Effects of sibling egg cannibalism on the development and survival of Chrysomela populi (Coleoptera: Chrysomelidae)

The adaptive significance of kin cannibalism among beetles has been predominantly reported for carnivorous ladybirds, seldom for herbivorous beetles. Eggs of the red poplar leaf beetle, Chrysomela populi L. (Coleoptera: Chrysomelidae), are deposited in clusters and often eaten by sibling larvae that hatched earlier. In this study, the effects of sibling egg cannibalism on development times, survival from hatching to adult emergence, adult body weight at emergence, and survival of hatchlings under starvation conditions were investigated. Regression analysis revealed that the number of eggs eaten per hatchling in each egg clutch increased adult body weight at emergence and survival under starvation conditions 48 and 60 h after hatching, but had no significant effect on development time, survival from hatching to adult emergence, or survival of hatchlings under starvation conditions 36 h after hatching. These results suggest that the adaptive significance of sibling egg cannibalism for C. populi is heavier body weight of adults and greater starvation tolerance of hatchlings compared with non-cannibal individuals.