

In early summer the larvæ burrow within the earth and pupate there

In early summer the larvæ burrow within the earth and pupate there; later they emerge as adults (Fig. 157, d and e). You observe the peculiar difference between the wingless female, d, and the winged male, e. It is the habit of this wingless female to crawl up the trunk of some near-by tree in order to deposit her eggs upon the twigs. These eggs (shown at a and b) hatch into the greedy larvæ that do so much damage to our orchards.

The cankerworm is the larva of a moth

The cankerworm is the larva of a moth

The cankerworm is the larva of a moth

The Cankerworm. The cankerworm is the larva of a moth. Because of its peculiar mode of crawling, by looping its body, it is often called the looping worm or measuring worm (Fig. 157, c). These worms are such greedy eaters that in a short time they can so cut the leaves of an orchard as to give it a scorched appearance. Such an attack practically destroys the crop and does lasting injury to the tree. The worms are green or brown and are striped lengthwise. If the tree is jarred, the worm has a peculiar habit of dropping toward the ground on a silken thread of its own making (Fig. 156).

Fig. 157. The Spring Cankerworm
a, egg mass; b, egg, magnified;
c, larva; d, female moth; e, male moth

Fig. 158. Eggs of the
Fall Cankerworm

The Clinton grape is most liable to injury from this pest

The Clinton grape is most liable to injury from this pest

The Clinton grape is most liable to injury from this pest

Treatment. The Clinton grape is most liable to injury from this pest. Hence it is better to grow other more resistant kinds. Sometimes the lice attack the roots of the grape vines. In many sections where irrigation is practiced the grape rows are flooded when the lice are thickest. The water drowns the lice and does no harm to the vines.

Fowls in the orchard do good by capturing

Fowls in the orchard do good by capturing

Fowls in the orchard do good by capturing

Fowls in the orchard do good by capturing the larvæ before they can burrow, while hogs will destroy the fallen fruit before the larvæ can escape.

The Grape Phylloxera. The grape phylloxera is a serious pest. You have no doubt seen its galls upon the grape leaf. These galls are caused by a small louse, the phylloxera. Each gall contains a female, which soon fills the gall with eggs. These hatch into more females, which emerge and form new galls, and so the phylloxera spreads (see Fig. 155).

Burn orchard trash which may serve as winter quarters

Burn orchard trash which may serve as winter quarters

Burn orchard trash which may serve as winter quarters

Treatment. Burn orchard trash which may serve as winter quarters. Spraying with arsenate of lead, using two pounds of the mixture to fifty gallons of water, is the only successful treatment for the curculio. For plums and peaches, spray first when the fruit is free from the calyx caps, or dried flower-buds. Repeat the spraying two weeks later. For late peaches spray a third time two weeks after the second spraying. This poisonous spray will kill the beetles while they are feeding or cutting holes in which to lay their eggs.

Fig. 156. The Cankerworm

Sometimes called the plum weevil

Sometimes called the plum weevil

Sometimes called the plum weevil

The Plum Curculio. The plum curculio, sometimes called the plum weevil, is a little creature about one fifth of an inch long. In spite of its small size the curculio does, if neglected, great damage to our fruit crop. It injures peaches, plums, and cherries by stinging the fruit as soon as it is formed. The word "stinging" when applied to insects—- and this case is no exception—means piercing the object with the egg-layer (ovipositor) and depositing the egg. Some insects occasionally use the ovipositor merely for defense. The curculio has an especially interesting method of laying her egg. First she digs a hole, in which she places the egg and pushes it well down. Then with her snout she makes a crescent-shaped cut in the skin of the plum, around the egg. This mark is shown in Fig. 154. As this peculiar cut is followed by a flow of gum, you will always be able to recognize the work of the curculio. Having finished with one plum, this industrious worker makes her way to other plums until her eggs are all laid. The maggotlike larva soon hatches, burrows through the fruit, and causes it to drop before ripening. The larva then enters the ground to a depth of several inches. There it becomes a pupa, and later, as a mature beetle, emerges and winters in cracks and crevices.

Thus one spraying serves against both fungi and insects

Thus one spraying serves against both fungi and insects

Thus one spraying serves against both fungi and insects

It is best to use lime-sulphur mixture or the Bordeaux mixture with arsenate of lead for a spray. Thus one spraying serves against both fungi and insects.

