Toxicity of Pesticides Registered for Use in Landscape Nurseries to the Acarine Biological Control Agent, Neoseiulus fallacis

Abstract The predatory mite Neoseiulus fallacis (Garman) is an important biological control agent of spider mites in landscape plants produced in the Pacific Northwest. Using pesticide toxicity information from the SELCTV database and recent literature reports, we estimated toxicity of several general pesticide classes to N. fallacis, compared susceptibility of N. fallacis to 3 other predatory mites and developed summary tables of pesticide toxicity to N. fallacis. Pesticide classes ranged from low or non-toxic to N. fallacis (i.e., organosulfur) to highly toxic (i.e., oxime carbamate). Pesticide susceptibility data for N. fallacis within or between chemical classes was similar to data for either of Typhlodromus pyri Scheuten, Galendromus occidentalis Nesbitt, or Phytoseiulus persimilis Athias-Henriot. While all pesticide types (i.e., insecticides, fungicides, herbicides, etc.) contained representatives that were highly toxic to N. fallacis, various compounds were rated low or non-toxic. On average, insecticides were most toxic to N. fallacis, fungicides least toxic and herbicides intermediate. Probability of exposure and integration of N. fallacis into current control practices are discussed.