Parasitism of Tabanus nigrovittatus immatures (Diptera: Tabanidae) by Trichopria sp. (Hymenoptera: Diapriidae)

A species of the diapriid hymenopteran Trichopria near but not identical to T. tabanivora Fouts emerged from pupae of Tabanus nigrovittatus Macq. in the laboratory in Connecticut. Subsequent collections of Tabanus larvae and pupae from a salt marsh in 1976-77 showed that the natural rate of parasitism was about 4.5%. Exposure of Tabanus larvae to Trichopria females resulted in the death of all host larvae within 3 months, and the finding of parasites in 2 of them. Trichopria adults mated within 48 h of emergence, and mated females examined and attacked host larvae almost immediately after being placed with them. Trichopria is thus a gregarious larval-pupal parasite, of minor importance in the natural control of Tabanus nigrovittatus, although it is considered that the rate of parasitism might be improved in laboratory cultures.