Larvicidal potential of rhizome extracts of Elettaria cardamomum (L.) Maton against filarial vector, Culex quinquefasciatus Say, 1823 (Diptera: Culicidae)

Abstract

Investigation on the larvicidal potential of Elettaria cardamomum (L.) Maton rhizome extracts against filarial vector, Culex quinquefasciatus Say, was undertaken with crude concentrations 0.1-0.5 per cent and 40, 50, and 60 ppm of each of petroleum ether, hexane and ethyl acetate rhizome extracts revealed that first instar larvae were most susceptible to crude rhizome extract with 100 per cent mortality at 0.5% after 24 hrs of exposure. Among three solvent extracts, ethyl acetate extract showed maximum mortality (96.66±3.33%) at 60 ppm after 72 hrs of exposure. LC50 values of larvicidal bioassays by crude rhizome extract were 0.1002, 0.0794, 0.1275 and 0.6334 ppm for 1st, 2nd, 3rd and 4th instars larvae after 72 hrs of exposure, respectively and LC50 values for larvicidal bioassays by petroleum ether, hexane, and ethyl acetate rhizome extracts were 48.3629, 40.9613 and 37.0282 ppm against 3rd instar larvae after 72 hrs of exposure, respectively. Preliminary phytochemical analyses of the rhizome extracts showed presence of secondary metabolites. Non target organisms, tadpoles of frog and 4th instar larvae of Chironomus circumdatus, were not affected by the crude as well as ethyl acetate rhizome extracts. Larvicidal efficacy of the rhizome extracts of E. Cardamomum against Cx. quinquefasciatus mosquito species has been reported first time.