Some of the groves beyond the Antelope, and many of the cottonwoods on the State Agricultural Farm were despoiled of their leaves by this insect. It prevailed as far north as Dakota and Dixon counties. I saw trees stripped of their foliage by it in Burt and Washington counties. It has done more or less damage in at least twenty counties in the state. During this season. however, it has greatly declined in numbers, and in the damage it has been doing for several past years. What has caused all this decrease, I am unable to say, but one element of the process has been the work of predatory insects. I have found ichneumons and chalcis flies at work on them. Rainy seasons also seem to be injurious to them. This, however, has been denied. The fears, however, that many began to entertain that this insect was going to place an embargo on the cultivation of the cottonwood, is proved to be not well-founded."

In 1886 Lawrence Bruner reported this insect as injurious, and suggested that the reason for its great numbers was because the hot and dry summer had killed off many of its delicate parasites.

My own observations upon the beetle began in 1884, when a few were seen upon trees near Peck's Grove, a suburb of Lincoln. In 1885 I noticed it in abundance along the Platte between Ashland and Plattsmouth and also in the western part of the state, near Indianola. In 1886, the beetles appeared in great number. They were found upon young shoots in the University campus at Lincoln and along Oak creek, where I observed several trees almost defoliated. The present season does not show so many-at least not in the south-eastern part of the state, where I have been working.

This year even more than last the beetles show a decided preference for shoots and secondgrowth trees. They are rarely seen more than five feet from the ground and confine their operations to the younger and tenderer leaves; thus showing that their numbers may have a distinct bearing upon their habits.

After the heavy rains in August infested shoots under my observation became almost clean; and this would appear to bear out the observations of Prof. Aughey that rainy seasons are distasteful to them.

Besides the ichneumon and chalcis flies, I have noticed other predatory insects, chief among which are the lady-birds. Tiger-beetles and ground-beetles both enjoy a meal of Plagiodera, and upon some specimens I have seen a small reddish-yellow mite clinging to the under side of the abdomen. There are probably other insects which assist in keeping the Plagiodera in check, but those mentioned comprise all with which I am familiar.

DESCRIPTION AND HABITS.

The Plagiodera scripta is a leaf-eating beetle, belonging to the same great order and family as the grape-vine Flea Beetle, elsewhere described.

In early spring, close upon the leafing-out of cottonwood trees, the beetles come forth from their winter hiding places-among old leaves, straw, in fences, etc.-and may be seen pairing and in the act of egg-laying. The eggs, according to Riley, are "elongate oval, of a pale yellowish-white color, rather soft and about 0.5 mill. long; and are laid in dense clusters, of ten, upwards to one hundred." I have observed a great many egg-clusters, but have never chanced upon any exhibiting the "pale yellowish-white" color alluded to. In every instance they have been a deep orange-yellow verging upon pure orange. This difference may be local rather than general. They are placed upon the under side of the leaves and are set up end

ways, like so many sacks of flour. Toward the time of hatching, which takes place in from five to ten days after laying, the eggs become darker and somewhat discolored and finally the black larva emerges and begins feeding. At first the larvæ remain together but soon they separate, and as they grow stronger they eat the coarser parts of the leaf as well as the finer.

(Fig. 2.)

When full grown the larva is a little over three eighths of an inch in length; in color yellowish-white with black legs and pale false-legs; two rows of blackish tubercles laterally and four dorsally, the outer ones glandular, from which when irritated the larva exudes a milky liquid very pungent and penetrating in odor. These glandular tubercles are conspicuously hairy.

As the larva becomes full-grown it selects a spot upon the leaf for pupation. The pupa remains within the partially thrown off larva skin which supports itself by means of its hook-like feet. The pupa is greenish-yellow or yellowishbrown aud comparatively smooth.

