Pediculosis capitis: behavioral activity and chemical analysis of head louse feces

GALASSI, F G; PICOLLO M I; GONZALEZ AUDINO, PAOLA

PARASITOLOGY RESEARCH

SPRINGER

Lugar: Berlin; Año: 2019

0932-0113

Head lice are insect parasites closely associated to human that feed on the blood ofthe host. Head louse infestation (pediculosis) is a major disease illness causing skinirritation and probable secondary infections. In spite of they are considered a severenuisance very few studies have been reported about intraspecific chemicalcommunication.In this study we evaluated the attractive response of head lice to volatile compoundsand solvent extracts of their feces. Also, we reported the chemical analysis of the mainvolatile components of the feces and those of the feces extracts.Head lice were attracted to the methanol extract of their feces, but not to the hexane ordichloromethane extracts, suggesting the polar nature of the bioactive chemicalspresent in head louse feces. Additionally, head lice were significantly attracted by thevolatiles emitted by samples containing feces.The volatiles emanated from feces contained nineteen identified substances: 2-pentanone, hexanal, heptanal, 3-buten-1-ol, 3-methyl, octanal, 1-octen-3-one,sulcatone, nonanal, acetic acid, 1-hexanol, 2-ethyl, decanal, 1-octanol, butyric acid, 1-nonanol, hexanoic acid, octanoic acid, 7-octen-2-ol, 2,5-dimethyl, 2-undecanone andhexadecane. The volatiles emanated from feces and lice showed three additionalcompounds: 1-octen-3-one, 2-nonenal, and geraniolene. However, the majorcompounds in both samples were decanal, nonanal, hexanal, and acetic acid,representing approximately the sixty percent of the identified compounds.This work represents the first chemical evidence of intra-species communicationamong head lice. The results support the existence of active substances present infeces of P humanus capitis potentially involved in its aggregation behavior.