Omalium repandum Erichson, 1840

Brunke, Adam J. & Marshall, Stephen A., 2011, Contributions to the faunistics and bionomics of Staphylinidae (Coleoptera) in northeastern North America: discoveries made through study of the University of Guelph Insect Collection, Ontario, Canada, ZooKeys 75, pp. 29-68 : 30-32

Omalium repandum Erichson, 1840

Materials.

CANADA: ON: Chatam-Kent Co., Tilbury, pitfall trap, 9-VI-1994 (2), T. Sawinksi; Essex Co., Leamington, pitfall trap, 15 to 22-V-1992 (1), 22-V-1992 (1), 9-VI-1993 (1), Palichuck; Point Pelee Natl. Pk., Visitor Centre, malaise and pans, 22 to 29-V-2000, (2), 26-IX to 10-sX-2000 (1) O. Lonsdale. Huron Co., Auburn, Londesboro Rd. nr. Hwy 8, 43.728, -81.529, hedgerow, pitfall, 26-X-2009, A. Brunke (1); Benmiller, Sharpes Creek Line, 43.691, -81.608, hedgerow nr. creek, pitfall, 2-XI-2009, A. Brunke (1); Brucefield, London Rd. nr. Centennial Rd., 43.509, -81.516, hedgrerow nr. creek, pitfall, 27-IX-2009 (1), 12-X-2009 (4) A. Brunke; Waterloo Reg., Blair, Dickie Settlement Rd. nr. WhistleBear golf course, 43.373, -80.400, hedgerow, pitfall, 28-IX-2009 (6), 13-X-2009 (2) A. Brunke; Blair, Dickie Settlement Rd. nr. WhistleBear golf course, 43.373, -80.400, hedgerow, canopy trap in buckthorn, 10-XI-2009, A. Brunke (1); Blair, Fountain St. S. nr Speed River, 43.391, -80.373, hedgerow, pitfall, 24-XI-2009, A. Brunke (1); Blair, Whistlebare Rd. and Township Rd.1, 43.372, -80.362, hedgerow, canopy trap in buckthorn, 18-V-2010, A. Brunke (2); Blair, Whistlebare Rd. and Township Rd.1, 43.372, -80.362, hedgerow, pitfall, 1-VI-2010, A. Brunke (1); Blair, Whistlebare Rd. and Township Rd. 1, 43.367, -80.358, hedgerow, canopy trap in buckthorn, 18-V-2010 (1), 21-IX-2010 (1), A. Brunke; Blair, Whistlebare Rd. and Township Rd. 1, 43.367, -80.358, hedgerow, pitfall, 5-X-2010, A. Brunke (1); St. Jacobs, 'Stuart pitfall’, 3-VI-1993 (1), 14-VI-1994 (1), T. Sawinksi.

Diagnosis.

As the genus Omalium currently lacks a rigorous definition and consists of a heterogeneous assemblage of species ( Newton et al. 2000), this species is distinguished from all others of the subfamily occurring in the northeast by the combination of: tarsomere five longer than one to four combined; tarsomeres one to four not conspicuously broadened and without dense setae ventrally; maxillary palpomere three not greatly enlarged relative to segment four ( Newton et al. 2000); antennomeres eight to ten elongate; pronotum bright orange with finely crenulate, evenly arcuate margins (Fig. 1).

Omalium repandum was previously known from Missouri, South Carolina, Texas ( Herman 2001), Indiana ( Blatchley 1910), Minnesota, Massachusetts, Georgia ( Lundgren 1998) and Quebec ( Campbell and Davies 1991). Herein we provide the first specimen-based records of this species in Canada and newly record it from Ontario based on several, relatively recent collections made in southern Ontario (Map 1). The above specimens were caught by passive traps placed in or near forests and thus no microhabitat data was available but Blatchley (1910) reported it as 'frequent, under dead leaves’. Omalium repandum therefore appears to be forest litter dwelling and is probably widespread in central and eastern North America. The specimens from Huron County, Ontario and the provincial record from Quebec probably represent the northern limit of its range.