Influence of natal host on parasitism by Spalangia cameroni (Hymenoptera: Pteromalidae)

Abstract

Spalangia cameroni Perkins (Hymenoptera: Pteromalidae) is sold commercially as a biocontrol agent of fi lth fl ies, including the house fl y, Musca domestica L. (Diptera: Muscidae). For this reason, S. cameroni is mass-reared for inundative releases to control harmful fl ies. However, the mass-rearing protocols include very little information on the infl uence of natal host on subsequent host selection by parasitoids with more than one potential host as in the genus Spalangia. Here, we report on the use of S. cameroni against M. domestica. The S. cameroni were reared using Ceratitis capitata Wiedemann (Diptera: Tephritidae) (natal host) pupae for several generations. Freeze-killed fl y pupae were used in assays to determine the fecundity, number of adult progeny and sex-ratio of this parasitoid. Realized fecundity and number of adult progeny were greater when provided with house fl y pupae than Mediterranean fruit fl y pupae. Thus S. cameroni parasitized more house fl y pupae than C. capitata pupae, even though the parasitoid was reared on Mediterranean fruit fl y for many generations. These results indicate that S. cameroni reared on C. capitata can be successfully used in inundative releases against both fruit fl ies (agriculture) and house fl ies (livestock farming).