Résumé
Reproduction and dispersal are key aspects of species life history that
influence spatial genetic structure in populations. Several ant species in
the genus Cataglyphis have evolved a unique breeding system in which new
reproductives (that is, queens and males) are produced asexually by
parthenogenesis; in contrast, non-reproductives (that is, workers) are
produced via sexual reproduction by mates from distinct genetic lineages.
We investigated how these two coexisting reproductive methods affect
population-level spatial genetic structure using the ant Cataglyphis
mauritanica as a model. We obtained genotypes for queens and their male
mates from 338 colonies, and we found that the two lineages present in the
study population occurred with equal frequency. Furthermore, analysis of
spatial genetic structure revealed strong sex-biased dispersal. Because
queens were produced by parthenogenesis and because they dispersed over
short distances, there was an extreme level of spatial structuring: a
mosaic of patches composed of clonal queens was formed. Males, on the
other hand, dispersed over several hundred metres and, thus, across
patches, ensuring successful interlineage mating.