The aim of the present investigation is to test the larvicidal activity of Azadirachta indica (A. Juss) and Datura metel (Linn.) leaf extract against the third instar larvae of C. quinquefasciatus (Say) (Diptera: Culicidae). A. indica and D. metel leaf extracted by hexane and chloroform extract method at various concentrations. The hexane extract of A. indica and D. metel at 62.5, 125, 250, 500 and 1000 ppm were showed 24, 36, 55, 64 and 72.50% mortality where second one shows 9, 17.50, 30, 42 and 57% mortality, respectively. The chloroform extract of A. indica was showed 12, 48.50, 56.50, 73 and 87% mortality where D. metel shows 13.75, 27, 32, 47 and 62% mortality respectively. The hexane and chloroform extract of A. indica and D. metel had significant larvicidal effect with LC50 values were 246.38, 198.82, 709.96 and 562.07 ppm respectively. At 24 h post-treatment against late third instar larvae, the chloroform extracts of A. indica and D. metel were found to be more effective than hexane extracts and caused a larval mortality of 87 and 62%, respectively at 1000 ppm concentration. The larvicidal effect of A. indica and D. metel against C. quinquefasciatus make these plant products are potential alternative to synthetic insecticide in mosquito control plans.
V.M. Chakkaravarthy, T. Ambrose, S. Vincent, R. Arunachalam, M.G. Paulraj, S. Ignacimuthu and G. Annadurai, 2011. Bioefficacy of Azadirachta indica (A. Juss) and Datura metel (Linn.) Leaves Extracts in Controlling Culex quinquefasciatus (Diptera: Culicidae). Journal of Entomology, 8: 191-197.