Topical Toxicity of Pesticides Used in Virginia Vineyards to the Predatory Mite, Neoseiulus fallacis (Garman)

Slide dip bioassays were conducted to determine the direct toxicity of insecticides, acaricides, fungicides, and herbicides commonly used in vineyards in Virginia to Neoseiulus fallacis (Garman) (Acari: Phytoseiidae), a predatory mite under consideration as a biological control agent for spider mites (Acari: Tetranychidae). Among the insecticides and acaricides tested in the laboratory, carbaryl, azinphos-methyl, phosmet, cyhexatin, and pyridaben caused significantly (P ≤ 0.05) higher mortality than the control treatment. None of the fungicides tested were toxic to the predator, but three herbicides caused high mortality. Glufosinate caused 100% mortality after 24 h, and both oxyfluorfen and paraquat had adverse effects on N. fallacis. The use of materials that were found to be toxic to the predator may not be compatible with releases of N. fallacis into Virginia vineyards. However, incorporating materials that appear to have no direct toxicity to the predator into an integrated pet management program could improve the survival rate of released N. fallacis while still protecting this high value crop from other pests.