Acrotona brachyoptera Klimaszewski & Webster

Webster, Reginald P., Klimaszewski, Jan, Bourdon, Caroline, Sweeney, Jon D., Hughes, Cory C. & Labrecque, Myriam, 2016, Further contributions to the Aleocharinae (Coleoptera, Staphylinidae) fauna of New Brunswick and Canada including descriptions of 27 new species, ZooKeys 573, pp. 85-216 : 90-94

Taxon classification Animalia Coleoptera Staphylinidae

Acrotona brachyoptera Klimaszewski & Webster sp. n. Figs 34-41

Holotype (male).

Canada, New Brunswick, Saint John Co., Chance Harbour off Rt. 790, 45.1355°N, 66.3672°W, 12.V.2008, R.P. Webster, coll. // Calcareous fen, in sphagnum and litter in depression with Carex (LFC). Paratypes: Canada, New Brunswick, Carleton Co., Wakefield, "Bell Forest Nature Preserve", 46.2210°N, 67.7210°W, 19.IV.2005, R.P. Webster, coll. // Rich Appalachian hardwood forest, in leaf litter on mound of soil (1 ♀, LFC). Queens Co., ca. 3.5 km W of Lower Gagetown, 45.7497°N, 66.1846°W, 13.V.2008, R.P. Webster // Old red oak / red maple forest, in moist leaves on margin of vernal pool (1 ♂, RWC). Sunbury Co., Acadia Research Forest, 29.VI.1999, 21.IX.1999, Site 2, Clearcut, Pitfall trap, G. Gesner, Coll. (2 ♂, LFC); same data but 22.VI.1999, Site 2, Select 2, (1 ♀, LFC); Acadia Research Forest, 45.9799°N, 66.3394°W, 18.VI.2007, R.P. Webster, coll. // Road 7 control, mature red spruce & red maple forest, sifting moss near brook (1 ♂, 1 ♀, RWC); same data but 14.V.2007, 18.VI.2007 // sifting leaf litter (2 sex undetermined, 1 ♂, 1 ♀, AFC); same data but 18.IX.2007 // sifting leaf litter & moss (1 sex undetermined, AFC); Acadia Research Forest, 45.9816°N, 66.3374°W, 18.IX.2007, R.P. Webster, coll. // Road 7 Regenerating Forest, 8.5 year old regenerating mixed forest, in sphagnum and leaf litter at bottom of old tire depression (2 sex undetermined, AFC); Acadia Research Forest, 46.0188°N, 66.3765°W, 14.V.2007, 14.V.2007, 17.VIII.2007, R.P. Webster, coll. // Road 16 control, mature red spruce & red maple forest, sifting moss (1 sex undetermined, 1 ♂, 1 ♀, AFC; 1 ♂, RWC); same data but 14.V.2007, 18.VII.2007 // sifting leaf litter (1 sex undetermined, 1 ♀, AFC); same data but 18.IX.2007 // sifting leaf litter & moss (1 sex undetermined, AFC); Acadia Research Forest, 46.0173°N, 66.3741°W, 14.V.2007, R.P. Webster, coll. // Road 16 Regenerating Forest, 8.5 year old regenerating mixed forest, sifting leaf litter & moss (1 sex undetermined, AFC); same data but 18.IX.2007 // in sphagnum and leaf litter at bottom of old tire depression (1 sex undetermined, AFC). York Co., Canterbury, Browns Mtn. Fen, 45.8967°N, 67.6343°W, 2.V.2005, M. Giguère & R. Webster, coll. // Forested cedar fen, in litter at base of cedar (1 ♀, NBM); New Maryland, off Hwy 2, E of Baker Brook, 45.8760°N, 66.6252°W, 6.IV.2006, R.P. Webster, coll. // Old-growth cedar swamp, in moss & litter at base of cedar (1 sex undetermined, LFC); same data but 20.IV.2005 (1 ♂, LFC); New Maryland, Charters Settlement, 45.8331°N, 66.7410°W, 16.IV.2004, R.P. Webster, coll. // Mature red spruce & cedar forest, in moss & litter near small brook (1 ♀, CNC); New Maryland, Charters Settlement, 45.8428°N, 66.7279°W, 15.IV.2005, 20.IV.2005, R.P. Webster, coll. // Mixed forest, small sedge marsh in moist grass litter & sphagnum (1 ♂, CNC; 1 ♂, LFC); New Maryland, Charters Settlement, 45.8282°N, 66.7367°W, 9.IV.2005, R.P. Webster, coll. // Carex marsh, in moist sphagnum in Carex marsh (1 ♂, LFC); New Maryland, Charters Settlement, 45.8341°N, 66.7445°W, 22.IV.2005, R.P. Webster, coll. // Mature spruce & cedar forest, seepage area in saturated sphagnum & leaf litter (1 ♂, 1 ♀, NBM); New Maryland, Charters Settlement, 45.8428°N, 66.7235°W, 1.IV.2006, R.P. Webster, coll. (1 ♂, RWC); New Maryland, Charters Settlement, 45.8395°N, 66.7391°W, 29.III.2006, R.P. Webster, coll. // Mixed forest, under alders near small stream, in leaf litter (1 ♀, RWC); same data but 22.IV.2004 // Mixed forest, in leaf litter & moss near small shaded brook (1 ♂, LFC); New Maryland, Charters Settlement, 45.8342°N, 66.7450°W, 21.IV.2006, R.P. Webster, coll. // Mixed forest, margin of vernal pond in moist leaf litter (1 ♀, RWC); New Maryland, Charters Settlement, 45.8286°N, 66.7365°W, 11.VII.2006, R.P. Webster // Mature mixed forest, in gilled mushroom (1 ♂, RWC); Hwy 2 near Exit 271, 45.8986°N, 66.7918°W, 8.VI.2008, R.P. Webster, coll. // Mixed forest in leaf litter (sifting) (1 sex undetermined, 1 ♀, RWC); Kingsclear near Mazerolle Settlement, 45.8987°N, 66.7903°W, 9.IV.2006, R.P. Webster, coll. // Marsh with scattered alders, sifting grass & sphagnum at base of alders (1 ♀, LFC); 8.5 km W of Tracy, off Rt. 645, 45.6821°N, 66.7894°W, 6.V.2008, R.P. Webster // wet alder swamp, in leaf litter & grass on hummocks (1 ♀, RWC). Ontario, Alfred Bog, 17.VII.1982, L. LeSage, berl., litter, for., trail (1 ♂, 1 ♀, CNC).

