Abstract
To evaluate the bioefficacy of crude extract and fractions from the leaves of Couroupita guianensis Aubl. against second and fourth instar larvae of Culex quinquefasciatus Say and Aedes aegypti L. The phytochemical parameters of hexane extract derived fraction were analyzed. Chromatographically enriched fractions from hexane extract were eluted by hexane: ethyl acetate solvent system through silica gel. Larval toxicity assay was conducted with water containing the crude extract from 125 to 1000 ppm and fractions of effective crude extract was tested from 25 to 200 ppm concentrations against C. quinquefasciatus and A. aegypti. Among the three solvent crude extracts hexane extract of C. guianensis showed promising larvicidal activity against the two vector mosquitoes followed by chloroform and ethyl acetate. Chromatographically eluted fraction 3 showed promising larvicidal activity followed by fractions 2 & 8 compared with the crude extract. It is concluded that C. guianensis extract has the potential to control Cx. quinquefasciatus and Ae. aegypti without harming nontarget fish. (C) 2019 SAAB. Published by Elsevier B.V. All rights reserved.