Effect of Some Neem (Azadirachta indica) Organic Extracts Against Mosquitoes Anopheles arabiensis Patton

Abstract

Laboratory experiments were carried out at the National Malaria Centre, Sinnar State, Sudan, to investigate the effect of organic extracts of leaves and seed kernels of neem (Azadirachta indica A. juss.) against larvae and adults of the main malaria vector in Sudan Anopheles arabiensis Patton. Larvicidal activity, oviposition deterrency and adult mortality after 24 hours exposure were measured according to the WHO standards, using ethanol and hexane extracts of the mentioned neem parts. Results indicated that all tested extracts exhibited larvicidal properties against Anopheles arabiensis mosquito. However the seed hexane extract was superior over other ones, depicting minimum LC50 of 1998 mgℓ-1. Oviposition deterrency to Anopheles adult was noticed from all tested extracts, with their different concentrations. Meanwhile, the extracts showed negligible insecticidal characteristics to the tested mosquito. It can be concluded from the present investigation that the tested neem extracts could be compatible to apply with other conventional biological measures used in malaria vector control program after field verifications, keeping in mind the great concern raised about vector resistance and environmental hazards of conventional pesticides.