Metoecus paradoxus in The Netherlands (Coleoptera: Rhipiphoridae).
Metoecus paradoxus is predominantly a parasitoid of Vespula vulgaris, but has a wide range of host species. Before 1966 there were only 3 records of this northern Palaearctic species from the The Netherlands, but during the last 30 years the beetle was present in 10 of the 12 Dutch provinces. The beetle occurs in various rural and urban environments. The beetle's complex life history is summarized and the recent increase of records is discussed. Possible mechanisms for differential parasitism and coexistence of different Metoecus species are also discussed.