Beetles appear in from four to eight days after pupation and are characterized by yellow-bordered black thorax, yellow or yellowish-green elytra with three interrupted black lines extending longitudinally on each, and yellow legs marked with black. Sometimes the beetle is found more striped than at others, and occasionally specimens are seen of a uniform blue color. The normally striped form is altogether the most common about Lincoln, but the blue form has been sent me from

Larva much enlarged, show- near Rulo, on the Missouri river. ing tubercles.

This

According to Prof. Snow, fifteen days suffices the insect to pass through its intermediate stages, and this would indicate that there may be as high as five broods during the season. I have personally observed but four, and Prof. Aughey reported, as quoted in the American Entomologist, but three would indicate that the number of broods is elastic and is probably greatly influenced by the temperature and rainfall during the summer. Prof. Riley predicted in 1880 that, between the cottonwood beetle and the cottonwood borer (Saperda calcarata Say), the cottonwood would be exterminated. Owing to the increase of insect enemies and the evident tenderness of the leaf-beetle, together with the almost universal harmlessness of the Saperda throughout Nebraska, it is probable that these fears will never be realized. However, should the two foes to this decidedly second-grade tree suddenly multiply, measures for extermination might have to be undertaken. The following remedies are proposed:

REMEDIES.

(1) Sprinkling trees with solution of London purple.

(Fig. 24.)

Imagos, showing variations.

Sprinkling with putrid whale-oil soap emulsion in early spring.

In the case of young shoots, pouring naphthaline (a product of coal tar) upon the ground near the stem. A very little will raise a powerful stench and I have found that it drives away or kills all the beetles.

THE WHITE-MARKED TUSSOCK MOTH-(Orgyia leucostigma, Sm. Abb.)

ORDER LEPIDOPTERA, FAMILY ARCTIDE.

Harris Ins. Inj. to Veg.; 1st Ill. Rep., LeBaron; 1st Mo. Rep., Riley; Am. Entomologist, vol. 2; Insects Inj. to Fruit Trees of California, Matthew Cooke."

The white-marked tussock moth is seldom seen in its perfect stage, but the conspicuous larvæ and cocoons are among our most common natural objects. Over the whole eastern part of the state this insect is omnipresent, and although it is not so injurious as many other forms, its abundance makes it worthy of attention.

DESCRIPTION AND HABITS.

During the winter months one may see on apple, box-elder, plum, maple, quince, pear, elm, or black-walnut trees shriveled leaves still clinging to the branches. Upon examination it will usually be found that the leaves are held in place by the presence of a gray cocoon, composed of a glistening agglutinated silk. Upon the surface of many of these cocoons will be found a large number-twenty-five to two hundred and fifty-perfectly spherical eggs, creamcolored or grayish, and imbedded in a silvery and frothy substance. Other cocoons have no such egg-clusters nor any of the frothy imbedding material.

Upon tearing open either of these cocoons-one with eggs or one without-the contents will be found to be the same. In each case one will discover a sub-conical, brown, papery skin with four grayish-yellow bars across the back. It may be easily crushed between the fingers. This brown skin usually has, at one end a few shreds of bristly substance which does not seem to belong to it. What now is the explanation of all this? The cocoons were spun by hairy larvæ the year before. larva within sheds its larva-skin, and this shed skin

After completing its cocoon, the bristly substance alluded to above.

The insect is now a pupa. In a few days the pupa-skin is shed, and the perfect moth, dissolving a portion of its cocoon by a liquid secretion, escapes to the open air, leaving the brown pupa-skin to keep company with the larva skin in the abandoned cocoon.

If one looks closely at the two kinds of cocoons described above, it will be seen that those bearing the egg masses are the largest and the most solidly built. The others are lighter, and often so thinly woven that one may see the pupa-skin within, before tearing it open. These lighter cocoons are the ones which produced the male moths, and the denser cocoons are the ones which produced the female moths. But this does not entirely explain the presence of the eggs; something must be added. The interesting and remarkable fact is this: the female differs from the male in that she has no wings whatever, while he has two strong pairs-a fact which explains the peculiar permanency of the egg location. Moreover, the female is sluggish and does not care to walk about; she emerges from her cocoon, stands upon it waiting for the visit of the male, lays her eggs, and drops to the ground to die. Not much of a life, to be sure, but it does for all practical purposes. Neither male nor female take any nutriment during the perfect or imago state-they have stored away enough while caterpillars.

(Fig. 25.)

The White-Marked Tussock Moth.

a Cocoon, adult female and eggs.
b Young larva with thread.
c Female pupa.

d

d Male pupa.

From the eggs, which have weathered the winter, come little, pale, yellow larvæ, at just about the time when the leaves are well developed in the spring. These begin to feed at once and grow rapidly. At intervals of six days the larva sheds its skin, or moults, as the phrase is. The male undergoes three larval moults, and when full grown is about three-fourths of an inch in length. The female has four moults, and when full grown is one and one-half inches in length. Otherwise the two sexes are similar.

This caterpillar is one of the most showy of all our common larvæ, and almost everyone must have seen it. The head and neck are bright coralred, as are the retractile warts upon the ninth and tenth rings The sides are yellowish and the back is velvety black and bears four broom-like, cream-colored tufts of hair, rounded and compact. Along the sides are scanty tufts of cream-colored hairs, and springing from behind the head are two pencil-like tufts of long, black, club-shaped hairs, pointing forward like horns, and there is a similar tuft on the top of the twelfth ring,

pointing up and backward. The whole presents a very unique appearance. In casting its skin, during the larval moults, tufts and all are cast, new tufts forming underneath.

The pupa stage lasts from nine to fourteen days, and then the perfect insects appear. The wingless females are light gray with three straw-colored blotches on the back of the thorax, and are very plump in outline. The males are of somewhat darker gray, with slenderer body, upon the back of which are four little tufts of hair; and they have ashen gray wings, marked wavily with black, which expand one and one-eighth inches. The antennæ are pectinated (feather-like) and the fore legs are very hairy, and are extended straight forward when the insect is at rest. In this pos tion the upper wings are slanted backward, covering the lower pair and giving the insect a somewhat heart-shaped appearance, the head being at the apex. When the female lays her eggs she places them upon the side of the cocoon from which she emerged, and covers them with frothy substance, which becomes hard and glistening as it dries.

(Fig. 27.) Male Imago.

White-Marked Tussock Moth.

One fact which may be mentioned in connection with the caterpillar is, that it has the habit of dropping when disturbed; but, spider-like, it retains communication with its old haunts by a silken thread, spun from its mouth. When it imagines that the danger is over, it proceeds to climb back again, using its six, horny, thoracic legs for the purpose, and swaying from side to side in the ascent, just as a man does when climbing a rope. This habit is instinctive and protective. In this latitude there are three annual broods.

INSECT ENEMIES.

The larva is parasitized upon by at least six different species of ichneumon, chalcis, or Tachina flies. They are of the greatest importauce in keeping the insects in check, and cocoons, without eggs, should nover be destroyed for fear of killing some of the friendly parasites within.

There is a species of Cincindella, or tiger-beetle, which I have seen running over the leaves of box-elder trees in quest of young larvæ, and perhaps it may be of some benefit to treegrowers in a quiet way. It is a very interesting sight to see the beetles steal up upon the unsuspecting caterpillar and seize it before it had a chance to drop. Other cannibal insects, socalled, prey upon the tussock moth, but their work is scarcely great enough to demand further attention.

METHOD OF TRAVELING.

