Corresponding author: Adam J. Brunke (
Academic editor: Volker Assing
A long tradition of separate Nearctic and Palaearctic taxonomic studies of the diverse aleocharine rove beetles (
Brunke AJ, Pentinsaari M, Klimaszewski J (2021) Integrative taxonomy of Nearctic and Palaearctic Aleocharinae: new species, synonymies, and records (Coleoptera, Staphylinidae). ZooKeys 1041: 27–99.
Historically, taxonomic research on the hyperdiverse aleocharine rove beetle (
In combination with careful morphological study, large-scale DNA barcoding (e.g.,
Here we broadly compare morphological and molecular data across the Nearctic and West Palaearctic
Almost all specimens used in this study were dissected and their genitalia were subsequently examined on microslides. The genital structures were dehydrated in absolute ethanol, mounted in Canada balsam on celluloid microslides, and pinned with the specimens from which they originated. The photographs of the entire body and the genital structures were taken using an image processing system (Nikon SMZ 1500 stereoscopic microscope; Nikon Digital Camera DXM 1200F) and processed in Adobe Photoshop. Terminology mainly follows that used by
Depository abbreviations:
We have examined all DNA barcode data for
All COI barcode sequences in BOLD that fulfill quality criteria (minimum length 500 bp, less than 1% ambiguous bases) are automatically assigned into BIN clusters (Barcode Index Numbers;
The DNA barcode sequences studied here, including both previously unpublished data and the sequences published in earlier studies, have been compiled into a publicly available dataset on BOLD (DS-ALEO2020,
In its native range,
Newly reported as adventive in North America, from several localities in southern and eastern Ontario. It is native to the West Palaearctic and is known from most of Central Europe, Russian Central Territory, Armenia, and Georgia (
1A | Antennomere 10 only weakly transverse (Fig. |
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– | Antennomere 10 strongly transverse, at least twice as wide as long (native species); abdominal tergite VI with, at most, coarse punctures at base |
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1B | Pronotum with strong microsculpture and coarse, dense punctation, surface almost matte |
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– | Pronotum without microsculpture or with fine microsculpture, and with fine sparse to moderately dense punctation, surface moderately to highly glossy |
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All members of
The genus
8A | Pronotum strongly converging anteriad; posterolateral margin of elytra with strong sinuate emargination |
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– | Pronotum not or, at most, weakly converging anteriad |
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8B | Pronotum with fine punctures, not clearly visible at moderate magnification, shape strongly transverse, ~ 1.5 × wider than long |
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– | Pronotum with coarse punctures, clearly visible with low magnification, shape weakly transverse, no more than 1.4 × wider than long |
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Little is known about the microhabitat preferences of this species, but it likely occurs in in nests or cavities within trees as does
This recently described species, previously known from New Brunswick and Alberta (
With the above synonymy, the genus
In
The species epithet refers to the remarkably separated triangular apex of the median lobe of the aedeagus, distinguishing it from all other members of the
Body length 3.0–3.3 mm, dark brown with elytra, antennomeres 1–2 or 1–3, legs and apical part of abdomen yellow-brown, forebody moderately glossy and abdomen strongly so (Fig.
The specimens were collected in a Malaise trap on an open field surrounded by mixed forest.
