Larvicidal Efficacy of Plant Extracts against the Malarial Vector Anopheles stephensi Liston (Diptera: Culicidae)

Malaria is transmitted by Anopheles stephensi and for controlling the malaria parasite Plasmodium spp., the vector mosquito has to be controlled. Extensive use of synthetic and chemical insecticides has resulted in environmental hazards and also in development of physiological resistance among vector mosquito species. Plant products are considered to be a potential alternative approach as they are environmentally safe, target specific and biodegradable. The extracts of seven plants viz., leaves of Abutilon indicum, Cleistanthus collinus, Leucas aspera, Murraya koenigii, aerial parts of Hyptis suaveolens and whole plants of Citrullus colocynthis and Sphaeranthus indicus with four different solvents viz., hexane, diethyl ether, dichloromethane and ethyl acetate were tested against the early third instar larvae of Anopheles stephensi. The larval mortality was calculated after 24 hours exposure period. The ethyl acetate extract of Leucas aspera was found to be effective with a LC value of 352.84 ppm. 50