Larvicidal effect of some plant extracts against Spodoptera litura (Fab.) and Pieris brassicae (Linn.).

The aqueous extract of eight plant species, namely Azadirachta indica A. Juss, Melia azedarach Linn., Lantana camara L. Moldenke., Cannabis sativa Linn., Nerium indicum Mill., Eucalyptus sp., Ricinus communis Linn. and Solanum nigrum Linn. were tested for larvicidal effect against Spodoptera litura and Pieris brassicae. The ethanol extract of potential plants were further tested for their biological activity against the test insects. The aqueous extract of A. indica and M. azedarach resulted in statistically higher larvicidal (killing 20.9% and 19.2% larvae of S. litura by A. indica and M. azedarach, respectively and 18.5% and 19.6% larvae of P. brassicae by A. indica and M. azedarach, respectively) effect against S. litura and P. brassicae as compared to other plant extracts. In case of ethanol extract also seed extract of A. indica and M. azedarach were highly effective against S. litura and P. brassicae giving statistically higher larvicidal (22.2% and 25% and 13.2–50% and 10.5–39.5%, respectively) effect, as compared to other plant extracts.