Comparative toxicity of some acaricides to the predatory mite, Phytoseiulus persimilis and the twospotted spider mite, Tetranychus urticae

The relative toxicity of some acaricides to the predatory mite, Phytoseiulus persimilis and the twospotted spider mite, Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) was evaluated in laboratory. Five of the acaricides tested, including bifenazate, acequinocyl, chlorfenapyr, flufenoxuron and fenbutatin oxide, were much less toxic to adult females and immatures of P. persimilis than to those of T. urticae, and adult female predators treated with these five acaricides produced 84+/-96% as many eggs as did control females. Etoxazole did not seriously affect the survival and reproduction of adult female predators but caused high mortality rates in eggs and larvae of P. persimilis. Milbemectin and fenazaquin were very toxic to adult females and immatures of P. persimilis. Adult female predators survived on a diet of spider mites treated with bifenazate, acequinocyl, chlorfenapyr, flufenoxuron and fenbutatin oxide, and their fecundity, prey consumption and the sex ratio of the progeny were not substantially affected. Based on the results, bifenazate, acequinocyl, chlorfenapyr, flufenoxuron and fenbutatin oxide appeared to be the promising candidates for use in integrated mite management programs where P. persimilis is the major natural enemy.