Stenus (Tesnus) formicetorum Mannerheim, 1843

Webster, Reginald P., Davies, Anthony E., Klimaszewski, Jan & Bourdon, Caroline, 2016, Further contributions to the staphylinid fauna of New Brunswick, Canada, and the USA, with descriptions of two new Proteinus species (Coleoptera, Staphylinidae), ZooKeys 573, pp. 31-83 : 62

Taxon classification Animalia Coleoptera Staphylinidae

Stenus (Tesnus) formicetorum Mannerheim, 1843

Material examined.

New Brunswick, Albert Co., Caledonia Gorge P.N.A., 45.7930°N, 64.7764°W, 1.VII.2011, R.P. Webster // Small rocky clear cold river margin (Caledonia Creek), sifting drift material (tree bud material) near eddy area (1 ♂, RWC). Restigouche Co., Wild Goose Lake, 420 m elev., 47.8540°N, 68.3219°W, 7.VI.2011, R.P. Webster // Lake margin with emergent Carex and grasses, treading Carex and grasses (3 ♂, 5 ♀, RWC). York Co., Douglas, Currie Mountain, 45.9844°N, 66.7592°W, 27.V-10.VI.2013, C. Alderson & V. Webster // Mixed forest with Quercus rubra , Lindgren funnel trap in canopy of Quercus rubra (1 sex undetermined, AFC); Charters Settlement, 45.8456°N, 66.7267°W, 1.V.2010, R.P. Webster // Margin of beaver pond in leaf litter (1 ♂, RWC). Ontario, Manitouwadge, Black River, 18.IX.1989, under weeds in dried-up pool, T. Bakker (1 ♂, CNC).

Distribution in Canada and Alaska.

YK, AB, MB, ON, QC, NB ( Bousquet et al. 2013). This species is newly recorded from ON and NB.

Natural history.

Most specimens of Stenus formicetorum were found along a lake margin with emergent vegetation of Carex and grasses. Adults were collected by treading vegetation into water. One individual was sifted from leaf litter along the margin of a beaver pond, one was sifted from drift material (tree bud material) near an eddy area along a small rocky, clear, cold river margin, and another adult was captured in a Lindgren funnel trap in the canopy of a red oak in a mixed forest. This species was collected in May, June, and July in NB, and September in ON.