Evaluation of toxicity of plant extracts against vector of lymphatic filariasis, Culex quinquefasciatus

BACKGROUND & OBJECTIVES Conventional insecticides are generally used as larvicides to control Culex quinquefasciatus, vector of lymphatic filariasis. This study was undertaken to evaluate the larvicidal activity of some potential larvicidal plants leaf extracts against Cx. quinquefasciatus larvae. METHODS The toxic effects of petroleum ether leaf extracts of plants viz., Argemone mexicana (Mexican prickly poppy), Clausena dentata (Dentate), Cipadessa baccifera (Rana bili), Dodonaea angustifolia (Hop bush) and Melia dubia (Pride of India) were evaluated under laboratory conditions in individual and in combination against 3 rd - 4 th instar larvae of Cx. quinquefasciatus. RESULTS The results indicated that among the selected plants, A. mexicana showed maximum larvicidal activity with an LC 50 value of 48.89 ppm. Its toxicity was enhanced when the extract was mixed (1:1) with that of C. dentata as the LC 50 value became 28.60 ppm indicating synergistic action of A. mexicana. INTERPRETATION & CONCLUSIONS Our results showed high larvicidal potential in A. mexicana leaf extract, and it also showed additive effect when mixed with C. dentata extract.