Compatibility of Chemical Disease and Insect Management Practices Used in New York Vineyards with Biological Control by Anagrus spp. (Hymenoptera: Mymaridae), Parasitoids of Erythroneura Leafhoppers

Abstract

Toxicity to Anagrus spp. of fungicides and insecticides used in grape production was assessed with laboratory and field bioassays. Field-equivalent rates of fungicides were relatively nontoxic to Anagrus spp. adults in laboratory bioassays. In bioassays with field-weathered residues, sulfur (9600 ppm) caused elevated mortality of adults for 14 to 21 days posttreatment. Residues of microencapsulated methyl parathion (600 and 1200 ppm) increased mortality relative to the control up to 43 days posttreatment. Duration of elevated mortality of adults exposed to carbaryl was dose dependent and ranged from 14 (at 1200 ppm) to >43 days (at 4800 ppm). Residues of carbaryl and methyl parathion applied over parasitized eggs had little effect on emergence, but may have delayed development. In a field trial, adults trapped in carbaryl-treated plots were significantly reduced starting 3 weeks after treatment. Subsequent lower trap catches may have been related to effects of residues on Anagrus spp. adults or to lower leafhopper egg densities in treated plots.