Fig. 154. Plum Curculio
Larva, pupa, adult, and mark on the fruit.
(Enlarged)

Fig. 155. Leaf Galls of
Phylloxera On Clinton
Grape Leaf

Destroy orchard trash which may serve as a winter home

Destroy orchard trash which may serve as a winter home

Destroy orchard trash which may serve as a winter home

Treatment. Destroy orchard trash which may serve as a winter home. Scrape all loose bark from the tree. Spray the tree with arsenate of lead as soon as the flowers fall. A former method of fighting this pest was as follows: bands of burlap four inches wide tied around the tree furnished a hiding-place for larvæ that came from windfalls or crawled from wormy apples on the tree. The larvæ caught under the bands were killed every five or six days. We know now, however, that a thorough spraying just after the blossoms fall kills the worms and renders the bands unnecessary. Furthermore, spraying prevents wormy apples, while banding does not. Follow the first spraying by a second two weeks later.

There are several ways of making the lime-sulphur mixture

There are several ways of making the lime-sulphur mixture

There are several ways of making the lime-sulphur mixture

There are several ways of making the lime-sulphur mixture. It is generally best to buy a prepared mixture from some trustworthy dealer. If you find the scale on your trees, write to your state experiment station for directions for combating it.

The Codling Moth. The codling moth attacks the apple and often causes a loss of from twenty-five to seventy-five per cent of the crop. In the state of New York this insect is causing an annual loss of about three million dollars. The effect it has on the fruit is most clearly seen in Fig. 152. The moth lays its egg upon the young leaves just after the falling of the blossom. She flies on from apple to apple, depositing an egg each time until from fifty to seventy-five eggs are deposited. The larva, or "worm," soon hatches and eats its way into the apple. Many affected apples ripen too soon and drop as "windfalls." Others remain on the tree and become the common wormy apples so familiar to growers. The larva that emerges from the windfalls moves generally to a tree, crawls up the trunk, and spins its cocoon under a ridge in the bark. From the cocoon the moth comes ready to start a new generation. The last generation of the larvæ spends the winter in the cocoon.

Fig. 153. Spraying the Orchard brings Luscious Fruit
The picture in the corner at the top shows the right time to spray for codling moth

Orchard Insects

Orchard Insects

The San Jose Scale. The San Jose scale is one of the most dreaded enemies of fruit trees. It is in fact an outlaw in many states. It is an unlawful act to sell fruit trees affected by it. Fig. 150 shows a view of a branch nearly covered with this pest. Although this scale is a very minute animal, yet so rapidly does it multiply that it is very dangerous to the tree. Never allow new trees to be brought into your orchard until you feel certain that they are free from the San Jose scale. If, however, it should in any way gain access to your orchard, you can prevent its spreading by thorough spraying with what is known as the lime-sulphur mixture. This mixture has long been used on the Pacific coast as a remedy for various scale insects. When it was first tried in other parts of the United States the results were not satisfactory and its use was abandoned. However, later experiments with it have proved that the mixture is thoroughly effective in killing this scale and that it is perfectly harmless to the trees. Until the lime-sulphur mixture proved to be successful the San Jose scale was a most dreaded nursery and orchard foe. It was even thought necessary to destroy infected trees. The lime-sulphur mixture and some other sulphur washes not only kill the San Jose scale but are also useful in reducing fungous injury.

Fig. 150. San Jose Scale

Fig. 151. Single San Jose Scale Magnified

Fig. 152. The Codling Moth

a, burrow of worm in apple; b, place where worm enters;
c, place where worm leaves; e, the larva;
d, the pupa; i, the cocoon; f and g, moths;
h, magnified head of larva

EXERCISE

EXERCISE

EXERCISE

EXERCISE

Collect cocoons and pupæ of insects and hatch them in a breeding-cage similar to the one illustrated in Fig. 149. Make several cages of this kind. Collect larvæ of several kinds; supply them with food from plants upon which you found them. Find out the time it takes them to change into another stage. Write a description of this process.

The plant louse could produce in its twelfth brood 10,000,000,000,000,000,000,000 offspring. Each louse is about one tenth of an inch long. If all should live and be arranged in single file, how many miles long would such a procession be?

