Fumigant and Repellent Properties of Essential Oils and components against Permethrin resistance Pediculus humanus capitis (Anoplura: Pediculidae) from Argentina

TOLOZA A.C. ZYGADLO J., MOUGABURE CUETO G., BIURRUN F., ZERBA E. AND PICOLLO M.I.

Journal Medical Entomology

ntomological Society of America

Lugar: Lanham, Maryland; Año: 2006 vol. 43 p. 890 - 895

Abstract. The repeated use of permethrin and other insecticides for the control of head lice, Pediculus humanus capitis De Geer, during past decades has resulted in the development of marked levels of resistance. Thus, new alternative insecticides are needed for the control of head lice. We studied the fumigant and repellent properties of essential oils from 16 native and exotic plants in Argentina, and 21 chemical components against permethrin-resistant head lice from Argentina. With a direct vapor-exposure bioassay, the most effective oil was from the native Myrcianthes cisplatensis (Myrtaceae) with a time to 50% knockdown (KT50) value of 1.3 min, followed by exotic species, Eucalyptus cinerea, Eucalyptus viminalis and Eucalyptus saligna with KT50s of 12.0, 14.9 and 17.4 min, respectively. The most effective components were 1,8 cineole and anisole, with KT50s of 11.1 and 12.7 mins, respectively. Regression analysis of KT50s and  vapor pressures water-partition coefficients for the essential oil components revealed that the most effective fumigants were among the more volatile components. Repellency assays indicated that the essential oil from Mentha pulegium and its benzyl alcohol component were the most effective repellents, having repellency indices (RIs) of 75.5 and 57.8%, respectively. Thus, some Argentinean plants contain essential oils and components that function as fumigants or as repellents, and thereby show potential for development of new control products for head lice.