Impact of exposure length and pupal source on Muscidifurax raptorellus andNasonia vitripennis (Hymenoptera : Pteromalidae) parasitism in a New York poultry facility

Commercially obtained Nasonia vitripennis Walker and Muscidifurax raptorell us Kogan & Legner were released weekly for 12 wk into a high-rise, caged-la yer poultry house. After the release period, parasitoids were sampled using sentinel house fly (Musca domestica L.) pupae that were either laboratory- reared or field-collected as larvae and exposed for 2, 4, 7, and 14 d. Para sitoid-induced mortality was observed in 31% of laboratory colony pupae and in 26% of field-collected pupae, whereas successful parasitism rates of 48 and 51% were observed from these pupal sources, respectively. Parasitism w as primarily by M raptorellus (88%), and Muscidifurax raptor Girault & Sand ers (11%), while N vitripennis accounted for <1%. Percent female progeny ra nged from 43% in M. raptorellus to 76% in N. vitripennis. Parasitoid emerge nce from 2-d exposed sentinel pupae was the lowest of all treatments. Paras itoid emergence from 7-d exposed sentinel pupae was the highest of all trea tments. We found no differences between pupal source, suggesting that when sampling for M.raptor, M. raptorellus, and N. vitripennis, in poultry facil ities, pupal source is not a confounding factor.