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

Toxicity to Anagrus spp. of fungicides and insecticides used in grape produ ction was assessed with laboratory and field bioassays. Field-equivalent ra tes of fungicides were relatively nontoxic to Anagrus spp. adults in labora tory bioassays. In bioassays with field-weathered residues, sulfur (9600 pp m) caused elevated mortality of adults for 14 to 21 days posttreatment. Res idues of microencapsulated methyl parathion (600 and 1200 ppm) increased mo rtality relative to the control up to 43 days posttreatment. Duration of el evated mortality of adults exposed to carbaryl was dose dependent and range d from 14 (at 1200 ppm) to > 43 days (at 4800 ppm). Residues of carbaryl an d methyl parathion applied over parasitized eggs had little effect on emerg ence, but may have delayed development. In a field trial, adults trapped in carbaryl-treated plots were significantly reduced starting 3 weeks after t reatment. Subsequent lower trap catches may have been related to effects of residues on Anagrus spp. adults or to lower leafhopper egg densities in tr eated Plots. (C) 2001 Academic Press.