Procladius bellus ( Loew, 1866 )

Brodin, Yngve, 2025, Procladius (Diptera, Chironomidae) of Europe and a global view, Zootaxa 5591 (1), pp. 1-127 : 41-43

Procladius bellus ( Loew, 1866)

Tanypus bellus Loew, 1866 — Loew (1866), United States, adult male, adult female, description.

Tanypus pusillus Loew, 1866 — Loew (1866), United States, adult male, adult female, description.

Tanypus rufovittatus van der Wulp, 1874 —Wulp van der (1874), Netherlands, adult female, description.

Procladius adumbratus Johannsen, 1905 — Johannsen (1905), United States, adult female, pupa, larva, key, description.

Procladius bellus ( Loew, 1866) — Johannsen (1905), United States, adult male, adult female, key, description.

Procladius pusillus ( Loew, 1866) — Johannsen (1905), United States, adult male, adult female, key, description, illustration.

Protenthes bellus ( Loew, 1866) — Malloch (1915), United States, adult male, adult female, pupa, larva, key, description.

Procladius concinnus ( Coquillett, 1895) — Malloch (1915), United States, adult male, adult female, pupa, larva, key, description, illustrations.

Procladius rufovittatus (van der Wulp, 1874) —Kieffer (1918), Lithuania, adult female, key, description.

Procladius latifrons Kieffer, 1922 — Kieffer (1922), Poland and Germany, adult male, adult female, key, description.

Procladius leucocoma Kieffer, 1922 — Kieffer (1922), Poland, adult male, key, description.

Procladius flavidus Kieffer, 1923 — Kieffer (1923b), United States, adult female, description.

Procladius profundorum Kieffer, 1923 — Kieffer (1923b), Germany, adult male, description.

Procladius malifero Garrett, 1925 — Garrett (1925), Canada, adult male, adult female, description.

Procladius rufovittatus (van der Wulp, 1874) — Goetghebuer (1927), England and Netherlands, adult male, adult female, key, description.

Procladius rufovittatus (van der Wulp, 1874) — Edwards (1929), England and Ireland, adult male, adult female, description.

Psilotanypus rufovittatus (van der Wulp, 1874) — Goetghebuer & Lenz (1936a), Netherlands and England, adult male, adult female, key, description.

Procladius adumbratus Johannsen, 1905 — Johannsen (1937), United States, pupa, larva, description.

Procladius bellus ( Loew, 1866) — Johannsen (1937), United States, larva, description.

Procladius rufovittatus (van der Wulp, 1874) — Coe (1950), England and Ireland, adult male, key, illustration.

Procladius adumbratus Johannsen, 1905 — Johannsen & Townes (1952), United States, adult female, key.

Procladius bellus ( Loew, 1866) — Johannsen & Townes (1952), United States, adult male, adult female, key.

Procladius pusillus ( Loew, 1866) — Johannsen & Townes (1952), United States, adult male, key.

Procladius riparius ( Malloch, 1915) — Johannsen & Townes (1952), United States, adult male, key.

Psilotanypus rufovittatus (van der Wulp, 1874) — Muragina-Koreneva (1957), Russia, adult male, adult female, pupa, larva, descriptions, keys, illustrations.

Procladius bellus ( Loew, 1866) — Roback (1957), United States, pupa, larva, key.

Procladius bellus ( Loew, 1866) — Sublette (1964), United States, adult male, adult female, descriptions.

Procladius rufovittatus (van der Wulp, 1874) — Shilova (1969), Russia, adult male, key, illustration.

Procladius bellus ( Loew, 1866) — Roback (1971), Canada and United States, adult male, key, description, illustrations.

Procladius rufovittatus (van der Wulp, 1874) — Pankratova (1977), Russia, pupa, larva, key, illustrations.

Procladius bellus ( Loew, 1866) — Saether (1977), Canada, adult female, key, illustration.

Procladius bellus ( Loew, 1866) — Moore & Moore (1978), Canada, larva, description, illustration.

Procladius rufovittatus (van der Wulp, 1874) — Pinder (1978), adult male, key, illustrations.