Fig. 148. Plant Lice

Fig. 149. Cage in which to breed Insects Flower-pot, lamp-chimney, and cloth

The number of insects which are hurtful to crops

The number of insects which are hurtful to crops

The number of insects which are hurtful to crops

The number of insects which are hurtful to crops, gardens, flowers, and forests seems to be increasing each season. Therefore farm boys and girls should learn to recognize these harmful insects and to know how they live and how they may be destroyed. Those who know the forms and habits of these enemies of plants and trees are far better prepared to fight them than are those who strike in the dark. Moreover such knowledge is always a source of interest and pleasure. If you begin to study insects, you will soon find your love for the study growing.

Insects lay many eggs and reproduce with remarkable rapidity

Insects lay many eggs and reproduce with remarkable rapidity

Insects lay many eggs and reproduce with remarkable rapidity

Insects lay many eggs and reproduce with remarkable rapidity. Their number therefore makes them a foe to be much dreaded. The queen honeybee often lays as many as 4000 eggs in twenty-four hours. A single house fly lays between 100 and 150 eggs in one day. The mosquito lays eggs in quantities of from 200 to 400. The white ant often lays 80,000 in a day, and so continues for two years, probably laying no less than 40,000,000 eggs. In one summer the bluebottle fly could have 500,000,000 descendants if they all lived. The plant louse, at the end of the fifth brood, has laid in a single year enough eggs to produce 300,000,000 young. Of course every one knows that, owing to enemies and diseases (for the insects have enemies which prey on them just as they prey on plants) comparatively few of the insects hatched from these eggs live till they are grown.

Do not completely change their form

Do not completely change their form

Do not completely change their form

Some insects, the grasshopper for example, do not completely change their form. Fig. 147 represents some young grasshoppers, which very closely resemble their parents.

Fig. 143. Butterfly

Fig. 144. Structure of the Caterpillar

Fig. 145. Moth Pupa in Cocoon

Fig. 146. A Butterfly Pupa
Note outline of the butterfly

Fig. 147. The Growth of a Grasshopper

It is generally the larvæ that do the most harm

It is generally the larvæ that do the most harm

It is generally the larvæ that do the most harm

From this you can see that it is especially important to know all you can about the life of injurious insects, since it is often easier to kill these pests at one stage of their life than at another. Often it is better to aim at destroying the seemingly harmless beetle or butterfly than to try to destroy the larvæ that hatch from its eggs, although, as you must remember, it is generally the larvæ that do the most harm. Larvæ grow very rapidly; therefore the food supply must be great to meet the needs of the insect.

Fig. 142. Moth and Cocoon

The egg hatches into a worm-like animal known as a grub

The egg hatches into a worm-like animal known as a grub

The egg hatches into a worm-like animal known as a grub

Many insects change their form from youth to old age so much that you can scarcely recognize them as the same creatures. First comes the egg. The egg hatches into a worm-like animal known as a grub, maggot, or caterpillar, or, as scientists call it, a larva. This creature feeds and grows until finally it settles down and spins a home of silk, called a cocoon (Fig. 145). If we open the cocoon we shall find that the animal is now covered with a hard outside skeleton, that it cannot move freely, and that it cannot eat at all. The animal in this state is known as the pupa (Figs. 145 and 146). Sometimes, however, the pupa is not covered by a cocoon, sometimes it is soft, and sometimes it has some power of motion (Fig. 141). After a rest in the pupa stage the animal comes out a mature insect (Figs. 142 and 143).

It is important to know how insects take their food

It is important to know how insects take their food

It is important to know how insects take their food

It is important to know how insects take their food, for by knowing this we are often able to destroy insect pests. Some are provided with mouth parts for chewing their food; others have a long tube with which they pierce plants or animals and, like the mosquito, suck their food from the inside. Insects of this latter class cannot of course be harmed by poison on the surface of the leaves on which they feed.

Fig. 141. Beetle
a, larva;
b, pupa;
c, adult;
d, burrow

The chief classes of insects are as follows

The chief classes of insects are as follows

The chief classes of insects are as follows

The chief classes of insects are as follows: the flies, with two wings only; the bees, wasps, and ants, with four delicate wings; the beetles, with four wings—two hard, horny ones covering the two more delicate ones. When the beetle is at rest its two hard wings meet in a straight line down the back. This peculiarity distinguishes it from the true bug, which has four wings. The two outer wings are partly horny, and in folding lap over each other. Butterflies and moths are much alike in appearance but differ in habit. The butterfly works by day and the moth by night. Note the knob on the end of the butterfly's feeler (Fig. 143). The moth has no such knob.

