156 



PROCEEDINGS ENTOMOLOGICAL SOCIETY 



ternal parasite larva. It was evidently in the first stage, the head 

 being dark and distinctly marked off from the rest of the body. 

 It was semitransparent and of a pale greenish color. The peculiar 

 thing about it, however, was the fact that its caudal end was in- 

 serted in a shining black, goblet-like receptacle, the base of which 

 was firmly attached to the body of the caterpillar. The receptacle, 

 or egg-shell as it turned out to be, is shown in figure 2a, the larva 

 and egg-shell at figure 2b, and the larva in situ on its host at figure 

 2c. When- found the parasite was about one-eighth of an inch 

 long and rather slender. As development progressed it became 

 stouter and the head less distinct until, at full growth, when it 



C 



ct. 



Fig. 2. Stages of Pam'scws geminatus Say. a, egg shell; b, young larva 

 attached to egg shell; c, young larva in situ on host; d, three larval skins 

 attached to egg shell. 



left its host and spun its cocoon, it was about one-half an inch long 

 and a third as thick. During all this time it remained attached 

 to its host by the egg-shell. Not. until it left its host and spun its 

 cocoon was it discovered that it had molted without releasing its 

 hold on the egg-shell. Then it was found that there were attached 

 to the shell three molted skins varying in size and texture with the 

 age of the larva when they were discarded. The earliest molted 

 skin was densest and the head shield quite heavily chitinized, 

 the second somewhat less so, and the third very delicate and the 

 head shield barely heavier than the body skin. This is shown in 

 figure 2d. 



