Abstract
Dicofol-susceptible and resistant strains of the two-spotted spider mite, Tetranychus urticae, were treated with 3H-dicofol. The resistant strain appeared to have a higher ability to metabolize dicofol to water soluble metabolites than the susceptible strain. No significant difference in cuticle permeability between susceptible and resistant strains was found. It is suggested that the difference in dicofol metabolism is one of the factors responsible for dicofol resistance. Two dicofol metabolites were detected; one was a chloroform extractable metabolite which behaved like 4, 4'-dichlorobenzohydrol or benzohydrol by thin-layer chromatography, and the other was a water soluble metabolite. The metabolic pathway of dicofol seems to be as follows: dicofol→chloroform extractable metabolite→water soluble metabolite.
