Procladius exilis Brodin, 2025

Procladius exilis Brodin , new species

Procladius sp. — Ratnasingham et al. (2024), Finland, Sweden and Canada, adult males, adult female, pupae, larvae, photos.

Material examined (n = 4). FINLAND, 2 adult males (Paratypes of P. exilis , as P. islandicus -t, ZMUO), Oulunsalo, Riutunkari, 65.00°N 25.23°E, 2 m a.s.l., +2 °C m.a.t., 5.viii.2015, leg. L. Paasivirta [Barcode CHIFI 1436-16 and CHIFI 1437-16].— SWEDEN, 1 adult male (Holotype of P. exilis, NHRS ), Lake Stor-Björsjön, 63.61°N 12.23°E, 566 m a.s.l., 0 °C m.a.t., 16.vi‒23.vi.2019, leg. S. Persson [Barcoded]; 1 adult male (Paratype of P. exilis, NHRS ), Lake Stor-Björsjön, 63.61°N 12.23°E, 566 m a.s.l., 0 °C m.a.t., 16.vi‒23.vi.2019, leg. S. Persson.

Diagnostic characters. Figs. 29 View FIGURES 28‒31 , 74‒76 View FIGURES 74‒76 , key couplet 11. P. exilis has a rather short gonostylus process with a GspR that overlaps that of nine other species of Procladius in Europe. Of these, P. breviatus , P. clavus , P. bellus , P. nudipennis , P. choreus , P. gemma and P. culiciformis are separated from P. exilis by their broader gonostylus, reflected by the GsmR, and one or more other morphological characters in the key and the helpdesk.

The gonostylus of P. exilis and P. saeticubitus are very similar with entirely overlapping GspR (0.14‒0.19 versus 0.14‒0.20) and GsmR (5.9‒6.9 versus 5.8‒6.9). P. exilis can, however, readably be separated from P. saeticubitus by several other characters, particularly the lower number of hind tibia comb spines (7‒9 versus 11‒14), more median anepisternal setae (10‒18 versus 0‒3) and higher antennal ration (2.6‒2.7 versus 1.7‒2.0).

The GspR of P. exilis to some degree overlaps that of P. islandicus (0.14‒0.19 versus 0.18‒0.24). The gonostylus of P exilis is on average narrower than that of P. islandicus , but the overlap is considerable (GsmR 5.9‒6.9 versus 5.3‒6.4). P. exilis can, however, be distinguished from P. islandicus by a lower number of hind tibia comb spines (7‒9 versus 10‒13) and more median anepisternal setae (10‒18 versus 0‒3).

Barcodes of specimens from Canada belong to the same BIN-cluster as those of P. exilis from Europe, but no published paper on Procladius in North America includes a species which reminds of P. exilis . Neither adult female, pupa or larva have been described. Barcodes of adult males, adult females, pupae and larvae are available.

Geographical distribution and ecology. P. exilis has so far only been found at two sites in Europe at 64‒ 65°N in Sweden and Finland with mean annual temperature ranging from +2 to 0 ° C. Findings in Canada are from seven colder sites with mean annual temperature at two sites as low as ‒15 °C on an island in the Arctic Ocean at latitude 70°N .

Several localities are close to the sea at 2‒10 m above sea level, which suggests that the species occurs in brackish as well as freshwater conditions. The highest recorded altitude is at about 570 m above sea level. Ultraoligotrophic or oligotrophic conditions prevail in lakes in areas with findings.

Countries with records of P. exilis in Europe are Finland and Sweden. The species is also found in Canada.

References. Hebert et al. 2016; Pentinsaari et al. 2020; Porinchu et al. 2009; Ratnasingham et al. 2024.