INSECTICIDAL BIOACTIVITY OF CRUDE EXTRACTS OF AGLAIA SPECIES (MELIACEAE)

Crude foliar extracts of 19 species of Aglaia (Meliaceae), mostly of Indo-Malaysian origin, were screened for larval growth inhibiting and insecticidal effects on the polyphagous lepidopteran Peridroma saucia (Noctuidae). Extracts of at least seven of these species significantly reduce larval growth of P. saucia. Aglaia odorata yielded the most inhibitory extracts, but there is significant (35-fold) geographical variation in the bioactivity of extracts within this widespread species. In addition, extracts of bark are significantly more active than foliar extracts. Foliar extracts significantly deter neonate larvae, but nutritional analyses of fourth instar larvae fed artificial diets laced with A. odorata extracts indicate that both diet consumption and dietary utilization are impaired. These results are similar to that obtained with pure (-)-rocaglamide, an insecticidal principle isolated from A. odorata. This species should provide a useful starting point for the development of a botanical insecticide.