Nicosulfuron Plus Atrazine herbicides and Trichogrammatidae (Hymenoptera) in no-choice test: selectivity and hormesis

Abstract

The aim of this study was to evaluate the effect of the herbicide mixture nicosulfuron + atrazine on 10 trichogrammatid species. A female of each trichogramma- tid was placed in a test tube (no-choice) with a card with 45 Anagasta kuehniella eggs. Parasitism was allowed over a 48 h period, then the cards were sprayed with a solution containing nicosulfuron (30 g ha^−1 ) + atrazine (1500 g ha^−1 ), besides the control (distilled water). The nicosulfuron + atra- zine mixture increased the Trichogramma atopovirilia and T. pretiosum female emergence. The percentage of T. acacioi , T. atopovilia and T. pretiosum male parasitoids emerged was higher in the control, and for T. demoraesi and Trichogrammatoidea annulata with nicosulfuron + atra- zine. Sex ratio of the trichogrammatids was similar with nicosulfuron + atrazine.