Repellent activity of plant essential oil extracts against malaria vector Anopheles arabiensis Patton (Diptera: Culicidae)

Abstract

Repellent activity of essential oils extracted from the leaves of Otostegia integrifolia and Stephania abyssinica, roots of Echinops kebericho and seeds of Millettia ferruginea and Datura stramonium were tested against malaria vector, Anopheles arabienses. The repellent activity was determined at 125, 250, 500 and 1000 ppm concentration by human volunteer. The dorsal side of each human arm 153.86 cm2 of the skin was exposed for twenty minutes by covering the remaining area with rubber glove. The control and treated arm were introduced simultaneously into mosquito cage under laboratory condition maintained at 27 +/- 1°C, 65-70% RH. Among the four different concentrations tested, maximum repellent activity was observed at 1000 ppm of O. integrifolia, S. Abyssinica and M. ferruginea and also E. kebericho has strong repellent properties in all concentrations. O. integrifolia, S. abyssinica, M. ferruginea and E. kebericho may contain repellent chemicals which can be used for the development of safer mosquito repellent product.