title: Resistance status of house flies (Diptera: Muscidae) from southeastern Nebraska beef cattle feedlots to selected insecticides.
abstract: The status of resistance to three 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. Topical application and residual exposure to treated glass surfaces were suitable methods for determining the resistance status of house flies to permethrin, stirofos, or methoxychlor. However, in most cases, residual exposure was more sensitive in resistance detection (i.e., higher resistance ratios). The field populations tested were moderately resistant to permethrin (RR = 4.9-fold and RR = 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.
authors.affiliation: Dupont Productos Agricolas Estacao Experimental Agricola, Rua Bortola Ferro, No. 500 Paulina SP 13140-000 Brazil.
authors.forename: Paula C R G
authors.initials: PC
authors.lastname: Marçon
authors.forename: Gustave D
authors.initials: GD
authors.lastname: Thomas
authors.forename: Blair D
authors.initials: BD
authors.lastname: Siegfried
authors.forename: John B
authors.initials: JB
authors.lastname: Campbell
authors.forename: Steven R
authors.initials: SR
authors.lastname: Skoda
mesh_terms: D000818:Animals; D002417:Cattle / Q000469:parasitology*; D007300:Insect Control; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D008731:Methoxychlor / Q000494:pharmacology; D009117:Muscidae / Q000187:drug effects* / Q000502:physiology*; D009329:Nebraska; D026023:Permethrin / Q000494:pharmacology; D013751:Tetrachlorvinphos / Q000494:pharmacology
chemical_list: D007306:Insecticides; D026023:Permethrin; D013751:Tetrachlorvinphos; D008731:Methoxychlor