Effect of Cold Hexane Extract of Karanja (Pongamia Glabra Vent) Seed Kernel on the Development of Mosquito Larvae.

ABSTRACT

Cold Hexane extract of karanja, Pongamia glabra Vent (Fabaceae) seed kernel (HKSK) ranging at the concentrations of 4 ppm to 28 ppm was evaluated against the freshly emerged larvae of Aedes aegypti and Culex quinquefasciatus. Treatment of HKSK imparted the mortality that was correlated with the level of dosage. Before pupation,100% fatality occurred in Ae. aegypti at a concentration of 20 ppm whereas in Cx. quinquefasciatus the same degree of mortality occurred at the extract concentration of 12 ppm in the first instar larvae only. At low doses, the emerging adults of Cx. quinquefasciatus had deformed legs, wings and truncated abdomen but the adults of Ae. aegypti showed no deformities. The developmental period was prolonged significantly in a dose-dependent manner for both the species treated. In Cx. quinquefasciatus this effect was more pronounced because of increased intermoult period showing an IGR effect of the extract. The calculated growth index also decreased in dose-dependent manner significantly more in Cx. quinquefasciatus. Indeed, Ae. aegypti appeared more susceptible to HKSK than Cx. quinquefasciatus.