Abstract
The Balkan Peninsula is treated as a hotspot of biodiversity with over 40% of European bush-crickets occurring there. Poecilimon Fischer, 1853 is one of the largest Palaearctic orthopteran genera containing several species groups. One of them is the Poecilimon ornatus group (Schmidt, 1850) with 13 species and 5 subspecies. Among the group, the Poecilimon affinis complex is designated as consisting of P. pseudornatus Ingrisch & Pavićević, 2010, P. nonveilleri Ingrisch & Pavićević, 2010, and five subspecies of P. affinis (Frivaldszky, 1868). The aim of this study is to reconstruct the phylogenetic relationships among taxa of the P. ornatus group and to elucidate the position of taxa related to the P. affinis complex. Molecular phylogeny supported the monophyly of the P. ornatus group and showed that their ancestor probably originated in the southern Balkans. The underlying processes are thought to be six dispersals and five vicariance events linked to geological events and climate changes in the Pleistocene. The species delimitation analysis showed mostly nine hypothetical species among the group.