New York Agricultukal Experiment Station. 371 



rate would consume 400 leaves per day. While no very- 

 extensive data bearing on this point were obtained from the cater- 

 pillars kept in the insectary, it was observed that in one instance 

 a single caterpillar, nearly full grown, devoured one large sized 

 peach leaf during the day, and several instances were noted where 

 an entire apple leaf, not exceeding 2 inches in length, was con- 

 sumed during the forenoon. 



During favorable weather the caterpillars feed at quite regular 

 intervals. Their favorite time is during the middle of the day. 

 When not feeding they stay in or upon the nest and also retreat 

 to it during cold or stormy weather. In going to and from the 

 nest the caterpillars follow the same path, usually preferring the 

 upper side of the limb and always spinning a thread of silk as they 

 pass along. Thus the branches in the vicinity of the nest over 

 which the caterpillars have frequently passed become covered with 

 silk on the upper surface. 



Plate XXXII is from a photograph of a nest full of caterpillars 

 with some on the outside. The photograph was taken about 4 

 o'clock in the afternoon, just before a severe thunderstorm. Half 

 an hour before this the caterpillars were scattered about the 

 neighboring branches. As a rule they seem to prefer not to wan- 

 der far from the nest, but as long as food is plenty will feed near 

 by. They also seem to prefer to go toward the top of the tree for 

 their food rather than toward lower branches. In going to and 

 from the nest they follow each other closely; sometimes in single 

 file or two or more together. Figure 5 is from a photograph of 

 some caterpillars on a peach twig about to begin feeding on the 

 leaves. 



The full grown caterpillars measure nearly two inches in length. 

 The body is sparsely covered with long yellowish hairs. The gen- 

 eral color is black. A prominent white stripe extends the entire 

 length of the back. Numerous shorter irregular lines extend 

 along the sides. A row of oval, pale blue spots, one upon the mid- 

 dle of each segment, extends along the sides. The under side of 



