In Saskatchewan, one female was captured on a sandy beach. In Labrador, adults were collected in carrion traps and flight intercept traps in spruce-moss forests (Klimaszewski et al. 2011). Elsewhere, adults were captured from animal carcasses and some from Carex and moss near a lake (Klimaszewski 1984). The adults were collected from May to August.

In Saskatchewan, one male was captured in horse manure. Elsewhere, adults were collected from decaying organic matter, fungi, animal droppings, human feces, and carrion (Klimaszewski et al. 2002). Larvae are parasitic on fly pupae (Klimaszewski et al. 2002). The adults were collected from June to September.

Body narrowly subparallel (Fig. 1), length 1.7–1.8 mm, dark brown with two large reddish-brown spots on posterior sutural part of elytra and lighter colour tarsi (Fig. 1); head, pronotum and elytra coarsely and sparsely punctate, punctures large; pubescence sparse; integument strongly glossy; pronotum transverse, slightly narrower than elytra, pubescence directed laterad from median line; elytra at suture about as long as pronotum; abdomen subparallel. MALE. Median lobe of aedeagus with oval bulbus and narrowly elongate and rounded tubus in dorsal view (Fig. 3), in lateral view tubus slightly arcuate basally and straight apically (Fig. 2); internal sac structures not pronounced; tergite VIII truncate apically (Fig. 4); sternite VIII slightly emarginated at apex and with broad distance between base of disc and antecostal suture (Fig. 5). FEMALE. Tergite VIII truncate apically (Fig. 7); sternite VIII broadly arcuate apically (Fig. 8); spermatheca with narrowly elongate club-shaped capsule angularly connected to narrow and long stem, together forming L-shaped structure (Fig. 6).

Figures 1–8. 

Acrotona recondita (Casey): 1 habitus in dorsal view 2 median lobe of aedeagus in lateral view, and 3 in dorsal view 4 male tergite VIII 5 male sternite VIII 6 spermatheca in lateral view 7 female tergite VIII 8 female sternite VIII; 1, 6–8 based on female from Saskatchewan 2–5 based on male from Pennsylvania.

The single female in Saskatchewan was captured in horse manure.

This species was originally described by Erichson (1839) as Homalota recondita, from Pennsylvania. It clearly does not belong to Homalota and was subsequently listed by Moore and Legner (1975) as belonging to the subgenus Dimetrota of Atheta. Gusarov, V.I. identified types of H. recondita as Acrotona. The inclusion of this species in Acrotona needs confirmation because it has scarcly visible minute part of pronotal hypomeron visible in lateral view.

In Saskatchewan, one female was captured in dry litter on the banks of the Red River. In Newfoundland, adults were collected in mixedwood forest litter, in litter in riparian zones along forested streams, a sandy lakeshore and a marsh. Elsewhere, adults were recorded from organic debris, fungi and carrion, and often found in caves in the USA (Klimaszewski and Peck 1986, Klimaszewski et al. 2011). The adults were collected from June to October.

In Saskatchewan, adults were captured on a sandy beach and in wet spruce litter. In Newfoundland, one specimen was collected in a carrion-baited pitfall trap in a forest (Klimaszewski et al. 2011). In Nova Scotia, adults were collected in nests of boreal and saw-whet owls (Klimaszewski and Majka 2007). The adults were collected in July and August.

This species is strongly associated with forests. The habitats of adults include bison faeces in British Columbia and wet spruce litter and poplar-spruce litter in Saskatchewan. In Newfoundland, adults were collected using carrion traps and flight intercept traps in various mixedwood and coniferous forest types (Klimaszewski et al. 2011). Some specimens were found in rotting mushrooms in forests and under the bark of decaying spruce logs (Klimaszewski et al. 2011). Elsewhere in North America it was collected from fungi and in pitfall traps in forests. The adults were collected from June to August.

