Toxicity of Andira paniculata (Fabaceae) Extracts to Helicoverpa armigera (Lepidoptera: Noctuidae)

Abstract

Helicoverpa armigera is one of the most important pests of soybean crop in Brazil. The purpose of this work was to evaluate the effect of organic Andira paniculata extracts on its biology, feeding and the attractiveness of soybean plants to H. armigera. Hexane, dichloromethane, ethyl acetate and hydroalcoholic fractions at concentrations of 0.01, 0.1, 0.5 and 1% were evaluated. For the biological parameters the period and viability of larval stage, caterpillar weight at ten days, period, viability and pupal weight at 24 hours, total longevity, LC50 and deterrence were evaluated. The non-preference for feeding and attractiveness, the number of caterpillars and the dry matter consumed in each fraction of the extracts were evaluated. The extract of A. paniculata in hexane (0.01%) resulted up to 85% mortality of H. armigera. The A. paniculata extract did not affect the larval period, weight, pupal period and mortality or the consumption of H. armigera. The hydroalcoholic extracts obtained the better results for deterrence. The A. paniculata extract in dichloromethane fraction had the lowest LC50. The A. paniculata extracts in the hexane fractions (0.1%), ethyl acetate (0.01 and 0.5%) and hydroalcoholic (0.01 and 0.5%) were fagodeterrents for H. armigera. Thus, A. paniculata extract in hexane fraction is the most promising for use in the control of H. armigera in soybean.