Efeito de extrato aquoso de Melia azedarach no desenvolvimento das fases imatura e reprodutiva de Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)

Abstract

The effect of different concentrations of aqueous extracts of Melia azedarach on Spodoptera frugiperda biology was investigated under laboratory conditions. Corn leaves were immersed in solutions with extract concentrations of 0.1%; 1.0% and 5.0% and offered to newly-born larvae. At higher doses (1.0% and 5.0%) the extracts caused 100 % mortality of larvae. Observations of dead larvae showed abnormal moults and death at ecdysis. At the concentration of 0.1%, chinaberry extract increased the larval phase and reduced significantly the larval and pupal weight. Reproduction parameters, as the number of eggs per female, eggs per oviposition and eggs viability were affected using emerged adults from treated larvae with concentration of 0.1% Melia extract. The fecundity was drastically reduced. Survival and duration of egg stage were not affected by the extracts. No effect was observed in relation to attractiveness of caterpillars at first instar in tests with possibility of choice. The chinaberry aqueous extract showed good potential to be used as a control agent for S. frugiperda.