Procladius bellus ( Loew, 1866) — Roback (1980), United States and Canada, adult male, pupa, larva, keys, descriptions, photos, illustrations.

Procladius bellus ( Loew, 1866) — Fittkau & Murray (1986), pupa, illustrations.

Procladius rufovittatus (van der Wulp, 1874) — Langton (1991), pupa, key, illustrations.

Procladius rufovittatus (van der Wulp, 1874) — Langton & Visser (2003), pupa, key, illustrations.

Procladius rufovittatus (van der Wulp, 1874) — Langton & Pinder (2007), adult male, key, illustrations.

Procladius bellus ( Loew, 1866) — Jacobsen (2008), United States, pupa, key, description, illustrations.

Procladius bellus ( Loew, 1866) — Saether (2010), Canada, adult male, adult female, pupa, larva, keys, descriptions, illustrations.

Procladius bellus ( Loew, 1866) — Cranston & Epler (2013), larva, illustration.

Procladius rufovittatus (van der Wulp, 1874) — Ratnasingham et al. (2024), Finland, Germany, Netherlands, Canada and United States, adult males, adult females, larvae, photos.

? Procladius anomalus Kieffer, 1906 — Kieffer (1906a), France, adult female, description.

? Procladius anomalus Kieffer, 1906 — Kieffer (1918a), Lithuania, adult female, key, description.

? Procladius anomalus Kieffer, 1906 — Goetghebuer (1927), France, adult female, key, description.

? Psilotanypus anomalus Kieffer, 1906 — Goetghebuer & Lenz (1936a), France, adult female, key, description.

? Procladius adumbratus Johannsen, 1905 — Roback (1957), United States, larva, key.

? Procladius bellus ( Loew, 1866) — Fittkau & Roback (1983), larva, illustration.

? Procladius bellus ( Loew, 1866) — Cranston & Epler (2013), larva, illustration.

Material examined (n = 29). AUSTRIA, 1 adult male (as P. rufovittatus, ZSMG ), Stift Schlägl , Böhmer Wald, Glashüttenteich pond, 48.64°N 13.97°E, 552 m a.s.l., +8 °C m.a.t., 2.vi.1982, leg. H. Malicky. — CANADA, 1 adult male (Holotype of P. malifero, CNCC ), Cranbrook , 49.50°N 115.79°W, 919 m a.s.l., +5 °C m.a.t., 20.v.1925, leg. C.B.D. Garrett ; 2 adult males (Paratypes of P. malifero, CNCC ), Cranbrook , 49.50°N 115.79°W, 919 m a.s.l., +5 °C m.a.t., 20.v.1925, leg. C.B.D. Garrett. — CZECHIA, 4 adult males (as P. rufovittatus, NHRS ), Divcice , Lake Blatec, 49.11°N 14.31°E, 397 m a.s.l., +7 °C m.a.t., 19.vi.1991, leg. Y. Brodin. — ENGLAND, 1 adult male (as P. rufovittatus, BMNH ), Ruislip Lido Reservoir , 51.59°N 0.43°W, 50 m a.s.l., +11 °C m.a.t., 1948 .— FINLAND, 2 adult males (as P. nudipennis, MZHF ), Lake Puruvesi , Punkasalmi, Akonniemi, 61.74°N 29.35°E, 75 m a.s.l., +3 °C m.a.t., 10.viii.1974, leg. B. Lindeberg ; 2 adult males (as P. rufovittatus, ZMUO ), Pihlava , Lake Enäjärvi, 61.55°N 21.61°E, 5 m a.s.l., +4 °C m.a.t., 4.vi.2015, leg. L. Paasivirta [ Barcode LEFIJ3499-16 and LEFIJ3500- 16 ] .— GERMANY, 1 adult male (as P. crassinervis, ZSMG ), Plön , Eutinerstrasse, 54.15°N 10.62°E, 18 m a.s.l., +9 °C m.a.t., vi.1964, leg. E.J. Fittkau. — NETHERLANDS, 1 adult male (as P. rufovittatus ), Almere-Verzetswijk , 52.37°N 5.24°E, ‒ 3 m a.s.l., +10 °C m.a.t., 14.v.2022, leg. P. Hoekstra. — RUSSIA, 1 adult male (as P. rufovittatus, IBIB ), Rybinsk Reservoir , 58.1°N 38.6°E, 97 m a.s.l., +4 °C m.a.t., viii.1972, leg. A.I. Shilova. — SLOVAKIA, 5 adult males (as P. rufovittatus, NHRS ), Lake Liptovska Mara , Liptovsky Mikulas, 49.10°N 19.57°E, 555 m a.s.l., +6 °C m.a.t., 19.vi.1991, leg. Y. Brodin. — SWEDEN, 1 adult male (as P. rufovittatus, NHRS ), Lake Boren , 58.58°N 15.13°E, 74 m a.s.l., +6 °C m.a.t., 10‒11.vi.1980, leg. Y. Brodin ; 1 adult male (as P. rufovittatus, NHRS ), Lake Mälaren , Drottningholm, 59.33°N 17.87°E, 3 m a.s.l., +6 °C m.a.t., 26‒29.v.1989 , leg. T. Sandberg ; 3 adult males (as P. rufovittatus, NHRS ), Lake Grytsjö , 58.59°N 15.52°E, 96 m a.s.l., +6 °C m.a.t., 28.v.1990, leg. Y. Brodin. — UNITED STATES, 2 adult males (Paratypes of P. riparius, INHS ), Havana , Chautauqua Lake, 40.37°N 49.99°W, 147 m a.s.l., +9 °C m.a.t., 24.iv.1914 , leg. J. R. Malloch ; 1 adult male ( USNM), Edgerton , Lake Koshkanong, 42.86°N 89.00°W, 312 m a.s.l., +8 °C m.a.t., 9.viii.1947, leg. H.S. Dybas.

