Toxicidade de pesticidas recomendados na produção integrada de maçã (PIM) a populações de Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae)

Abstract

The goal of this work was to evaluate the effects of the pesticides abamectin, carbaryl, fenitrothion, methidathion, sulphur and trichlorfon on eggs of two Chrysoperla externa (Hagen) populations, as well as on the subsequent developmental stages and reproduction capacity of this green lacewing. Pesticide exposure and distilled water (control) were accomplished using a Potter’s tower. None of the evaluated pesticides affected the egg viability of the C. externa populations studied, but abamectin and carbaryl caused signifi cant mortality of other developmental stages of the predator. Sex ratio and reproduction capacity of females originated from treated eggs were unaffected. However, egg viability of C. externa from Bento Gonçalves, RS, Brazil, was reduced by sulphur. Considering to the total effect (E) of each pesticide, trichlorfon, fenitrothion, methidathion and abamectin were harmless to both C. externa populations (Bento Gonçalves and Vacaria), when applied on eggs, whereas carbaryl was slightly harmful. On the other hand, the fungicide sulphur was slightly harmful to C. externa from Bento Gonçalves, but harmless to those from Vacaria.