Procladius pruinosus ( Kieffer, 1924 )

Procladius pruinosus ( Kieffer, 1924) View in CoL

Trichotanypus pruinosus Kieffer, 1924 View in CoL — Kieffer (1924), Austria and Czechia, adult male, key, description.

Procladius pruinosus ( Kieffer, 1924) View in CoL — Goetghebuer & Lenz (1936a), Goetghebuer & Lenz (1936b), Belgium and Czechia, adult male, key, description, illustration.

Procladius? cinereus (Goetghebuer, 1936) View in CoL — Brundin (1949), Sweden, adult male, pupa in part, key, illustration.

Procladius sp. — Muragina-Koreneva (1957), Russia, adult male, description, key, illustration.

Procladius choreus ( Meigen, 1804) View in CoL — Graham (2020), Wales, adult male, photos.

Procladius cf. fuscus Brundin, 1949 View in CoL — Ratnasingham et al. (2024), Canada, adult males, adult females, photos.

Procladius crassinervis ( Zetterstedt, 1838) View in CoL — Ratnasingham et al. (2024), England, adult male.

Procladius pruinosus ( Kieffer, 1924) View in CoL — Ratnasingham et al. (2024), Norway and Sweden, adult males, adult female, pupa, larva, photos.

Procladius sp. — Ratnasingham et al. (2024), England, Finland, Germany, Norway, Slovakia, Canada and United States, adult males, adult females, photos.

? Trichotanypus bathocryptus Kieffer, 1924 — Kieffer (1924), Germany, adult male, key, description.

? Trichotanypus niger Kieffer, 1924 — Kieffer (1924), Germany, adult male, key, description.

? Procladius bathocryptus ( Kieffer, 1924) — Goetghebuer & Lenz (1936a), Germany, adult male, key, description.

? Procladius zernyi Goetghebuer, 1936 View in CoL — Goetghebuer & Lenz (1936a), Goetghebuer & Lenz (1936b), Austria, adult male, key, description, illustration.

