Residual effects of acaricides on Typhlodromus pyri (Acari, Phytoseiidae)

Understanding the effects of pesticide residues on leaf surfaces through time on phytoseiid mites is important to their successful integration into augmentation and/or conservation programs. The residual toxicities of fenpyroximate , acequinocyl, etoxazole, spiromesifen and abamectin on leaflets to Typhlodromus pyri Scheut (Acari:Phytoseiidae) were assessed 0, 7, 14, 24, and 36 days post treatment. Impacts on mortality, fecundity and fertility were determined following 3 days of exposure to each leaf surface residue interval. Total effects (E) on adult female reproductive potential thus measured were used to assess each acaricide’s persistence and toxicity. All the acaricides tested were toxic to T. pyri after 0 days of treatment. Overall, older residues were not harmful but increase T. pyri reproductive potential. Consideration of hormoligotic side effects of these acaricides on T. pyri biological performance is discussed.