The present study was aimed to investigate the mosquitocidal activity hexane, chloroform, petroleum ether and ethanol extract of Exacum pedunculatum Linn. against an important malarial vector mosquito, Anopheles stephensi Liston under laboratory condition. This experiment was designed according to the standards protocols. The larvicidal activity of different crude extracts of E. pedunculatum was tested with 50, 100,150,200 and 250ppm concentrations against fourth instar larvae of An. stephensi. The experimental larvae exposed to 250ppm concentration of E. pedunculatum showed more susceptibility to hexane extract, followed by petroleum ether, ethanol and chloroform. The LC50 value of hexane extract was recorded to be 127.45ppm; for chloroform 127.39ppm; petroleum ether with 151.96ppm and the least LC50 value of 121.24ppm was recorded with ethanol extract. Likewise, the LC90 values and their LCL-UCL concentrations were determined as 231.20 (215.07-252.44ppm), 249.13 (203.11-373.03ppm), 255.49 (234.22-271.74ppm) and 240.57 (194.81- 368.30pp) were noticed against hexane, chloroform, petroleum ether and ethanol extracts respectively towards the fourth instar larvae of An. stephensi. The data obtained in this experiment was pertinent to note that 200-300ppm concentration of the petroleum and ethanol extracts showed strong ovicidal activity with no hatchability in the experimental group eggs, contrarily 92.8 -100% egg hatchability was recorded with control. The percentage of egg hatchability was decreased with increasing concentration of the plant extracts. The information’s given are first report on E. pedunculatum against An. Stephensi