Material examined (n = 57). AUSTRIA, 1 adult male (as P. choreus, ZSMG ), Lake Lünzer Obersee , 47.80°N 15.08°E, 1 113 m a.s.l., +2 °C m.a.t., 1940, leg. F. Krüger GoogleMaps ; 1 adult male (as Procladius III, ZSMG ), Lunz , stream from pond, 47.85°N 15.05°E, 610 m a.s.l., +5 °C m.a.t., 7.v.1972, leg. N. Caspers. GoogleMaps — CZECHIA, 2 adult males ( NHRS), Cheb district, Lake Vodni Nadrz Skalka , 50.08°N 12.32°E, 439 m a.s.l., +7 °C m.a.t., 17.vi.1991, leg. Y. Brodin. GoogleMaps — ESTONIA, 1 adult male ( NHRS), Lake Ülemiste , 59.24°N 24.46°E, 36 m a.s.l., +6 °C m.a.t., 21.v.1993, leg. Y. Brodin. GoogleMaps — FINLAND, 1 adult male (as P. cfr. nigriventris, WIFE ), Lake Kuusijärvi , 60.31°N 25.12°E, 44 m a.s.l., +5 °C m.a.t., 15.vi.1965, leg. P. Armitage GoogleMaps ; 3 adult males (as Procladius sp. , HECH), Lake Karvastenlahti, Hiittiö , 61.16°N 24.03°E, 79 m a.s.l., +5 °C m.a.t., 25.v.1978, leg. P.H. Kansanen GoogleMaps ; 2 adult males (as P.? cinereus, HECH ), Aidassaari, Lake Vanajavesi , 61.17°N 24.08°E, 79 m a.s.l., +5 °C m.a.t., 22‒25.viii.1978, leg. P.H. Kansanen GoogleMaps ; 1 adult male (as Procladius sp. ), Baltic Sea, Lake Käringsund, Storskär Island , 63.43°N 21.07°E, 0 m a.s.l., +4 °C m.a.t., 30.v‒13.vi.2017, leg. L. Paasivirta. GoogleMaps — FRANCE, 2 adult males (as Procladius sp. I , LHST), Lake de L’ite, 42.85°N 0.16°E, 2 281 m a.s.l., +2 °C m.a.t., 16.vii.1965, leg. H. Lavillle GoogleMaps ; 1 adult male (as Procladius sp. I , LHST), Lake de Nere Inferior , 42.87°N 0.18°E, 2 209 m a.s.l., +2 °C m.a.t., 7.vii.1966, leg. H. Laville. GoogleMaps — GERMANY, 1 adult male (as P. bathocryptus, ZSMG ), Lake Schluensee , 54.19°N 10.46°E, 22 m a.s.l., +9 °C m.a.t., 1953, leg. I. Müller-Liebenau GoogleMaps ; 1 adult male (as P. choreus, ZSMG ), northeast of Sonneberg, Lake Königsee , 50.38°N 11.18°E, 627 m a.s.l., +7 °C m.a.t., 25‒27.iv.1957, leg. W. Engelhardt GoogleMaps ; 1 adult male (as Procladius sp. , ZSMG), Braunkohlerestgewerke, OS Boden , 51.0°N 6.5°E, 21 m a.s.l., +11 °C m.a.t., 13.xii.1966, leg. Herbst GoogleMaps ; 1 adult male (as P. choreus, ZSMG ), Lake Königsee , 50.38°N 11.19°E, 628 m a.s.l., +7 °C m.a.t., 25.v.1986, leg. R. Gerstmaier GoogleMaps ; 1 adult male (as P. crassinervis, ZSMG ), Lake Chiemsee, Herrenchiemsee , 47.87°N 12.40°E, 518 m a.s.l., +9 °C m.a.t., 13.vi.1988, leg. C. Orendt GoogleMaps ; 2 adult males (as P. choreus, ZFMK ), Meyenburg, Fleet , wet meadow, 52.51°N 9.38°E, 37 m a.s.l., +10 °C m.a.t., 21.vi.2017, leg. E. Resendiz and H.-G. Rudzinski GoogleMaps ; 1 adult male (as P. choreus, ZFMK ), Brettenbach stream, Brücke Vordere Zaismatt , 48.13°N 7.90°E, 242 m a.s.l., +10 °C m.a.t., 31.iii.2019 [Barcode GBOL-2625260] GoogleMaps .— IRELAND, 2 adult males (as Procladius sp. 1 , UCDZ), Lake Gougane Barra , 51.84°N 9.32°W, 165 m a.s.l., +8 °C m.a.t., 26.vii.1966, leg. D.A. Murray GoogleMaps ; 2 adult males (as P. pectinatus, UCDZ ), Lake Leane, O`Sullivans Cascade and pool, 52.04°N 9.58°W, 30 m a.s.l., +10 °C m.a.t., 17.iv.1973, leg. L. Bucheen GoogleMaps ; 1 adult male (as Procladius sp. A , UCDZ), Lake Doolough , 52.79°N 9.30°W, 83 m a.s.l., +8 °C m.a.t., 14.ix.1973, leg. D.A. Murray GoogleMaps ; 1 adult male (as Procladius sp. , UCDZ), Lake Carra , 53.66°N 9.26°W, 21 m a.s.l., +10 °C m.a.t., 2.iv.1974, leg. D.A. Murray GoogleMaps ; 4 adult males (as Procladius sp. , UCDZ), Lake Carra , 53.68°N 9.25°W, 19 m a.s.l., +10 °C m.a.t., 10.v.1974, leg. D.A. Murray. GoogleMaps — ITALY, 4 adult males ( NHRS), Lake Lago di Centro Cadore, Calazo , 46.44°N 12.39°E, 683 m a.s.l., +8 °C m.a.t., 29.vi.1991, leg. Y. Brodin GoogleMaps ; 2 adult males ( NHRS), Lake Lago di Valdaora, Monguelfo , 46.76°N 12.05°E, 1 087 m a.s.l., +5 °C m.a.t., 29.vi.1991, leg. Y. Brodin GoogleMaps ; 1 adult male (as P. choreus, MTSN ), Tre laghi Isole , 45°N 8°E, 238 m a.s.l., +11 °C m.a.t., 2.vii.1996, leg. L. Marziali. GoogleMaps — NORWAY, 1 adult male (as P. cf. fuscus, NTNU ), Trondheim, Lake Gjeddtjørna , 63.38°N 10.61°E, 158 m a.s.l., +4 °C m.a.t., 6.vi.2010, leg. J.K. Skei GoogleMaps [ Barcode CHMNO070-14 ] ; 1 adult male (as P. cf. fuscus, NTNU ), Trondheim, Lake Gjeddevatnet , 63.38°N 10.61°E, 157 m a.s.l., +4 °C m.a.t., 20.vi.2010, leg. J.K. Skei GoogleMaps [ Barcode MIDGE985-13 ] ; 2 adult males (as P. cf. fuscus, NTNU ), Melhus, Gammelelva nature reserve , 63.21°N 10.31°E, 28 m a.s.l., +4 °C m.a.t., 22.v‒5.vi.2014, leg. E. Stur GoogleMaps [ Barcode CHMNO205-15 and CHMNO354-15 ] .— POLAND, 1 adult male (as Procladius sp. , LUIZ), Spala, River Pilica , 51.54°N 20.13°E, 151 m a.s.l., +9 °C m.a.t., 5.vi‒9.vi.2007, leg. M. Plóciennek GoogleMaps ; 2 adult males (as Procladius sp. , LUIZ), Zabierzow , 51.54°N 19.79°E, 270 m a.s.l., +9 °C m.a.t., 17.v.2010, leg. M. Plóciennek. GoogleMaps — RUSSIA, 1 adult male (as P. culiciformis, NHRS ), Kamchatka, Petropavlovsk area , 53°N 158°E, 150 m a.s.l., ‒1 °C m.a.t., vii.1921, leg. R. Malaise GoogleMaps ; 2 adult males (as Procladius sp , IBIB), Rybinsk Reservoir , 58.1°N 38.6°E, 97 m a.s.l., +4 °C m.a.t., vii.1972, leg. A.I. Shilova. GoogleMaps — SWEDEN, 1 adult male (as Procladius sp. , NHRS), Lake Vitalampi , 59.55°N 15.13°E, 322 m a.s.l., +5 °C m.a.t., 7.v.1974, leg. P. Mossberg GoogleMaps ; 1 adult male ( NHRS), Lake Vristulven, Århult , 58.56°N 13.72°E, 113 m a.s.l., +6 °C m.a.t., 22‒24.iv.1987, leg. Y. Brodin GoogleMaps ; 1 adult male ( NHRS), Lake Vänern, Sjötorp , 58.84°N 13.97°E, 44 m a.s.l., +6 °C m.a.t., 16.vi.1987, leg. Y. Brodin GoogleMaps ; 2 adult males ( NHRS), Baltic Sea, Askö island, Askötorp , 58.80°N 17.67°E, 6 m a.s.l., +6 °C m.a.t., 31.v‒16.vi.2011, leg. B.E. Bengtsson GoogleMaps [ Barcode BSCHI536-17 and BSCHI551- 17 ] .— SWITZERLAND, 1 adult male (as P. cinereus, ZSMG ), Lake Bodensee, Egnach , 47.54°N 9.38°E, 396 m a.s.l., +9 °C m.a.t., 1938, leg. J. Geissbühler. GoogleMaps — WALES, 1 adult male (as P. choreus ), Trawscoed , 52.33°N 3.95°W, 70 m a.s.l., +8 °C m.a.t., iv.2020, leg. J. Graham. GoogleMaps

