fumigant and repellent properties of essential oils and components against permethrin-resistance pediculus humanus capitis (anoplura:pediculidae)

TOLOZA AC,; JULIO ALBERTO ZYGADLO; CUETO G, MOUGABURE; BIURRUM F,; ZERBA E,; PICOLLO MI,

journal medical entomology

entomological society of america

Lugar: Internacional; Año: 2006 vol. 43 p. 889 - 895

The repeated use of permethrin for the control of Pediculus humanus capitis De Geer 1778 during past decades has resulted in the development of marked levels of resistance. Thus, the findings of new alternative insecticides are of vital importance for the control of head lice. In this study the fumigant knockdown time 50% (KT50) and repellent indexes (RI) of 37 essential oils and components against permethrin-resistance P. humanus capitis from Argentina were examined. In the direct vapor exposure bioassay, the most effective was Myrcianthes cisplatensis with a KT50 value of 1.3, followed by E. cinerea, E. viminalis and E. saligna with values of 12.0, 14.9 and 17.4 respectively. The most effective components were 1,8 cineole and anisole with KT50 values of 11.1 and 12.7, respectively. Structure-activity correlation (p<0.05) was evaluated with the fumigant data. A multiple regression analysis among KT50 and the physicochemical parameters log P and vapor pressure of the essential oil components, showed a significant linear regression. The more volatile components were significantly the most effective fumigants. The repellency bioassay indicated that the essential oil of Mentha pulegium and the benzyl alcohol component were the most effective repellents with RI of 75.5 and 57.8, respectively. There was a differential response of the essential oil components in the vapor phase and in the repellency bioassay. The Argentinean essential oils and components described herein are promising as P. humanus capitis alternative control.