Potentiation of Heritiera littoralis (Aiton), Madhuca longifolia (König) Macbr., Nerium indicum (Mill.) and Sapium indicum (Willd.) Leaf Extracts against the Insect Vector Culex quinquefasciatus (Say) Larvae (original) (raw)

2020, Potentiation of Heritiera littoralis (Aiton), Madhuca longifolia (König) Macbr., Nerium indicum (Mill.) and Sapium indicum (Willd.) Leaf Extracts against the Insect Vector Culex quinquefasciatus (Say) Larvae

Pet. (Petroleum) ether, CHCl3 (Chloroform) and CH3OH (Methanol) extracts of Heritiera littoralis (Aiton), Madhuca longifolia (König) Macbr., Nerium indicum (Mill.) and Sapium indicum (Willd.) leaves have been tested against the significant insect vector Culex quinquefasciatus (Say) larvae through dose-mortality assay. The H. littoralis gave LC50 values 412.31, 146.92, 66.46, 44.31 and 33.91 ppm for the Pet. ether extract and 152.10, 97.12, 72.27, 45.00 and 28.96 ppm for the CHCl3 extract both after 18, 24, 30, 36 and 42 h of exposure; and 625.87, 231.46, 86.10, 15.26 and 2.15 ppm for the CH3OH extract after 12, 18, 24, 30 and 36 h of exposure respectively. The M. longifolia gave LC50 values 183.87, 87.56, 65.70, 33.27 and 18.02 ppm for the CHCl3 extract and 213.84, 127.05, 89.07, 54.32 and 31.51 ppm for the CH3OH extract both after 18, 24, 30, 36 and 42 h of exposure; however, the Pet. ether extract did not show any lethal effect against the test agent. The N. indicum gave LC50 values 420.46, 367.12, 65.35, 31.16, 19.28 and 15.89 ppm for the Pet. ether extract after 12, 18, 24, 30, 36 and 42 h of exposure respectively; while the CHCl3 and CH3OH extracts did not offer any mortality to the test larvae. The S. indicum gave LC50 values 383.43, 54.16, 16.48, 4.41 and 3.78 ppm for the Pet. ether extract after 12, 18, 24, 30 and 36 h of exposure and 414.11, 84.89 and 28.64 ppm for the CH3OH extract after 12, 18 and 24 h of exposure respectively; however, the CHCl3 extract did not show lethal effect against the test agent. The intensity of activity of the extracts could be arranged in the following descending order: H. littoralis (CH3OH extract) > S. indicum (Pet. ether extract) > N. indicum (Pet. ether extract) > M. longifolia (CHCl3 extract).