Antifeedant activity and toxic effect of some bioactive plant extracts against Spodoptera litura (Fabricius).

摘要

The antifeedant and toxic effects of 10 plant extracts (acetone, ethyl acetate and ethyl alcohol) from Uttaranchal, India were determined on S. litura reared on fresh castor leaves. The extracts were obtained from: Thuja compacta (Tc), Azadirachta indica (Ai), Lantana camara (Lc), Cannabis sativa (Cs), Datura alba [D. metel] (Da), Eucalyptus globulus (Eg), Achyranthes aspera (Aa), Lagerstroemia speciosa (Ls), Parthenium hysterophorus (Ph) and Terminalia arjuna (Ta). The acetone, ethyl acetate and ethyl alcohol extracts from Cs showed strong antifeedant activity with preference index values of 0.46, 0.50 and 0.50, respectively. Larval mortality due to bioactive plant extracts was observed at 24, 48 and 72 h after treatment. At 24 h, only Aa extracts caused mortality (6.68%). At 48 h, the highest larva mortality of 53.33% was recorded with ethyl acetate extracts of Ai and Da, followed by ethyl alcohol extract of Ai (40%) and acetone extract of Ai (33.33%). Larval mortality after 72 h was highest (93.33%) with ethyl acetate extract of Ai, followed by Ph (73.33%), Da (60.0%), ethyl alcohol extract of Ai (60.0%) and acetone extract of Ai (46.47%)..