Gene flow among populations of Xylocopa frontalis (Hymenoptera: Apidae: Xylocopini) of islands and continent: is the sea a geographical barrier?

The aim of this study was to investigate whether the sea acts as a geographical barrier to gene flow in Xylocopa frontalis . To achieve this, 90 female individuals from three geographic populations were analyzed. These populations were collected from the north coast of the state of São Paulo (Brazil) in mainland and insular areas. The genetic variability was assessed by sequencing two regions of the mitochondrial genome ( CO I and Cytb ) and by genotyping 12 microsatellite loci . The results showed that there was no population genetic structure for both mitochondrial and nuclear markers, indicating a low rate of inbreeding. The analyses suggest that gene flow occurs between mainland and island populations mediated by both females and males.