STUDIES ON LARVICIDAL ACTIVITY OF LEUCAS ASPERA, VITEX NEGUNDO AND EUCALYPTUS AGAINST CULEX QUINQUEFASCIATUS COLLECTED FROM COOVUM RIVER OF CHENNAI, INDIA

Abstract

Crude leaf extracts of Leucas aspera,Vitex negundo and Eucalyptus were tested for their larvicidal activity against Culex quinquefasciatus. There are four different solvents were used (Petroleum ether, Water, Acetone and Ethyl acetate) for the preparation of crude extracts from the plant leaves. The larval mortality of second and third instar larvae C. quinquefasciatus after 24 hour to 72 hour of treatment were observed separately in control, 125, 250, 500, and 1000 ppm concentrations of the leaf extract. The four different solvent extract of Vitex negundo showed good larvicidal activity. The highest mortality percentage of mosquito larvae was observed in 1% concentration of crude extracts. No mortality was observed in control. ANOVA for mortality percentage of mosquito larvae in different concentration and different solvent shows significant different at 5% level.