Procladius dentus Roback, 1971

Brodin, Yngve, 2025, Procladius (Diptera, Chironomidae) of Europe and a global view, Zootaxa 5591 (1), pp. 1-127 : 56

Procladius dentus Roback, 1971

Procladius dentus Roback, 1971 — Roback (1971), Canada and United States, adult male, adult female, key, description, illustrations.

Procladius dentus Roback, 1971 — Roback (1980), Canada and United States, pupa, key, description, photos, illustrations.

Procladius dentus Roback, 1971 — Ekrem et al. (2018), Norway, adult male, illustration.

Procladius dentus Roback, 1971 — Ratnasingham et al. (2024), Finland, Norway, Sweden and Canada, adult males, adult females, pupae, larvae, photos.

Procladius sp. — Ratnasingham et al. (2024), Canada, adult males, adult females, pupae, larvae photos.

? Procladius lundstroemi Goetghebuer, 1936 — Goetghebuer & Lenz (1936a), Goetghebuer & Lenz (1936b), Greenland, adult male, key, description, illustration.

? Procladius sp. — Fittkau & Murray (1986), pupa, illustration.

? Procladius sp. — Langton et al. (2013), Norway, pupa, key, illustration.

Material examined (n = 25). CANADA, 1 adult male (Paratype of P.dentus, CNCC ), Baffin Island, Camp Kungovik , 65°N 35°W, 0 m a.s.l., ‒10 °C m.a.t., 16.vii.1929, leg. J.D. Soper ; 1 adult male ( ISUA), Great Caribou Island , 52.27°N 55.59°W, 5 m a.s.l., +4 °C m.a.t., 8.vii.1943, leg. J.M. Harrison ; 1 adult male (Paratype of P. dentus, CNCC ), Great Deer , 52.58°N 107.05°W, 529 m a.s.l., +2 °C m.a.t., 20‒21.v.1949 , leg. V. R. Vockeroth ; 1 adult male (Paratype of P. dentus, CNCC ), River Great Whale , 54.75°N 75.10°W, 200 m a.s.l., ‒1 °C m.a.t., 30.vi.1949 , leg. V. R. Vockeroth ; 1 adult male (Holotype of P. dentus, CNCC ), Manitoba, Fort Churchill , 58.77°N 94.22°W, 0 m a.s.l., ‒6 °C m.a.t., 12.vii.1952, leg. J.G. Chillcott ; 1 adult male (Paratype of P. dentus, CNCC ), Manitoba, Fort Churchill , 58.77°N 94.22°W, 0 m a.s.l., ‒6 °C m.a.t., 12.vii.1952, leg. J.G. Chillcott. — FINLAND, 4 adult males, Baltic Sea, Storskär Island, Lake Käringsund , 63.43°N 21.06°E, 0 m a.s.l., +4 °C m.a.t., 9.vi‒23.vii.2009, leg. L. Paasivirta ; 1 adult male ( ZMUO), Pelkosenniemi, Kaetkaeaapa , 67.09°N 27.81°E, 179 m a.s.l., 0 °C m.a.t., 15.vi.2015, leg. L. Paasivirta [ Barcode CHIFI114-16 ] ; 4 adult males, Baltic Sea, Storskär Island, Lake Käringsund , 63.43°N 21.07°E, 1 m a.s.l., +4 °C m.a.t., 30.v‒13.vi.2017, leg. L. Paasivirta ; 4 adult males, Suvakoski , small lake, 67.31°N 28.16°E, 175 m a.s.l., +1 °C m.a.t., 9.vi‒23.vii.2009, leg. L. Paasivirta ; 1 adult male, Tulppio, Ainijärvi , 67.76°N 29.45°E, 269 m a.s.l., 0 °C m.a.t., 10‒14.vi.2018, leg. J. Salmela. — NORWAY, 1 adult male ( NTNU), Stabbursdalen, Rohkosjavri , 70.17°N 24.90°E, 12 m a.s.l., 0 °C m.a.t., 15.vi.2010 , leg. T. Ekrem and E. Stur [Barcode CHRFI499-11 ] ; 1 adult male ( NTNU), Sør-Varanger, Venstre Jakobselv , rockpools, 69.79°N 30.80°E, 7 m a.s.l., 0 °C m.a.t., 21.vi.2010 , leg. T. Ekrem and E. Stur [Barcode CHRFI445-11 ] .— SWEDEN, 2 adult males ( NHRS), Torne lappmark, 68°N 19°E, 650 m a.s.l., ‒1 °C m.a.t., 1.vii.2016, leg. H. Vårdal [1 Barcoded ].— United States , 1 adult male (Paratype of P. dentus, CNCC ), Alaska, Nome , 64.61°N 165.42°W, 10 m a.s.l., ‒4 °C m.a.t., 3.vi.1951, leg. D.P. Williams.

Diagnostic characters. Figs. 14 , 23 , 56‒58 , key couplet 6. The form of the medioapodeme and the distinct dorsal ridge on the gonocoxite readily separates P. dentus from other species of Procladius including its presumably closest relative P. signatus . The antennae AR-value of P. dentus is higher (AR 2.6‒3.0) than that of P. signatus (AR 1.9‒2.4).

Adult males of P. dentus seem not to have been confused with other species. The adult female and larva have not been described, but the pupal exuvia has. Barcodes of adult males, adult females, pupae and larvae are available.

Geographical distribution and ecology. P. dentus has only been found in six of the most northern countries of the world. Findings in Europe are from 63 to 70°N and outside Europe from 52 to 82°N in Canada and Alaska in the United States. Mean annual temperature at the twenty-two sites with quality assured findings ranges from +3 °C in mid Finland to ‒14 °C in northernmost Canada. Several sites are at 0‒10 m above sea level close to the Arctic Ocean or the Baltic Sea where the larvae live in brackish water conditions in rock pools or shallow lakes influenced by brackish sea water. The highest altitude recorded for P. dentus is in Canada at 1 130 m above sea level .

High tolerance towards, or possibly even preference for saline conditions can be illustrated by the findings of P. dentus larvae in a lake in Canada with salinity higher than that of the Atlantic Ocean and the Arctic Ocean.

Larvae of P. dentus have been reported to inhabit shallow water of 0‒2 m depth in lakes, pools, mires and swamps and in one case a tarn without fish. The habitats can be classified as oligotrophic, mesotrophic or eutrophic. No findings are known from profundal water. A few findings are from slowly running water. Adults are known to fly from the middle of May to the middle of August.

Countries with records of P. dentus in Europe are Finland, Norway, Russia and Sweden. It has also been recorded from Canada and the United States (Alaska).

References. Anikina 2009b; Cannings & Scudder 1978; Ekrem et al. 2018; Fittkau & Murray 1986; Langton et al. 2013; Paasivirta 2012; Paasivirta 2020; Roback 1971; Ratnasingham et al. 2024; Roback 1980; Roback 1984.

Figures

FIGURES 14‒15. Fig. 14: Dorsal view of interior apodemes of Procladius dentus, male from Finland, cf. Table 2 G2‒G3, G5‒G7. Fig. 15: Dorsal view of interior apodemes of Procladius islandicus, male from Germany, cf. Table 2 G3‒G9.

FIGURES 20‒23. Male genitalia of Procladius species. Fig. 20: P. fimbriatus from Sweden. Fig. 21: P. gemma from Finland. Fig. 22: P. clavus from Russia. Fig. 23: P. dentus from Finland.

FIGURES 56‒58. Male genitalia left gonostylus of Procladius dentus. Fig. 56: Norway. Fig. 57: Canada. Fig. 58: Finland.