PREDATORS AND PARASITOIDS OF HOUSE-FLIES AND STABLE FLIES (DIPTERA, MUSCIDAE) IN CATTLE CONFINEMENTS IN WEST CENTRAL NEBRASKA

In Lincoln County, NE, cattle confinements were sampled weekly during the summers of 1983 (n = 5) and 1984 (n = 4) for pupal parasitoids and arthropod predators of house fly, Musca domestica (L.), and stable fly, Stomoxys calcitrans (L.). Parasitism of these flies increased through the field season, peaking in August and September. The overall rate of parasitism was significantly influenced by specific fly breeding habitats but was not significantly influenced by confinement type or waste management efforts. In addition, parasitism of house flies was significantly different between years. The pteromalids Muscidifurax zaraptor Kogan & Legner and Spalangia nigroaenea Curtis accounted for most of the parasitism of house fly pupae. Aleochara lacertina Sharp and S. nigroaenea were the most abundant stable fly pupal parasitoids. Grass clippings, used as an artificial breeding habitat for stable flies, influenced the occurrence of parasitoids and increased the rate of stable fly parasitism. Adult stable fly populations peaked in late July 1983 and in late August 1984. House fly populations generally increased throughout the summer. Confinement type and waste management efforts influenced adult fly population trends. The staphylinids Philonthus americanus Erichson and Oxytelus sculptus Gravenhorst were the most abundant insect predators found in this study.