78 \ Farmers’ Bulletin 1270. 
are usually attacked year after year on account of the roughened or broken 
areas of the bark, and these places are preferred by the larvee for feeding 
purposes. The apple crotch-borer is a native pest; it is rather generally 
distributed in the Eastern States and has also been found farther West— 
in Michigan, Missouri, Mississippi, and Texas. The recorded food plants, 
in addition to the apple, include the juneberry, thorn, mountain ash, and black- 
knot of the cherry. 
During the winter the insect is in the larva stage, well protected in its 
silken hibernaculum, which is formed within its burrow. In the spring a 
cocoon (fig. 164) is made, usually beneath the bark scales, after which the 
Fie. 163.—Larva of 
apple crotch-borer Fie. 164. — Cocoon 
in hibernaculum. of apple crotch- 
borer, exposed hy 
removing seales of 
apple bark. En- 
larged. 
Fig. 162.—Young ap- 
ple tree injured at Fie, 165.— Adult meth of Fic. 166.—Eggs of ap- 
crotch by the ap- apple crotch-borer. En- ple crotch-borer. 
ple crotch-borer. larged. Enlarged. 
pupa stage is entered. The full-grown larva is yellowish white, with a brown 
head, and averages about three-fifths of an inch in length. The brownish pupa 
is about one-third of an inch long. The adult, which issues during the sum- 
mer, is a small moth (fig. 165) with a wing expanse of one-half to three-fourths 
of an inch. It has clear, fringed wings, the tips of which are metallic black. 
The upper part of the moth is purplish black, marked with white and yellow 
on the head, yellow on the thorax, and with three more or less distinct yellowish 
bands on the abdomen. The lower parts of the moth, including the legs, are 
conspicuously marked with golden yellow. The moths deposit their very 
minute, oval, glistening, brownish eggs (fig. 166) on roughened surfaces or in 
eracks or other broken places of the bark. Upon hatching, the larve feed on 
the inner bark as described. According to the life-history studies of the 
Bureau of Entomology, some individuals have a 1-year life cycle, while others 
