By monitoring weekly with house fly (Musca domesticaL.) pupae placed in mesh bags in the manure, 10 species of house fly parasites were found in confined poultry, dairy, beef, swine, and sheep housing:Muscidifurax raptorGirault and Sanders,Spalangia, sp. nov., neardrosophilaeAshmead,S. cameroniPerkins,S. endiusWalker,S. nigroaeneaCurtis,S. drosophilaeAshmead,Pachycrepoideus vindemiae(Rondani),Nasonia vitripennisWalker,Dirhinus texanus(Ashmead) andTrichopriasp. By the same monitoring method five species were recovered from beef and dairy cattle pastures:M. raptor, S. cameroni, S. endius, P. vindemiae, andD. texanus. All sampling was conducted in the Piedmont region of North Carolina.M. raptor, P. vindemiae, andS. cameroniwere the most prevalent parasites in both the confined systems and the pastures, accounting for 95 to 98% of all parasites recovered. House fly pupae exposed to parasites in the confined poultry, swine, and dairy systems exhibited higher rates of parasitism than in the pastures and the beef and sheep barns.