TWO INSECTS OF THE ORCHARD SNODGRASS. 491 



never saw one cut the anchorage before pulling up, it may be that 

 the caterpillar uses enough force to break the old threads each time. 

 As the process is repeated over and over, the little bag flops this way 

 and that in its progress, now stands vertical, now topples over or 

 hangs from the side of the twig, wavers, and goes forward again by 

 a short jerk. 



At last a place is found that appears to fill requirements for a 

 hibernation site, and the case is there firmly anchored to the twig by 

 a fan-shaped bunch of threads glued to the threshold (J). During 

 the journey both ends of the case are wide open, but when finally 

 attached the front door is closed by a wall of silk spun within the 

 vestibule. Later the back door is usually closed also, but by only a 

 very thin web. The occupant, now reversed, rests in this position 

 after its work and travel. The cater- 

 pillar observed through this period re- V J — ^^ — W/ 



mained thus until the 23d of October, A J_^ _^A 



when it shed its summer working 

 clothes and appeared in its soft orange- 

 colored suit for winter. Having cut its B 

 case on the loth and attached it to the 

 cork in the bottle the following day, 

 a week had elapsed before the molting. FlG 3 _ The upper Up (A) and Jawg 

 Others worked more rapidly than this (£) of the cocoon stage of the 

 one, and many tied up to a twig only a SK£L£ ** Resplendent 

 short distance from the deserted leaf. 



Examination of cases out of doors showed, however, that it is normal 

 for the caterpillars to molt a short time after the case is attached for 

 the winter. 



In its winter condition the caterpillar looks much more delicate 

 than in its summer form, being, as already stated, a soft, pale-orange 

 creature about one-twelfth of an inch in length, or one-sixth to one- 

 third shorter than in the mature feeding stage. (PI. 1, K.) It is 

 cylindrical in shape, consisting of a small head and 13 body seg- 

 ments, and lacks both legs and sucker pads, though there is a dark, 

 horny ridge across the under side of the first segment which in some 

 way may assist it to hold itself steady in the case. The skin is finely 

 granular all over and apparently naked, except for a few hairs on the 

 head and last body segment, though other very minute hairs are 

 present as in the preceding stage. The head is wider in proportion 

 to its length than in the feeding form, the upper lip is less deeply 

 notched (fig. 3, J.), and the jaws (B) are relatively smaller. The 

 spinneret (fig. 2, C, Spn) , however, is still well developed and is soon 

 put to work. The caterpillars in the summer cocoons change also to 

 the orange-colored form, but remain in this stage only a few days 

 before transforming to the pupa. 



