Efeitos da aplicação de agrotóxicos utilizados na produção integrada de maçã sobre pupas de Chrysoperla externa

Abstract

Chrysoperla externa (Neuroptera: Chrysopidae) is an important biological control agent of artropod-pests in apple crop. In this research the effects of the pesticides (g a.i. L-1) abamectin (0.02), carbaryl (1.73), fenitrothion (0.75), methidathion (0.40), sulphur (4.80) and trichlorfon (1.50), on C. externa pupae from Bento Gonçalves and Vacaria regions, Rio Grande do Sul, Brazil, as well as on the development of the adults obtained and its reproduction were evaluated. The sprayings of those compounds and distilled water (control) on pupae were accomplished using a Potter tower. Carbaryl and trichlorfon caused mortality of treated pupae in both studied populations. Abamectin only caused significant mortality of treated pupae from Vacaria; sulphur, fenitrothion and methidathion presented to be harmless to the predator. None of the compounds reduced the oviposition capacity of C. externa from Bento Gonçalves, originated from treated pupae; however, fenitrothion caused reductions in that biological parameter for females from Vacaria. Among the evaluated pesticides, only carbaryl and abamectin did not reduced the viability of eggs laid by C. externa from Bento Gonçalves and Vacaria, respectively. According to the total effect (E) of each pesticide, sulphur, fenitrothion and methidathion are harmless, whereas abamectin, carbaryl and trichlorfon are slightly harmful to insects from Bento Gonçalves. Abamectin and sulphur are harmless to insects from Vacaria, while carbaryl, fenitrothion, methidathion and trichlorfon are slightly harmful, according to the IOBC classification.