Procladius appropinquatus ( Lundström, 1916 )

Procladius appropinquatus ( Lundström, 1916) View in CoL

Trichotanypus appropinquatus Lundström, 1916 View in CoL — Poppius et al. (1916), Sweden, adult male, description.

Procladius appropinquatus ( Lundström, 1916) View in CoL — Brundin (1949), Sweden, adult male, key, illustration.

Procladius ruris Roback, 1971 View in CoL — Roback (1971), Canada and United States, adult male, adult female, description, illustrations.

Procladius ruris Roback, 1971 View in CoL — Roback (1980), Canada and United States, adult male, pupa, larva, keys, descriptions, photos, illustrations.

Procladius sp. A — Halvorsen et al. (1982), Norway, adult male, illustration.

Procladius sp. B — Halvorsen et al. (1982), Norway, adult male, illustration.

Procladius appropinquatus ( Lundström, 1916) View in CoL — Ratnasingham et al. (2024), Finland, Norway and Sweden, adult males, photos, barcodes.

Procladius cf. ruris Roback, 1971 View in CoL — Ratnasingham et al. (2024), Norway and Canada, adult males, adult females, photos.

Procladius sp. — Ratnasingham et al. (2024), Norway, Poland, Slovakia and Canada, adult males, adult females, larvae, photo.

? Procladius karahutoensis Tokunaga, 1940 View in CoL — Tokunaga (1940), Japan, adult male, key, illustration.

? Procladius karahutoensis Tokunaga, 1940 View in CoL —Sasa & Kikushi (1995), Japan, adult male, key, illustration.

? Procladius ruris Roback, 1971 View in CoL — Saether (2010), Canada, larva, key.

Material examined (n = 29). CANADA, 1 adult male (Paratype of P. ruris, CNCC ), Banff Alta , 51.24°N 115.56°W, 1 383 m a.s.l., ‒1 °C m.a.t., 25.vii.1922, leg. C.B.D. Garrett GoogleMaps ; 1 adult male (Paratype of P. ruris, CNCC ), Lake Cooking , 53.43°N 113.01°W, 732 m a.s.l., +3 °C m.a.t., 24.v.1937, leg. F.O. Morrison GoogleMaps ; 1 adult male (Paratype of P. ruris, CNCC ), Ottawa , 45.36°N 75.84°W, 70 m a.s.l., +7 °C m.a.t., 2.v.1952, leg. J.E. Mitchell GoogleMaps ; 1 adult male (Holotype of P. ruris, CNCC ), Lake Elkwater , 49.39°N 110.17°W, 1 234 m a.s.l., +2 °C m.a.t., 2.vi.1955 GoogleMaps , leg. V. R. Vockeroth ; 1 adult male (Paratype of P. ruris, CNCC ), Lake Scout , 49.36°N 105.99°W, 830 m a.s.l., +4 °C m.a.t., 17.vi.1955 GoogleMaps , leg. V. R. Vockeroth ; 1 adult male (as P. cf. ruris, NTNU ), Churchill town , 58.77°N 94.16°W, 8 m a.s.l., ‒6 °C m.a.t., 21.vii.2007, leg. J. McGovan GoogleMaps [ Barcode CHURC487-08 ] ; 1 adult male (as P. cf. ruris, NTNU ), River Churchill , 58.68°N 94.17°W, 1 m a.s.l., ‒6 °C m.a.t., 25.vii.2007 GoogleMaps , leg. T. Ekrem [Barcode CHURC507-08 ] .— FINLAND, 1 adult male, Lake Saanajärveniompolo , 69.04°N 20.88°E, 659 m a.s.l., ‒4 °C m.a.t., viii.1956, leg. P. Virtanen GoogleMaps ; 4 adult males ( MZHF), Tvärminne , rockpools, 59.83°N 23.30°E, 0‒1 m a.s.l., +5 °C m.a.t., vii.1957, leg. B. Lindeberg GoogleMaps ; 1 adult male ( ZMUO), Enontekiö , Lake Toskaljärvi, 69.19°N 21.44°E, 704 m a.s.l., ‒5 °C m.a.t., 1.viii.2014, leg. L. Paasivirta GoogleMaps ; 2 adult males ( ZMUO), Liminka , Liminganlahti, Liminka, 64.83°N 25.33°E, 1 m a.s.l., +3 °C m.a.t., 4.viii.2015, leg. L. Paasivirta GoogleMaps [ Barcode CHIFI412-16 and CHIFI413-16 ] ; 1 adult male ( ZMUO), Termislehto , Enontekiö, 68.69°N 23.73°E, 436 m a.s.l., ‒2 °C m.a.t., 15.vi.2016, leg. L. Paasivirta. GoogleMaps — NORWAY, 2 adult males (as P. sp. A and P. sp. B, ZMBM), River Ekse , 60.52°N 6.15°E, 580 m a.s.l., +2 °C m.a.t., 10‒23.viii.1976, leg. G.A. Halvorsen GoogleMaps ; 1 adult male (as P. cf. ruris, NTNU ), Sølandet , Kildebeck springbrook, 62.69°N 11.83°E, 785 m a.s.l., ‒1 °C m.a.t., 11‒22.vi.2006, leg. O. Hanssen GoogleMaps [ Barcode MIDGE701-08 ] .— RUSSIA, 3 adult males ( IANR), tundra ponds, east of Naryan-Mar , Yarey-shor, 67.62°N 53.70°E, 18 m a.s.l., ‒3 °C m.a.t., 29.vii.1990, leg. A. Rybakova. GoogleMaps — SWEDEN, 1 adult male (Holotype of P. appropinquatus, NHRS ), Sarek valley , Pelajauratjah, 67°N 18°E, 810 m a.s.l., ‒5 °C m.a.t., 2.viii.1907, leg. B. Poppius GoogleMaps ; 1 adult male (as P. simplicistilis, ZSMG ), Norrby archipelago, Ängerån stream, 63.3°N 19.5°E, 1‒3 m a.s.l., +3 °C m.a.t., 1‒10.viii.1981, leg. K. Müller GoogleMaps ; 1 adult male ( NHRS), Baltic Sea , Sillviksskatan Bay, 63.76°N 20.46°E, 0 m a.s.l., +3 °C m.a.t., 27.vii.2011, leg. N. Ericson GoogleMaps [ Barcode BSCHI390-17 ] ; 1 adult male ( NHRS), Lake Kåbdalisjaure , Kåbdalis, 66.14°N 19.99°E, 330 m a.s.l., 0 °C m.a.t., vii.1993, leg. B. Viklund GoogleMaps ; 1 adult male ( NHRS), Torne lappmark, 68°N 19°E, 650 m a.s.l., ‒1 °C m.a.t., 1.vii.2016, leg. H. Vårdal GoogleMaps [ Barcoded ] ; 2 adult males ( NHRS), Lake Stor-Björsjön , 63.61°N 12.23°E, 566 m a.s.l., 0 °C m.a.t., 16‒23.vi.2019, leg. S. Persson GoogleMaps [ Barcoded ] .

