Residual toxicity of acaricides to Galendromus occidentalis and Phytoseiulus persimilis reproductive potential

Resumen

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 (Fujimite ®), acequinocyl (Kanemite ®), etoxazole (Zeal ®), spiromesifen (Oberon ®), bifenazate (Acramite ®) and abamectin (Agri-mek ®) on leaflets to Galendromus occidentalis (Nesbitt) and Phytoseiulus persimilis Athias-Henriot (Acari:Phytoseiidae) were assessed 3, 6, 10, 14, 17, 24, 30 and 37 days post treatment. Impacts on mortality, fecundity and fertility were determined following 3 days of exposure to each leaf surface residue interval. Percent mortality and total effects (E) on adult female reproductive potential thus measured were used to assess each acaricide's persistence. Based on mortality, fenpyroximate was considered slightly (from 5 to 15 days) persistent for both species by IOBC standards, while abamectin was also slightly persistent for P. persimilis only. The remaining acaricides would be classified as short lived (less than 5 days) for both species. Persistence classified by considering E suggest that fenpyroximate and etoxazole would be the least compatible with G. occidentalis and P. persimilis. Both were persistent (longer than 30 days). Bifenazate and spiromesifen were slightly persistent to both predators. Acequinocyl was slightly persistent to G. occidentalis, but short lived to P. persimilis. Abamectin was slightly persistent to P. persimilis, but short lived to G. occidentalis. Consideration of both direct and side effects of these acaricides will improve pesticide selection, anabling better conditions for Phytoseiid conservation and augmentation. © 2006 Elsevier Inc. All rights reserved.