The caterpillars are solitary in their habits, and, though I have been once or twice given to understand the contrary, I do not believe that they ever travel in swarms, as does the army worm or the white ant. Their main method of distribution must be the passive one of accidental egg-dissemination. Nurserymen are often careless in sending out their stock, and may allow cocoons, bearing eggs, to be shipped to new localities, thus introducing the moth. In à conservative way the larva is something of a wanderer, and through the summer may be seen moving leisurely along over fences, sidewalks, or upon the roadside. Singularly enough, the female seems to possess this instinct far more than the male, and while I have never met but a few of the males, I have scores of times fallen in with the females plodding placidly along. It would seem almost as if the male understood that ne might save useless labor by waiting for his wins-appendages denied his more progressively inclined spouse.

FOOD PLANTS.

I believe that Nebraska observers will bear me out in the statement that, over the eastern part of the state, the tussock moth prefers box-elder to any other tree. My own experience teaches me that I can find more cocoons upon these trees than upon apple, pear, plum, or rose-bush-the plants usually mentioned as favorites. Last winter I secured forty-one cocoons from a single box-elder not more than twelve feet in height, and I have never found more than twenty-two upon apple trees of similar size. This summer (1887), in company with Prof. Bessey and Dr. Gustavus Egeling, I found ten caterpillars on box-elder trees along a street in Fremont, and saw none on the apple trees, which were almost as abundant in bordering door-yards as the others.

Upon maple and plum the cocoons are especially abundant this season, although I have not noticed so many in years past.

The tussock moth does not confine its working to cultivated fruit trees, for I have found it feeding upon Prunus pennsylvanica (the choke-cherry) and upon Prunus chicasa (the wild plum), both times in the vicinity of Lincoln. However, it is but right to say that its presence on these trees is somewhat unusual, the apple and box-elder being its favorites.

REMEDIES.

In planting an orchard every intelligent fruit-grower should see that all seedlings are examined for egg-masses. Should cocoons be found without egg-masses, they should be preserved, as in no case is there a live tussock moth within, but frequently there are parasites. This is rather of the nature of a preventive than of a remedy, but the old adage about "the ounce of prevention" holds good here as elsewhere. To carefully examine every tree is not a difficult matter, and it should certainly be done, for it is almost sure protection.

However, if the young trees have been allowed to pass without inspection, the same remedy may be brought into use by searching the orchard or shade-row in the middle of winter. The dead leaves and egg-masses are conspicuous objects, and may be easily destroyed. A farmer should know that leaves always fall off in the winter (I am referring to deciduous trees), and when they obstinately stay on there must be some reason for it. Dead leaves should be classed as "suspects," and destroyed.

Another way to capture a fair number of tussock caterpillars is to jar the trees when they are fully leaved out in the spring; about the 10th of May is the proper time in normal seasons. By this time the young caterpillars have hatched, and can be prevailed upon to let themselves down by their silken threads,thus revealing their presence and making it an easy matter to kill them.

Still another way is to substitute burning coal-tar, held in a long-handled dipper among the branches, for the jarring. The smell induces the larvæ to let themselves down, in search of a purer atmosphere, I presume, and they can be captured as before.

Spraying trees with Paris green or London purple solution could do no harm, and would probably kill the greater number of infesting larvæ. It should be applied three or four times during the season.

The methods of fighting the female, given for the plum curculio, would not work here. The female, in spite of the bad odor, would attract the male, and having no option in choice of location, she would lay her eggs upon the cocoon, and the "remedy" would be worthless. By paying attention to the simple preventives mentioned above, no one should be troubled with the white-marked tussock moth. It is more easily cared for than the majority of harmful insects.

THE APPLE TENT-CATERPILLAR-(Clisiocampa americana HARR.)

Harris' Ins. Inj. to Veg.; Riley's Insects of Mo., Vol. III.; Cook's Inj. Ins. of Mich., 1874.

Every apple-grower is familiar with the webs spun by caterpillars among the branches of his orchard trees, and pretty generally applies to such caterpillars the name at the head of this page. They are not so injurious as other apple pests, but if left alone are capable of doing great damage.

DESCRIPTION AND HABITS.

