Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2002
Publication Date: 6/1/2003
Citation: MARCON, P.C., THOMAS, G.D., SIEGFRIED, B.D., CAMPBELL, J.B., SKODA, S.R. RESISTANCE STATUS OF HOUSE FLIES (DIPTERA: MUSCIDAE) FROM SOUTHEASTERN NEBRASKA BEEF CATTLE FEEDLOTS TO SELECTED INSECTICIDES. 2003. JOURNAL OF ECONOMIC ENTOMOLOGY. 96(3): 1016-1020. Interpretive Summary: House flies do not bite but are quite annoying to humans and domestic animals. They often try to feed at the eyes or on open wounds of their hosts. They are also implicated as transmitters of disease causing organisms. House flies can be found in high numbers around livestock confinement operations throughout the late spring and summer months. There is increasing potential of confined livestock being implicated as the source of house fly problems in urban areas that could lead to litigation. Since insecticides are still the mainstay of fly control and there are now only a few that can be used on confined livestock, it is important to monitor the resistance status of house flies to these insecticides. Therefore, this study evaluated the effectiveness of 3 insecticides commonly used for house fly control.
Technical Abstract: The status of resistance to 3 insecticides (permethrin, stirofos, and methoxychlor), relative to a laboratory-susceptible colony, was evaluated in field populations of house flies, Musca domestica L., collected from two beef cattle feedlots in southeastern Nebraska. Two bioassay techniques, topical applications and residual exposure to treated glass surfaces, were compared to determine which would be more effective in resistance detection. Both techniques were suitable for testing susceptibility of house flies to permethrin, stirofos, or methoxychlor. However, in most cases, residual exposure resulted in better detection of resistance (i.e. higher resistance ratios). The field populations tested were moderately resistant to permethrin (RR less than or equal to 4.9-fold and RR less than or equal to 7.3-fold, for topical application and residual exposure, respectively) and extremely resistant to stirofos and methoxychlor (not accurately quantifiable because of low mortality at the highest possible concentrations or doses). Probable explanations for the resistance status of these house fly populations and implications for global feedlot fly management are discussed.