Daily Sensitivity Rhythm of the Two-Spotted Spider Mite, Tetranychus urticae , to DDVP

Abstract
Adult females of the two-spotted spider mite (Tetranychus urticae Koch), showed a daily rhythm of sensitivity to DDVP (dimethyl 2,2-dichlorovinyl phosphate). When the mites were maintained in alternating light-dark conditions, maximum susceptibility to the chemical occurred 2 hours after dawn and the mites were least sensitive 2 hours after nightfall.