CARNIVOROUS BUTTERFLIES — CLARK 499 



{^ized caterpillars, however, drop on a thread, and this is usual 

 until they are nearly of full size. 



iVIiss INIorton said that after the third molt the caterpillars go 

 about very quickly. They crawl steadily and fairly rapidly when 

 removed from the aphids; but in a vigorous aphid colony they 

 are extremel}^ sluggish, and I have rarely seen them elsewhere. 



I ha^e never observed anj'^ tendency on the part of Feniseca 

 caterpillars to eat each other, even when scores of various sizes were 

 confined Avithout food in the same small box. In spite of their 

 delicate skin the caterpillars arc well protected by their long 

 and partially grouped hairs, especially by those along the lower 

 edges of the sides, which bend downward and prevent attacks 

 from underneath. 



But while the caterpillars seem to pay no attention to each other, 

 my son, Hugh U. Clark, discovered that the smaller caterpillars 

 not yet fully fed eagerly devour the freshly formed pupae. These 

 they attack from the under side, tearing a large ragged hole in 

 them and completely devouring all the soft parts. 



Raplditif of firov'ih of the catevpillars. — Mr. Edwards noted that 

 the growth of these caterpillars is remarkable for its rapidity, 

 scarcely more than two days between molts, and there are but 

 three molts in all. There is no long interval preceding a molt 

 when the larva lies helpless, and this is particularly so at the third 

 molt when the larva is fully exposed to view. He Avatched several 

 most carefully when he anticipated the third molt, but Avas neA'er 

 able to see it, or to knoAv precisely when it occurred. He could see 

 that a molt must have taken place by the fresh and differently 

 colored skin of the body and the enlarged head. 



Miss Morton at first experienced the same difficulty. She AA-rote 

 on August 30, 1886 : " Thursday morning the larvae had devoured 

 every aphis in the box, and I remembered seeing some red aphids 

 on Avild cherry near the house. These I put in until I could go 

 to the SAvamp a mile aAvay. When I returned, three hours after, 

 three of the fiA^e larvae had molted, after eating nearly the whole 

 of the 2 square inches of aphids, though there Avas no appearance 

 of a molt Avhen I Avent aAvay." These three pupated Sunday morn- 

 ing, three days after the third molt. 



The pupal stage. — About three days after the third molt the 

 caterpillars pupate. Just where this takes place in a state of nature 

 has not been satisfactorily determined. INIiss Morton never found 

 a chrysalis, although she looked for them AAdienever she was in 

 the sAvamps. Her captive larvae generall}^ sought a leaf, but she 

 thought it probable that the wild ones crawl doAvn the stems and 

 pupate among sticks or grass. 



