Integrating morphology with phylogenomics to describe four island endemic species of Temnothorax from Sicily and Malta (Hymenoptera, Formicidae)

Temnothorax (Myrmicinae, Crematogastrini) is one of the most diverse Holarctic ant genera, and new taxonomic advancements are still frequent worldwide. The Mediterranean region, a global biodiversity hotspot characterized by a complex geographic history, is home to a substantial portion of its described diversity. Sicily is the region???s largest island and, as ongoing investigations are revealing, it is inhabited by a long-overlooked but highly diverse ant fauna that combines multiple biogeographic influences. We combined qualitative and quantitative morphology of multiple castes with phylogenomic analysis based on ultra-conserved elements (UCEs) to describe four species of Temnothorax endemic to Sicily and the neighboring Maltese Islands (Sicilian Channel). Three of these species, T. marae Alicata, Schifani & Prebus sp. nov., T. poldii Alicata, Schifani & Prebus sp. nov. and T. vivianoi Schifani, Alicata & Prebus sp. nov., are new to science, while a redescription clarifies the identity of T. lagrecai (Baroni Urbani, 1964). These descriptions highlight the current difficulties of delimiting monophyletic Temnothorax species groups based on morphological characters. The intra-insular endemicity patterns we revealed highlight the importance of Mediterranean paleogeography to contemporary ant diversity and distribution in the region.

Automated summary

This study describes four species of Temnothorax endemic to Sicily and the neighboring Maltese Islands using qualitative and quantitative morphology as well as phylogenomic analysis. Three of these species are new to science. The findings highlight the importance of Mediterranean paleogeography to ant diversity and distribution in the region.