The action of environmental effects in the natural mortality of the froghopper Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) compared with alternative insecticides in the sugar-cane organic culture

Abstract

The neem oil obtained from the neem tree,Azadirachta indica, and the formulations that contain the Metharizium anisoplae and Beauveria bassiana fungi were used to control the froghopper, Mahanarva fimbriolata, in sugarcane crops. The action of these products was compared with the insect natural mortality, through portions with untreated check. The experiment was performed in the period from March to May 2008, on a plot of sugarcane RB 85 5536 variety conducted in organic system, in Sertãozinho, São Paulo state, Brazil. It was used a statistic outlining in subdivided plots, with 7 treatments, 3 replications and 4 periods. Expressive statistic differences were not observed among the studied treatments. The natural mortality ranged from 55,50% to 80,81%. This suggests that the action of the environmental agents is sufficient to reduce the incidence of leafhopper, M. fimbriolata, without using of inseticides.