The species groups of the genus Ppoecilimon (Orthoptera,Tettigoniidae): Their monophyly, phylogeny and determination of the species compositions

The genus Poecilimon, which constitutes approximately one-eighth of Anatolia's Orthoptera (grasshoppers and crickets) fauna, is recognized as the second most diverse genus within this order in the Palearctic region. While numerous traditional taxonomic studies have focused on individual species groups within the genus, comprehensive analyses encompassing the entire genus have been limited to a small number of species and samples. As a result, the phylogeny, diversification patterns, and phylogeography of Poecilimon await investigation through rigorous methodologies and extensive datasets. This dissertation aims to characterize the phylogeny and phylogeography of Poecilimon species groups, most of which are endemic to Anatolia, using large-scale molecular data. These data include mitochondrial and nuclear gene segments obtained through Sanger sequencing, as well as complete mitochondrial genomes and ribosomal cistron regions generated via next-generation sequencing. Analyses conducted in this study have resolved the phylogenetic relationships of the genus, its subgenera, and species groups, in addition to determining species and subspecies compositions, diversification times, and centers of origin. The findings reveal that the genera Polysarcus Fieber, 1853, and Phonochorion Uvarov, 1916, are nested within Poecilimon and that the subgenus Poecilimon s.str. is monophyletic. Consequently, these two genera have been synonymized with Poecilimon. Furthermore, the monophyly of the subgenus Hamatopoecilimon has been supported. Based on the data obtained, the 22 species groups previously described in the literature have been revised into 17 groups, with updates to the species and subspecies compositions of each group. The diversification of Poecilimon, which originated from an ancestral stock approximately 12 million years ago on the Aegeid landmass, has occurred in three major phases. These correspond to the Tortonian-Messinian, Late Messinian-Early Pliocene, and Pleistocene periods. The basal diversification of the genus is attributed primarily to ecological speciation during the first phase. The second phase involved both vicariant and ecological speciation, followed by a wider geographic expansion. The third phase, driven by Pleistocene climatic cycles, resulted in the formation of contemporary species. The diversification patterns of Poecilimon align with those of other Anatolian-endemic lineages, corresponding to Middle-to-Late Miocene diversification events. The historical diversification, combined with current habitat and distribution characteristics—such as widespread endemism, preference for montane habitats, and phenological traits adapted to early seasonal activity—highlight the necessity of conserving Anatolia's mountainous regions.