Phygadeuon trichops Thoms. (Hymenoptera: Ichneumonidae), an Occasional Parasite of Hylemya spp. (Diptera: Anthomyiidae)

Abstract

In extensive surveys for parasites of Hylemya brassicae (Bouché), H. floralis (Fall.), and H. cilicrura (Rond.) on cruciferous crops in Canada and Europe, observations were made on the life-histories and behaviour of the parasites. Accounts of the two most abundant parasites, Aleochara bilineata Gyll. and Trybliographa rapae (Westw.), have already been published, the former by Colhoun (1953) and the latter by Wishart and Monteith (1954). The present paper deals with one of the minor parasites, Phygadeuon trichops Thoms. In the surveys this parasite was found in Norway, Holland, and Scotland but in such small numbers as to indicate that it has other, preferred hosts and that it only occasionally attacks Hylemya spp. Phygadeuon fumator (Grav.) was reared from Hylemya sp. from France and is recorded in the literature from Hylemya spp. in Russia (Meier, 1927; Vodinskaya, 1928) and in England (Wadsworth, 1915). No references were found to P. trichops from Hylemya spp. and no accounts of the biology of either species.