Giuseppe Nicolosi

A new species of the subfamily Pselaphinae (Coleoptera: Staphylinidae) has been discovered on Mount Etna (Sicily, Italy) and is described herein as Bryaxis aetnensis sp. nov. The new species is closely associated with the Bryaxis difficilis group, a highly homogeneous group of species living in the regions of Sicily and Sardinia. Diagnostic features and distribution of Sicilian species of this group are treated and illustrated herein. Bryaxis aetnensis sp. nov. exhibits similarities to B. marinae but can be distinguished by the darker color, longer antennal scape and terminal palpomere, and in the aedeagus morphology. The distribution of B. aetnensis sp. nov. spans a wide altitudinal range, demonstrating a remarkable climatic tolerance across the slopes and diverse habitats of Mount Etna. This broad tolerance reflects the species’ probable high ecological plasticity, which may also contribute to the observed morphological variability among individuals from different sampling sites. The significance of this new discovery on Mount Etna highlights the need to intensify sampling efforts in the region. Strengthening protection for these unexplored environments is crucial, and it also aids in unraveling biogeographic questions about the fauna inhabiting the area. As a relatively young volcanic environment, species colonization has occurred recently, making it an intriguing subject of investigation.