Parasitol Res (2010) 106:409–414DOI 10.1007/s00436-009-1676-6
Eucalyptus essential oil toxicity against permethrin-resistantPediculus humanus capitis (Phthiraptera: Pediculidae)
Ariel C. Toloza & Alejandro Lucía & Eduardo Zerba &Hector Masuh & María Inés Picollo
Received: 6 October 2009 / Accepted: 23 October 2009 / Published online: 10 November 2009
Abstract During the past decades, chemical control against
the head louse Pediculus humanus capitis De Geer has beenbased in the application of products containing permethrin.
The human head louse, Pediculus humanus capitis De Geer
The repetitive overuse of pediculicides has resulted in the
(Phthiraptera: Pediculidae), is an obligate ectoparasite that
development of high levels of resistance to one or more of
causes pediculosis capitis. The infestation of the human hair
these products worldwide. Essential oils obtained from
and scalp is an ancient medical problem whose main
aromatic plants like Eucalyptus are good and safe alter-
symptoms are itching and social embarrassment (Burgess
natives due to their low toxicity to mammals and easy
). Recently, experimental evidence mentioned that
biodegradability. In the present study, we reported the
head lice can be able to act as vectors of Rickettsia
chemical composition of Eucalyptus dunnii and Eucalyptus
prowazekii and Bartonella quintana, the causative agents
gunni, and the fumigant activity of five Eucalyptus essential
of typhus and trench fever, respectively (Robinson et al.
oils and their main compounds against permethrin-resistant
; Sasaki et al. Transmission of head louse
head lice from Argentina. The most effective essential oils
occurs mainly by direct host-to-host contact and by
were Eucalyptus sideroxylon, Eucalyptus globulus ssp
inanimate objects called fomites (Takano-Lee et al.
globulus, and Eucalyptus globulus ssp maidenii, with
In addition, the occurrence of head lice follows a seasonal
knockdown time 50% (KT50) values of 24.75, 27.73, and
pattern (Bauer et al. The infestation with head lice is
31.39 min. A linear regression analysis between percentage
widespread throughout the world (Falagas et al. ) and
of 1,8-Cineole and KT50 values of the essential oils showed
has been increasing since the beginning of the 1990s due to
a significant correlation at a p<0.01. Since Eucalyptus
the lack of effectiveness of pediculicides (Burgess
essential oils showed to be effective against head lice and
This lack of efficacy is mainly due to a variety of reason
are classified as safer compounds, they can be employed
such as the sale of ineffective products, the incorrect use of
pediculicides and that lice develop resistance to insecticidessuch as DDT, lindane, malathion, carbaryl, permethrin, andδ-phenotrin in several countries (Hunter and Barker ;Burgess ; Mumcuoglu et al. ). In Argentina,pediculosis is a serious sanitary problem affecting more
A. C. Toloza (*) A. Lucía E. Zerba H. Masuh M. I. Picollo
than 30% of the school children (Toloza et al. Thus,
the overuse of products containing permethrin has led to the
development of high levels of resistance (Picollo et al.
Juan Bautista de La Salle 4397, B1603ALO, Villa Martelli,
, Vassena et al. ; Mougabure Cueto et al.
Buenos Aires, Argentinae-mail: [email protected]
). Thus, there is a trend for the finding anddevelopment of new alternative insecticides, especially
those containing plant-derivative active ingredients,
Instituto de Investigación e Ingeniería Ambiental,
claimed as "natural" products. Essential oils (EOs) are a
Universidad Nacional de General San Martín,Buenos Aires, Argentina
mixture of monoterpenes and phenols which are obtained
• Universidad: Universidad Nacional de Educación a Distancia. UNED • Nº de volúmenes/títulos: 358.534 (biblioteca central)• Naturaleza jurídica: Universidad Pública de ámbito estatal, creada por • Rectora: Juan Antonio Gimeno Ullastres • Prácticas en empresas (%) alumnos: 0.04% • Nº de convenios de colaboración educativa para prácticas de • Nº de alumnos que se
LAKEWOOD PRESBYTERIAN CHURCH Rev. Terence A. Lucarelli PALM SUNDAY . April 17, 2011 GUESS WHO? Matthew 21:1-11 “Guess who?” I know you’ve played the game. You slip up behind someone, cover their eyes and say, “Guess who?” And they always know! I do that with the preschool kids every once in a while. It’s such a kick. They know who it is . because they’ve usually