Sublethal effects of selected insecticides on growth and reproduction of a laboratory susceptible strain of tufted apple bud moth (lepidoptera : Tortricidae)

The sublethal effects on development and reproduction of previously estimated LC sub(10) and LC sub(25) of azinphosmethyl, several classes of insect growth regulators (IGRs), and abamectin were evaluated on a laboratory susceptible strain of the tufted apple bud moth, Platynota idaeusalis (Walker). Neonates (5th instars in the case of fenoxycarb) were exposed through ingestion of diet treated on the surface. The following parameters were evaluated: larval and pupal duration, mortality of each stage and sex, pupal weights, and fecundity and fertility. At the concentrations evaluated, azinphosmethyl and diflubenzuron did not affect development or reproduction of either sex, but diflubenzuron caused higher pupal mortality in males compared with females. Tebufenozide reduced fecundity in matings in which the larvae of both sexes had been treated, whereas abamectin increased the developmental time from neonate to adult eclosion and greatly affected fecundity. Exposure of 5th instars to fenoxycarb greatly increased duration of the larval stage and pupal weight in female larvae, but not in male larvae. Fecundity and fertility also were affected.