Diagnostic characters. Figs. 27 View FIGURES 24‒27 , 68‒70 View FIGURES 68‒70 , key couplet 9. Male P. appropinquatus and P. simplicistilus have an only slightly indicated gonostylus process which separates them from all other European Procladius species with wing macrotrichia.

The gonostylus process of P. appropinquatus is on average somewhat longer than that of P. simplicistilus (GspR 0.04‒0.10 versus 0.02‒0.06). P. appropinquatus is smaller than P. simplicistilus exemplified by wing length (2.5‒3.7 mm versus 3.7‒4.6 mm), body length (4.3‒6.0 mm versus 6.5‒8.1 mm) and gonocoxite width (282‒350 µm versus 377‒451 µm). The antenna AR-ratio of P. appropinquatus is mostly lower than that of P. simplicistilus (AR 1.8‒2.6 versus 2.5‒3.2). Hairiness is often also useful to distinguish P. appropinquatus from P. simplicistilus (scutellum 40‒73 setae versus 74‒117 setae, wing vein Cu stem 4‒36 setae versus 0‒4 setae).

P. appropinquatus has often been identified as P. ruris in Canada. Studied males including types, both with and without barcodes, shows that P. ruris is a synonym. The adult female, pupa and larva have been described as P. ruris . Barcodes of adult males, adult females and larvae are available.

Geographical distribution and ecology. P. appropinquatus has been found in northern Europe from Slovakia at latitude 49°N to northern Finland and Russia at latitude 69°N. It has been found from 45°N to 59°N in North America. The species has records from sites in boreal coniferous forests, subalpine mountain birch forests, taiga and completely treeless tundra. The 34 sites with findings have a mean annual temperature ranging from +7 to ‒6 °C, with the highest temperature at sea level in the Baltic Sea and the coldest in the arctic tundra. Highest altitude is at about 1 900 m above sea level in a high plain above the tree limit in northern Slovakia .

Larvae of P. appropinquatus have been collected at water depth from 0 to 5 m in oligohaline to mesohaline brackish water of bays and rockpools in the Baltic Sea. In freshwater, findings have been reported from ponds, bog systems, shallow lakes, tarns and small streams with low velocity. All findings are from ultraoligotrophic to mesotrophic conditions. Adults have been caught from late May to mid-August.

Countries with records of P. appropinquatus in Europe are Finland, Norway, Poland, Russia, Slovakia and Sweden. It is also known from Canada, Japan and the United States.

References. Brundin 1949; Ekrem et al. 2018; Ekrem & Majaneva 2019; Halvorsen et al. 1982; Lindeberg 1958; Paasivirta 2012; Paasivirta 2014; Poppius et al. 1916; Ratnasingham et al. 2024; Roback 1971; Saether 2010; Sasa & Kikushi 1995; Säwedal 1977; Tokunaga 1940.