The effects of aqueous extracts of plants on the biology, preference for oviposition and embryonic period of Plutella xylostella were evaluated. Concentrations between 0.03 and 0.8 % for kernel of Azadirachta indica, 0.5 and 7.0% for peel of Aspidosperma pyrifolium and 0.5 and 12.5% for fruits of Melia azedarach were used, with LC50 values of 0.06; 2.17 and 2.90%, respectively, being obtained. It was verified that the aqueous extracts of all of the appraised vegetable species affected the development of the insect, mainly in the larval phase. In the pupae phase, the extracts reduced the weight and the viability. There was adults' deformation for the extracts of A. pyrifolium and M. azedarach, being it of A. indica what caused larger percentage. Toxics effects on the eggs of P. xylostella were observed for all extracts. The extracts from A. pyrifolium (peel); M. azedarach (fruit) and A. indica (kernel) presented ovicide action in the lethal concentration of caterpillars at first instar of the pest. Observations of P. xylostella eggs with the aid of an electronic microscope showed presence of microspore, revealing ovicide action, besides wrinkled texture of the eggs peel retaining the extracts.
Insecticide plants; diamondback moth; cruciferae
