Bioefficacy of crude extracts of <i>Aglaia</i> species (Meliaceae) and some active fractions against lepidopteran larvae

Abstract

Abstract Foliar and twig extracts of three species of Aglaia were screened for larval growth inhibiting and antifeedant effects against the polyphagous lepidopteran larvae of Spodopteva litura and Helicoverpa armigera. A. elaeagnoidea and A. odorata crude ethanolic extracts were at par in their activity at an initial treatment level of 5 mg/g of dry diet weight, while A. roxburghiana was half as active as the other two species. Detailed investigation of A. elaeagnoidea species revealed the presence of complex limonoid fractions responsible for this activity. The nutritional analyses showed impaired diet consumption and dietary utilization at 200 ppm level of treatment when limonoid fractions Fr 2 J and Fr 6 K were provided orally to S. litura larvae, indicating centrally mediated anorexic effect. The isolation of the limonoid complex from A. elaeagnoidea should provide useful starting point for the development of a botanical anti‐insect preparation.