The eggs are deposited in May or June, and may be found upon the smaller twigs, forming barrel-shaped rings around them. The eggs are grayish, spherical, usually with one side pressed in-as one may press in the side of a rubber ball-and covered with a dull, glutinous secretion, protecting them from the wet. They remain during the autumn and winter, and at the first breath of spring the caterpillars emerge, ready for the campaign.

According to Prof. Riley, these caterpiliars are extremely hardy, and in case they accidentally hatch. before the tree has leafed out, they fast patiently until food is provided. They make their first meal from the egg-shells which produced them, and will also eat the glutinous secretion. They never feed upon bark,

As soon as they have left the eggs, the caterpillars begin to spin, and this habit they continue until passing into the pupa stage. They never move about without leaving a little silken thread as a "tracer," and in a short time-for they are exceedingly gregarious-a large web is formed. This is of a cobwebby appearance, but stronger than spider's silk, and grows in size as the caterpillars grow. Often a single web will cover whole branches of a large tree, and under its protection the two hundred and fifty or more caterpillars will do serious damage.

The web is spun in obedience to an instinct-marvelous, as are all instincts -which teaches the caterpillars that community of action and ceaseless individual spinning will, at last, produce a covering strong enough to protect them from birds and predaceous insects.

When full-grown, these caterpillars are about two inches in length, sparsely clothed with long gray-black hairs, and spotted and striped with blue, black, white, and tawny-red. They are rather cleanly in their habits, and, when any part of their tent becomes obnoxiously befouled with their pellets of black excrement, they pass on to a nei hboring twig, spinning as they go. The family is entirely harmonious, and has its reg ular meal hours with which all seem to be satisfied. They feed twice a day, in the forenoon and in the afternoon, After feeding from thirty-six to forty-eight days, the caterpillars become full-grown, having in this time passed through four moults, and leave the tent, scattering in all directions to find suitable p aces for their cocoons. They commonly select fence-corners, crevices in bark, or similarly sheltered places, and each one spins an oblong, oval, yellow cocoon, inside of which it sheds its larva-skin and becomes a pupa. This is reddish-brown and hairy. Some of the caterpillars usually prove to be timid, and spin their cocoons near the old web or even within it.

(Fig. 28.)

The Apple Tent-Caterpillar.

a and b Larvæ.

c Egg-cluster.

d Cocoon.

In about two weeks after pupation the moth comes forth and the round of life is completed. The female is a trifle larger and lighter than the male; they spread about one and three-fourths inches, and are of a pretty brown color, with two transverse whitish stripes on the fore wing,

The moths are attracted by light and by sweets, and may often be seen flying about the evening lamp in early summer. They take no nourish ment, it is stated; but I have occasionally caught them in molasses-traps set for night-flying species Their sole duty seems to be to provide for a new

brood of caterpillars, this done they soon die. The female lays about two hundred and fifty eggs, placing them all in one cluster. She be gins with the bottom row and stands head downward, walking slowly around the twig and placing her little globes with great regularity. As the successive tiers are placed she soon comes to walk over and upon the eggs of the first tiers, thus pushing and kicking any irregularly laid ones into shape. With the eggs is poured out the glutinous secretion which covers them, and protects them.

INSECT ENEMIES.

Chief among these is a chalcid fly, belonging to the same genus with one which parasitises upon the Hessian fly. I have often found chrysalides filled with the tiny maggots of these flies, and have noticed that such infested chrysalides are exceeding y common in those cocoons spun under the shelter of the old web-giving, it may be, a hint as to the sluggishness of some caterpillars while the majority are so active. On this point my observations have been too few to lay down a general rule, but such facts as I have obtained are, at least, significant. Pupa containing these parasites never come to maturity, and by these means the tent-caterpillar is held in a certain check.

There are, moreover, many predatory insects which prey upon the caterpillars, but not parasitically. Among these are two species of plant-bugs and a tiger-beetle (Ca, abides).