INTERACTIONS BETWEEN AN EUCOILID [HYMENOPTERA] AND A STAPHYLINID [COLEOPTERA] PARASITOID OF THE CABBAGE ROOT FLY

The interaction between Trybliographa rapae and Aleochara bilineata, 2 parasitoids of the cabbage root fly, is discussed. Larvae of A. bilineata could not differentiate between cabbage root fly pupae containing T. rapae in its endoparasitic state and unparasitized pupae but could recognize pupae containing T. rapae once the latter had reached its ectoparasitic state. Attack by A. bilineata while T. rapae was still in its endoparasitic state usually resulted in the staphylinid killing the eucoilid. If T. rapae had reached the ectoparasitic state before the host pupa was attacked by A. bilineata larvae the eucoilid survived attack by the beetle larva. Multiparasitism, however, resulted in increased levels of mortality of both parasitoid populations. © 1990 Lavoisier Abonnements.