The obliquebanded leafroller (OBLR), Choristoneura rosaceana, is one of the most economically important insect pests in Michigan apple production. With the enactment of the Food Quality Protection Act broad spectrum organophosphates (OP) are swiftly being eliminated and several new chemistries have been registered that more selectively target pest species. We tested the effects of residues from the formulated product of six insecticides: GuthionŽ (azinphos-methyl; OP), AsanaŽ (fenvalerate; pyrethroid), SevinŽ (carbaryl), ProvadoŽ (imidacloprid; neonicotinoid), IntrepidTM (methoxyfenozide; diacylhydrazine), SpinTorTM(spinosad; naturalyte) and a water control, on the survival of Bassus dimidiator (Hymenoptera: Braconidae) one of the more prevalent parasitoids of OBLR in Michigan. Insecticides were sprayed onto petri dishes using an auto-load Potter Spray Tower (Burkard Scientific) and allowed to dry for one hour before parasitoid exposure. In a second trial apple leaves were sprayed using the same methods and allowed to dry for 1h or 24h before parasitoid exposure. Parasitoid mortality was assessed at 4, 24, 48, 72, 96, and 120h. With the exception of IntrepidTM, all insecticides significantly reduced B. dimidiator survival versus the control. Spraying leaves reduced toxicity of ProvadoŽ and IntrepidTM, while aging residues increased parasitoid survival for most chemicals.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA