Larvicidal, pupicidal and repellent activities of Gaultheria oil (Plantae: Ericaceae) against the filarial vector, Culex quinquefasciatus (Insecta: Diptera: Culicidae)

Over the world, more than 50% of persons with filariasis receive their infections from the bites of mosquitoes, particularly C. quinquefasciatus. Some photochemical comprise toxic compounds that can be exploited to control mosquito larvae. Gaultheria oil or wintergreen oil which contains methyl salicylate as a major component and has been used in the present study to investigate the larvicidal, pupicidal and repellent activities against the different instar (I, II, III and IV) larvae and pupae of C. quinquefasciatus at different concentrations (100, 200, 300 and 400 ppm). The LC50 values of Gaultheria oil against different instar larvae were 166.40, 214.95, 303.47, 386.63, respectively and the LC90 values were 613.91, 669.40, 755.80, 883.46, and 866.12, respectively. LC50 and LC90 values of pupae were 435.82 and 866.12, respectively. Gaultheria oil showed 100% repellency in 250 min and showed complete protection in 90 min at 450 ppm against C. quinquefasciatus. The results obtained show that this plant material exhibited significant activity and could be considered as potent natural larvicidal, pupicidal and repellent agent against C. quinquefasciatus.