The cannibalistic behaviour of various developmental stages of Coccinella
septempunctata L. and Hippodamia variegata (Goeze) were investigated at satiety and
starved conditions. Both species were cannibalistic. However the rate of cannibalism was
greater in the former species. In all experiments and in both coccinellids, no significant
differences were detected at satiety conditions but at starved conditions, a significant effect
of different predator and prey instar were recorded. Cannibalistic rate of ladybirds increased
at low densities of Schizaphis graminum (Rondani) population and this is because of high
relative frequently of encounters between predator coccinellids and the aphid.
