Spilogona cordyluraeformis (Schnabl, 1915)

Spilogona cordyluraeformis (Schnabl, 1915) View in CoL

Figs 4 E–K View FIGURE 4

Scatocoenosia cordyluraeformis Schnabl in Becker et al., 1915: 3. Type-locality: “in der Karskaja Tundra” [ RUSSIA, West Siberia, Yugorskiy Peninsula, Kara district; actually Yamalo-Nenetskiy AO, east slope of Polar Urals, Mt Minisey, 180 m, 21.vii.1909, F. Zaitsev] [seen].

Spilogona albinepennis Huckett, 1965: 210 View in CoL . Type-locality: “ Spence Bay , Northwest Territories, 7.30 ... 51 [i.e. 30.vii.1951] (A.E.R. Downe)” [ CANADA, NWT] [seen]. Syn. nov.

Spilogona dorsostriata Huckett, 1965: 217 View in CoL . Type-locality: “Point Barrow, Alaska, 7.18.52 [i.e. 18.vii.1952]” [ USA, Alaska; collector P.D. Hurd] [seen]. Syn. nov.

Spilogona cordyluraeformis (Schnabl, 1915) View in CoL ; Sorokina & Pont, 2013: 581 View Cited Treatment (Polar Urals, Cape Otto Schmidt, Wrangel Island); Sorokina, 2017: 53 (Yamalo-Nenez AO, Taymyr, Wrangel Island).

Spilogona sp. 1 ; Sorokina & Khruleva, 2012: 557 (Wrangel Island); Sorokina & Tridrikh, 2021: 221 (Cape Otto Schmidt).

Notes. Huckett (1965) described two very similar species from different populations of the arctic coastal regions: Spilogona albinepennis View in CoL (Nunavut /NWT, Quebec) and Spilogona dorsostriata View in CoL (Alaska). Both species are very distinctive, with a very broad frons in male which is about as broad as in female, very small size, with small yellow subequal calypters, black unmarked abdomen with subshining margins, often with subshining/shining stripes on scutum, and whitish wings in male and brownish tinged along veins in female.

According to Huckett (1965: 217), Spilogona dorsostriata differs from Spilogona albinepennis by “four black glossy stripes on mesonotum, which often fuse or merge together, thus partly blurring their identity as separate stripes”. In my opinion, the pattern of scutal stripes cannot be a reliable character for describing a new species, given that reliable characters such as the width of the frons, small subequal calypters etc. are the same in both species. The types of both species were examined by the author in Canadian National Collection. Additionally, 77 females and 74 males with the same characters were found in unsorted material from different populations in Canada (Yukon, NWT, Quebec). It was impossible to separate these specimens into two species, as the dusting varied greatly, from completely matt, to glossy streaks, to narrow glossy stripes and to broad glossy marks ( Figs 4E–K View FIGURE 4 ). I also dissected the male terminalia in specimens from different populations with different scutal markings, and they were the same .

The descriptions and the male terminalia of Spilogona dorsostriata and Spilogona albinepennis are identical with those in the recently discussed Spilogona cordyluraeformis . The differences between all these species consist only in the different degrees of brown pollination on the scutum. Scatocoenosia cordyluraeformis was described only from the female and for a long time raised questions as to its correct family assignment. A large series of males and females of this species from Cape Otto Schmidt, Taymyr and Wrangel Island enabled us to resolve these issues ( Sorokina & Pont, 2013; Sorokina & Tridrikh, 2021). The female holotype of Scatocoenosia cordyluraeformis has a shining scutum with a median dusted vitta. Specimens from Taymyr have a shining, or subshining, or dusted scutum; specimens from Wrangel Island mostly have a completely dusted scutum; specimens from Cape Otto Schmidt have a completely shining scutum, or with a narrow median dusted vitta. In my opinion, the dusting of the scutum is a variable character.

I can therefore conclude that Spilogona albinepennis Huckett, 1965 and Spilogona dorsostriata Huckett, 1965 are new junior synonyms of Scatocoenosia cordyluraeformis Schnabl, 1915 .

Distribution. PALAEARCTIC: Russia (Yamalo-Nenez AO, Taymyr, Wrangel Island). NEARCTIC: Alaska, Yukon, Nunavut/NWT, Quebec.