Title: Fine-scale population structure analysis in Armadillidium vulgare (Isopoda: Oniscidea) reveals strong female philopatry,
Abstract: In the last decades, dispersal studies have benefitted from the use of
molecular markers for detecting patterns differing between categories of
individuals, and have highlighted sex-biased dispersal in several species. To
explain this phenomenon, sex-related handicaps such as parental care have been
recently proposed as a hypothesis. Herein we tested this hypothesis in
Armadillidium vulgare, a terrestrial isopod in which females bear the totality
of the high parental care costs. We performed a fine-scale analysis of
sex-specific dispersal patterns, using males and females originating from five
sampling points located within 70 meters of each other. Based on microsatellite
markers and both F-statistics and spatial autocorrelation analyses, our results
revealed that while males did not present a significant structure at this
geographic scale, females were significantly more similar to each other when
they were collected in the same sampling point. These results support the
sex-handicap hypothesis, and we suggest that widening dispersal studies to
other isopods or crustaceans, displaying varying levels of parental care but
differing in their ecology or mating system, might shed light on the processes
underlying the evolution of sex-biased dispersal.