Response of Pediculus humanus capitis (Phthiraptera: Pediculidae) to Volatiles of Whole and Individual Components of the Human Scalp

TOLOZA, A C; GALASSI, F G; PICOLLO, M I; FRONZA, G; GONZÁLEZ-AUDINO, P; TOLOZA, A C; GALASSI, F G; PICOLLO, M I; FRONZA, G; GONZÁLEZ-AUDINO, P

JOURNAL OF MEDICAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Año: 2018 vol. XX p. 1 - 8

0022-2585

The head louse Pediculus humanus capitis (De Geer) (Phthiraptera: Pediculidae) is a cosmopolitan humanectoparasite causing pediculosis, one of the most common arthropod parasitic conditions of humans. Themechanisms and/or chemicals involved in host environment recognition by head lice are still unknown. In thisstudy, we evaluated the response of head lice to volatiles that emanate from the human scalp. In addition, weidentified the volatile components of the odor and evaluated the attractive or repellent activity of their pure maincomponents. The volatiles were collected by means of Solid Phase microextraction and the extract obtained waschemically analyzed by gas chromatograph-mass spectrometer. Twenty-four volatile were identified in the humanscalp odor, with the main compounds being the following: nonanal, sulcatone, geranylacetone, and palmitic acid.Head lice were highly attracted by the blend human scalp volatiles, as well as by the individual major components.A significant finding of our study was to demonstrate that nonanal activity depends on the mass of the compoundas it is repellent at high concentrations and an attractant at low concentrations. The results of this study indicate thathead lice may use chemical signals in addition to other mechanisms to remain on the host.