Abstract
Methanol extracts of different plants namely, Trichodesma africanum (Boraginaceae), Cleome rupicola (Capparceae) and Ochradenus baccatus (Resedaceae), were tested for larvicidal activity against 4th instar larvae of Aedes caspius and Culex pipiens mosquitoes. All plant extracts tested against Ae. caspius showed 100% mortality at 10 mu g/ml except the stem of O. baccatus which showed 90% mortality. However, most of the plant extracts tested against Cx. pipiens showed more than 50% mortality at 10 mu g/ml. Ae. caspius reported lower LD50 than Cx. pipiens. The LD50 of the extracts tested ranged between 5.3-0.99. The lowest LD50 calculated against Ae. caspius was 1.2+/-0.06 and 0.99+/-0.16 mu g/ml for the stem of T. africanum and C. rupicola, respectively. In conclusion, we have documented promising larvicidal potential of xerophytic plants, which could be considered as a potentially alternative source for developing novel larvicides to be used in controlling vectors of mosquito-borne diseases.