Diagnostic characters. Figs. 5 View FIGURE 5 , 8 View FIGURES 7‒8 , 16 View FIGURES 16‒17 , 36 View FIGURES 36‒39 , 95‒97 View FIGURES 95‒97 , key couplet 18. P. pruinosus has a medium long gonostylus process with a GspR that overlaps that of eight other species of Procladius in Europe. Of these, P. lugubris and P. ferrugineus are distinctly separated from P. pruinosus by more than one other morphological character in the key and the helpdesk.

The GspR of P. pruinosus slightly overlaps that of P. islandicus (0.23‒0.30 versus 0.18‒0.24). If overlapping, P. pruinosus can be separated from P. islandicus by the on average lower front leg tarsi BR (2‒4.5 versus 3‒6.5) and the longer and narrower gonostylus process (length/width 1.2‒1.7 versus 0.9‒1.2).

The GspR of P. pruinosus to some degree overlaps that of P. culiciformis (0.23‒0.30 versus 0.18‒0.25). When overlapping, P. pruinosus can be distinguished from P. culiciformis by the narrower gonostylus (GsmR 5.2‒6.3 versus 4.2‒5.2) and the on average darker mid-section of the front leg tibia (light brown to dark brown versus whitish to light brown).

The GspR of P. pruinosus almost completely overlaps that of P. tenebricosus (0.23‒0.30 versus 0.23‒0.29). P. pruinosus can be separated from P. tenebricosus by the less dark marked wing (anal cell patch absent to faint versus distinct to very distinct) and almost always larger size (wing length 2.6‒3.5 mm versus 1.8‒2.6 mm, mid leg tibia length 1.0‒ 1.4 mm versus 0.7‒1.1 mm, body length 4.3‒5.9 mm versus 3.2‒4.3 mm).

