QUALITATIVE PHYTOCHEMICAL SCREENING AND MOSQUITO REPELLENCY OF CHROMOLAENA ODORATA (ASTERACEAE) LEAF EXTRACT AGAINST ADULTS OF CULEX QUINQUEFASCIATUS (DIPTERA: CULICIDAE)

Mosquito repellents could be one of the most effective tools for protecting humans from mosquito attack and from mosquito-borne diseases. Therefore the aim of the present study was to assess the repellent efficacy of the petroleum ether, chloroform and ethanol leaf extracts of the selected plant Chromolaena odorata against Culex quinquefasciatus mosquito and to screen the bioactive compounds present in them. The efficacy of the extracts as repellent were assessed on three day blood starved female Cx. quinquefasciatus mosquito. The results suggested that leaf ethanol extract of C. odorata showed a higher repellency on the adult of female Cx. quinquefasciatus mosquito than the other two extracts. The repellent activity was found to be dose dependent and the percentage of protection was found to be directly proportional to the concentration of extract and inversely proportional to the period of exposure. The results of phytochemical screening showed the presence of bioactive compounds such as alkaloids, phenols, flavonoids, sterols, saponins, proteins and quinones in the different leaf extracts. It may be concluded from the results that ethanol extract of C. odorata leaf was effective in mosquito vector control and has an excellent potential in controlling the mosquito. Keywords: Culex quinquefasciatus, Mosquito, Chromolaena odorata, Leaf extracts, Repellent activity, Phytochemicals