200 TRANS. ST. LOUIS ACAD. SCIENCE. 



second brood fall with the leaf and hibernate huddled together in 

 companies of five and upwards (Fig. 6, q). They have a habit, 

 before separating, of feeding side by side, eating the leaf from the 

 tip downwards but leaving the stouter ribs. Spinning a thread 

 wherever they go, they often, in traveling from leaf to leaf, make 

 quite a pathway of silk ; and if the branch be suddenly jarred 

 they will drop and hang suspended in midair, and, after reassur- 

 ance, climb up again with the thoracic legs. 



I have not reared this species from the egg to the imago as 1 have 

 Lycaon, but it doubtless goes through the same number of molts,, 

 as I possess five different sized heads. It is probable, however, 

 that the number will not correspond in the asstival and autumnal 

 broods ; for/iJ have reason to believe that some of my first brood 

 of Lycaon larvae went through but three molts; while I have 

 watched Herse go through the third molt after it had ceased feed- 

 ing in the fall, with scarcely any perceptible enlargement of the 

 head — this third head being of smaller size and browner color 

 than the corresponding one from the first brood. 



Both species are found on the lower branches of the trees more 

 especially, and very seldom on the higher. 



Parasites. 



The larger species is evidently most prolific, and one would 

 suppose that it would be the most numerous ; but its eggs, being 

 laid in a batch, are more apt to be destroyed in great numbers by 

 cannibal and parasitic insects. Such indeed is actually the case, 

 for, while I have yet found no parasites on Lycaon, of ten batches 

 of Herse eggs eight have been found more or less infested with a 

 minute Chalcid fly, one fly to each egg. 



The egg thus infested becomes purplish, so as readily to be dis- 

 tinguished from the sound ones, and even when empty an egg 

 that has been parasitized is easily recognized by the crown being 

 perforated instead of lifted up. I have not leared the parasite, 

 and have been unable to extricate any perfect specimens. From 

 fragments, the species seems to be blue-black ; what appear to be 

 the front tibiae have a prominent spur lacking in the others, while 

 the antennae seem to be 6-jointed, 2 being twice as long as bulbus, 

 3, 4 and 5 subequal and half as long, 6 fusiform and as long as 2. 

 It evidently belongs to the Trichogrammidce, and comes near Bra- 

 chista. 



