The species of the Poecilimon heroicus-group occur around the Caucasus (from north-eastern Turkey to south-eastern Ukraine). We describe the diagnostic morphological characters of all these species and the male calling song of three of the four species. Based on this data the following phylogenetic relationship is derived (P. tschorochensis (P. tricuspis (P. heroicus, P. bifenestratus))). Within the genus Poecilimon, the species can be recognised by a relatively wide pronotum and large tegmina. In one species, Poecilimon tschorochensis Adelung, 1907 (type species of the monotypic genus Artvinia Karabag, 1962, syn. n.; P. rammei Miram, 1938, syn. n.), the tegmina are very large and the song has unusually low spectral components. This species produced di-syllabic echemes at intervals of about 10 s. In two other species of the group, P. heroicus and P. bifenestratus, the calling song of males consists of an uninterrupted dense sequence of long syllables (syllable duration around 0.5 s; ca. 1 syllable/s at 20°C). In these species the auditory spiracles are reduced in size in both sexes, and the females have extremely small tegmina and are unable to respond to the male song acoustically, which would be typical for Phaneropteridae. The change in communication from acoustically responding to mute females has not been previously documented within a group of closely related species.
The Poecilimon ornatus group has an exclusively European distribution and includes the largest species in the genus. A revision of the taxa belonging to this group in Bulgaria and Macedonia (Central and Eastern Balkan Peninsula) is presented. Nine taxa described from Bulgaria are synonymised with 3 previously known species, as follows: Poecilimon ornatus (= P. mistshenkoi marzani, syn. n., P. mistshenkoi tinkae, syn. n., P. mistshenkoi vlachinensis, syn. n.), P. affinis s. str. (= P. mistshenkoi mistshenkoi, syn. n., P. affinis ruenensis, syn. n., P. affinis rilensis, syn. n., P. affinis medimontanus, syn. n., P. harzi, syn. n.) and P. hoelzeli (= P. kisi, syn. n.). The synonymy of P. poecilus with P. affinis and the subspecific status of P. affinis komareki are confirmed. One species, Poecilimon jablanicensis, sp. n., is described as new to science. A tabulated key, lists and maps of all known localities and oscillograms of the songs of all the species in this group are presented. The phylogenetic relationships and evolutionary trends in the Poecilimon ornatus group are discussed.