LEPIDOrXERA. 361 



other, and to the bark, by a grayish varnish, which is iinprr- 

 vious to water; and the clusters arc 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 of 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 mak- 

 ing their escape from the eggs, gather upon the tender leaves, 

 and, oh the occurrence of cold and wet weather, creep for shel- 

 ter into the bosom of the bud, or into the flowers, when the 

 latter appear. As this treatise may fall into the hands of per- 

 sons who are not acquainted with the habits and devastations 

 of our canker-AVorms, it should be stated that, where these in- 

 sects prevail, they are most abundant on apple and elm trees ; 

 but that cherry, plum, and lime trees, and some other cultivated 

 and native trees, as well as many shrubs, often suffer severely 

 from their voracity. The leaves first attacked will be found 

 pierced with small holes; these become larger and more irreg- 

 ular when the canker-worms increase in size ; and, at last, the 

 latter eat nearly all the pulpy parts of the leaves, leaving little 

 more than the midrib and veins. 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 

 species ; but it is also true that the same species varies much 

 in color. When very young, they have two minute warts on 

 the toj) of the last ring; and they are then generally of a black- 

 ish or dusky brown color, with a yellowish stripe on each side 

 of the body; there are two whitish bands across the head; and 

 the belly is also whitish. When fully grown, these individuals 

 become ash-colored on the back, 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 green, with two white 

 stripes on the back. The head and the feet partake of the 

 46 



