Cannibalism Among Lepidopterous Larvae
Psyche: A Journal of Entomology
The occurrence of the carnivorous habit in lepidopterous larvm is known in certain rather widely separated groups, one of which, the Lycmnidm, is outstanding (Brues, 1936) . It is known also that some phytophagous larvm will become carnivorous for a period of time either regularly or in the absence of a plentiful food supply (Brues, 1920) . I have observed this and also cannibalism many times while breeding various species) A few ex.amples may be cited. When larvm of the Arctiid, Apantesis arge
... iid, Apantesis arge Drury, were confined to a limited area (three to four larvm to eight square inches) with a moderate supply of food, the smallest, least healthy, or least active larva was usually attacked while still alive and almost entirely eaten by a more robust specimen. Fifty of these larvm were divided into lots of two, three, and four, each lot being limited to an area of eight square inches. In nearly seventy-five percent of all cases cannibalism occurred. It was noted more frequently when four larvm were confined together or when one larva was smaller or weaker than its neighbors, as stated above. Moore (1912) reported that Phobis eubule L., when confined even in the presence of an ample food supply, ate smaller larvm of its own species. The more aggressive individuals also devoured the. more peaceful ones. Perkins (1928) found that Nemoria viridata L. in the presence of an abundance of food also showed cannibalistic tendencies. The larvm from a large batch of eggs feasted upon one another till there was but one left. This animal pupated and a normal adult emerged. Subsequent breedings with other batches of eggs of the same species revealed no further cases of cannibalism. I have. observed that larvm of Estigmene acrtva Drury and Diacrisia virginica Fab. when confined with those of other 1For cases of oSphagy see Schultz (1928 Schultz ( , 1935.