EFFECT OF AQUEOUS EXTRACT OF SEED AND BARK OF Melia azedarach AND RHIZOME of Zingiber officinale AGAINST Anopheles arabiensis LARVAE

<strong>Abstract</strong>: mosquito Rapidly emerging mosquito resistance to the chemicals and logistical problems in transporting supplies to remote locations threaten the long-term sustainability of these controlling techniques of vector that transmit malaria parasite and malarial disease. Theseproblemshavenecessitatedtheneedtoexploreanddevelopalternativestrategies.Usingenvironm entally safe, bio-degradableplantproductswhicharenon-toxictonon-targetorganisms are the best controlling strategies. The present study was aimed to evaluate the larvicidal effects of aqueous extracts of Seed and Bark parts of Melia azedrach and Rhizomes of Zingiber officinale against3rd instars larvae of Anopheles arabiensis. Aqueous extraction was done by following maceration technique by extracting bioactive components.Collected larvaewere tested under the laboratory condition by adopting the WHO standard protocols with 10 individual larvae in each treatment level and positive and negative control.Thevarious concentrations (10, 15, 25, 50, 100 and 500 ppm) of aqueous extracts of seeds, and barks of M. azedarach and Rhizomes of Z. officinale were tested for larvicidal activity against A. arabiensis. The mortality rate of both treatment and control group were recoreded after 24 hrs. The 2ml of malaria vector standard larvicide Temephos (Abate®)was used as positive control. The revealed mortality rate of 3rd instars larvae of A. arabiensis was depended on increase in dose of the extracts of plants. At 10 ppm, the seed extract caused 36.7+ 0.577 % mortality, barks extract 6.66+ 0.577 % and Rhizomes of Z. officinale extract caused 10.0 + 0.816 % mortality. The LC50 and LC90 value for seed extract was 17ppm and 158ppm, bark extract, 56 and 380 ppm, rhizome extract 41 and 224 ppm. Among the aqueous extracts of the seed, bark and Rhizomes of Z. officinale, the aqueous extract of seed was proved to be most toxic and an efficient larvicidal against A. arabiensis next to positive control. The findings of the present study indicate that the aqueous extract of M. azedarach and Z. officinale of Dilla, Ethiopia can serve as a good source of preparations for pest control especially mosquito control. Organic solvent extraction of the plants in different methods was recommended in both laboratory condition and field testing.