Note sul gruppo di Ceutorhynchus (s. str.) nanus Gyllenhal, 1837 con descrizione di due nuove specie (Coleoptera, Curculionidae)

New distribution and collection data for some species of Ceutorhynchus nanus group are given. C. gracilis Dieckm. et Smrecz. is considered a valid species and not a subspecies of C. nanus (status novus). C. nanoides n. sp. from the high mountains of Abruzzes (Central Italy) and from Northwestern Italy (Friuli) is described; the new species is very closely related to C. korotyaevi Colonn. from Gruzia and Krasnodar region (SE European part of Russia), from which it differs for the body broader, more rounded elytral sides, more convex upper surface and female antenna inserted behind of mid-point of rostrum; the specimens from Abruzzes were collected on Alyssum montanum L. while those from Friuli were founded on A. petraeum L. which very likely are the true host plants. It also described C. dieckmannianus n. sp. from Northern Greece (Mount Smolikas), closely related to the European C. angustus Dieckm. et Smrecz. but differing from the latter for the stouter legs, shorter tarsus and female rostrum similar in shape and in length to the male one; all the types were collected on Iberis cfr. sempervirens L. On the same plant were found in Greece (Katara) some specimens of C. karamani Muller, 1921; this are the first data on ecology of this species. A checklist and a key to the 15 species of the group is also provided.