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

Abstract

Oil of Mentha piperita L. (Peppermint oil), a widely used essential oil, was evaluated for larvicidal activity against different mosquito species: Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus by exposing IIIrd instar larvae of mosquitoes in enamel trays 6 × 4 inch² size filled to a depth of 3 inch with water. Of the three species tested Cx. quinquefasciatus was most susceptible followed by Ae. aegypti and An. stephensi. Application of oil at 3 ml/m² of water surface area resulted in 100% mortality within 24 h for Cx. quinquefasciatus, 90% for Ae. aegypti and 85% for An. stephensi. For Ae. aegypti 100% mortality was achieved at 3 ml/m² in 48 h or 4 ml/m² in 24 h. For An. stephensi 100% mortality was observed at 4 ml/m² in 72 h. The emergence at 3 ml/m² was also inhibited to a great extent and the few adults which emerged did not ovipost even after taking a blood meal. The oil showed strong repellent action against adult mosquitoes when applied on human skin. Percent protection obtained against An. annularis, An. culicifacies, and Cx. quinquefasciatus was 100%, 92.3% and 84.5%, respectively. The repellent action of Mentha oil was comparable to that of Mylol oil consisting of dibutyl and dimethyl phthalates.

Introduction

The essential oils of mints, a group of plants belonging to the family Labiateae, are widely used. The various types of mints, which are cultivated commercially in different parts of the world are Japanese mint (Mentha arvensis), Peppermint (M. piperita L.), Spearmint (M. spicata) and Bergamont mint (M. citrata) (Husain et al., 1988). The present study was carried out on the oil of Mentha piperita L. This plant is a native of the Mediterranean region, which is now grown all over the world. The plant is a perennial glabrous herb with a strong, pepper-like, pungent odour and hence the specific name ‘piperita’. Peppermint oil is a colourless, pale yellow liquid with a strong agreeable odour and a powerful aromatic taste. Menthol is the major constituent of this oil. Peppermint oil is the most popular and widely used essential oil employed in flavouring, pharmaceuticals, confectionery and medicines. The Wealth of India, 1962, Chaudhry et al., 1957.

Several phytochemicals extracted from various botanical sources have been reported to have detrimental effects on mosquitoes (Syamala Devi and Vasudevan, 1995). Some of the promising essential oils which have shown biocidal activity are plants from the genus Tagetes Wells et al., 1992, Perich et al., 1995, Vasudevan et al., 1997a, Vasudevan et al., 1997b and Ocimum (Bhatnagar et al., 1993). Oils extracted from plants are also repellents for adult mosquitoes (Curtis et al., 1990). Protection against mosquito bite was reported for the genus Cymbopogan Ansari and Razdan, 1995, Rutledge et al., 1983, Osmani et al., 1972, Pelargonium citrosum (Matsude et al., 1996) and extracts of neem seed (Sharma et al., 1993) and Lantana camara flowers (Dua et al., 1996). Since no report was available on peppermint oil, studies were carried out to evaluate this oil as a larvicide, adulticide as well as mosquito repellent.