A contribution to the knowledge of the weevils of the subgenus Nubidanus Rtt., allied to Otiorhynchus impexus Schh. (Coleoptera, Curculionidae)

Results of the investigation of the subgenus Nubidanus Rtt. (sensu Reitter) of the genus Otiorhynchus are reported. The impexus species-group of the subgenus Nubidanus comprises 5 species from the Caucasus: O. impexus, O. juvenilis, O. poricollis, O. jarpachlinus, and O. hajastani. Morphological diagnoses and detailed distribution patterns of the species are given. Lectotypes of O. poricollis and O. jarpachlinus are designated. A new synonymy is established: O. poricollis Schoenherr, 1832 = O. breviusculus Stierlin, 1875, syn. n. Variants of the genesis scenario of the impexus species-group in the eastern part of the Caucasus are discussed.