Mosquito larvicidal activity of solvent extracts of fruits of Acacia auriculiformis against Japanese encephalitis vector Culex vishnui group

Abstract

The purpose of present study was to determine the larvicidal activity of different solvent extracts of fruits of Acacia auriculiformis against the 3 rd larval instar of Culex vishnui group. The solvent extracts of fruits of A. auriculiformis (concentrations were 100, 200, 300 ppm) showed varied results against 3 rd larval instars with highest mortality at 300 ppm. The percent mortality was higher in chloroform: methanol (1:1 v/v) extract than other extracts. The order of efficacy of different solvent extracts was chloroform: methanol (1:1 v/v) > absolute alcohol > n-Hexane > acetone > petroleum ether. Results of regression analyses showed that percentage mortalities were positively correlated with the concentrations. Probit analysis revealed LC 50 value and their LCL and UCL values at different time intervals and the lowest LC 50 value was obtained at 72 h of exposures. There was no mortality of non-target organisms after 24 h of exposure to lethal concentration (LC 50 value of chloroform: methanol (1:1 v/v) solvent extract at 24 h determined against 3rd instar larvae).