Procladius clavus Roback, 1971

Procladius clavus Roback, 1971 View in CoL

Procladius clavus Roback, 1971 View in CoL — Roback (1971), Canada, adult male, adult female, key, description, illustrations.

? Procladius clavus Roback, 1971 View in CoL — Egan & Langton (2018), Canada, adult male, pupa, description, photo.

Material examined (n = 5). CANADA, 1 adult male (Holotype of P. clavus, CNCC ), Spence Bay , Taloyoak, 69.5°N 93.3°W, 3 m a.s.l., ‒14 °C m.a.t., 22.vii.1951, leg. J.G. Chillcott GoogleMaps ; 1 adult male (Paratype of P. clavus, CNCC ), Lake Ceillini , Taloyoak, 69.5°N 93.4°W, 20 m a.s.l., ‒14 °C m.a.t., 19.vii.1952, leg. J.G. Chillcott. GoogleMaps — RUSSIA, 2 adult males ( IANR), tundra ponds, east of Naryan-Mar , Yarey-shor, 67.62°N 53.70°E, 20 m a.s.l., ‒3 °C m.a.t., 29.vii.1990, leg. A. Rybakova GoogleMaps ; RUSSIA ( Asia ), 1 adult male ( NHRS), Chaunskaya Gulf, Ajon Island, 69.55°N 169.18°E, 10 m a.s.l., ‒10 °C m.a.t., 15‒18.vii.2015, leg. P. Mortensen GoogleMaps [ Barcoded ] .

Diagnostic characters. Figs. 22 View FIGURES 20‒23 , 53‒55 View FIGURES 53‒55 , key couplet 5. P. clavus is easily distinguished from all other Procladius of Europe and North America. The semicircular projection posteriorly of tergite IX, the short, broad gonostylus and the long medioapodeme with a strongly curved inner section form a unique combination of characters.

Description of P. clavus male genitalia and pupal exuvia in Egan & Langton (2018) might be another species considering the small size. The adult female has been described, but the larva is unknown. No barcoded material has been identified.

Geographical distribution and ecology. Confirmed records of P. clavus are from four sites only, so knowledge of its ecology and geographical distribution is very limited. The sites are in the tundra at 68‒ 70°N in Russia and Canada with mean annual temperature between ‒3 to ‒14 °C. This means that P. clavus is the only species of Procladius that has not been found at mean annual temperature of 0 or warmer, and only P. exilis and P. frigidus are known from colder conditions.

The sites with P. clavus are in environments with small oligotrophic to possibly mesotrophic ponds at 3‒20 m above sea level within 60 km from the Arctic Ocean. Food requirements of the larvae are not known.

Countries with records of P. clavus in Europe is only Russia. P. clavus is also present in Canada and the Asian part of Russia.

References. Cannings & Scudder 1978; Egan & Langton 2018; Oliver 1963; Roback 1971.