FUMIGANT AND REPELLENT PROPERTIES OF ESSENTIAL OILS AND COMPONENT COMPOUNDS AGAINST PERMETHRIN-RESISTANCE PEDICULUS HUMANUS CAPITIS (ANOPLURA: PEDICULIDAE).

ARIEL CEFERINO TOLOZA, JULIO ZYGADLO, GASTÓN MOUGABURE CUETO, FERNANDO BIURRUN, EDUARDO ZERBA AND MARÍA INÉS PICOLLO.

JOURNAL OF MEDICAL ENTOMOLOGY

Año: 2006 vol. 43 p. 889 - 895

0022-2585

ABSTRACT. The repeated use of permethrin and other insecticides for the control of head lice,Pediculus humanus capitis De Geer (Anoplura: Pediculidae), 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 Cambess (Myrtaceae) with a time to 50% knockdown (KT50) of 1.3 min, followed by exotic species, Eucalyptus cinerea F.V. Muell., Eucalyptus viminalis Labill., and Eucalyptus saligna Smith. withKT50 values of 12.0, 14.9, and 17.4 min, respectively. The most effective components were 1,8-cineole and anisole, with KT50 values of 11.1 and 12.7 min, respectively. Regression analysis of KT50 values and vapor pressures and water-partition coefÞcients 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 L. and its benzyl alcohol component were the most effective repellents, having repellency indices 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.