Body narrowly elongate (Fig. 9), length 1.8–2.3 mm, dark brown to black, legs with at least tarsi reddish-brown; head, pronotum and elytra finely and densely punctate, punctures small; pubescence dense; integument strongly glossy; pronotum transverse, slightly narrower than elytra, with median line of disc well defined, pubescence directed laterad from median line; elytra at suture slightly longer than pronotum; abdomen subparallel. MALE. Median lobe of aedeagus with oval bulbus and narrowly elongate and pointed tubus in ventral view (Fig. 11), in lateral view tubus slightly sinuate and slightly pointed ventrally at apex (Fig. 10); internal sac structures not pronounced; tergite VIII with four small dents apically (Fig. 12); sternite VIII broadly rounded apically. FEMALE. Tergite VIII truncate and slightly concave apically (Fig. 14); sternite VIII broadly arcuate apically with shallow apical emargination (Fig. 15); spermatheca with narrowly elongate and angularly bent capsule bearing large and long apical invagination, stem narrow, and with a single posterior coil bearing swollen apical part (Fig. 13).

Figures 9–15. 

Atheta (Datomicra) nigra (Kraatz): 9 habitus in dorsal view 10 median lobe of aedeagus in lateral view, and 11 in ventral view 12 apical part of male abdomen with visible 4 dents on apical margin of male tergite VIII 13 spermatheca 14 female tergite VIII 15 female sternite VIII; 9, 13–15 based on a female from Saskatchewan 10, 11 after Benick and Lohse (1974) 12 based on a male from Germany.

The single female in Saskatchewan was captured in horse manure in September.

This species is similar to our native Atheta (D.) acadiensis Klimaszewski & Majka (2007) described from Nova Scotia but it is readily distinguishable by the morphology of genital structures. For illustrations of A. acadiensis, see Klimaszewski and Majka (2007).

In British Columbia, adults were captured in willow-aspen litter. In Newfoundland, adults were collected using pitfall traps in fir forests (Klimaszewski et al. 2011). In Yukon Territory, adults were collected from sifted willow litter (Salix sp.) (Klimaszewski et al. 2008). The adults were collected from May to July.

In Saskatchewan, a female was captured in wet spruce litter, and one Newfoundland specimen was captured using a carrion-baited pitfall trap in a spruce/moss forest (Klimaszewski et al. 2011). In Alberta, one male was captured in an early decay stage of a white spruce log in spruce-aspen mixed forest. Elsewhere, adults were collected in the nests of several owl species, in maple forest, in oyster mushrooms (Pleurotus sp.), and in organic material on standing trees (Majka et al. 2006, Webster et al. 2009). The adults were collected from June to August.

In Saskatchewan, adults were captured on a sandy beach. In Newfoundland, some adults were collected using a flight intercept trap in a mixed forest (Klimaszewski et al. 2011). Elsewhere, adults occur in forest leaf litter, at edges of streams and pools, in moss and in drift material (Lohse et al. 1990, Webster et al. 2009). The adults were collected from April to June.

In Saskatchewan, one male was captured from the riparian zone of a pond. In Newfoundland, most adults were collected in forests of various types (deciduous, coniferous, mixedwood, riparian) using carrion-baited pitfall traps and flight intercept traps, as well as on coastal barrens using pitfall traps and on rotting mushrooms (Klimaszewski et al. 2011). Elsewhere, adults were collected on gilled, polypore and coral fungi, in compost and other organic debris, and in rotten logs, and the usual habitat is forest, e.g., hardwoods, eastern white cedar swamps, red spruce/yellow birch, hemlock, mixedwood (Klimaszewski and Peck 1986, Klimaszewski et al. 2005, 2007b, Majka and Klimaszewski 2008, Webster et al. 2009, Majka and Klimaszewski 2010). The adults were collected from April to August.

In Saskatchewan, specimens were captured in horse manure. Elsewhere, adults are usually associated with cow dung, carrion, compost, rotting mushrooms, and other rotting organic substrates (Klimaszewski et al. 2007a, Webster et al. 2009, Michaud et al. 2010). The adults were collected from May to October.

