Azadirachtin-A content of neem fruits has been found to reduce on artificial ripening. There was no detectable azadirachtin-A in the 3d fully ripened samples as against 0.069% in 0 d raw fruits. However, the efficacy against Spodoptera litura larvae was affected the least by azadirachtin-A content alone as shown by ED50 values of unripened (Od, 10.58 ppm) to that of the ripened (3d, 13.16 ppm) fruits. The growth of the larvae was influenced by the total methanolic extract of the artificially ripened fruits in a dose-dependent manner, presumably due to the presence of antifeedant allelochemicals.
Azadirachtin-A, neem, Spodoptera litura, growth inhibition, antifeedant
