Brachygluta Thomson, 1859

Chandler, Donald S., Sabella, Giorgio & Bückle, Christoph, 2015, A revision of the Nearctic species of Brachygluta Thomson, 1859 (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 3928 (1), pp. 1-91 : 7-8

Brachygluta Thomson, 1859

Bryaxis (of authors, not North American; not Leach, 1817 nor Kugelann, 1794). Brendel 1865a: 29; 1866a: 33; 1866b: 194 (discussion of female characters of 7 species); 1888a: 300; 1888b: 261. Brendel & Wickham 1890: 225, 267 (key). LeConte 1861: 57; 1863: 21; 1880: 181 (key). LeConte & Horn 1883: 88. Blatchley 1910: 318 (key).

Bryaxis (Bryaxis) : Brendel & Wickham 1890: 267.

Brachygluta Thomson, 1859: 54 . Type-species: Pselaphus fossulatus Reichenbach (orig. design.). Casey 1886: 182; 1908: 259. Raffray 1904: 218; 1908: 196, 228; 1911: 90. Leng 1920: 130. Bowman 1934: 77, 82 (key to groups and species). Park 1953: 307, 314. Arnett 1963: 317, 322. Newton & Chandler 1989: 42. Chandler 1990: 1184; 1997: 54; 2000: 293, 350; 2002: 53, 68, 87. Davies 1991: 128. Downie & Arnett 1996: 580 (key). Poole & Gentili 1996: 380. Bousquet et al. 2013 (checklist for Canada).

Nisa Casey, 1886: 182 . Type-species: Bryaxis cavicornis Brendel (design. by Newton and Chandler 1989). Raffray 1904: 218 (synonymy).

Reichenbachia (Brachygluta) : Ganglbauer 1895: 807.

Bryaxis (Nisa) : Brendel & Wickham 1890: 267 (key). Raffray 1890: 118, 124. Casey 1894: 477.

The morphology of this genus was covered in depth by Sabella et al. (2004). The following text provides a brief characterization of the Nearctic taxa of the genus.

Body: light to dark brown, setae on head and pronotum short, curved and suberect, setae over rest of body usually longer and varying from suberect to appressed, but usually decumbent, setae often modified in areas of male modifications.

Head: longer than wide across eyes, or about as long as wide. Eyes large, tempora short and rounded, usually about half length of eyes. Large median and lateral vertexal foveae present and setose, median fovea may be weak or absent in Nisa , distance between foveae subequal. Eleven antennomeres, antennal clubs modified in Nisa and one species in the dentata species-group has the intermediate flagellomeres modified. Gular foveae close.

Prothorax: pronotum about as wide as long, slightly wider than head across eyes; with median and lateral antebasal foveae large and setose, median fovea usually slightly smaller, foveae of Nisa smaller than in other species groups; with lateral procoxal foveae widely separated.

Elytra: with two basal and two subbasal foveae, discal stria elongate, extending from lateral fovea about fourfifths elytral length.

Meso- metathorax: mesoventrite with lateral mesosternal foveae large and simple, meeting internally, median mesosternal fovea short, lacking in Nisa ; lateral mesocoxal foveae present; lateral metasternal foveae present.

Legs: with trochanters and metatibiae modified in males of some species; metatibiae with apical brush on mesal margin.

Abdomen: five visible abdominal tergites, for males tergites 1 and/or 2 typically modified, rarely simple, 3–4 modified in some species; ventrite 3 modified in one species; basal discal carinae present, but very short in some species, lacking in some members of Nisa . Visible tergites 1–4 with laterobasal foveae, tergite 1 with small one to two laterobasal foveae; with mediobasal foveae widely separated. Ventrite 1 with laterobasal foveae; ventrite 2 with mediobasal foveae widely separated, meeting internally, lateral basal foveae distinct. Ventrites often broadly rounded in males, flattened medially in a few species; six visible ventrites in both sexes.

Aedeagus: aedeagal form symmetrical or nearly so, with parameres and dorsal plate, parameres with preapical large, flattened, hyaline seta; internal sac with few large spines or shorter complex multidentate spine.