Diagnostic characters. Figs. 42 , 113‒115 , key couplet 24. The gonostylus with its distinctly convex inner margin in combination with a distinct outer process readily separates P. bellus and P. nudipennis from all other European Procladius .

The gonostylus of P. bellus is comparatively broader (gonostylus GsmR 2.6‒3.3 versus 3.2‒3.9), more bulging and usually with more strong setae (6‒12 versus 4‒8) than that of P. nudipennis , while the gonostylus process is on average slightly shorter (gonostylus GspR 0.10‒0.17 versus 0.13‒0.19). P. bellus can usually also be separated from P. nudipennis by the relatively short gonostylus in relation to the length of the gonocoxite (0.42‒0.50 versus 0.50‒0.59).

P. bellus is on average somewhat larger than P. nudipennis exemplified by an often broader gonocoxite base (206‒285 µm versus 178‒216 µm), wing length (2.0‒ 2.7 mm versus 1.8‒2.4 mm) and body length (3.5‒4.5 mm versus 3.1‒3.8 mm).

Some light-coloured specimens of P. bellus are, as its name applies, regarded as nice-looking owing to a whitish to light yellowish scutellum, mid-section of tibia and abdomen tergites I‒ V, contrasting with darker parts of the body. Oher specimens of P. bellus are as P. nudipennis more uniformly brownish.

P. bellus has since about one hundred and fifty years been referred to as P. rufovittatus in Europe. Studied specimens from North America and Europe, in some cases also barcoded, reveals that P. rufovittatus is a synonym. The adult female, pupa and larva of P. bellus have been described in several papers. Barcodes of adult males, adult females and larvae are available.

Geographical distribution and ecology. The southernmost finding of P. bellus in Europe is at latitude 47°N in France and the most northern at 63°N in Finland. Climate conditions in Europe range from +11 °C mean annual temperature in the south and to +2 °C in the north. It has a wider geographical range in the United States and Canada, namely from 39°N to 68°N, and with a temperature span from +12° to ‒8 °C on the Arctic coast of northern Canada. Findings in Europe are from altitude 3 m below to 560 m above sea level. The highest altitude records are from a lake in Canada at 1570 m and one in Mongolia at about 1 650 m.

