The reproductive performance of Nasonia vitripennis Walker (Hymenoptera: Pteromalidae) was evaluated on pupae of Chrysomya megacephala Fabricius (Diptera: Calliphoridae) kept at -20ºC, during 77 days, with and no previous passage for liquid nitrogen (NL) by one, three and 15 minutes. Control groups were characterized for fresh pupae hosts. There was one pupa for each parasitoid. The sample of fresh pupae exhibited average of 15 emergent parasitoids / pupa while pupae stored directly at freezer (-20ºC) presented an average of 10 emergent parasitoids / pupa. In the samples exposed at one, three and 15 minutes in NL, accentuated decrease was observed on emergent hymenopterans reproductive performance (<img border=0 id="_x0000_i1028" src="../../../../img/revistas/cr/v34n1/n1a32fr01.gif">: 6.1; 5.5 and 5.7 respectively). The dissection of pupae revealed a large number of immature pteromalid in the groups with liquid nitrogen passage and farate adults in all the groups.
Biological control; Chrysomya megacephala; cold storage; cryoconservation; Nasonia vitripennis