Abstract

Received 12 January 2017 Received in revised form 24 January 2017 Accepted 24 January 2017 Available online 27 January 2017 Keywords: Pediculosis Morphometrics Sexual dimorphism Mummies SEM Variable pressure 1. Introduction Pediculus humanus capitis, causal agent of pediculosis, is an insect of the suborder Anoplura including the Pediculidae Fam- ily with the genera Pediculus humanus var corporis and Pediculus humanus capitis var (Linnaeus 1758) and Phthiridae family with the genera Phthirus pubis (Linnaeus, 1758) (Espinosa and Vázquez, 2002). This species does not recognize geographical, socioeco- nomic, or cultural barriers and it is probably one of the oldest ectoparasites of humanity (Boutellis et al., 2014; Espinosa and Vázquez, 2002; Retana-Salazar, 1994). Its morphology and genomic variation allow for discussion on our evolutionary pass and the peopling of the Americas (Retana-Salazar, 2005; Weiss, 2009). Pediculus humanus capitis (P. h. capitis) feed directly from venules, has a simple metamorphosis, and three life stages: egg, nymph and adult (Espinosa and Vázquez, 2002). P. h. capitis has no ∗ Corresponding author at: Calle Antofagasta 1520, Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile. E-mail address: [email protected] (B. Arriaza). http://dx.doi.org/10.1016/j.micron.2017.01.007 0968-4328/© 2017 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Micron journal homepage: www.elsevier.com/locate/micron Comparative study of the claws of Pediculus humanus capitis between archaeological and modern specimens Hipólito Nún ̃eza, Bernardo Arriazab,∗, Vivien Standenc, Natalia Aravenab a Departamento de Biología, Universidad de Tarapacá, Arica, Chile b Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile c Departamento de Antropología, Universidad de Tarapacá, Arica, Chile abstract Metric data of the claws of archaeological specimens of Pediculus humanus capitis (dating between 1500 B.C. and A.D. 1500) and modern lice specimens coming from school children were analyzed and com- pared. Both sets of samples come from Arica in northern Chile. The overall sample is comprised of 14 archaeological specimens (6 females and 8 males) of Pediculus humanus capitis and 22 modern speci- mens (13 females and 9 males). All specimens were studied with scanning electron microscopy (SEM), uncoated, using variable pressure mode. The objective of this study was to metrically analyze the first couple of clutches of ancient and modern adult lice specimens (width and length of the tibio-tarsal claw and tarsus length) to test if morphological changes have taken place throughout time in these anatomical elements. We found that archaeological male and female specimens presented significant differences in the tibio- tarsal width (right and left). When comparing data between archaeological and modern male specimens, statistically significant differences were found in almost all the parameters studied, except for the right tarsal length. On the other hand, archaeological and modern female specimens showed no statistically significant change in the variables studied. In brief, our data suggest that modern male specimens have undergone a process of claw reduction, but females have maintained the same dimensions.