1937] Cannibalism among Lepidopterous Larvae 111 
species, notably Papilio polyxenes Fab., P. philenor L., and 
Danaus plexippus L., in ample space but with a limited 
food supply, readily attacked and ate pupating larvae and 
chrysalids of the butterflies. They also ate pupae of their 
own species, devouring all the hair and silk of the cocoon as 
well. Papilio philenor L. speedily attacked chrysalids and 
pupating larvae of its own species as soon as the food supply 
dried up or diminished. This has also been reported by 
Clark (1925) as occurring in P. polyxenes Fab. and Danaus 
plexippus L. Orfila (1927) reported that Ecpantheria 
indecisa Walkr. in the presence of an abundance of food 
devoured chrysalids of Tatochila autodice Hb. and also the 
parasites ( Apanteles spl) with which the chrysalids were 
infected. 
The most striking example that I observed was the case of 
a noctuid, Autographa sp ?, which attacked other larvae of its 
own species although plenty of food was available. It is 
interesting to note that this noctuid also fiercely attacked 
healthy and active larvae of Danaus plexippus L. and 
Malacosoma americanum Fab. While the victim struggled 
the noctuid stood upon it and chewed its way rapidly into 
the flesh. 
Bell is quoted (de Niceville 1901) as being of the opinion 
that a larva will never eat another larva feeding on a food 
plant different from its own. He also advanced the idea that 
“ — cannibal larvae are hardly conscious that they are eating 
up each other, being only guided to their proper food by the 
sense of taste, or possibly to a less extent by the sense of 
smell”. The noctuid referred to above could not be induced 
to feed either upon cherry (the food plant upon which M. 
americanum was feeding) or upon milkweed (the food plant 
of D. plexippus) although it would feed upon other plants. 
The question had been raised by Bird (1925) as to whether 
or not the food plant imparted a flavor to larvae which was 
repellent to internal parasites (the conditions would be the 
same in the case of cannibals). Whether or not this is the 
case can not be definitely stated at the present time. Un- 
doubtedly the gut of the larva attacked would, if it contained 
food, taste of the food plant which had been eaten. It 
appears unlikely that the cannibal larva would be able to 
distinguish its prey before it had attacked it, and, therefore, 
