title: Enhanced activation is the mechanism of negative cross-resistance to Chlorpyrifos in the Dicofol-IR strain of Tetranychus urticae (Acari: Tetranychidae).
abstract: The mechanism responsible for negative cross-resistance to chlorpyrifos was examined in isogenic dicofol susceptible (Orchard-12) and resistant (Dicofol-IR) two-spotted spider mites, Tetranychus urticae Koch. The acetylcholinesterase of both strains was equally sensitive to inhibition by chlorpyrifos oxon. However, the Dicofol-IR strain showed increased oxidative activation of chlorpyrifos to chlorpyrifos oxon relative to the Orchard-12 strain, suggesting this mechanism is responsible for the observed negative cross-resistance.
authors.affiliation: Department of Entomology, Cornell University, Ithaca, New York 14853.
authors.forename: R
authors.initials: R
authors.lastname: Hatano
authors.forename: J G
authors.initials: JG
authors.lastname: Scott
authors.forename: T J
authors.initials: TJ
authors.lastname: Dennehy
mesh_terms: D000818:Animals; D004390:Chlorpyrifos / Q000494:pharmacology; D007305:Insecticide Resistance; D008925:Mites / Q000187:drug effects; D013045:Species Specificity
chemical_list: D004390:Chlorpyrifos