Bledius gallicus (Gravenhorst, 1806)

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

Bledius gallicus (Gravenhorst, 1806) Figure 9

= Bledius philadelphicus Fall, 1919, syn. nov.

Distribution.

Native to the Palaearctic region, trans-Palaearctic ( Schülke 2012a). Adventive in the Nearctic region (Maryland, Massachusetts, New Jersey, New York, and Pennsylvania, United States, and Ontario, Quebec, New Brunswick, and Newfoundland, Canada ( Herman 1972, Bousquet et al. 2013, as B. philadelphicus ).

Canadian records

(DNA barcoded specimens). Ontario: Georgian Bay Islands National Park, 19-Aug-2013 to 27-Aug-2013 (1 ex, CBG); Grundy Lake Provincial Park, 13-Jul-1995 (1 ex, CNC); Hamilton, 21-Jul-2017 (3 exx, CBG). Quebec: Montreal, 19-Aug-1981 (1 ex, CNC).

Additional Canadian records.

See Herman (1972) for a list of earlier records from Canada and the United States (as B. philadelphicus ).

Diagnostic information.

Body length: 3.7-4.8 mm. Habitus as in Fig. 9A, B . Male sternite VII as in Fig. 9D . Aedeagus as in Fig. 9C .

Bionomic notes.

Palm (1961) (as synonym B. fracticornis ) states that this species can be found in half-moist sand, gravel, clay or mineral soil mixed with humus, with or without vegetation cover. In Central Europe, this species occurs on sandy to muddy river banks, and also in damp field edges ( Schülke 2012a). Three of the CBG specimens were collected at a UV light at a forest edge, one was caught in a Malaise trap in a forested peninsula.

Comments.

Bledius gallicus can be recognized within Herman’s (1972) 'semiferrugineus group’ using the following combination of characters: last segment of metatarsus in dorsal view gradually expanded to apex, male sternite VII emarginate, with membranous lobe but emargination not bordered by a pair of spines, pronotum with midlongitudinal groove. The species will key easily to B. philadelphicus Fall, 1919 in Herman’s (1972) key and we here consider these two species synonyms. Specimens in the CNC identified as B. philadelphicus by Lee Herman and included in his revision of the ' semiferrugineus group’ ( Herman 1972) were dissected and revealed to be B. gallicus . The description of Bledius philadelphicus in Herman (1972) corresponds to that of B. gallicus in Schülke (2012a), including the characteristic male sternite VII (though the membranous part is slightly deeper in both Nearctic and Palaearctic populations than indicated by the illustration). Bledius gallicus is closely related to the Palaearctic B. femoralis (Gyllenhal, 1827) ( Schülke 2012a). The two species have extremely similar aedeagi, differing only in the apex of the ventral lamella ( Fig. 9C ) (acute in B. femoralis and broadly truncate in B. gallicus ). These two species are more easily separated by the shape of male sternite VII ( Schülke 2012a).

Based on the specimens available at the CNC and reported by Herman (1972), B. gallicus has been in North America for quite a long time, since at least as early as 1910, when Fall (1910) first described B. philadelphicus as B. dissimilis (not Erichson 1840, preoccupied name replaced by Fall (1919)). The earliest Canadian specimens are from the 1920s.

Figures

Figures 9, 10. 9 Bledius gallicus (Gravenhorst) 9 A habitus, black elytra, L. Borowiec 9 B habitus, red-brown elytra, L. Borowiec 9 C aedeagus, ventral view, VL = ventral lamella M. Schuelke 9 D male sternite VII 10 Carpelimus elongatulus (Erichson) 10 A habitus 10 B aedeagus, ventral view, H. Schillhammer. Scale bars: 1.0 mm (9 A, B; 10 A), 0.2 mm (9 C), 0.2 mm (9 D), 0.25 mm (10 B).