In Saskatchewan, adults were found on ferns and scat, and in wet spruce litter. In Newfoundland, adults were collected using carrion-baited pitfall traps and flight intercept traps in various mixedwood and coniferous forest types (Klimaszewski et al. 2011). In New Brunswick, adults were captured from litter in a red spruce forest (Klimaszewski et al. 2005). The adults were collected from June to August.

In Saskatchewan, adults were found in horse manure. In Newfoundland, adults were collected using carrion-baited pitfall traps and flight intercept traps in conifer-dominated forests, including upland and riparian habitats (Klimaszewski et al. 2011). Elsewhere, adults were collected from gilled mushrooms, compost, and leaf litter in various forest types, e.g., birch, maple, oak, hemlock mixed forests and spruce forest (Lohse et al. 1990, Klimaszewski et al. 2007a, Webster et al. 2009). The adults were collected from June to September.

In Alberta, one female was found in a white spruce dominated aggregated retention patch (5.93 ha) surrounded by 10-year-old regenerating coniferous trees using a window trap attached to the trunk of white spruce snag. Elsewhere, adults were collected from unbaited and baited pitfall traps and flight intercept traps in various coniferous and mixedwood forest types (Klimaszewski et al. 2011). The adults were collected from June to August.

In Saskatchewan, one male was captured in the riparian zone of a pond. In Newfoundland, adults were collected in unbaited and carrion-baited pitfall traps and flight intercept traps in various coniferous and mixedwood forest types (Klimaszewski et al. 2011). Elsewhere, adults were found in coniferous forests and in organic litter in mixed forests (Klimaszewski et al. 2005, Majka and Klimaszewski 2008).The adults were collected from May to October.

In Alberta, adults were collected using window traps installed on the trunk of a recently girdled white spruce tree and on snags. The adults were found in white spruce dominated aggregated retention patches (> 1.43 ha) surrounded by 10-year-old coniferous regenerating matrix, small aggregated retention patch (0.20 ha) surrounded by 20% dispersed retention, 10-year-old regenerating aspen stand, and intact white spuce forest. In Yukon Territory, adults were collected using pitfall traps and sifting organic litters in various coniferous and mixedwood forest types (Klimaszewski et al. 2012). The adults were collected from May to September.

In Alberta, one female was collected in June in an aggregated retention patch (0.46 ha) surrounded by 20% dispersed retention of a white spruce dominated stand, using an emergence trap attached to the trunk of intermediate decay stage of white spruce log. The other female was captured in 10-year-old regenerating trembling aspen, using a window trap. This is the first habitat record of the species.

In the Northwest Territories, adults were found in aspen and birch-spruce litter. In Newfoundland, adults were collected mostly using pitfall traps in fir and spruce forests (Klimaszewski et al. 2011). One specimen was found in a rotting mushroom and another under detritus on a sandy beach (Klimaszewski et al. 2011). The adults were collected from May to August.

One female was captured in the Yukon using a Lindgren funnel trap in a white spruce stand. Adults in Newfoundland and Labrador were collected using pitfall traps and flight intercept traps in various coniferous forest types, and one specimen was collected under the bark of a dead red pine (Klimaszewski et al. 2011). In British Columbia, adults were caught in emergence traps attached to the trunks of lodgepole pine (Pinus contorta Dougl. ex Loud. latifolia Engelm.) infested by mountain pine beetle (Dendroctonus ponderosae Hopkins) (Langor, unpublished). In New Brunswick, adults were found: under the bark of large fallen spruce in an old-growth eastern white cedar swamp; under tight bark of American elm; in a silver maple forest; in fleshy polypore fungi at the base of a dead standing Populus sp. in a wet alder swamp; in a group of Pholiota sp. at the base of a dead Populus sp. in a mixed forest. In Quebec, adults were found in dead black spruce in a black spruce forest. Adults were also captured in Lindgren funnel traps deployed in an old-growth white spruce (Picea glauca (Moench) Voss) and balsam fir forest, an old mixed forest with red and white spruce, red and white pine (Pinus strobus L.), and a rich Appalachian hardwood forest with some conifers (Klimaszewski et al. 2013). The adults were collected from March to September.