The GspR of P. pruinosus strongly overlaps that of P. frigidus (0.23‒0.30 versus 0.25‒0.33). Despite that, there are generally no problems to separate the species by consulting other morphological characters. P. pruinosus has fewer median anepisternal setae compared to that of P. frigidus (0‒5 versus 5‒26), the antenna AR is usually lower (1.7‒2.3 versus 2.2‒2.8) and the length of palpomere five divided with its width is lower (9.3‒12.2 versus 8.0‒9.3).

The GspR of P. pruinosus considerably overlaps that of P. longistilus (0.23‒0.30 versus 0.25‒0.34). P. pruinosus can mostly be separated from P. longistilus by the ratio between the length of the outer phallapodeme section divided by the length of the sternapodeme (0.27‒0.36 versus 0.34‒0.46). The length of the outer phallapodeme is however frequently difficult to measure accurately and requires good slide preparations. In addition, the on average broader gonostylus and gonostylus process of P. pruinosus than that of P. logngistilus (GsmR 5.2‒6.3 versus 5.5‒ 6.9, gonostylus process length/width 1.2‒1.7 versus 1.3‒1.9) can be useful for species separation.

The GspR of P. pruinosus partly overlaps that of P. floralis (0.23‒0.30 versus 0.28‒0.37). If overlapping, P. pruinosus can be separated from P. floralis by the less marked gonostylus process divergence (10‒25° versus 30‒50°) and the mostly longer body (4.3‒5.9 versus 3.6‒4.4 mm).

P. pruinosus has been described or mentioned under numerous species-names in the literature, frequently as P. choreus , but also P. bathocryptus , P. cinereus , P. culiciformis , P. fuscus , P. niger , P. nigriventris , P. pectinatus and P. zernyi .

The adult female and pupal exuvia have been briefly described, but not the larva. The distinct pruinosity of the thorax of male P. pruinosus , which gave the species its name, can be observed on dry or alive specimens. Barcodes of adult males, adult female, pupa and larva are available.

Geographical distribution and ecology. In Europe, P. pruinosus is known from latitude 43°N in southern France to 68°N in northern Norway. In North America, the known latitude range is from 43°N to 62°N in the United States and Canada. Altitudes records range from 5 m and up to 2 280 m above sea level in the Pyrenean Mountains of France. The 76 sites with quality assured findings of P. pruinosus have a mean annual temperature span of +14 to ‒2 °C.

P. pruinosus can be regarded as a common species in European lakes and lake-like reservoirs classified as oligotropic to eutrophic. It is less frequently found in hypereutrophic reservoirs and not found in ultraoligotrophic lakes or reservoirs.

Larvae of P. pruinosus have been recorded from 0‒6 m water depth in the littoral of lakes over bottoms of sand, stone or mud with vegetation of quillworts ( Isoetes ), common reed ( Phragmites ), water lilies ( Nymphaea and Nuphar ) and green macroalgae of the genus Cladophora . Larvae are also known from the profundal zone at 1‒16 m water depth. Most findings of P. pruinosus are from lakes, but it has also been recorded from reservoirs, ponds on meadows, pools on peat bogs with Carex , constructed pools in brown coal excavations, slowly running rivers and rivulets. The larvae can thrive and develop into the pupal stage in very small water bodies, such as in a rowing boat filled with lake water full of green algae.

The gut content of P. pruinosus larvae indicates that they consume diatoms, green algae, and smaller animals such as crustaceans (Copepoda and Cladocera) and Chironomidae larvae.

Adult P. pruinosus can possibly be found throughout the entire year in Europe, at least from late March to late January in southern Europe.

Countries or autonomous regions with records of P. pruinosus in Europe are Austria, Belgium, Czechia, England, Estonia, Finland, France, Germany, Ireland, Italy, Norway, Poland, Russia, Slovakia, Sweden, Switzerland and Wales. It is also present in the Asian part of Russia, Canada and the United States including Alaska, possibly also in Iran.

References. Aagaard 1978b; Armitage 1968; Bowser & Bowser 2020; Brundin 1949; Edwards 1928; Ekrem et al. 2018; Geissbühler 1938; Goetghebuer & Lenz 1936a; Goetghebuer & Lenz 1936b; Graham 2020; Hebert et al. 2016; Izvekova 1975; Kansanen 1985; Kieffer 1924; Mothes 1966; Muragina-Koreneva 1957; Paasivirta 2012; Paasivirta et al. 1988; Prat 1979; Prat 1980; Ratnasingham et al. 2024; Rieradevall & Prat 1991; Sandberg 1969; Sherk & Rau 1996; Shilova 1976; Sokolowa 1971; Theissinger et al. 2018.