Stenichnus scutellaris ( Mueller & Kunze, 1822)

Pentinsaari, Mikko, Anderson, Robert, Borowiec, Lech, Bouchard, Patrice, Brunke, Adam, Douglas, Hume, Smith, Andrew B. T. & Hebert, Paul D. N., 2019, DNA barcodes reveal 63 overlooked species of Canadian beetles (Insecta, Coleoptera), ZooKeys 894, pp. 53-150 : 53

Stenichnus scutellaris ( Mueller & Kunze, 1822) Figure 12

Distribution.

Native to the western Palaearctic region, widespread in Europe ( Schülke and Smetana 2015). Adventive in the Nearctic region (Ontario, Canada).

Canadian records.

Ontario: Cambridge, 07-May-2015 to 14-May-2015 (5 exx, CBG); Cambridge, 15-Jul-2017 (15 exx, CBG); Cambridge, 25-May-2015 to 01-Jun-2015 (1 ex, CBG); Cambridge, 25-May-2015 to 31-May-2015 (4 exx, CBG); Cambridge, 29-Apr-2015 to 07-May-2015 (1 ex, CBG); Guelph, 13-May-2017 (1 ex, CBG); Guelph, 22-Apr-2013 to 03-May-2013 (2 exx, CBG); Guelph, 22-Apr-2017 (1 ex, CBG); Kitchener, 22-Apr-2013 to 03-May-2013 (1 ex, CBG); Mississauga, 15-Sep-2015 to 17-Sep-2015 (3 exx, CBG); Owen Sound, 22-Apr-2013 to 03-May-2013 (1 ex, CBG); Pickering, 24-Jun-2017 to 25-Jun-2017 (1 ex, CBG); Rouge National Urban Park, 03-Jun-2013 to 09-Jun-2013 (7 exx, CBG); Rouge National Urban Park, 11-Jun-2013 to 18-Jun-2013 (1 ex, CBG); Rouge National Urban Park, 15-Sep-2013 (1 ex, CBG); Rouge National Urban Park, 24-Jun-2017 (1 ex, CBG); Rouge National Urban Park, 29-Apr-2013 to 03-May-2013 (1 ex, CBG); Warsaw, 05-May-2014 to 23-May-2013 (1 ex, CBG); Whitby, 22-Apr-2013 to 03-May-2013 (1 ex, CBG).

Diagnostic information.

Body length: 1.4-1.5 mm. Habitus as in Fig. 12A . Male profemur widened apicad to form an abrupt 90° angle in dorsal view. Aedeagus as in Fig. 12B .

Bionomic notes.

This species lives in leaf litter and dead wood ( Koch 1989a). It is mostly collected in forests or at forest edges, occasionally in wetlands and grasslands ( Koch 1989a). Most Canadian specimens were collected using Malaise traps, pitfall traps, or by sifting leaf litter. Most specimens were collected in disturbed forest fragments but some were from grasslands and wetlands.

Comments.

As the Nearctic Stenichnus fauna remains unrevised, it is only possible to associate Nearctic specimens with Palaearctic species through dissected males or barcodes. The Canadian specimens share identical barcode haplotypes with European material, and the identification was verified by examination of the male genitalia. The modified male profemur of S. scutellaris is unique among the Central European fauna ( Franz and Besuchet 1971). Without a revision of the Nearctic fauna, it is not possible to know whether other North American species also possess this character.

Figures

Figures 11, 12. 11 Stenichnus collaris (Mueller & Kunze) 11 A habitus, L. Borowiec 11 B aedeagus, dorsal view 12 Stenichnus scutellaris (Mueller & Kunze) 12 A habitus, L. Borowiec 12 B aedeagus, dorsal view. Scale bars: 0.5 mm (11 A; 12 A), 0.1 mm (11 B; 12 B).