CANKER-WORN. 'The moth from which this destructive worm is produced belongs to the genus Anisopteryx, so named from the faet that in some species the sexes are very unequal in size, 'and in others the females are wingless. This is the case with the Canker-worm. Tbe cuts repre sent the insect in its various stages of develop ment. The following description of the Canker worm is from Dr. Harris' Insects Injurious to Vegetation : Their general time of rising is in the spring, beginning about the middle of March, but sornetimes before and sometimes after this time; and they continue to come forth for the space of about three weeks. It has been observed that there are more females than males among those that appear in the autumn and winter, and that the males are most abundant in the spring. The sluggish females instinctively make their way towards the nearest trees, and creep slowly up their trunks. In a few days afterwards they are followed by the winged and active males, which flutter about and accompany them in their ascent, during which the insects pair. Soon after this, the females lay their eggs upon the branches of the trees, placing them on their ends, dose together in rows, forming clusters of from sixty to one hundred eggs or more, which is the number usually laid by each female. The eggs are glued to each other, and to the bark, by a grayish varnish, which is impervious to water; and the clusters are thus securely fastened in the forks of the small branches, or close to the young twigs and buds. Immediately after the. insects have thus provided for a succession ot their kind, they begin to languish, and soon die The eggs are usually hatched between the first and the middle of May, or about the time that the red currant is in blossom, and the young leaves of the apple-tree begin to start from the bud and grow. The little Canker-worms, upon making their escape from the eggs, gather upon the tender leaves, and, on the occurrence of cold and wet weather, creep for shelter into the bosom of the bud, or into the flowers when the latter appears. A very great difference of color is observable among Canker-worms of different ages, and even among those of the same age and size. It is possible that some of these variations may arise from a difference of specimi; but it is also true that the same species vary much in . color. When very young they have two minute warts on the top of tbe last ring, and they are then generally of a blackish or dusky-hrown color, with a yellowish stripe on each side of the hody; there are two whitish bands across the head, and the belly is also whitish. When fully grown these individuals become ash-colored on the baek, and black on the sides, below which the pale yellowish line remains. Some are found of a dull greenish-yellow and others of a clay color, with slender interrupted blackish lines on the sides, and small spots of the same color on the back. Some are gyeen, with two white stripes on the back. The head and the feet partake of the general color of the body; the belly is paler. When not eating, they remain stretched out at full length, and resting on their fore and hind legs, beneath the leaves. When fully grown and well fed, they measure nearly or quite one inch in length. They leave off eat ing when about four weeks old, and begin to quit the trees; some creep down by the trunk, but great numbers let themselves down by their threads from the branches, tbeir instinet prompt, ing them to get to the ground by the most direct and easiest course. When thus descending, and suspended in great numbers under the limbs of trees overhanging the road, they are often swept off by passing earriages, and are thus conveyed to other places. After reaehing the ground, they immediately bwrow in the earth to the depth of from two to six inches, unless prevented by weakness or the nature of the soil. In the latter case, they die, or undergo their transforma tions on the surface. We give cuts of the Fall
Canker-worm, maleand female, larva and chrys alis. Fig. 1 represents • a, b, egg, side and top views; c, d, joints of larva, side and top views, magnified; e, batch of eggs; f, full grown larva; g, female chrysalis, natural size; it, top view of, and tubercle of, chrysalis enlarged. Fig. 2 shows : a, male moth; b, female, natural size: c, joints of female antennte ; d, joints of female abdomen, magnified, to bring out their pecular markings. The Spring Canker-worm (A. vernata) is repre sented by the cut as shown below, male and female, and also the larva or caterpillar ; shows the eggs natural size; b, eggs magnified; c, cater pillar; d, cocoon of the worm while passing to the chrysalis state; e, chrysalis of male; f, male moth (winged); g, female (wingless). In relation to means of extermination, the Spring Canker worm (A. vernata), with its chrysalis in a simple earthen cell, is severely injured and often killed, by late fall plowing. The Fall Canker-worm will not be injured severely by plowing, since the cocoon is thick, yielding, and interwoven with particles of earth. Many plans for preventing the ravages of the larv on orchard trees are adopted, among which, easing the trees with bands and circles of tin, tightly attached to the trees, and flaring from it. This is smeared with petroleum or eastor-oil, or a mixture of both, which causes the worms to drop to the ground as soon as they touch it. It is evident that any means that will prevent the wingless females from climbing the trees will protect; yet, except in the ease of fern trees, the expense has caused this means to be abandoned. In relation to reme dies, Dr. Thomas says: Like most other eater pillar foes, birds and predaceous ground-beetles help man in keeping them in cheek. Of the artificial means that have been from time to time recommended, the following seems to be the most desirable, as embracing simplicity with lightness of expense . First. To prevent the fe males from ascending the trees to deposit their eggs, a band of coarse cloth, six inches or more wide, may be put around the tree, and then smeared with tar or a. mixture of tar and molasses. Second. A hay rope may be put around the tree, and over this a ring of tin, wide enough, so that there will be free tin below the rope, and the whole securely fastened, being careful that there are no crevices between the tin and the tree through which the insects may pass. The tin should be smeared on the inside with a mixture of castor-oil and kerosene. In both these cases, the moths will lay their eggs below the bands if prevented from going above them. To insure success, these should be sought and killed, as if allowed to hatch, it will be much more difficult to keep them from ascending the trees than it was the moths. Third. When the worms are al ready in the trees, and if the trees are not too large, a sudden jarring will cause them to be detached from the leaves or twigs, and hang sus pended, when they may be swept down by pass ing a switch between them and their support, and they may be destroyed. Fourth. Washes of Paris green and other substances may be resort ed to when they are in the tree, but it is probable that where the tree is small enough to make the application of washes practicable, a few times jarring will answer the same purpose. Fifth. If the worms have entered the ground and chang ed to chrysalides, fall plowing will, if the ground be mellow, break up their slender cocoons, and expose them to the action of the weather, which, with the birds, will destroy most of them. In extensive orchards, jarring and catching the worms with a hay wisp fastened to a pole, and passed between the branches and ground as they drop and hang by their fine spur filaments, is effective, more so is showering the trees with a mixture of Paris green, or London purple, and water; the latter in about the proportion as used for the Colorado Potatoe-beetle.