Effect of Methanolic Extract and its Fractions of Karanj (Pongamia pinnata) Seeds on Oviposition and Egg Hatching of Plutella xylostella (Lepidoptera: Yponomeutidae)
Patil, Sureshgouda; Singh, Ram; Kalidhar, S B
The effect of methanolic extract and its fractions (acetone, chloroform and hexane) of karanj (Pongamia pinnata (Linnaeus 1758) Pierre 1781) seeds on the oviposition behaviour and hatachability of eggs of Plutella xylostella Linnaeus 1758 were investigated under laboratory conditions. The treatments included 2.5, 5.0, 7.5 and 10.0% of methanol extract and 0.5, 1.0, 1.5 and 2.0% concentrations of fractions to compare with karanj oil (1.0%), acetone and water as controls. Under choice condition, the adults preferred to lay a greater number of eggs on the untreated portion of the oviposition substrate (glass wall) compared with the extract treated portion. The extract also manifested repellent activity by reducing the number of eggs laid even when the ovipositing females were not in direct contact with the extract. Eggs laid on extract and fraction treated oviposition substrates exhibited reduced hatching. Adults fed on an extract and fractions containing sucrose diet laid significantly fewer eggs with poor hatching in comparison to control and the adverse effects were more pronounced.