Pseudomedon obscurellus (Erichson, 1840)

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

Pseudomedon obscurellus (Erichson, 1840) Figure 19

Distribution.

Native to the western Palaearctic region, widespread in Europe and also reported from Algeria, Morocco, Madeira, Tunisia, Cyprus, and Turkey ( Schülke and Smetana 2015). Adventive in the Neotropical region (Chile; Assing 2009) and the Nearctic region (Nova Scotia, Canada).

Canadian records.

Nova Scotia: Cape Breton Highlands National Park, 07-Jun-2013 to 24-Jun-2013 (1 ex, CBG).

Diagnostic information.

Body length: 3.0-3.4 mm. Habitus as in Fig. 19A . Male sternite VIII as in Fig. 19C . Aedeagus as in Fig. 19B .

Bionomic notes.

This species inhabits wetlands and can be collected from rotting organic matter ( Assing 2012). The Canadian specimen was collected at the same site and in the same Malaise trap as the M. ripicola specimen.

Comments.

A single female voucher from Canada was available for study and, while males would normally be necessary to confirm a positive identification in Pseudomedon , its barcode sequence is identical to German specimens of P. obscurellus . The morphologically similar Palaearctic species P. obsoletus forms a separate BIN cluster (BOLD:ABY0636). The female voucher from Canada also was consistent with the typical coloration of P. obscurellus given by Assing (2012). As the Nearctic fauna of Pseudomedon is unrevised, comparisons with North American species are not yet possible. Recognizing this species in the Nearctic region is reliably accomplished, at present, using dissected males or DNA barcoding.

Due to taxonomic confusion until the 1970s, reports of Pseudomedon obscurellus and P. obsoletus from regions outside of the Palaearctic need re-confirmation ( Assing 2009, Klimaszewski et al. 2013). The record of P. obsoletus from British Columbia from Hatch (1957) is doubtful and likely refers to P. obscurellus as it was described as being partly dark rufous, a color more typically associated with this species ( Assing 2012). To our knowledge, this is the first verified record of any Palaearctic Pseudomedon species from the Nearctic.

Figures

Figures 17 - 19. 17 Medon apicalis (Kraatz) 17 A habitus 17 B aedeagus, ventral and lateral view, V. Assing 17 C male sternite VII, V. Assing 18 Medon ripicola (Kraatz) 18 A habitus 18 B aedeagus, ventral and lateral view, V. Assing 18 C male sternite VII, V. Assing 19 Pseudomedon obscurellus (Erichson) 19 A habitus 19 B aedeagus, lateral view, V. Assing 19 C male sternite VIII, V. Assing. Scale bars: 1.0 mm (17 A; 18 A; 19 A), 0.2 mm (17 B, C; 18 B, C; 19 B, C).