COMMON APPLE-TREE. 319 



worms of different ages, and even among those of the same age and size. When 

 very young, they have two minute warts on the top of the last rings, and they 

 are then generally of a blackish or dusky-brown colour, with a yellowish stripe 

 on each side of the body ; there arc two whitish bands across the head ; and the 

 belly is whitish. When fully grown, these individuals become ash-coloured on 

 the back, and black on the sides, below which, the pale, yellowish hue remains. 

 Some are found of a dull greenish-yellow, and others of a clay-colour, with slen- 

 der interrupted blackish lines on the sides, and small spots of the same colour on 

 the back. The head and feet partake of the general colour 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 an inch in length. They cease feeding when about 

 four weeks old, at which time they begin to quit the trees. Some creep down 

 by the trunks, but great numbers let themselves down by their slender threads 

 from the branches, their instincts prompting them to get to the ground by the 

 easiest and most direct course possible. After reaching the ground, they imme- 

 diately burrow into the earth, to the depth of two to six inches, unless prevented 

 by weakness, or by the hardness of the soil. In the latter case, they die, or 

 undergo their transformations on the surface. In the former, they make little 

 cavities or cells in the ground, by turning round repeatedly, and fastening the 

 loose grains of earth about them with a few silken threads; and, within twenty- 

 four hours afterwards, they are changed into chrysalides, and in due time, emerge 

 from these retreats in their perfect form. In order to protect the trees from the 

 ravages of the canker-worm, the only thing that would seem necessary would be 

 to prevent the wingless females from ascending the trunks to deposit their eggs. 

 The expedients usually resorted to for this purpose, are, to fit a close collar of 

 lead, tin, wood, or other materials, around the trunks of the trees, or a circular 

 trough filled with oil. The application of belts of tar, liquid Indian rubber, and 

 other viscid substances, to the bodies of the trees have been employed with 

 partial success. 



The apple-tree is also infested by the larvae of the white-marked orgia, or 

 tussock-moth {Orgia leucoslig-ma, Harris.) These small, slender caterpillars 

 are of a bright-yellow colour, and are sparingly clothed with long and fine yellow 

 hairs on the sides of their bodies. The females, in the adult state, though seem- 

 ingly wingless, have two little scales or stinted wings, while the males have 

 large ashen-gray wings, the upper pair of which are crossed by dark wavy 

 bands, with a small black spot near the tip, and a minute white crescent near 

 the outer hind angle. The body of the male is small and slender, with a row of 

 little tufts along the back, and the wings expand one inch and three eighths. The 

 females are of a lighter gray than the males, and their bodies are much thicker, 

 and are of an oblong-oval shape. Difierent broods of these insects appear at 

 various times in the course of the summer, but the greater number come to 

 maturity and lay their eggs in the latter part of August and the beginning of 

 September, which are not hatched before the following spring. It is stated by 

 the late Mr. B. H. Ives, of Salem, Massachusetts, in vol. i., p. 52, of Hovey's " Gar- 

 dener's Magazine," that on passing through an apple orchard in February, he 

 " perceived nearly all the trees speckled with occasional dead leaves, adhering so 

 firmly to the branches as to require considerable force to dislodge them. Each 

 leaf covered a small patch of from one to two hundred eggs, united together, as 

 well as the leaf, by a gummy and silken fibre, peculiar to the moth." In the 

 March following, he visited the same orchard, and as an experiment, cleared 

 three trees, from which he took twenty-one bunches of eggs. The remainder of 

 the trees he left untouched until the 10th of May, when he found the caterpillars 

 were hatched from the egg, and had commenced their slow, but sure work of 



