98 



Agricultural Experiment Station, Ithaca, N. Y. 



They are disc-like, very nuicli flattened, 

 usually oval in outline, a few are circular, and 

 measure .8 mm. by .7 mm. A flat outer rim 

 .2 mm. wide adheres closely to the leaf, leaving 

 a central slightly elevated rounded disc in which 

 the larva develops. About nine days after the 

 eggs are laid the developing greenish caterpillar 



Fig. 37.— Egsof Liudmoth 1 . , , • ,i , -, 



showinp: the developing i^J^ng curlect Up in the Central portion can be 



caterpillar within — i^i 



greatly enlarged. plainly Seen tlirough the shell. The egg-stage 



lasts from seven to ten days. 

 Suvimer habits of the caterjnllar. — Soon after emerging through 

 a hole near the edge of the central portion of the egg-shell, the 

 little greenish caterpillar begins to feed upon the skin of the leaf, 

 usually upon the underside. A few hours later it makes for itself 

 a tube of silk open at both ends and usually made alongside the 

 mid-rib. From these silken homes the caterpillars sally forth to 

 feed upon the surrounding tissues, protecting themselves as they 

 go by a thin layer of silk spun over their feeding grounds (Fig. 

 38). They feed upon one 

 epidermis and the inner tis- 

 sues of the leaf, leaving the 

 net-work of veinlets ; the 

 opposite epidermis forms the 

 floor of its feeding grounds. 

 The veinlets and the epider- 

 mis soon turn brown, thus ^g.-Leaf showing the work of a young caterpillar 



rendering the summer work during the summer. 



of the insect quite conspicuous. Rarely more than one caterpillar 



works on a leaf. 



The caterpillars continue to feed in this manner during July and 

 August, and a part of September. Soon after the third or fourth 

 moulting of the skin, they cease feeding and seem to know in- 

 stinctively that they have reached that point in their develop- 

 ment when it is necessary for them to make preparations to go 

 into winter quarters, even though it be several weeks yet before 

 the leaves become unlit for food, or fall from the trees. 



Jlihernation. — Ourobservationsin 1891 and 1802 definitely showed 

 that the bud moth passes the winter as a half-grown caterpillar 



