Parasitism of Tufted Apple Bud Moth (Lepidoptera: Tortricidae) in Conventional Insecticide and Pheromone-Treated Pennsylvania Apple Orchards

Abstract

A faunistic study was conducted over a four year period in apple orchards utilizing different pesticide management strategies to determine the parasitoid complex of the tufted apple bud moth, Platynota idaeusalis (Walker). The relative effectiveness of these parasitoids as control agents in conventional orchards using broad-spectrum insecticides was compared to those using pheromone-mediated mating disruption to control P. idaeusalis. Limited samples were also taken of other tortricids found in these orchards to determine if they were serving as alternate hosts for P. idaeusalis parasitoids. Thirty-one parasitoid and two hyperparasitoid species were recovered during this study which, when combined with other records, present a total parasitoid complex of 41 species for P. idaeusalis. Total parasitism was higher for summer brood P. idaeusalis larvae in mating disruption orchards than in conventional orchards. Total parasitism of the overwintering brood of P. idaeusalis was higher than the summer brood in conventional orchards. Rates of parasitism were comparable in mating disruption blocks during both broods. The ichneumon Exochus atriceps Walsh. was the most common parasitoid species, and it attacked both broods of P. idaeusalis. The braconids Meteorus trachynotus Viereck, Bassus anulipes (Cresson), B. cinctus (Cresson), Apanteles polychrosidis Viereck, and an Apanteles sp. near edwardsii Riley were also common but they attacked only the overwintering brood. Four undescribed species of braconids were found during this study.