Larvicidal and mosquito repellent action of peppermint (Mentha piperita) oil

Oil of Mentha piperita L. (Peppermint oil), a widely used essential oil, wa s evaluated for larvicidal activity against different mosquito species: Aed es aegypti, Anopheles stephensi and Culex quinquefasciatus by exposing IIIr d instar larvae of mosquitoes in enamel trays 6x4 inch(2) size filled to a depth of 3 inch with water. Of the three species tested Cx. quinquefasciatu s was most susceptible followed by Ae. aegypti and An. stephensi. Applicati on of oil at 3 ml/m(2) of water surface area resulted in 100% mortality wit hin 24 h for Cx. quinquefasciatus, 90% for Ae. aegypti and 85% for An. step hensi For Ae. aegypti 100% mortality was achieved at 3 ml/m(2) in 48 h or 4 ml/m(2) in 24 h. For An. stephensi 100% mortality was observed at 4 ml/m(2 ) in 72 h. The emergence at 3 ml/m2 was also inhibited to a great extent an d the few adults which emerged did not ovipost even after taking a blood me al. The oil showed strong repellent action against adult mosquitoes when ap plied on human skin. Percent protection obtained against An. annularis, An. culicifacies, and Cx. quinquefasciatus was 100%, 92.3% and 84.5%, respecti vely. The repellent action of Mentha oil was comparable to that of Mylol oi l consisting of dibutyl and dimethyl phthalates. (C) 1999 Elsevier Science Ltd. All rights reserved.