Larvicidal activity of Gmelina asiatica L. leaf extracts against Aedes aegypti and Culex quinquefasciatus

Mosquitoes are responsible for the spread of many dreadful human diseases.  Phytochemicals with mosquitocidal potential are now recognized as potent alternative insecticides to replace synthetic insecticides. To determine the larvicidal activities of leaf extracts of Gmelina asiatica in different solvents against mosquito vector, Aedes aegypti and Culex quinquefasciatus.  Larvicidal efficacy of the crude leaf extracts of G. asiatica with four different solvents such as petroleum ether, chloroform, ethanol and acetone were tested against the five day old mosquitoes (A. aegypti and C. quinquefasciatus). The larvae mortality and the larvicidal efficacy were determined against the mosquito species with different concentrations (ranging from10-100ppm) under laboratory conditions.  Among the tested solvents, maximum efficacy was observed in the chloroform extract of both types of mosquitoes.  The LC50, LC90 and LC95 values of G. asiatica against the larvae of A. aegypti were 47.32, 81.03 and 86.90 ppm (petroleum ether) 37.39, 64.29 and 69.02 ppm (chloroform) 38.15, 71.71 and 78.31 ppm (ethanol) 45.88, 79.66 and 86.43 ppm (acetone) exracts and the values of C. quinquefasciatus were 36.22, 71.93 and 78.69 ppm (petroleum ether) 19.51, 53.51 and 63.09 ppm (chloroform) 39.52, 77.48 and 84.45 ppm (ethanol) 50.98, 85.66 and 89.53 ppm (acetone) extracts respectively. No mortality was observed in controls.  These results suggested that G. asiatica leaf extract possess larvicidal potential to be used as an ecofriendly approach for the control of vectors A. aegypti and C. quinquefasciatus and the study provides the first report on the larvicidal activity of Aedes and Culex mosquitoes.