The impact of insecticides applied in apple orchards on the predatory mite Kampimodromus aberrans (Acari: Phytoseiidae)

Kampimodromus aberrans is an effective predatory mite in fruit orchards. A number of experiments were conducted to evaluate the effects of insecticides on K. aberrans. Field experiments showed the detrimental effects of etofenprox, tau-fluvalinate and spinosad on predatory mite populations. Panonychus ulmi populations reached higher densities on plots treated with etofenprox and tau-fluvalinate. Apparently neonicotinoids did not cause detrimental effects on predatory mites. In the laboratory, spinosad and tau-fluvalinate caused 100 % mortality. Etofenprox was associated to a significant mortality and a reduced fecundity. The remaining insecticides did not affect female survival except for imidacloprid. Thiamethoxam, clothianidin, thiacloprid, chlorpyrifos, lufenuron and methoxyfenozide reduced fecundity. Escape rate of K. aberrans in laboratory was relatively high for etofenprox and spinosad. The use of etofenprox and tau-fluvalinate induced spider mite population increases. Some pesticides (associated to reduced fecundity and repellence) should be considered with caution in integrated pest management programs.