New data on taxonomy, biology and distribution of weevils of the subgenus Pliadonus Reitter, 1912 (Coleoptera: Curculionidae: Otiorhynchus) from the West Caucasus

New data on the morphology, biology and distribution of Otiorhynchus (Pliadonus) abagoensis Reitter, 1888, O. brachialis Boheman, 1843, O. dentitibia Reitter, 1888, O. dolmenicus Davidian et Savitsky, 2006, O. granulatissimus Reitter, 1914, O. helenae Reitter, 1914, O. impressiceps Reitter, 1888, O. pseudobrachialis Reitter, 1914, O. schamylianus Reitter, 1888, O. starcki Retowski, 1885, and Otiorhynchus sp. pr. longipes Stierlin, 1872 are given. All of them are local endemic species distributed only in the West Caucasus (Russia: Stavropol and Krasnodar regions, Adygea; Abkhazia). A key to 11 species of the subgenus Pliadonus Reitter, 1912 is given. Few host plants are established for O. starcki, O. pseudobrachialis and O. granulatissimus. Otiorhynchus pseudobrachialis was collected for the first time after its description by E. Reitter in 1914; all of specimens were found only on Epimedium colchicum (Boiss.) Trautv. (Berberidaceae). Otiorhynchus starcki and O. granulatissimus occurr on different plants, from which on Epimedium colchicum O. starcki was found in the south part of its range and O. granulatissimus in the northwestern part of Abkhazia. In our opinion Epimedium colchicum together with O. starcki, O. pseudobrachialis and O. granulatissimus represent the autochthonous nature complexes in the West Caucasus. The holotype of O. fortispinus Reitter, 1909 was examined, and lectotypes of O. starcki, O. pseudobrachialis, O. granulatissimus and O. dentitibia are designated. The following new synonymy is proposed: O. schamylianus Reitter, 1888 = O. tbatanicus Reitter, 1914, syn. n. Otiorhynchus lilligi Keskin et Cevik, 2007 is transferred from the subgenus Pliadonus to Pocodalemes Reitter, 1912.