Antifeedant Activity of Leaves Extracts of Millettia pachycarpa (Bentham) against Spodoptera litura (Fabricius)

Antifeedant activity of various extracts of M. pachycarpa leaves viz. hexane extract, methanol extract, DCM extract, butanol extract and one of the fractions obtained from DCM extract was investigated against third instar larvae of Spodoptera litura through choice method and compared with technical azadirachtin (20%). Activity was observed after 24 and 48 h. Based on antifeedant activity at individual concentrations, antifeedant index (AI₅₀) of each extract, fraction and technical azadirachtin (20%) was calculated. When the antifeedant activity of various extracts and fractions was observed through choice method after 24 h, methanol extract showed lowest AI₅₀ as 228.79 ppm followed by butanol (242.49 ppm). Both these extracts showed very good antifeedancy compared to azadirachtin. The order of antifeedancy in increasing order was DCM extract <hexane extract < aza <FR 5 <butanol extract <methanol extract. Although after 48 h, azadirachtin showed antifeedant activity better than these two extracts, but DCM extract showed the highest AI₅₀ value in both periods of exposure.