Enhanced activation is the mechanism of negative cross-resistance to Chlorpyrifos in the Dicofol-IR strain of Tetranychus urticae (Acari: Tetranychidae).
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.
Hatano
R
R
Department of Entomology, Cornell University, Ithaca, New York 14853.
Scott
J G
JG
Dennehy
T J
TJ
D000818:Animals; D004390:Chlorpyrifos / Q000494:pharmacology; D007305:Insecticide Resistance; D008925:Mites / Q000187:drug effects; D013045:Species Specificity
D004390:Chlorpyrifos