Mortality of Plutella xylostella larvae treated with Aspidosperma pyrifolium ethanol extracts

Abstract

The objective of this work was to assess the effects of Aspidosperma pyrifolium ethanol extracts on cabbage moth (Plutella xylostella) larvae. The ethanol extracts of the stem bark, fruits and roots of A. pyrifolium were obtained by classical phytochemical methods, and the resulting subfractions were tested on P. xylostella, using 4 and 5 mg L-1. The crude ethanol extract of the stem bark was more lethal. The alkaloid-rich aqueous subfraction derived from the stem bark extract caused 100% larval mortality at 4 mg L-1. Insecticidal activity was associated with the presence of the monoterpenoid indole alkaloids aspidofractinine, 15-demethoxypyrifoline, and N-formylaspidofractinine. These alkaloids presented excellent insecticidal properties against P. xylostella.

O objetivo deste trabalho foi avaliar os efeitos dos extratos etanólicos de Aspidosperma pyrifolium sobre lagartas da traça-das-crucíferas (Plutella xylostella). Os extratos etanólicos da casca do caule, do fruto e da raiz de A. pyrifolium foram obtidos pelos métodos fitoquímicos clássicos, e as subfrações resultantes foram testadas contra P. xylostella, nas dosagens 4 e 5 mg L-1. O extrato bruto etanólico da casca do caule foi mais letal. A subfração aquosa rica em alcalóides, derivada do extrato da casca do caule, causou 100% de mortalidade larval a 4 mg L-1. A atividade inseticida foi associada à presença dos alcalóides monoterpenóides indólicos aspidofractinina, 15-demetoxipirifolina e N-formilaspidofractinin. Estes alcalóides apresentaram excelente propriedade inseticida contra P. xylostella.