Evaluation of reduced-risk alternative control programs for insect pests of apple and their impact on beneficial insects

Ontario apple growers rely on the use of organophoshporus (OP) insecticides to manage several pests of apple including plum curculio (Conotrachelus nenuphar Herbst), apple maggot (Rhagoletis pomonella Walsh), European apple sawfly (Hoplocampa testudinea Klug), codling moth (Cydia pomonella Linnaeus) and mullein bug ( Campylomma verbasci Meyer). Due to regulatory concerns regarding the impact of OP insecticides on worker safety, the use of these products may be severely restricted or eliminated. Alternatives to OP insecticides must be efficacious against pests and have minimal impact on beneficial insects. Reduced-risk insecticide programs tested were as efficacious as OP insecticide programs. Laboratory bioassays revealed that the reduced-risk insecticide, acetamiprid, was more toxic to some beneficial insects than OP insecticides. In field trials, the OP and reduced-risk insecticide programs were similar in toxicity to beneficial insects. Long-term studies are needed to evaluate the toxicity of reduced-risk insecticides to insect pests and beneficial insects.