title: Mosquito larvicidal activities of Solanum nigrum L. leaf extract against Culex quinquefasciatus Say.
abstract: The present study was carried out to establish the larvicidal activities of crude and solvent extracts of Solanum nigrum L. leaves against Culex quinquefasciatus Say as target species. The results indicated that the mortality rates at 0.5% concentration were highest amongst all concentrations of the crude extracts tested against all the larval instars at 24, 48 and 72 h of exposure. Result of log probit analysis (at 95% confidence level) revealed that lethal concentration LC(50) and LC(90) values gradually decreased with the exposure periods in bioassay experiment with the crude plant extract. The results of regression analysis of crude extract of S. nigrum revealed that the mortality rate is positively correlated with the concentration of the extracts. Mature leaves of S. nigrum were also extracted with six different solvents [viz. petroleum ether, benzene, ethyl acetate, chloroform: methanol (1:1 v/v), acetone and absolute alcohol] to determine the best extractant for subsequent isolation and characterization of active ingredient. Mortality rate with ethyl acetate extract was significantly higher (p < 0.05) than other extracts when 50-ppm doses were used. The corresponding LC(50) value of acetone, absolute alcohol, petroleum ether, chloroform: methanol (1:1 v/v), benzene and ethyl acetate extracts were 72.91 ppm, 59.81 ppm, 54.11 ppm, 32.69 ppm, 27.95 ppm and 17.04 ppm, respectively, after 24 h of exposure period. Results of this study show that the ethyl acetate extract of S. nigrum may be considered as a potent source of a mosquito larvicidal agent.
authors.affiliation: Mosquito and Microbiology Research Units, Parasitology Laboratory, Department of Zoology, The University of Burdwan, Burdwan, 713104 West Bengal, India.
authors.forename: Anjali
authors.initials: A
authors.lastname: Rawani
authors.forename: Anupam
authors.initials: A
authors.lastname: Ghosh
authors.forename: Goutam
authors.initials: G
authors.lastname: Chandra
mesh_terms: D000818:Animals; D005591:Chemical Fractionation / Q000379:methods; D003465:Culex / Q000187:drug effects*; D007306:Insecticides / Q000302:isolation & purification / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D032324:Solanum nigrum / Q000737:chemistry*; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D007306:Insecticides; D010936:Plant Extracts