Eficiência das diferentes concentrações de Metarhizium anisopliae (Metsch.) Sorokin no controle da Mahanarva fimbriolata (Stål, 1854) (Hemiptera: cercopidae) em condições de campo

Abstract

The objective was to evaluate the effectiveness of different concentrations of Metarhizium anisopliae in controlling Mahanarva fimbriolata. The study was conducted under field conditions in the municipality of Ponta Porã, Mato Grosso do Sul. The treatments consisted of the witness in the trial, chemical Actara ® (thiamethoxam 250WG) at a dose of 1Kg/ha-1 and isolated BIO 08 , UFGD 21, IBCB 348 and IBCB 425 of the M. anisopliae, in the doses 3Kg/ha-1, 4 Kg/ha-1 and 5Kg/ha-1. The conidial suspensions prepared from washing rice in water containing surfactant (Tween 80®) at 0.1%. We used a randomized block design with four replications for each treatment, each share represented by 10 grooves spaced 10 meters by 1.4 meters and 2 rows of edging. In samples collected 15 days after application (DAA), the most efficient in controlling the nymphs of M. fimbriolata was obtained by the strain BIO 08 at the rate of 4Kg/ha-1. At ages 30, 45, 60 and 105 DAA there were no significant differences between treatments. At 75 and 90 DAA IBCB isolate 425 at a dose of 5 Kg/ha-1 obtained the highest efficiency. The treatments with the isolated IBCB 425 and BIO 08 at doses of 5 Kg/ha-1 and 4Kg/ha-1, respectively, were the most outstanding during the 105 days. These results demonstrate the efficiency of the fungus M. anisopliae on nymphs of the leafhopper-the-root of cane sugar.