DNA-barcoding of the Italian members of the Aphaenogaster testaceopilosa-group (Hymenoptera: Formicidae). Hybridization and biogeographic hypothesis

The thermophilic Aphaenogaster testaceopilosa-group is a taxon consisting of 14 species in Europe. Recently, this group was recently revisited using morphological characters suggesting different changes in the systematic of this group. For the first time, in this work we used a molecular approach using the DNA barcoding on the european members of the genus Aphaenogaster in order to: i) validate the current systematic of the A. testaceopilosa group in Italy, ii) test the efficiency of COI marker to delimit the species belonging to the genus Aphaenogaster. In the first phase, we morphologically identified 54 specimens of A. testaceopilosa group collected along the entire Italian range. In the second phase, fragments of COI and CAD markers were sequenced from phenotyped individuals. Phylogenetic reconstructions and genetic distances clearly showed six lineages (MOTUs) in agreement with morphological identification except for one specimen collected in a likely contact zone between Aphaenogaster picena and Aphaenogaster semipolita. Furthermore, this study confirms the powerful of DNA barcoding to support the morphological analysis to delimit the species belonging to Aphaenogaster testaceopilosa-group. Therefore, genetic data could be a valid tool to investigate other more problematics groups of this little-known genus.