Etymology.

This species is named for the short (brachyopterous, alternative spelling of brachypterous) elytra.

Description.

Body length 2.8-3.0 mm, very narrow, uniformly dark brown except for paler elytra, apex of abdomen, legs and basal antennal articles (Fig. 34); integument strongly glossy, moderately densely punctate and pubescent, pubescence short and adhering to body; head about one-sixth narrower than pronotum, rounded posteriorly with small eyes about three times shorter than postocular area; antennae with articles V–X transverse; pronotum broad, transverse, distinctly broader than elytra, posterolateral margin completely rounded; elytra shorter than pronotum; abdomen tapering apically. Male. Median lobe of aedeagus with bulbus broad, oval, tubus narrowly triangular in dorsal view (Fig. 35), arcuate ventrally in lateral view (Fig. 36); internal sac structures as illustrated (Figs 35, 36); tergite VIII slightly pointed apically (Fig. 37); sternite VIII elongate, truncate apically with base sinuate (Fig. 38). Female. Tergite VIII more apically produced than that of male (Fig. 39); sternite VIII deeply emarginate apically (Fig. 40); spermatheca with club-shaped capsule and coiled stem (Fig. 41).

Distribution.

Known from ON and NB, Canada.

Natural history.

In NB, this species was found in an old red maple ( Acer rubrum L.) forest, mixed forests, a wet alder ( Alnus sp.) swamp, a mature red spruce ( Picea rubens Sarg.) and red maple forest, a rich Appalachian hardwood forest, in a Carex marsh, small sedge marsh, marsh with scattered alders, in old-growth eastern white cedar ( Thuja occidentalis L.) swamps and forests, and in 8.5-year-old regenerating mixed forests. Adults occurred in moss and litter near brooks, in moss and litter at the base of cedar, in moss and litter in red spruce and cedar forests, in leaf litter under alders near a stream, in leaf litter and grass on hummocks in a wet alder swamp, in grass litter and sphagnum in marshes, moist leaves on the margin of a vernal pool, in sphagnum and leaf litter at the bottom of old tire depressions, and one specimen was collected from a gilled mushroom. Adults were collected during March, April, May, June, July, August, and September.

Comments.

This species has genitalic structures similar to those of Acrotona subpygmaea but differs by its narrower body, the pronotum broader than the elytra with posterolateral margin completely rounded near base, elytra shorter than pronotum, and its body is darker with paler, reddish-brown elytra and apical portion of the abdomen. In Acrotona subpygmaea , the posterolateral margin of pronotum is slightly angulate near the base and the body is uniformly dark brown.