ABSTRACT:
The present study was aimed to evaluate the larvicidal activity of Terminalia arjuna bark extracts on dengue fever mosquito Ades Aegypti. Terminalia arjuna barks were collected in and around Yelagiri Hills, Tirupattur, Vellore District and the bark powder of Terminalia arjuna was extracted with solvents namely hexane, chloroform, ethyl acetate and methanol. The solvent extracts were evaluated for the presence of phytochemicals qualitatively. It was noted that the chloroform extract showed the presence of 6 phytochemical constituents. Total flavonoid content in the chloroform bark extract, using the calibration curve, was found to be 34.92 mg and the total phenol content in the chloroform bark extract was found to be 58.23 mg. Aedes aegypti mosquito larvae were exposed to different concentrations of the crude extracts (10, 25, 50, 100 and 200 µg/mL) to find out the larvicidal activity using standard protocol. Among the extracts tested, chloroform bark extract showed maximum mortality on A. aegypti larvae. The LC50 and LC90 values of T. arjuna on A. aegypti larvae were 4.61 and 24.17. The GC-MS analysis of Terminalia arjuna chloroform bark extract showed the presence of 11 phytochemical constituents. The findings of the study will direct new investigations in purifying the active larvicidal compounds and applying the same against the dengue causing mosquito.