Fig. 140. A Typical Bug
a, adult;
b, side view of sucking
mouth-part Both a and b
are much enlarged

Therefore these do not belong to the true insects

Therefore these do not belong to the true insects

Therefore these do not belong to the true insects

An examination of spiders, mites, and ticks shows eight legs; therefore these do not belong to the true insects, nor do the thousand-legged worms and their relatives.

Fig. 139. The House Fly
a, egg;
b, larva, or maggot;
c, pupa;
(All enlarged)

Fig. 139a. The House Fly
adult male. (Enlarged)

The eyes of insects are especially noticeable

The eyes of insects are especially noticeable

The eyes of insects are especially noticeable

The eyes of insects are especially noticeable. Close examination shows them to be made up of a thousand or more simple eyes. Such an eye is called a compound eye. An enlarged view of one of these is shown in Fig. 138.

Attached to the thorax are the legs and also the wings, if the insect has wings. The rear portion is the abdomen, and this, like the other parts, is composed of parts known as segments. The insect breathes through openings in the abdomen and thorax called spiracles (see Fig. 137).

Every one thinks he knows what an insect is

Every one thinks he knows what an insect is

Every one thinks he knows what an insect is

Every one thinks he knows what an insect is. If, however, we are willing in this matter to make our notion agree with that of the people who have studied insects most and know them best, we must include among the true insects only such air-breathing animals as have six legs, no more, and have the body divided into three parts—head, thorax, and abdomen. These parts are clearly shown in Fig. 136, which represents the ant, a true insect. All insects do not show the divisions of the body so clearly as this figure shows them, but on careful examination you can usually make them out. The head bears one pair of feelers, and these in many insects serve also as organs of smell and sometimes of hearing. Less prominent feelers are to be found in the region of the mouth. These serve as organs of taste.

Fig. 137. Parts of an Insect

Fig. 138. Compound Eye
Of Dragon Fly

Insects in General

Insects in General

Fig. 136. Ants

The farmer who has fought "bugs" on crop after crop needs no argument to convince him that insects are serious enemies to agriculture. Yet even he may be surprised to learn that the damage done by them, as estimated by good authority, amounts to millions and millions of dollars yearly in the United States and Canada.

Often attacks the unripe fruit on the tree

Often attacks the unripe fruit on the tree

Often attacks the unripe fruit on the tree

Fruit Mold. Fruit mold, or brown rot, often attacks the unripe fruit on the tree, and turns it soft and brown and finally fuzzy with a coat of mildew. Fig. 133 shows some peaches thus attacked. Often the fruits do not fall from the trees but shrivel up and become "mummies" (Fig. 134). This rot is one of the most serious diseases of plums and peaches. It probably diminishes the value of the peach harvest from 50 to 75 per cent. Spraying according to the directions in the Appendix will kill the disease.

Fig. 135. Half of Tree sprayed to prevent Peach Curl

Note The Difference in Foliage And Fruit on The Sprayed And Unsprayed Halves of The Tree, And The Difference in Yield Shown Below

Peach leaf curl does damage amounting to about $3

Peach leaf curl does damage amounting to about $3

Peach leaf curl does damage amounting to about $3

Peach Leaf Curl. Peach leaf curl does damage amounting to about $3,000,000 yearly in the United States. It can be almost entirely prevented by spraying the tree with Bordeaux mixture or lime-sulphur wash before the buds open in the spring. It is not safe to use strong Bordeaux mixture on peach trees when they are in leaf.

Cotton Wilt. Cotton wilt when it once establishes itself in the soil completely destroys the crop. The fungus remains in the soil, and no amount of spraying will kill it. The only known remedy is to cultivate a resistant variety of cotton or to rotate the crop.

Club root is a disease of the cabbage

Club root is a disease of the cabbage

Club root is a disease of the cabbage

Club Root. Club root is a disease of the cabbage, turnip, cauliflower, etc. Its general effect is shown in the illustration (Fig. 131). Sometimes this disease does great damage. It can be prevented by using from eighty to ninety bushels of lime to an acre.

