EFEITO DE PRÉ-MISTURAS DE BACULOVÍRUS NO CONTROLE DE Chrysodeixis includens (WALKER, 1858) (LEPIDOPTERA: NOCTUIDAE) NA CULTURA DA SOJA (Glycine max L.)

Abstract

Companies that commercialize NPVs have advanced to the problem of resistance induction and, therefore, developed viral products containing the mixture of several viral species. But this new biotechnology still has few results evaluated in real production systems, against the soybean looper. The objective was to evaluate the population fluctuation of Chrysodeixis includens (Lepidoptera: Noctuidae) caterpillars sampled in soybean plants after foliar spraying of treatments T1 (water only, control), T2 (Indoxacarb), T3 (Bacillus thuringiensis var. kurstaki), T4 (Surtivo®Soja100, HearNPV + ChinNPV), T5 (Surtivo®Soja100 + molasses), T6 (Surtivo®Plus140, AcMNPV + HearNPV + ChinNPV + SfMNPV) and T7 (Surtivo®Plus140 + molasses) under field conditions. The test was conducted in a commercial soybean crop (cv. Syngenta 1163 RR®) in Campo Alegre de Goiás, southeastern Goiás state, Brazil. After detection of the application time, the sprayings were carried out and the number of small, medium, large and total caterpillars quantified by beating cloth at 0, 4, 8, 14 and 21 DAA (days after application). Although only smaller caterpillars have been the target of applications with NPVs, our results have shown that the population of this insect also suffered interference from virus treatments, perpetuating its effects, even in larger caterpillars. Surtivo®Plus140 + molasses (T7) was the best treatment in order to reduce the incidence of caterpillars, regardless the pest size. The presence of cane molasses may have triggered benefits capable of generating greater infectious effects. The observed biological responses are discussed and expand the opportunities for the practice of integrated management for the soybean looper in Brazil.