ACUTE TOXICITY OF AZADIRACHTA INDICA AND BALANITE AEGYPTIACA ON CULEX PIPIENS LARVAE

Mosquitoes are the major vectors of malaria, dengue fever, yellow fever, filariasis, schistosomiasis and Japanese encephalitis (JE). In Nigeria, malaria is one of the most important causes of direct or indirect infant, child and adult mortality and the major reason behind miscarriage. Chemical larvicides play a vital role in controlling mosquitoes in their breeding sites but these also show a negative impact on non-target organisms. In view of an increasing interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal potential of the extracts from the medicinal plants Azadirachta indica and Balanite aegyptiaca (seed, bark and leaves) in aqueous extraction against Culex pipiens. All plants parts were dried in shade and prepared into powder form and extracted separately, (100 gm powder in 1000 ml of water) (10%) as stock solution, which was further diluted to obtain concentrations of 0.5%, 1.0%,2.0%, 3.0%, 5.0% and 10.0%. Larvae of Culex pipiens were exposed to concentrations of plants and their parts continuously for 24 hours. In both cases seed extract had most effective at the lowest concentration (0.5%) and leaves extract at higher concentration while bark extract showed least efficacy against tested larvae