Studies on effects of Pelargonium citrosa leaf extracts on malarial vector, Anopheles stephensi Liston

Methanol extracts of Pelargonium citrosa leaf were tested for their biological, larvicidal, pupicidal, adulticidal, antiovipositional activity, repellency and bitingdeterrency against Anopheles stephensi. Larval mortality was dose dependent with the highest dose of 4% plant extract evoking98% mortality. The extracts affected pupicidal and adulticidal activity and significantly decreased fecundity and longevity of A. stephensi. The larval, pupal and adult development were completely inhibited by the treatment. At 4% the extracts evoked strong repellent action. They also interfered with oviposition, egg hatchability, and exhibited a growth inhibiting effect against larvae and good repellency against adults of A. stephensi. The leaf extract treatment significantly enhanced biting deterrency. As naturally occurringinsecticides, these plant derived materials could be useful as an alternative for synthetic insecticides controllingfield populations of mosquitoes.