Microsaurus, Dejean, 1833

Brunke, A. J., Zmudzinska, A. & Buffam, J., 2020, An Integrative Taxonomic Review of the Quedius erythrogaster Mannerheim Species Group in North America (Coleoptera: Staphylinidae: Quediini), The Coleopterists Bulletin 74 (4), pp. 897-921 : 904-905

Microsaurus lineage (sensu Brunke et al. 2019b)

Diagnosis and Comments. Based on a total evidence phylogeny, Brunke et al. (2019b) recently defined the monophyletic Microsaurus lineage to include generalized Quediini (subgenus Microsaurus ) which formed multiple clades with more morphologically derived relatives that are currently treated as genera (e.g., Korgella Özdikmen ) or subgenera (Megaquedius Casey, Velleius). This large lineage is recognized by the following combination of characters given in Brunke et al. (2019b): Head with genal puncture, elytra with at least asetose punctures on disc in addition to macrosetal rows, and with basal puncture doubled.

Erythrogaster Species Group

Diagnosis. Members of the erythrogaster group ( Fig. 1 ) may be recognized among other Nearctic members of the Microsaurus lineage by the following combination of characters:Scutellar shield impunctate; innermost of two basal punctures of the head each situated close to nuchal ridge, at a distance equal to the size of the puncture impression or closer ( Fig. 3A ); male sternite VI with semicircular patch of dense setae ( Fig. 3B ). The two latter character states are unique to this group in at least Nearctic Quediini .

Distribution. Holarctic. Transcontinental in the Nearctic region: From the Canadian Maritimes in the northeast to Alaska in the northwest, extending south to southern California, across the central USA and Texas to northern Florida ( Fig. 8 ). Some members of this group are endemic to the Great Plains ecoregion or to the sandy pine-oak forests of the southeastern United States, where it is otherwise too seasonally dry and warm to support species of Quediini .

Comments. The concept of this group is here extended to include Q. compransor [sole member of the compransor group in Smetana (1971a)] and several new species.This group also includes the Palearctic Q.brevis based on the presence of the morphological character states above and its recovered position in Fig. 2 . It is likely that with closer examination of other nidicolous Palearctic Quedius (Microsaurus) , additional members will be added to the erythrogaster group. Based on the recovered topology ( Fig. 2 ), there appears to have been a transition from facultative nidicoly in forests (members of the erythrogaster complex) to more specialized nidicoly in open habitats. Quedius brevis , the sister group to the specialized mammal-associated nidicolous clade, lives in forests with mound-building Formica Linnaeus ants or less commonly in nests of Lasius ( Dendrolasius Rusky ) ants ( Hymenoptera : Formicidae ) (Assing and Schülke 2012).

CHECKLIST OF THE ERYTHROGASTER SPECIES GROUP IN NORTH AMERICA

Erythrogaster complex

Quedius bicoloris Smetana and Webster, 2011 (northeastern North America)

Quedius erythrogaster Mannerheim, 1852 (western North America)

Quedius miltoni Brunke , new species (Rocky Mountains)

Quedius alesi Brunke , new species (eastern North America)

Compransor complex

Quedius pullmani Hatch, 1957 ( northwestern North America , east to southern Indiana)

Quedius compransor Fall, 1912 (prairie regions of United States)

Quedius pinetis Brunke , new species (southeastern United States)

Quedius praticola Brunke , new species (prairie regions of the United States)

Figures

Fig. 1. Habitus of erythrogaster species group members. A) Quedius bicoloris, B) Q. alesi, new species, C) Q. miltoni, new species, D) Q. pullmani, E) Q. praticola, new species, F) Q. compransor, G) Q. pinetis, new species. Arrows indicate abdominal segment VI. Scale bars = 1 mm.

Fig. 3. A) Quedius compransor, hind margin of head, basal puncture close to nuchal ridge, B) Q. pinetis, new species, male abdominal sternites, arrow indicates setose patch of sternite VI, C) Q. compransor, distal antennomeres, D) Q. praticola, new species, distal antennomeres, E) Q. compransor, detail of pronotal microsculpture, F) Q. pinetis, new species, detail of pronotal microsculpture. Scale bars: A–B = 1 mm; C–F = 0.5 mm.

Fig. 8. Distributions of erythrogaster species group. A) Quedius bicoloris, B) Q. erythrogaster (circles), Q. miltoni, new species (pink triangles), Q. alesi, new species (blue squares), C) Q. pullmani, D) Q. praticola, new species (pink triangles), Q. compransor (circles), Q. pinetis, new species (blue squares).

Fig. 2. Fifty percent majority rule consensus tree from an unpartitioned Bayesian phylogenetic analysis of the “barcoding” region of COI. Posterior probability, SH-aLRT, and ultrafast bootstrap values, respectively, to the left of the corresponding node. Nodes colored as: green, PP ≥ 0.90, and either SH-aLRT ≥ 80 or UFB ≥ 95; yellow, one of PP ≥ 0.90, SH-aLRT ≥ 80, or UFB ≥ 95; red, PP <0.90, SH-aLRT <80, and UFB <95. Inset photo: Quedius alesi, new species.