Comparative Selectivity of Herbicides Used in Wheat Crop on the Predators Chrysoperla externa and Eriopis connexa

Abstract

The selectivity of eight herbicides registered for use in the wheat crop was assessed on the predators Chrysoperla externa and Eriopis connexa. Bioassays were conducted in the laboratory by exposing larvae, eggs, and pupae of these predators to dry residues of the herbicides 2,4-D amine, bentazon, glyphosate 1.200, glyphosate 1.440, ammonium glufosinate, iodosulfuron-methyl, metsulfuron-methyl, and pyrimidinedione. The herbicide ammonium glufosinate was classified as moderately harmful (class 3) to the larval stage of both predators. In the egg stage, only metsulfuron-methyl showed a reduction in larval hatching higher than 30% and was classified as slightly harmful (class 2) to eggs of E. connexa. The herbicide 2,4-D amine was classified as slightly harmful (class 2) to pupae of C. externa, while pyrimidinedione presented the same classification to pupae of E. connexa. The herbicides bentazon, glyphosate 1.200, glyphosate 1.440, and iodosulfuron-methyl were considered as innocuous to the stages of larva, egg, and pupa of C. externa and E. connexa and can be used in the integrated pest management of wheat crop, assisting in predator conservation.