This study was carried out from August 1999 to July 2000 to evaluate the population dynamics and to know the parasitoids of Chrysomya megacephala (Fabricius, 1794) at the Instituto Oswaldo Cruz (IOC/ FIOCRUZ) and Jardim Zoológico, in Rio de Janeiro City. Samplings were conducted weekly with third instar larvae of the fly and putrefying ground beef. It was identified three species of hymenopterans parasitoids: Tachinaephagus zealandicus Ashmead, 1904 (Encyrtidae), Pachycrepoideus vindemiae (Rondani, 1875) (Pteromalidae) and Nasonia vitripennis (Walker, 1836) (Pteromalidae). In both sampling areas, T. zealandicus was the species with the highest parasitism rate of C. megacephala, followed by P. vindemiae and N. vitripennis. Parasitoid population decreases drastically in the summer (average temperature = 28°C; precipitation = 6.5 mm). The population peak of parasitoids was verified at the end of autunm and during the whole winter. At Jardim Zoológico, supply of garbage was a strong influence in the population dynamics of himenopteran parasitoids identified in this study, and the population peak in this area was verified in June and July 2000.
Nasonia vitripennis; Pachycrepoideus vindemiae; parasitoids; synantropic flies; Tachinaephagus zealandicus