In Alberta, adults were collected using window traps attached to a girdled white spruce tree and a snag, and were reared from white spruce logs in early and intermediate decay stages. In Quebec, adults were found in dead and dying black spruce (Picea mariana Mill. (BSP)) in black spruce dominated stands. The adults were collected from June to September.

In Alberta, adults were reared from well-decayed white spruce logs. Elsewhere, adults were captured in various forest types including a recently burned forest. The adults were collected from July to October.

In Saskatchewan, one male was captured on a sandy beach. In Newfoundland, a single specimen was collected in a pitfall trap in a balsam fir stand (Klimaszewski et al. 2011). Elsewhere, adults were captured in litter in spruce bogs, birch bogs, in moss and lichens, and in coniferous and deciduous forests (Gusarov 2004). The adults were collected from May to September.

In Saskatchewan, one male was captured in wet willow stand. In Newfoundland, adults were collected using flight intercept traps in mixedwood and coniferous forests, and along the margins of streams (Klimaszewski et al. 2011). In New Brunswick, adults were found on muddy soil, near margins of water in alder swamps, in mixed forests, in drift material on a lakeshore, and in moist leaves under a sap flow from a yellow birch (Webster et al. 2009). The adults were collected from May to August.

The Manitoba male was captured in litter on the bank of the Red River. In New Brunswick, it was found in red spruce (P. rubens) forests (Klimaszewski et al. 2005), whereas in Quebec it was found in yellow birch (B. alleghaniensis) forests (Klimaszewski et al. 2007b). The adults were collected from June to October.

The holotype was captured in a flight intercept trap in a mixedwood forest in Newfoundland (Klimaszewski et al. 2011). In Saskatchewan, adults were found in birch-alder litter, on a sandy beach, and in the riparian zone of a pond. The adults were collected from June to September.

In Saskatchewan, one male was captured on a sandy beach. Adults were collected from May to August (Klimaszewski et al 2011).

In Northwest Territories, one male was captured in birch/spruce forest. In Saskatchewan, adults were found in wet willow thicket, spruce-alder litter, ditch litter in a deciduous forest, and on ferns and in scat. In Newfoundland, a single adult was collected from treading vegetation and sphagnum moss in a boggy area (Klimaszewski et al. 2011). In Yukon Territory, the species was found in moss in a meadow (Klimaszewski et al. 2012). The adults were collected from June to September.

In Saskatchewan, one male was captured on a sandy beach. In Newfoundland, one specimen was collected amongst litter and stones on the sandy shore of a lake (Klimaszewski et al. 2011). The adults were collected in June and July.

In Saskatchewan, adults were captured in a wet willow stand and in birch-alder and birch-spruce litter. The Yukon specimen was collected from ground litter (Klimaszewski et al. 2012). The adults were collected from June to September.

In Alberta, adults were captured in window traps attached to a recent white spruce snag. In British Columbia, adults were captured by treading Sphagnum and Carex at the edge of a marsh (Klimaszewski et al. 2009a). The adults were collected in July and August.

In Saskatchewan, one female was captured on a sandy beach. In British Columbia, adults were captured by treading Sphagnum and Carex at the edge of a marsh (Klimaszewski et al. 2009a). The adults were collected from June to August.

In Alberta, one female was captured in a window trap attached to a recently girdled white spruce tree. Elsewhere, adults were captured in Salix, Vaccinium and Chamaedaphne leaf litter (Klimaszewski et al. 2009a). The adults were collected from June to September.

