Cannibalism by the Larvae of Coccinella septempunctata bruckii Mulsant (Coleoptera: Coccinellidae) in Mass-Rearing Experiments

Abstract

Laboratory tests for the detection of egg, larval and pupal cannibalism by the larvae of Coccinella septempunctata bruckii were carried out. When no aphids were supplied, most of the eggs were attacked by larvae in each instar, and most of the first and the second instar larvae molted to the next stages only with eggs. When an adequate number of aphids was supplied, only the first and the second instar larvae attacked a few eggs, and the third and the fourth instar larvae never attacked eggs. When no aphids were supplied, larval cannibalism occurred frequently in the second, the third and the fourth instar larvae, but most of the first instar larvae were starved to death or attacked by other instar larvae, whereas, when an adequate number of aphids was supplied, larval cannibalism was minimal. Pupal cannibalism by the larvae did not occur except in one instance when no aphids were supplied. © 1987, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.