Priochirus (Eutriacanthus) curticornis, Wu & Zhou, 2007

Wu, Jie & Zhou, Hong-zhang, 2007, Taxonomy Of The Subgenus Eutriacanthus Jakobson, Of The Genus Priochirus Sharp, From Southern China, With The Description Of Two New Species From Guangxi And Yunnan (Coleoptera: Staphylinidae: Osoriinae), Raffles Bulletin of Zoology 55 (2), pp. 267-276 : 268-269

Priochirus (Eutriacanthus) curticornis , new species

( Figs. 1 , 2)

Material examined. – Holotype: male, China, Guangxi, Langping , 1400 m, 1 Jun.2002, Guofang Jiang coll. ( IOZ-CAS) . Paratype: 1 female, same data as holotype ( IOZ-CAS) .

Description. – Body moderately depressed.Antennae brown; head, pronotum and elytra black; legs black, tarsi red-brown; abdomen black, 8th segment slightly dark red.

Head transverse ( Fig. 1 ), almost parallel-sided, frontal angle weakly convex behind lateral teeth; frontal impression about 2.5 times as wide as median length, posterior margin slightly rounded; median tooth bluntly projecting, slightly shorter than two lateral teeth, base distinctly convex and weakly contracted behind anterior margin; lateral teeth pointed and divergent anteriorly, lateral face with 5 or 6 setae turning upward, medial face with row of setae extending onto anterior margin; median sulcus deep, scarcely connected with frontal impression, gradually broadened backwards, posterior end almost as wide as middle width of median longitudinal sulcus on pronotum; vertex smooth, with some scattered punctures and setae along lateral and postero-lateral margin; posterior margin near posterior end of sulcus, with distinct fovea bearing 3 or 4 setae; clypeus short and declivous anteriorly, its anterior margin almost truncate. Eyes glabrous and distinctly convex, longitudinal diameter at most as long as 1/2 length of head.

Mandible moderately protruding, anterior half strongly bent, with row of setae along lateral margin, dorsal tooth short and blunt, apically curved inwards, medial face of first ventral tooth distinctly convex. Mentum trapeziform and setose, anterior margin truncate, median tooth pointed and broadened at base, lateral margin convex, with two distinct transverse ridges, anterior ridge moderately convex laterally and moderately depressed in middle, posterior ridge less convex, gradually indistinct mediad (Fig. 2).

Antennae almost reaching shoulder of elytra posteriorly; 1st segment baculiform, emarginate at apex; 2nd segment smallest and slightly transverse; 3rd segment elongate and narrowed at base, about 2.5 times as long as 2nd; 4th segment longer than wide; 5th and 6th segments slightly quadrate; 7–10th segments transverse; 11th segment slightly elongate, apically rounded, about 1.8 times as long as 10th.

Pronotum wider than long, anterior margin weakly bisinuate, sides distinctly convergent anteriorly, posterior margin slightly protruding backwards in middle; surface smooth with fine coriaceous sculptures; median longitudinal sulcus deep, widest in middle, not reaching both anterior and posterior margins; disc on each side of sulcus with indistinct puncture; marginal area with some scattered, coarse setiferous punctures, especially dense at posterior angle; lateral line continuing along posterior margin and reaching basal line. Mesoscutellum heart-shaped, smooth and shiny.

Protibiae lateral with 13–16 denticles, which gradually become shorter basally, dorsal side with indistinct spine close behind apical spur, slightly shorter and thicker than other erect dorsal setae. Middle and hind tibiae densely setose.

Elytra slightly longer than wide, humeri rounded, sides slightly convex along posterior 1/3, combined posterior margins shallowly emarginate; surface glabrous with dense micropunctuations; base and sides with dense setae of various length.

Abdomen cylindrical, broadened posteriorly and widest at 7th segment; all segments, except 8th, narrowed at base; surface with moderately dense, mostly long and erect setae, which are relatively denser at lateral sides; punctures small, especially denser in basal half of tergites, with longitudinal glabrous region in the middle.

Measurements. – Body length: 12.0–13.0 mm. HL: 0.78 mm; HW: 1.69 mm; PL: 1.95 mm; PW: 2.65 mm; EL: 2.47 mm; EW: 2.34 mm (n = 2).

Etymology. – The species name is derived from the combination of the Latin words “ curtus ” (meaning “short”) and “ cornis ” (meaning “corn-like”) to indicate the short median tooth on the anterior margin of frontal impression, characteristic to this species.

Remarks. – This new species is similar to P. (E.) unicolor , but may be distinguished from the latter by the smaller body size and anteriorly convergent sides of pronotum.

Distribution. – China (Guangxi).

Figures

Figs. 1 and 2. Priochirus (Eutriacanthus) curticornis, new species: 1, head and pronotum, dorsal view; 2, mentum. Scale bars: (Fig. 1) = 1.00 mm; (Fig. 2) = 0.25 mm.