Evaluation Of Gluta Renghas And Mangifera Indica Leaf Extracts As Biorational Larvicides Against Dengue Vectors
Biopesticides may influence the population of dengue vectors by being innocuous to the environment and also to the non-target organisms. Mangifera indica and Gluta renghas from family Anacardiaceae were chosen in this study for their larvicidal effects against dengue vectors in different field conditions and seasons, in Pulau Pinang, Malaysia. Ovitraps filled with methanolic leaf extracts of selected plants were used for Aedes mosquito egg collection. Collected eggs were counted to evaluate the effects of different seasons and conditions on efficiency of plant extracts in controlling the vector population. Both of plants extracts were compared with the abate treatment. Least number of eggs was observed for Gl. renghas in shaded and unshaded areas with 1637 and 1237 eggs respectively in dry season. Whereas in wet season, total number of eggs were 2089 and 1692 in shaded and unshaded conditions respectively. Mangifera indica also followed the same pattern by getting lower number of eggs during dry season with 1672 and 1323 in shaded and unshaded conditions respectively, as compared to wet season where the number were higher at 2186 and 1787 eggs in shaded and unshaded conditions respectively. On the contrary, abate performed better in wet season by getting lower number of eggs as compared to dry season. Statistical analysis of the results showed that conditions didnít have any significant effect (P=0.807) on the treatments, whereas the seasons had significantly affected the treatments (P=0.00). Effects of plant treatments were found significant on population densities of dengue vectors. These results suggest the capability of these plant extracts to be used as an economical and ecofriendly alternate larvicide for the dengue vector.
Keywords- Gluta renghas, Mangifera indica, leaf extracts, dengue vector, larvicide.