G. it. Ent., 14 (60): 223-240
March 2015
Revisione sistematica del genere Cotaster Motschulsky:
nuove sinonimie e descrizione di due nuove specie (Coleoptera, Curculionidae)
di
LUCIANO DIOTTI, CARLO PESARINI & ROBERTO CALDARA
Abstract - Systematic revision of genus Cotaster Motschulsky: new synonymies and descriptions of two new species (Coleoptera, Curculionidae) - The Palaearctic weevil genus Cotaster Motschulsky, 1851 is revised for the first time. Four species are considered valid: two previously described, C. uncipes (Boheman, 1838) and C. cuneipennis (Aubé, 1850), and two new to Science, C. speziai n. sp. (north-eastern Italy, Austria, southern Germany) and C. kostali n. sp. (southern Italy). Through the study of the types, it is established that C. cuneipennis sensu auctorum is actually C. uncipes (Boheman, 1838), and C. uncipes sensu auctorum is actually C. cuneipennis (Aubé, 1850). The two following synonymies are proposed: C. cuneipennis (Aubé, 1850) (= Styphlus pilosus Motschulsky, 1851, n. syn. = C. orientalis Solari, 1941, n. syn.). The taxon described as C. uncipes f. carniolicus Voss, 1955 is actually of infrasubspecific rank, and thus the respective name is unavailable. Through the original description, Caenocotaster Voss, 1971, described as subgenus of Cotaster based on a single species from South Africa, is raised to genus rank, as follows: Caenocotaster Voss, 1971, stat. nov., and Caenocotaster remotus Voss, 1971, comb. nov. On the basis of the pattern of the punctures and vestiture of the elytral interstriae, and the shape of the antennal scape, C. speziai is more closely related to C. cuneipennis, whereas C. kostali is more similar to C. uncipes. These relationships were further supported by the study of the mt COI gene, which demonstrated a genetic divergence of 4.0-4.3% between C. cuneipennis and C. speziai, 11.9-12.2% between C. uncipes and C. cuneipennis, and 11.4% between C. uncipes e C. speziai. For each species, detailed notes on type specimens, diagnosis, description, synonymies, comparative notes, distribution, photographs and drawings of the habitus and useful taxonomical characters are provided, together with two keys to species (one in English).
