Diphascon alpinum, Murray, 1906

Status of Diphascon alpinum View in CoL

The validity of the species Diphascon alpinum was a subject of a long-lasting discussion (see Pilato & Binda, 1977, 1998; Dastych, 1988, 1989, 2015). Based on the incomplete and contradictory description of this species, Dastych (1988, 1989) considered D. alpinum as a species that “probably should be recognized as ‘nomen nudum’”* while Pilato & Binda (1998) based on the specimen from Siberia considered D. alpinum as a rare but valid species. Later on, after re-investigation of this material Pilato re-assigned the Siberian material as D. tenue and noted that he has never found a specimen surely attributable to the species D. alpinum (Pilato, pers. comm., 25 October 2017). In our opinion, D. alpinum is very likely a senior synonym of A. tenue , comb. nov., but due to the incompleteness of its description should be considered a nomen dubium.