Abstract

M. Ramar , M. Gabriel Paulraj and S.Ignacimuthu

The effect of leaf extract of Croton sparciflorus (Euphorbiaceae) on larvae and pupae of Culex quinquefasciatus say was studied under laboratory conditions. Preliminary screening of hexane, chloroform and ethyl acetate extracts at 1000ppm showed that hexane extract was the most effective treatment, which killed 100 and 89 percent larvae and pupae after 24hours. At various concentrations, viz. 25, 50, 100, 200 and 400ppm, the hexane extract caused concentration dependent larval and pupal mortality. The LC50 and LC90 of hexane extract were 145.3 and 466.9 ppm respectively for larvicidal and 335.2 and 714.7 ppm respectively for pupicidal activities. The results suggest that the leaf extract of C. sparciflorus is an effective larvicidal and pupicidal agent against Cx. quinquefasciatus