Strategy for sneaking into a host's home: The cuckoo wasp Omalus biaccinctus (Hymenoptera: Chrysididae) inserts its eggs into living aphids that are the prey of its host

摘要

Parasitic Hymenoptera usually need to have direct access to their host or its offspring or to be able to enter and place their offspring in a nest of their host, where their progeny develop at the expense of the host. In the case of the cleptoparasitic cuckoo wasps (Chrysididae) their main target is the nest of the host and they have various strategies for locating and entering their host's brood cells for ovipositing. The chrysidid Omalus biaccinctus (Buysson, 1893), a parasitoid of aphid hunting crabronid wasps, was observed apparently inserting its eggs into living aphids at the hunting site of their host and the presence of the parasitoid's egg and DNA in aphids after oviposition was confirmed. It is concluded that O. biaccinctus "hitch-hikes" into a host's brood cell concealed in the aphid prey collected by the host wasp and the adult parasites do not need to enter the nest of their host in order to lay their eggs.