In Saskatchewan, one male was captured in an aspen stand. In Newfoundland, adults were collected using pitfall traps in fir and riparian forests (Klimaszewski et al. 2011). Elsewhere, adults were found in leaf litter near a body of water, in litter near the sea and in mountain forests (Klimaszewski et al. 2011). The adults were collected from March to September.

Body broadly oval (Fig. 16), length 1.5–1.8 mm, dark brown with reddish tinge and slightly paler base of abdomen or uniformly black, appendages usually lighter than rest of body (Fig. 16); sparsely punctate and pubescent; setae straight and erect, particularly on pronotum; integument strongly glossy; head slightly narrower than pronotum; pronotum moderately transverse, rounded laterally and basally, distinctly narrower than elytra; elytra broad at suture about as long as pronotum; abdomen arcuate laterally and broadest at middle of its length. MALE. Median lobe of aedeagus with oval bulbus and triangularly shaped tubus in dorsal view (Fig. 18), in lateral view tubus slightly sinuate and narrow apically with apex narrowly rounded (Fig. 17); internal sac structures not pronounced; tergite VIII short and truncate apically (Fig. 19); sternite VIII slightly produced apically and rounded at apex and with narrow distance between base of disc and antecostal suture (Fig. 20). FEMALE. Tergite VIII short and truncate apically (Fig. 22); sternite VIII broadly arcuate apically (Fig. 23); spermatheca with broad and sac-shaped capsule with minute apical invagination, stem narrow, sinuate and narrowly twisted apically (Fig. 21).

Figures 16–23. 

Trichiusa pilosa Casey: 16 habitus in dorsal view 17 median lobe of aedeagus in lateral view, and 18 in dorsal view 19 male tergite VIII 20 male sternite VIII 21 spermatheca in lateral view 22 female tergite VIII 23 female sternite VIII 17–23 based on type material from Rhode Island, USA.

In Alberta, one female was collected using a window trap deployed in a 10-year-old regenerating white spruce stand. The British Columbia specimens were found on bison scat. The adults were collected from June to September.

The two specimens from British Columbia agree with the type series in external morphology and shape of genitalia except for the entirely black body. It is well known that many aleocharine species exhibit darker colour at higher latitudes compared with more southern populations.

In Saskatchewan, one female was captured on a sandy beach. In Newfoundland, adults were collected in riparian areas (Klimaszewski et al. 2011). Elsewhere, adults were collected by treading wet moss on muddy shores of shallow lakes (Klimaszewski et al. 2011). The adults were collected from June to August.

In Saskatchewan, adults were captured on a mushroom in pine forest. In Newfoundland, adults were collected using flight intercept traps in spruce-poplar forest (Klimaszewski et al. 2011). Elsewhere, adults were collected from gilled mushrooms in pine, hardwood and mixedwood forests (Seevers 1951, Klimaszewski et al. 2009b). The adults were collected in August and September.

In Saskatchewan, adults were collected from mushrooms in a pine forest. In Labrador, adults were collected using flight intercept traps in spruce-birch and spruce-poplar forests (Klimaszewski et al. 2011). Elsewhere, adults were collected from gilled mushrooms (Russula sp.) in mixed forests, white and red spruce forests, white cedar swamps, yellow birch and spruce forests, and oak and maple forests (Seevers 1951, Klimaszewski et al. 2009b, 2011). The adults were collected in August and September.

The Saskatchewan specimens were found in June in an aspen stand and in alder/spruce litter in a forest.

In Alberta, most adults were collected using window traps attached to boles of recently girdled trees and snags of white spruce in white spruce dominated stands. Elsewhere, adults were found under bark of coniferous trees (Klimaszewski et al. 2007a, 2011). The adults were collected from June to September.

In Saskatchewan, adults were captured in birch and alder litter in a forest. Elsewhere, the species appears to be riparian. Adults were collected from February to November from debris near streams and lakes, and from a beaver lodge (Klimaszewski et al. 2008, 2011).

