On "intercolonial" cannibalism in Japanese paper wasps, Polistes chinensis antennalis Pérez and P. Jadwigae dalla torre (hymenoptera: Vespidae)

Foundresses of two species of Japanese paper wasps, Polistes chinensis antennalis and P. jadwigae, attacked other colonies of the same species. A foundress of P. chinensis antennalis visited two nests of the same species, and ate larvae from them, while two foundresses of P. jadwigae each visited a nest of the same species, eating larvae and pupae even when the foundress of the attacked nest was on her nest. In addition, a foundress of P. jadwigae distributed flesh balls thus obtained among their larvae. Discussion was made on the adaptive significance of the inter-colonial cannibalism. It was considered that, at first, it increases the foraging efficiency and secondly it plays a role in regulating population density.