Based on a combination of small size (< 4.5 mm), superficial, meshed microsculpture, sparse pronotal punctation, with punctures separated by more than two puncture diameters, pronotum transverse, shorter and narrower than elytra, and the transverse antennomeres 5–10,
In North America, most specimens of this species have been collected from near water, including a sandy creek bank, in a dried streambed and in moss near the splash zone of a waterfall (
Although all available sequences of this species are partial (382–407 bp) and a BIN has not been established as that would require at least one founding member with a minimum sequence length of 500 bp, Nearctic and Palaearctic sequences form a distinct cluster with only a single variable nucleotide site. External morphology and that of the spermatheca are identical. As spermathecae are of generally poor diagnostic value (especially the distal part) in
Recently,
Tribe
Adapted from
1 | Elytra at humerus only slightly broader than pronotum at base (Figs |
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– | Elytra at humerus distinctly broader than pronotum at base (Figs |
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2 | Pronotum with pubescence directed straight posteriad; hind tarsus subequal in length to hind tibia or longer (Fig. |
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– | Pronotum with pubescence directly posteriolaterad from midline; hind tarsus shorter, slightly longer than half the length of hind tibia or shorter (Fig. |
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3 | Abdomen clavate, at base distinctly narrower than head (Fig. |
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– | Abdomen at most slightly constricted at base, subequal to or wider than head (Figs |
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4 | Abdomen at base elongate and moderately constricted, ca. as wide as head (Figs |
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– | Abdomen at base at most slightly constricted, wider than head (Fig. |
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This species has been collected from various wetland microhabitats including the edges of lakes, rivers, and a beaver pond (
In his key to the genera of
The type series was collected by sifting litter (
We here transfer this species to
Collected along the edge of a variety of running and standing water-based habitats.
We here transfer this species to
Nearctic specimens have been collected most frequently along the margins of running water but also along the margins of a forest pool (
This species has been collected together with
The species epithet refers to the longitudinal impression on the pronotum, most strongly developed in males.
Body length 3.2–3.4 mm; colour dark brown, elytra brown with irregular rust-brown patches, first two or three basal tergites rust-brown with posterior edge yellow, apex of abdomen rust-brown, legs and antennae rust-brown; integument highly glossy (Fig.
Specimens were collected by sifting leaf litter along a lake margin and by treading pond vegetation.
It was challenging to place this species in either
This species is generally found in anthropogenic habitats, including compost, dung, and old hay and grass (
Among Canadian species of
This species occurs in a wide variety of habitats across a broad elevational range, including hollow trees, plant debris, old hay in cattle barns, moldy substrates and in mushrooms (
This species occurs in a variety of moist to dry, decaying organic matter including rotting hay, compost, hollow trees, and ant nests (
Non-sequenced specimens.
The MB specimens were collected under bark, confirming that this species lives in a way similar to other members of the genus.
Males and females of the syntype series were morphologically consistent with the specimens forming molecular cluster
Aedeagi of
Male tergite VIII of
A photo record of this species from Ontario is available on
Putative undescribed
This species occurs under the bark of dead trees. One specimen (NB) was collected from a Lindgren funnel.
After the results of the present study, two species of
The aedeagi of the male paratype (holotype in collection of the California Academy of Sciences) of
Aedeagi of
Specimens have been collected in Malaise traps, window traps and Lindgren funnels placed in forests. Both the closely related West Palaearctic
Sequenced Nearctic specimens of
Sequenced Nearctic specimens from ON, AB, NB, and QC form a distinct barcode cluster, separate from all sequenced Palearctic specimens and divergent by 4.65%. This pattern is inconsistent with a species that is adventive in North America and we remove
Specimens have been collected from a partly dried
The new record from QC, near the ON border, bridges the wide gap between previous records in NB and WI.
The Canadian specimens were collected by sifting mushrooms in a deciduous forest. No detailed data on the host fungus were recorded.
Specimens occur under bark of dead trees.