Black Knot. Black knot is a serious disease of the plum and of the cherry tree. It attacks the branches of the tree; it is well illustrated in Fig. 132. Since it is a contagious disease, great care should be exercised to destroy all diseased branches of either wild or cultivated plums or cherries. In many states its destruction is enforced by law. All black knot should be cut out and burned some time before February of each year. This will cost little and save much.

Fig. 132. Black Knot

Fig. 133. Moldy Peaches

Fig. 134. Peach Mummies

Watch the potatoes at the next harvest

Watch the potatoes at the next harvest

EXERCISE

EXERCISE

Watch the potatoes at the next harvest and estimate the number that is damaged by scab. You will remember that formalin is the substance used to prevent grain smuts. Write to your state experiment station for a bulletin telling how to use formalin, as well as for information regarding other potato diseases. Give the treatment a fair trial in a portion of your field this year and watch carefully for results. Make an estimate of the cost of treatment and of the profits. How does the scab injure the value of the potato? The late blight can often be recognized by its odor. Did you ever smell it as you passed an affected field?

Fig. 131. Club Root

Spraying is the remedy for potato blight

Spraying is the remedy for potato blight

Spraying is the remedy for potato blight

Spraying is the remedy for potato blight. Fig. 128 shows the effect of spraying upon the yield. In this case the sprayed field yielded three hundred and twenty-four bushels an acre, while the unsprayed yielded only one hundred bushels to an acre. Fig. 127 shows the result of three applications of the spraying mixture on the diseased field. Figs. 129 and 130 show how the spraying is done.

Fig. 129. Spraying Machine

Fig. 130. Spraying Machine

The blight is another serious disease of the potato

The blight is another serious disease of the potato

The blight is another serious disease of the potato

Late Potato Blight. The blight is another serious disease of the potato. This is quite a different disease from the scab and so requires different treatment. The blight is caused by another fungus, which attacks the foliage of the potato plant. When the blight seriously attacks a crop, it generally destroys the crop completely. In the year 1845 a potato famine extending over all the United States and Europe was caused by this disease.

Fig. 128. Yield from Two Fields of the Same Size
The one at the top was sprayed; the one at the bottom was unsprayed

Or enough for thirty gallons of water

Or enough for thirty gallons of water

Or enough for thirty gallons of water

One pint of formalin, or enough for thirty gallons of water, will cost but thirty-five cents. Since this solution can be used repeatedly, it will do for many bushels of seed potatoes.

Fig. 127. Effect of Spraying
Sprayed potatoes on left; unsprayed on right

123 shows a very scabby potato

123 shows a very scabby potato

123 shows a very scabby potato

Potato Scab. The scab of the white, or Irish, potato is one of the commonest and at the same time most easily prevented of plant diseases. Yet this disease diminishes the profits of the potato-grower very materially. Fig. 123 shows a very scabby potato, while Fig. 124 represents a healthy one. This scab is caused by a fungous growth on the surface of the potato. Of course it lessens the selling-price of the potatoes. If seed potatoes be treated to a bath of formalin just before they are planted, the formalin will kill the fungi on the potatoes and greatly diminish the amount of scab at the next harvest. Therefore before they are planted, seed potatoes should be soaked in a weak solution of formalin for about two hours. One-half pint of formalin to fifteen gallons of water makes a proper solution.

Fig. 125.
From a scabby potato,
like the one in Fig. 123,
this yield was obtained

Fig. 126.
From a healthy potato,
like the one in Fig. 124,
this yield was obtained

Mix this with three gallons of water

Mix this with three gallons of water

Mix this with three gallons of water

At planting time get an ounce of formalin at your drug store or from the state experiment station. Mix this with three gallons of water. This amount will treat three bushels of seeds. Spread the seeds thinly on the barn floor and sprinkle them with the mixture, being careful that all the seeds are thoroughly moistened. Cover closely with blankets for a few hours and plant very soon after treatment. Try this and estimate the per cent of smut at next harvest-time. Write to your experiment station for a bulletin on smut treatment.

Fig. 123. A Scabby Seed Potato

Fig. 124. A Healthy Seed Potato