It has the potential to parasitize 20 fly pupae per day for one to four weeks. Early season inundatives releases have been helpful against house flies. M. raptor populations increase in late September and October when temperatures drop. Spalangia nigroaena Stable Fly pupae preferred. Also attacks house fly, horn fly, little house fly, dump fly, false stable fly, etc.
Comments Works well against both stable flies and house flies.
S. nigroaenea digs deep into manure where stable fly pupae are found. Populations peak in summer, often July and August when fly populations peak. Muscidifurax zaraptor House Fly pupae preferred. Also attacks Stable Flies. Comments Often the dominant parasitoid species in Midwest feedlots.