P. bellus larvae are mostly found in lakes and lake-like reservoirs. They are also reported from smaller stagnant water bodies such as ponds or puddles in peatlands, fens, gravel pits or sand dunes along the sea. A few records are from slow running water. In Europe and North America most findings are from mesotrophic to eutrophic conditions where the larvae can be among the dominant benthic species in terms of abundance and biomass, e.g. 1 600 individuals and 2 g dry weight per m 2. Larvae have less frequently been recorded from oligotrophic lakes and hypereutrophic lakes or reservoirs.

P. bellus larvae have been found in the littoral zone at 0‒4 m in lakes with vegetation dominated by plants such as Elodea and Myriophyllum . They have been frequently found in the profundal and emerging from 3 to 15 m. The larvae have been reported to have a diapaus during summer stagnation with strong oxygen shortage in deeper zones of eutrophic or hypereutrophic lakes and reservoirs. A kind of diapause with very little growth is also reported to occur during cold winter months when the larvae mostly are at their 3 rd stage, but some also in their 2 nd or last 4 th stage. Gut content studies of P. bellus indicate that the larvae are detritivore or omnivore and consume algae, bacteria and animals. The amount of animals remains increases in the final fourth instar.

Adult P. bellus are known from late April to August and sometimes also until late September. One to three generations per year have been reported in Europe. Emergence may sometimes take place during daytime but mainly during night with a peak at dawn. Ascending pupae can emerge to adults immediately after they reached the water surface. Adult P. bellus have been found to feed on honeydew from aphids.

Countries or autonomous regions with records of P. bellus in Europe are Austria, Czechia, Denmark, England, Estonia, Finland, France, Germany, Ireland, Latvia, Netherlands, Northern Ireland, Poland, Russia, Scotland, Slovakia, Sweden and Wales. The species has also been found in Canada, Mongolia and the United States.

References. Anikina 2009b; Bitušík & Langton 1994; Burtt et al. 1986; Charles et al. 1974; Charles et al. 1976; Coe 1950; Coquillett 1895; Cranston & Epler 2013; Edwards 1929; Erbaeva & Safronov 2016; Fittkau & Murray 1986; Fittkau & Roback 1983; Garrett 1925; Goetghebuer 1927; Goetghebuer & Lenz 1936a; Jacobsen 2008; Janeċek 1985; Johannsen 1905; Johannsen 1937; Johannsen & Townes 1952; Kieffer 1906a; Kieffer 1906b; Kieffer 1918a; Kieffer 1922; Kieffer 1923b; Langton 1991; Langton 1993; Langton & Pinder 2007; Langton & Visser 2003; Lindegaard & Brodersen 2000; Loew 1866; Malloch 1915; Mol 1984; Moore & Moore 1978; Moubayed-Breil 2007; Mundie 1957; Muragina-Koreneva 1957; Murray et al. 2018; Orendt 1991; Orendt 1993; Paasivirta 2012; Pankratova 1977; Pinder 1978; Płóciennik et al. 2018; Potter & Learner 1974; Ratnasingham & Hebert 2007; Ratnasingham et al. 2024; Roback 1971; Roback 1980; Saether 1977; Saether 2010; Sephton 1987; Sephton & Paterson 1986; Shcherbina 1989; Shilova 1969; Shilova 1976; Smukalla & Meyer 1988; Sokolowa 1968a; Sokolowa 1968b; Sublette 1964; Timm et al. 1996a; Timm et al. 1996b; Titmus 1979; Tomlin et al. 2024; Wulp van der 1874; Vallenduuk & Moller Pillot 2007; Vasques et al. 2022.

Figures

FIGURES 40‒43. Male genitalia of Procladius species. 40: P. culiciformis from Sweden. 41: P. choreus from Romania. 42: P. bellus from Sweden. 43: P. nudipennis from Finland.

FIGURES 113‒115. Male genitalia left gonostylus of Procladius bellus. Fig. 113: Finland. Fig. 114: Czechia. Fig. 115: Austria.