Sequenced Nearctic specimens from ON form a distinct barcode cluster, separate from all sequenced Palearctic specimens and divergent by 7.58%. This pattern is inconsistent with a species adventive in North America and we remove
Several males and females of
Canadian specimens were collected by car-netting in mixedwood forests, while Palaearctic specimens are known from compost and other plant-based debris (
Nearctic and Palaearctic populations do not differ in male and female genitalia or in external morphology. Molecular data were unavailable for the Nearctic population, which was recently reported from Canada (
The species epithet refers to the similarity to related species
Body length 2.4–2.7 mm, moderately flattened (stronger so on elytra), narrowly subparallel, colour of head, pronotum, scutellar region of elytra, apical part of abdomen and antennomeres 5–11 dark brown to dark reddish brown, elytra and antennomeres 1–3 paler, red-brown and legs yellow; forebody finely and densely punctate, microsculpture shallow, consisting of meshes; head slightly elongate and with small, shallow impression medially, head slightly narrower than pronotum, postocular region elongate, ca. as long as maximum diameter of eye, tempora with carinae dorsally only; antennae slender, as long as pronotum and elytra combined, basal three antennomeres strongly elongate, 4 subquadrate, 5–10 subquadrate to slightly transverse, and terminal one strongly elongate and ca. as long as two preceding antennomeres combined; pronotum slightly transverse (width/length ratio 1.3), trapezoidal in shape, flattened, pubescence directed straight posteriad in central part of disc and obliquely posteriad laterally; elytra at suture ca. as long as pronotum along midline, flat, distinctly transverse (width/length ratio 1.5), ~ 1/3 broader than pronotum, humeri angular, posterior margins slightly sinuate laterally, pubescence directed straight posteriad forming slightly arcuate lines in sutural region of disc; abdomen subparallel, tergites III–VI distinctly impressed at base; basal metatarsomere ~ 1/3 longer than the following one. MALE. Tergite VIII rounded apically with minute median emargination, lacking apical teeth (Fig.
This species has only been collected by passive traps, including malaise and pitfall traps. All specimens have been collected from at least partly disturbed habitats, such as forest edges, agricultural fields, and suburban environments. This species corresponds to ‘
Canadian specimens have been collected on farmland and directly from horse manure.
The Canadian specimen was collected from forest litter with a Berlese funnel but nothing specific is known about this species’ microhabitat preferences.
The aedeagus, coloration and punctation of the Canadian specimen are consistent with type material of
2a | Pronotum much broader than elytra; antennal articles 5–10 in specimens slightly elongate; spermatheca forming concentric circles posteriorly |
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– | Pronotum ca. as broad as elytra or slightly narrower (Fig. |
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2b | Pronotum coarsely punctate and extremely transverse with weakly rounded base and apex; antennal articles 5–10 subquadrate; median lobe in lateral view strongly produced ventrad |
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– | Pronotum finely punctate and transverse, but more rounded at base and apex (Fig. |
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As with other species of the genus,
This species can be readily recognized by a combination of its small size, large eyes and relatively simple, ventrally projecting median lobe of the aedeagus in lateral view (Fig.
Nothing specific is known about this species’ microhabitat preferences but it probably occurs near water as do other species of the genus. The series of Ontario specimens was collected using a car net, which is typically effective for collecting small staphylinids.
Specimens have been collected from clear cut areas, transitional zone of a coniferous forest, seepages, and river and creek edges, from moss, leaf litter, gravel, dung, carrion and pitfall traps (
Neither this species nor
Males of this species are easily recognized among other Canadian
Most specimens of this species were collected by passive traps in a variety of habitats. In Sweden,
This species was reported from Canada (Manitoba) for the first time in the checklist by
Prefix -
This species is similar externally and genitally to
Body narrowly subparallel, moderately flattened, length 3.0–4.2 mm; colour dark brown, elytra dark brownish to brownish yellow, except for darker scutellar area and paler legs, basal antennomeres rust-brown (Fig.
This species has been recorded from various wetland and riparian habitats in NB: in moss and leaf litter near brook and in litter, grasses, and moss on hummocks in old-growth eastern white cedar swamps and a wet alder swamp, in moist leaves along vernal pond margins in various mixed forests, and a red oak/red maple forest; also from pitfall traps in regenerating red spruce forests (NB) and from vernal pool litter in ON (summarized by
Although they were not re-examined here, the specimens reported by
In its native range, this species has been collected in a variety of decaying plant matter, especially near water. This species was also common in compost in NB. In Europe, this species has been collected from similar microhabitats including grass clippings and compost (
When describing his new species,
We would like to thank the curators listed under Materials and methods for access to the material under their care. Thanks to J. Pedersen (NMHD) and V. Assing (Hanover, Germany) for their valuable input regarding the synonymy of Nearctic and Palaearctic species, and to V. Assing, A. Hansen (
Specimen voucher data and corresponding DNA barcode accession numbers
specimen data
All specimen data and sequence accession numbers associated with the DNA barcode dataset used in this study.