 Toxic interactions between the constituents of geranium essential oil in Pediculus humanus capitis

GALLARDO A., G. MOUGABURE CUETO & M.I. PICOLLO

Urgup, Cappadocia

Congreso; 9. Fourth International Conference on Phthiraptera (ICP4); 2010

International Society of Phthirapterists

In the absence of effectiveness of conventional insecticides due to the evolution of insecticide resistance, investigations were focused to the development of selective human louse control alternatives. Plant essential oils and its constituents have been proposed as an alternative for insect control. Previous works evaluated the acute toxicity of different essential oils and its constituents against head lice, and demonstrated that the activity of essential oils is not just explained by the simple addition of the activities of its constituents, suggesting toxic interactions. The aim of this work was to determine the occurrence of toxic interactions between the components of the geranium essential oil. Bioassays were conducted using females of Pediculus humanus capitis (head lice). Head lice were collected from heads of infested children (6-12 yr old). We tested the toxic activity of the geranium essential oil, its major constituents, and different artificial mixtures of those constituents. Acute toxicity of compounds was determined by application of 0.1 µl of acetone solution of evaluated compounds on each insect’s abdomen. Mortality was measured 18 h after treatment. Citronellol showed the highest activity meanwhile citronellyl-fomate showed the lowest. The activity of geranium essential oil compared with those of artificial mixtures of individual constituents, demonstrated the occurrence of toxic interaction.