Morphology and phenology of sexuals and new distribution data on the blind Mediterranean ant Hypoponera abeillei (Hymenoptera, Formicidae)

Hypoponera abeillei is the sole member of the otherwise exclusively Afrotropical abeillei group to occur in the West-Palearctic and since its first description on the basis of two Corsican workers in 1881, it remained little-known. Workers of this species are thought to entirely lack eyes, a rare trait among ants of the region, yet their lifestyle remains undocumented. On the other hand, the male caste has been described from 4 Tunisian specimens in 1921, and queens remained so far undescribed. We present an updated description of the male caste based on 45 specimens and a first description of the queen caste based on 14 specimens. The H. abeillei material we examined comes from Italy, Spain and Malta (mostly originating from coastal localities), and comprises 11 inedit distribution records, including the first findings in the islands of Mallorca, Malta and Sardinia. Moreover, we provide a first phenological overview of the species’ nuptial flights. Our data show that H. abeillei sexuals flight during the summer, mostly in August, and demonstrate that they can easily be distinguished from all the other Hypoponera species inhabiting the Mediterranean region based on their morphology. The remarkable diversity of Mediterranean Hypoponera males and queens suggest that sexuals may have a role in future attempts to understand relationships within this genus, yet the number of species in which sexual castes are documented is still extremely reduced.