1939 ] 
Cannibalism Among Larvae 
29 
FURTHER NOTES ON CANNIBALISM AMONG 
LARViE 
By V. G. Dethier 
Biological Laboratories, Harvard University 
In a previous communication (Dethier, 1937) most of the 
reported cases of cannibalism among lepidopterous larvae 
were discussed. Hunger and crowding, with thirst as a 
contributing cause were found to be the prime factors in- 
ducing this anomalous diet. This confirms the conclusions 
of Hering (1926) whose book was previously unavailable to 
the writer. The present notes offer further explanatory 
data pertaining to hunger and crowding as causes of a meat 
diet. The effects of such a diet and the ability of a phyto- 
phagous larva to survive on one are considered. Additional 
cases are also cited. 
I 
In an effort to understand more fully the various causes 
initiating cannibalism and the carnivorous habit in general 
among lepidopterous larvae the following experiments were 
designed. 
Two final instar larvae of Estigmene acrea Drury and one 
last instar larva of Isia isabella A. & S. were placed in a 
dry jar approximately twenty inches in volume. Also placed 
in the jar were one pupating E. acrea larva from which the 
cocoon had been removed, a smaller arctiid in similar con- 
dition, and one freshly killed I. isabella larva which had 
been slit open longitudinally. The experimental animals had 
neither eaten nor drunk for four days. It was observed 
that they crawled ceaselessly around the bottom of the con- 
tainer exploring the surface with their antennae and mouth- 
parts. Some dry faeces when encountered were nibbled at 
slightly. No unusual behavior occurred until the slit carcass 
was encountered. Here the live animals immediately sucked 
up the body fluids. After a period of five minutes all three 
