Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2005
Publication Date: 2/1/2006
Citation: Geden, C.J., Hogsette Jr, J.A. 2006. Suppression of house flies (diptera: muscidae) in florida poultry houses by sustained releases of muscidifurax raptorellus and spalangia cameroni (hymenoptera: pteromalidae). Environmental Entomology. 35(1):75-82. Interpretive Summary: Biological control is an important component of integrated management systems for flies associated with livestock, poultry and horses. Parasitic wasps are among the most important biocontrol agents for flies, and there are several commercial insectaries that provide these wasps to farmers. There are about a dozen native species of wasps that are available for commercial production, but it remains unclear which species are most effective in different situations. Previous research by ARS researchers suggested that releases of more than one species with complimentary biological traits might be more effective than releases of single species. In this study, conducted by scientists at USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, releases of Muscidifurax raptorellus and Spalangia cameroni were made in Florida poultry houses to control house flies. Fly pupal mortality in the release houses was about double that in the control houses, and parasitism was 2-10 times higher. Adult fly populations were significantly lower in the release houses than in the control houses but were still higher than generally-accepted levels of control. Further work is needed to integrate parasitoid releases with other compatable management tactics such as baits and light traps to provide an effective IPM program for flies in poultry houses.
Technical Abstract: Weekly releases of Muscidifurax raptorellus and Spalangia cameroni were made for 12 weeks after house cleanouts in Florida pullet houses in either spring/summer (May-August) or fall (September-December). Releases were made by weekly placement of 62,500 and 85,000 pupae parasitized by M. raptorellus and S. cameroni, respectively, which produced an average of 79,049 and 32,841 adult female parasitoids per week. Fly pupal mortality, as measured by sentinel pupae, was about twice as high in the release house (40.2%) as in the two control houses (21.5 and 21.8%) in the summer release. Pupal mortality in the fall was 3- to 4- times higher in the release house (45.6%) as in the two control houses (13.6 and 8.4%). Although successful parasitism of sentinel pupae was only about 8.4 % in the release houses in both studies, parasitism was significantly higher than the control houses in both summer (3.9 and 1.7%) and fall (0.0 and 0.8%) releases. Fly populations were high in both studies, but significantly lower in the release houses than the controls in both summer (361.5 vs. 450.3 and 584.4 spots/ spot card/week) and fall (477.1 vs. 971.4 and 851.8 spots/card/week) releases. An average of 4.8 M. raptorellus emerged from each pupa parasitized by this species, with parasite loads ranging from 1 (8.6%) to 17 (0.07%) adults emerged per parasitized pupa.