Larvicidal and repellent activity of Vetiveria zizanioides L, Ocimum basilicum Linn and the microbial pesticide spinosad against malarial vector, Anopheles stephensi Liston (Insecta: Diptera: Culicidae)

Use of synthetic pesticides causes some unfortunate consequences such as environmental pollution, pests/ vector resistance and toxicity to other non-target organisms including human beings, biological pesticides from plant, microbial origin are environmentally safe pesticides. Microbial insecticides are especially valuable because their non-toxicity to non-target animals and human beings. Laboratory investigation using the plants such as, Vetiveria zizanioides (Linn.) (Poaceae), Ocimum basilicum (Linn.) (Lamiaceae) and the microbial pesticide spinosad against the malarial vector Anopheles stephensi Liston showed 85% mortality. The observed mortality rate suggests the above extract can be used as biopesticides. The LC 50 of second, third and fourth instar larvae of A. stephensi were 0.276%, 0.285% and 0.305%, respectively.