pretreatment of adults of iraq strain of afhstephenst with a sub-letlial dose of pcrmethrin resulted in a 65% enliancemenl of tolerance to this insecticide. similarly, pre-exposure of dub-lpr larvae to a sub-lethal dose of pcrmethrin resulted in increased tolerance to pcrmethrin. for the sensitive ind-s strain, the inductive effect was smaller. tiie results of bioassays of resistant and suscept...