PROCEEDINGS, 1918 63 



posited. The young larvae feed on the tender foliage until 

 about the middle of September, when they seek some suitable 

 place wherein to hibernate. They resume their feeding when 

 the warm days of spring cause the young leaves to unfold, be- 

 coming fully grown about the first week in July. The cocoon 

 is generally spun in crevices and under loose bark on the trunks 

 of the trees, the adult emerging from fifteen to sixteen days af- 

 ter the cocoon has been completed. Full particulars regard- 

 ing the life history are given in the accompanying table and 

 under the discussion of the different stages. 



The Egg. 



The eggs are laid on the upper surface of a leaf in a flat 

 mass, the individual eggs numbering from 300 to 450, being 

 closely contiguous. They are fastened together and to the 

 leaf by a greyish gelatinous substance secreted by the female. 



Description 



The egg is spherical in shape, with a slight median depres- 

 sion on the upper surface. Chorion, minutely roughened on 

 upper, smooth and glistening on under surface. Centre of cap 

 very finely punctate. Color, greenish white turning to white, 

 with centre of cap grey-green. Diameter, .87 m. m.-.93 m. m. 



The Larva. 



The young larva, in emerging from the egg, eats through 

 the depressed area, increasing the size of the hole until it is 

 large enough to permit escape. After freeing itself in this man- 

 ner, it does not start feeding on the shell of the egg from which 

 it has just emerged, as is the habit of some of the closely allied 

 species, but crawls away in search of tender foliage and starts 

 feeding on the pulp of the leaf, skeletonizing it. As the larvae 

 increase in size, they consume the whole leaf with the exception 

 of the midrib and larger veins. When young, the larvae are 

 more or less gregarious in habit, feeding closely together, but as 

 they advance in age, are more often found singly. The young 

 larvae, when disturbed, spin down by a silken thread, ascend- 

 ing again after danger is past to the nearest foliage. In the 

 more advanced stages, however, the larvae when disturbed do 

 not spin down by a silken thread, but curl up in a ball and drop 

 suddenly,clinging to the first object they strike in their descent. 