In Saskatchewan, adults were collected from alder/spruce and wet spruce litter in forests. In Newfoundland, adults were collected in abundance using pitfall traps in a patch of mixedwood forest in an urban area but were uncommon in a disturbed field with forbs and grasses (Klimaszewski et al. 2011). Elsewhere, adults were collected in human settlements from stables, barns, heaps of straw, haystacks, rotting organic debris, mushrooms, and forest litter (Klimaszewski et al. 2007a). The adults were collected from June to August.

The Saskatchewan specimens were captured in a wet willow stand. Elsewhere, adults were collected at lake margins, on moist soil/gravel among sedges and by treading Carex and grasses (Klimaszewski et al. 2014). The adults were collected from June to September.

In Newfoundland, adults were collected using pitfall traps, carrion traps and flight intercept traps in various forest types (coniferous, deciduous, mixedwood and riparian) and on coastal limestone barrens of Labrador (Klimaszewski et al. 2011). Some specimens were collected from rotting mushrooms in forests (Klimaszewski et al. 2011). Elsewhere, adults were collected from leaf litter, moss, fungi, in natural and harvested deciduous and coniferous forests (Klimaszewski et al. 2006). It is a very adaptable and common Oxypoda species in Canada. The adults were collected from May to October.

In Alberta, a single female was collected in a white spruce dominated stand using a window trap installed on the trunk of a recently girdled white spruce. Elsewhere, adults were captured in various forest types, agricultural fields, a disturbed meadow with Salix shrubs, and vegetation on coastal sand dunes (Klimaszewski et al. 2011). The adults were collected from March to October.

In Saskatchewan and Manitoba, specimens were found in alder/spruce litter in a forest stand and in litter on river banks. In Newfoundland, adults were collected using pitfall traps in birch forests, burned forest, fir forest, coastal sand dunes and coastal barrens (Klimaszewski et al. 2011). Elsewhere, adults were collected in forest litter, moss, gopher burrows, and muskrat nests (Klimaszewski et al. 2006, Webster et al. 2009). The adults were collected from June to September.

In Saskatchewan, specimens were found on a mushroom in a pine forest. In Labrador, specimens were collected using pitfall traps in various coniferous, deciduous and mixedwood forest types (Klimaszewski et al. 2011). Elsewhere, adults were collected in forest litter in deciduous-dominated stands and in balsam fir forest, as well as in sphagnum moss (Klimaszewski et al. 2006). The adults were collected from June to September.

In Saskatchewan, adults were captured in an aspen stand. In Newfoundland, adults were reared from the boles of dead balsam fir, collected with pitfall traps in fir forests and collected from coastal sand dunes (Klimaszewski et al. 2011). Elsewhere, adults were collected mostly from sphagnum moss near small bodies of water, other moss, forest litter in coniferous and deciduous forests and organic litter in alpine and subalpine habitats. Most adults were collected from May through October, with some records from November and December (details in Klimaszewski et al. 2006).

In Alberta, adults were collected from dead or dying white spruce in aggregated retention patches surrounded by different levels of dispersed retention, using emergence traps and window traps. Elsewhere, adults were found in various deciduous and coniferous forests, using a pit-light trap and ethanol-baited Lindgren funnel traps (Klimaszewski et al. 2001, 2011). The adults in northwestern Alberta were collected from June to September.

In Alberta, adults were collected from dead or dying white spruce in aggregated retention patches surrounded by different levels of dispersed retention, using window traps. Elsewhere, adults were found in mature coniferous forests, using pit-light traps and ethanol-baited Lindgren funnel traps (Klimaszewski et al. 2011). The adults were collected in July and August.

In Alberta, adults were reared from white spruce logs in early and intermediate decay stages in white spruce dominated stands. Elsewhere, adults were found in various deciduous and coniferous forests, using a flight intercept trap, ethanol-baited Lindgren funnel traps, pit-light traps, and pitfall traps.