Brachygluta (Brachygluta) shawnee Chandler

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 : 31-33

9. Brachygluta (Brachygluta) shawnee Chandler , sp. n.

( Figs 11 , 37 B)

Material examined, 9 specimens. HOLOTYPE male: USA: Maryland: Montgomery Co.: // at light/ Plummers Id., 28.V.14 Md./ R.C. Shannon/ [red label] HOLOTYPE Brachygluta shawnee Chandler // ( USNM). PARATYPES, 8, all males: USA: Alabama: Jefferson Co.: Vestavia, VII-18-1981, T. King, at light ( FMNH, 1). Walker Co.: Jasper, Devils Ladder, V-27-1979, T. King, at light ( FMNH, 1). District of Columbia: D.C., ♂, Brend, Horn Coll H1919 ( MCZC, 1); D.C. ( CMNH, 1). Georgia: Clarke Co.: Whitehall Forest, 7-14 Aug. 1978, R. Turnbow, bl trap ( DSCC, 1). Indiana: Knox Co.: 6-28-1946, Plot 10, S.A. Summerland Coll./ LSAM 0 267298 ( LSAM, 1). Ohio: Vinton Co.: 72660 Gambill Hollow Rd., Albany, 2.27 km West of Rt. 356, 6.5 km SE Zaleski, 39 15.218N, 82 19.641W, 30-July to 06-August-2011, K. D. Karns/ flight intercept trap, north facing slope, upland hardwood beech, oak, buckeye ( DSCC, 1). Virginia: Henrico Co.: 4 km upstream from Bottoms Bridge, Chickahominy River, VII-4-1999, I.T. Wilson, UV trap ( DSCC, 1).

Description. BODY: Length 1.88–2.10 mm; brown to dark brown, elytra orange to red-brown; setae short, decumbent. Head: surface smooth, shining, punctures indistinct; setose are of median vertexal fovea slightly smaller than those of lateral foveae. Antennomeres III–VI longer than wide, VII about as long as wide, VIII-X transverse; VIII two-thirds width of IX ( Fig. 11 C). Pronotum: surface smooth, shining, punctures indistinct. Setose area of median antebasal fovea slightly smaller than those of lateral antebasal foveae. Elytra: surface smooth, shining to opaque where faintly microreticulate on much of elytral disc, discal stria extending to about four-fifths of elytral length. Abdomen: surface with small distinct punctures, punctures denser in apical half; tergite 1 with divergent basal striae extending about half length of paratergite, basal striae separated by about two-fifths basal width of tergite 1, setose brush between bases of striae short.

MALE: Antennae and trochanters lacking modifications. Metaventrite with semicircular patch of denser setae between bases of metatrochanters present but indistinct. Usually only tergites 1–2 visible in dorsal view ( Fig. 11 A), tergite 1 twice length of 2; tergite 1 broadly and shallowly emarginate at apex, with broad hyaline lamina at middle, lamina apex emarginate, setal fringe along tergite apex densest by lamina; tergite 2 with deep narrow impression at base, impression extending to tergite apex in middle third, flanked by prominent rounded ridges, with band of golden setae between bases of ridges and ventral to lamina ( Fig. 11 B); in lateral view outline of tergites 1–2 confluent. Abdominal ventrites broadly convex. Metatibiae narrow basally, slightly widening through length to apex, with dense comb of setae on mesal margin in apical fifth where slightly curved medially ( Fig.11 D). Aedeagus 0.30 mm long; with dorsal plate elongate, slightly asymmetrical, with short hook at apex; parameres with three thin setae at posterior margin of preapical constriction, hyaline setae small, flattened, widest at middle and gradually tapering to acute point; internal sac with one large curved spine ( Fig. 11 E).

FEMALE: unknown. The female is expected to have long basal discal striae on tergite 1.

Collecting data. The specimens were either taken by light or ultraviolet light (4), or with a flight intercept trap in an upland deciduous forest (1). Collected from May to August.

Distribution ( Fig. 37 B). This uncommon species is widely distributed through the eastern United States from Ohio to Maryland and Georgia; it does not occur in the Atlantic coastal marshes.

Comments. The relatively simple structure of the male abdominal tergites is shared with B. belfragei , with the disc of tergite 1 lacking dorsally projecting lobes, with a median emargination at the apex, and tergite 2 having a deep basal transverse sulcus. These two may be separated by B. shawnee being more densely punctate and having a more opaque body surface; the presence of a broad hyaline lamina at the posterior margin of the emargination of tergite 1; and tergite two having lateral setose lobes. Brachygluta belfragei has sparse punctures on the abdominal tergites with a more glabrous body surface, the hyaline lamina in the emargination of tergite 1 is narrower, and tergite 2 is smoothly convex and glabrous laterally.

Etymology. The name is that given to an American Indian tribe that was active within the range of this species.

Figures

FIGURE 11. Brachygluta shawnee Chandler (Virginia, Henrico Co., paratype). A: Abdomen, dorsal view. B: Abdomen, caudal view. C: Right antenna. D: Left metatibia, anterior view. E: Aedeagus.

FIGURE 37. Distribution map of Brachygluta abdominalis species-group. A: Brachygluta belfragei (LeConte). B: Brachygluta shawnee Chandler.