OVICIDAL AND REPELLENT ACTIVITIES OF CASSAVA PLANTManihot esculenta EXTRACTS AGAINST Cu/ex quinquefasciatus

摘要

Mosquitoes are the vectors for the dreadful diseases of mankind. Synthetic pesticides causes major health problem to the human so this investigation has undergone to use the plant extract to control the mosquito. The present study deals with the insecticidal activity of ethanol extracts of Cassava, Manihot esculenta leaves against ovicidal and repellent activity of Culex quinquefasciatus. The ovicidal activity was determined against Cx. quinquefasciatus at various concentration ranging from 50-300ppmunder the laboratory condition. The hatch rate was assessed after 48 h after treatment. The repellent efficacy was determined at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under the laboratory conditions. The crude ehanolic extract of cassava, manihot esculenta leaf extract exerted zero hatchability (100% mortality) at 250 and 300 ppm. A higher concentration of 5.0 mg/cm2 provided 100% protection up to 150 minutes against Cx. quinquefasciatus. The result clearly showed the repellent activity was dose dependent. From this result we can conclude the crude extract of cassava leaf has effective potential against the species Cx. quinquefasciatus.