Scymnus rubromaculatus (Goeze, 1777)

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

Scymnus rubromaculatus (Goeze, 1777) Figure 35

Distribution.

Native to the Palaearctic region, widespread across Eurasia from western Europe to the Russian Far East ( Kovář 2007). Adventive in the Nearctic region (Ontario and Nova Scotia, Canada).

Canadian records.

Ontario: Barrie, 22-Apr-2013 to 03-May-2013 (1 ex, CBG); Burlington, 21-Jul-2017 (1 ex, CBG); Guelph, 06-Jun-2013 to 13-Jun-2013 (1 ex, CBG); Guelph, 20-Jun-2013 to 27-Jun-2013 (2 exx, CBG); Guelph, 01-Aug-2013 to 08-Aug-2013 (1 ex, CBG); Guelph, 15-Aug-2013 to 22-Aug-2013 (1 ex, CBG); Mississauga, 15-Sep-2015 to 17-Sep-2015 (1 ex, CBG); Mississauga, 19-Sep-2016 to 30-Sep-2016 (3 exx, CBG); Toronto, 19-Jun-2017 to 27-Jun-2017 (1 ex, CBG). Nova Scotia: Berwick, 20-Apr-2015 to 08-May-2015 (1 ex, CBG).

Diagnostic information

(based on Fürsch 1967). Body length 1.8-2.3 mm. Habitus as in Fig. 35A, B . Color sexually dimorphic. Male: head, pronotum (apart from a black mediobasal spot), and legs yellow, otherwise black. Female: almost completely black with only the mouthparts, labrum and legs yellow. Femora often darkened. Postcoxal lines on 1st abdominal ventrite reaching the hind edge of the ventrite. Male genitalia as in Fig. 35C−E .

Bionomic notes.

This species prefers dry, warm habitats in Europe and is found mainly on Brassicaceae , occasionally on trees and bushes ( Koch 1989b). Most Canadian specimens were collected with Malaise traps in suburban areas.

Comments.

Scymnus rubromaculatus leads to the couplets separating Scymnus americanus Mulsant, 1850, S. apicanus Chapin, 1973 and S. paracanus Chapin, 1973 in Gordon’s keys to North American Scymnus ( Gordon 1976, 1985). In S. rubromaculatus , the dorsal surface is more densely punctate and pubescent than in those three species, the hind margin of the elytra is slightly or not paler than the elytral disc, and the female has no pale markings on head (apart from labrum and mouthparts) or pronotum. The male genitalia differ: the apical hook of the penis (sipho), which is typical for S. americanus and related species, is absent in S. rubromaculatus .

Figures

Figure 35. Scymnus rubromaculatus (Goeze) A female habitus, L. Borowiec B male habitus C median lobe (penis guide) and parameres, ventral view D median lobe (penis guide) and parameres, lateral view E penis (sipho), lateral view. Scale bars: 1.0 mm (A, B), 0.2 mm (C, D), 0.5 mm (E).