Boreostiba frigida

Boreostiba frigida (J. Sahlberg, 1880), sp. propr.

(Figs. 87–89 in Brundin 1940; Figs. 190–193 in Lohse et al. 1990 (as Boreostiba lamellifera))

Atheta frigida J. Sahlberg, 1880: 93.

Atheta (Oreostiba) frigida: Bernhauer & Scheerpeltz, 1926: 620 (as valid species).

Atheta (Oreostiba) frigida: Brundin, 1940: 115 (as valid species).

Boreostiba frigida: Lohse et al., 1990: 196 (as synonym of Boreostiba sibirica (Mäklin, 1880); misidentification).

Boreostiba lamellifera Lohse in Lohse et al., 1990: 195, syn. nov.

(Other (Palaearctic) references for Boreostiba frigida are omitted)

Type material. Holotype of Boreostiba lamellifera: CANADA: Québec: ♂, Payne Bay, 19.viii.1958 (W.R.M.Mason) (CNCI). Paratypes: CANADA: Québec: 4♀♀, Payne Bay, 19.viii.1958 (W.R.M.Mason) (CNCI); Yukon Territory: 2♂♂, British Mts., “Sunday Mt.”, 950 m, 69º17’N 140º03’W, under rocks at edge of snowfield, 17.vi.1984 (J.M.Campbell) (CNCI).

Additional material. RUSSIA: Chukotskiy Aut. Distr.: ♂, 1 specimen, 174 th km of the road Egvekinot – Iul’tin, 67º42’N 178º40’W, 17.vii.1989 (Yu.M.Marusik); ♂, 2 specimens, 161 th km of the road Egvekinot – Iul’tin, 24.vi.1989 (Yu.M.Marusik); 2♂♂, ♀, 3 specimens, 121 th km of the road Egvekinot – Iul’tin, 67º18’N 178º40’W, vi.1989 (Yu.M.Marusik) (SPSU); Magadan Region : ♂, 2 specimens, upper Kolyma River, Tundrovyy Creek, mountain tundra, under Salix, 1200 m, 11.vii.1986 (Yu.M.Marusik); 5 specimens, upper Kolyma River, Bol’shoy Annachag Ridge, env. of Sibit­Tyellah, 1400 m, the Tundrovaya River valley, small Salix bush with moss, 6.ix.1986 (Yu.M.Marusik); 3♂♂, ♀, 5 specimens, upper Kolyma River, Bol’shoy Annachag Ridge, env. of Sibit­ Tyellah, 800 m, Olen’ River, Alnus, Pinus pumila, in leaf litter, 15.vii.1985 (Yu.M.Marusik); SWEDEN: ♂, Abisko (L.Brundin) (MZHF).

Diagnosis. See Brundin (1940; as At. frigida) and Lohse et al. (1990; as Boreostiba lamellifera).

Discussion. Lohse (Lohse et al. 1990) did not examine the types of At. frigida and based his judgement on the status of this species on the drawings by Brundin (1940) who had examined the types of both At. frigida and H. sibirica (the type species of Boreostiba). Lohse (Lohse et al. 1990: 197) believed that the difference in Brundin’s drawings for At. frigida and At. sibirica resulted from “the variable extent of the evagination of the internal sac”. I do not agree with this interpretation of Brundin’s drawings (Brundin 1940: Figs. 85–88) which are, in my opinion, more accurate than the drawings in Lohse et al. (1990: Figs. 190–191, 194–196). When Brundin’s drawings of the median lobe of the aedeagus of At. sibirica (Figs. 85–86) and At. frigida (Figs. 87–88) are compared, the difference between the two species in the length of the athetine bridge (cf. Fig. 85 and Fig. 87 in Brundin 1940) and the shape of the apex of the median lobe (cf. Fig. 86 and Fig. 88 in Brundin 1940) is very clear. Both the athetine bridge and the apex of the median lobe are rigid structures which do not change their shape when the internal sac is everted. The differences in Brundin’s drawings for At. sibirica and At. frigida allow to easily separate both species (the first species has a shorter athetine bridge than the second species) and cannot be attributed to a different extent of the evagination of the internal sac. My examination of the holotype of Boreostiba lamellifera demonstrated that it was conspecific with examined Palaearctic specimens of Boreostiba frigida. The drawings of the aedeagus of Boreostiba lamellifera (Figs. 190–191, 193 in Lohse et al. 1990) match the corresponding drawings of Boreostiba frigida (Figs. 87–88 in Brundin 1940). Therefore I remove Boreostiba frigida from synonymy with Boreostiba sibirica and place Boreostiba lamellifera in synonymy with Boreostiba frigida.

Distribution. Boreostiba frigida has circumpolar distribution. In North America it is known from Canada (Québec and Yukon Territory).