Further clarifications to the systematics of the cave beetle genera Remyella and Rozajella (Coleoptera: Leiodidae: Cholevinae: Leptodirini)

The subtribe Leptodirina is one of the most species-rich subtribes of the tribe Leptodirini, comprising 36 genera and 103 species of beetles adapted to the subterranean environment and distributed in the West Paleartic. The genera of Leptodirina show potentially convergent morphological characters resulting from the adaptation to the subterranean environment. Two genera with uncertain systematic position, living in Sandžak, a geo-political region divided by the border of Serbia and Montenegro, Rozajella S. Ćurčić, Brajković & B. Ćurčić, 2007 and Remyella Jeannel, 1931, were recently tentatively placed in this subtribe. However, no molecular phylogenetic studies have been performed to support this placement. Both genera share morphological characters and live in neighbouring geographic areas (Pešter polje and surrounding massifs). We performed a molecular phylogenetic analysis to examine the phylogenetic position of these two genera. A more detailed molecular and morphological investigation of the taxa within Remyella clarified their systematics. The speciation events within Remyella occurred approximately from 5 to 2 million years ago, which corresponds to the end of the Miocene and the Pliocene, periods when Pešter was periodically filled by shallow lakes. The distribution area of the genus, confined to the periphery of Pešter, is probably contingent to the presence of these lakes that prevented species from spreading more uniformly over the entire area of the plateau. Additionally, the correlations between genetic and geographic distances were investigated using the Mantel test. Four synonymies inside Remyella are established and all species of the genus are briefly diagnosed. Identification tables and distribution maps of species of Remyella and Rozajella are provided, and the new species Rozajella madzgalji n.sp. is described.