Fruittree leafroller: Control of a Population Tolerant to Diazinon12

Abstract

Laboratory experiments confirmed suspected tolerance to diazinon by a strain of Archips argyrospilus (Walker) that attacks cherry in British Columbia. Diazinon has been the only insecticide recommended for control of fruittree leafroller on cherry in British Columbia since 1970. Suspected tolerant and known susceptible strains of fruittree leafroller larvae were reared on artificial media and exposed to a range of diazinon dosages. Significant differences in mortality between the 2 strains were recorded. Field experiments showed that azinphosmethyl, Penncap E® (encapsulated ethyl parathion), trichlorfon, and parathion gave good control of the tolerant strain on cherries with no evidence of cross tolerance. Trichlorfon caused marginal burn and interveinal chlorosis on cherry leaves, but the injury was not serious and did not affect the fruit.