Toxic effect of aliphatic alcohols against susceptible and permethrin-resistant Pediculus humanus capitis (Anoplura: Pediculidae).
The effectiveness of 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, and 1-dodecanol was evaluated by immersion method against susceptible and permethrin-resistant head lice, Pediculus humanus capitis De Geer, from Buenos Aires, Argentina. All the tested alcohols showed knockdown effect at 10 min and mortality 18 h after treatment. The highest activity was found for the 1-dodecanol (KC50 2.55%, LC50 2.28%) and the lowest for 1-octanol (KC50 8%, LC50 4.46%). The toxicity to the head lice systematically increased with the increase in carbon atoms in the n-aliphatic alcohol moiety, and with the octanol:water coefficient (r2 = 0.94). The pediculicidal activity of 1-dodecanol was not correlated with resistance to permethrin, because no significant difference was observed between toxicity parameters in the susceptible (MAR) and the permethrin-resistant populations which had different resistant levels (RR 5.77 x for E49 population, RR 9.5 x for HL population and RR > 35.3 x for GH population). The pediculicidal effect of aliphatic alcohols demonstrated in this study and the lack of correlation with the permethrin resistance may prove to have a practical value for use in susceptible and permethrin-resistant head lice control.
Mougabure Cueto
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Centro de Investigaciones de Plagas e Insecticidas (CITEFA-CONICET), Buenos Aires, Argentina.
Gonzalez Audino
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Vassena
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Picollo
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MI
Zerba
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EN
D000438:Alcohols / Q000494:pharmacology*; D000818:Animals; D007851:Dodecanol / Q000494:pharmacology; D005233:Fatty Alcohols / Q000494:pharmacology; D007300:Insect Control / Q000379:methods*; D007305:Insecticide Resistance; D000442:Octanols / Q000494:pharmacology; D010374:Pediculus / Q000187:drug effects*; D026023:Permethrin; D012536:Scalp Dermatoses / Q000469:parasitology* / Q000517:prevention & control
D000438:Alcohols; D005233:Fatty Alcohols; D000442:Octanols; D007851:Dodecanol; D026023:Permethrin; C029383:n-decyl alcohol; C014713:1-nonanol