Paederus xinjiangensis

Li, Xiao-Yan & Zhou, Hong-Zhang, 2009, A review of Chinese species of the subgenus Paederus s. str. (Coleoptera: Staphylinidae: Paederinae) with description of a new species, Zootaxa 2083, pp. 46-64 : 48-51

1. Paederus (s. str.) xinjiangensis Li & Zhou , sp. n.

(Figs. 1A–H)

Type material. Holotype, male, CHINA: Xinjiang Uyghur Autonomous Region: Tekesiyamatu, 850 m, 4.VII.1957, collected by Wang Guang ( IZCAS). Paratype: male, same data as holotype ( IZCAS).

Description. Male. Length: 7.6–8.0 mm; width: 1.4 mm. Length of body parts: HL AL PL ELL = 1.49 1.27 2.67 1.21 mm; width: HW PW ELW ABW = 1.27 1.38 1.11 1.15 mm.

Head black, labrum blackish brown. Mandibles brownish yellow, labial palpi brownish yellow with apex of 3rd segment black. Antennae blackish brown with first two segments and base of 3rd segment brownish yellow. Pronotum and 3rd–6th abdominal segments brownish red, 7th–8th segments black. Scutellum black, elytra blackish blue with metallic shine. Legs brown with coxae brownish yellow, basal 1/3 of femur and dorsal surface of tarsi yellow.

Head rounded, HL/HW = 1.05, lateral margin broadly rounded. Eyes relatively large, slightly protruded laterally. HL/EL = 3.36, diameter of eye longer than gena but shorter than temple (gena eye temple = 0.46 0.36 0.32 mm). Punctation on head irregular, of different size, dense and deep, but denser laterally, even denser and coarser around eyes. All punctures with blackish brown oblique setae of different length. Vertex and middle front smooth and glossy where punctures very sparse. Gular sutures separated; gular plate broad in anterior 1/2, gradually narrowed posteriorly, in posterior 1/2 nearly parallel.

Antennae extending back to basal 1/4 of pronotum; each segment longer than wide, thickened apically, covered with slightly brownish yellow pubescence, and on apex with black setae; ratios of antennomere length (1 to 11) 20 12 13 12 13 13 13 14 19 9.5 19.

Mouthparts: labrum (Fig. 1A) transverse, anterior margin slightly sinuate, medial notch with obtuse and tiny tooth. Mandibles long and robust, apex curved inward, outer surface near base punctured and covered with setae, inner margin with one bicuspidate tooth, behind it with corneous notch (Fig. 1B).

Pronotum nearly oviform, PL/PW = 1.14, widest in apical 2/3, anterolateral margin broadly rounded and posterolateral margin relatively straight. Disc very convex, longitudinal median area smooth and glabrous, lateral areas covered with sparse and small setiferous punctures, slightly denser laterally. Mesoventrite blackish brown, relatively broad, slightly concave, punctures very large and dense, slightly sparser laterally, pubescence slightly yellow, lateral part with several longitudinal grooves, where punctures sparse and fine. Metaventrite black and broad, broadly convex, surface with dense but fine setiferous punctures, middle of posterior part with a longitudinally elliptical and shallow groove, the groove gradually tapered anteriorly.

Scutellum U-shaped, longer than broad, surface lacking luster and with reticulate microsculpture and punctation, pubescence brownish yellow.

Elytra nearly parallel, ELL\ELW = 1.20, ESL/ELL = 0.78. Humeral angles well developed, posterior margin slightly sinuate. Punctures on elytra larger and denser than on head or pronotum, arranged irregularly, intervals between punctures slightly smaller than diameter of a puncture, each puncture with an oblique brown seta. Hind wings well developed.

Legs long, covered with brownish yellow macrosetae. Protarsi broadened, and first four segments gradually narrowed from 1st to 4th. Both meso- and metatarsi with basal four segments gradually shortened from 1st to 4th segments.

Abdomen elongate, widest at 6th (4th visible) segment, where wider than head or pronotum but distinctly narrower than elytra. Setiferous punctures on tergites fine and dense, denser laterally, base of each tergite with the same punctuation as more posterior area of tergite. Punctures on sternites finer and denser than on tergites. 7th sternite in posterior part with shallow depression, posterior margin slightly emarginated. 8th sternite (Fig. 1E) with hind margin deeply notched, notch slightly shorter than half of segment length, notch bottom relatively narrow and round, inner sides parallel. 9th sternite (Fig. 1C) with medial line near base.

Aedeagus (Figs. 1F–H) thick and symmetrical, length/width = 2.86. Median lobe (excluding dorsal plate) nearly longitudinally elliptical, short and thick, basal part bulgy and relatively straight laterally, apex obtusely pointed. Dorsal plate of median lobe irregular, its apex projected beyond apex of ventral plate but slightly not reaching apex of parameres; basal margin of dorsal plate slightly concave, lateral margin broadly rounded and gradually narrowed apically, apex thin and acute, slightly curved ventrally. Internal armature (Figs. 1F–G) with 4 strongly sclerotized thorns, each thorn slightly curved.

Remarks. The new species is similar to P. parallelus , but the labrum shape is different: in P. xinjiangensis the labrum has a distinct notch in the middle of the anterior margin (Fig. 1A) (absent in P. parallelus (Fig. 3A)). In addition, the new species has much broader parameres and more complex internal armature of the aedeagus than P. parallelus . Compared with P. riparius , a European species, the new species has more thorns in the internal armature (Figs. 1F–G) than P. riparius (cf. Coiffait, 1982: 37, Figs. 9B–D). In addition, in the two species the shape of anterior margin of the labrum is different, particularly in the shape of protrusions and the medial notch. The new species can be easily distinguished from other species of subgenus Paederus s. str. by a distinct shape of the aedeagus and labrum.

Distribution. China (Xinjiang).

Etymology. The specific epithet refers to the type locality, Xinjiang Uyghur Autonomous Region.

FIGURES 1A–H. Paederus xinjiangensis Li & Zhou , sp. n., holotype, male from Xinjiang, China. A—labrum; B—right mandible; C—9th sternite; D—8th tergite; E—8th sternite; F—aedeagus, dorsal view; G—aedeagus, ventral view; H—aedeagus, lateral view. Scale bar 0.5 mm.

FIGURES 2A–K. Paederus coxalis Fauvel , syntypes, male and female from Burma. A—labrum, male; B—labrum, female; C—right mandible, male; D—right mandible, female; E—8th sternite, male; F—9th sternite, male; G—8th sternite, female; H—9th sternite, female; I—aedeagus, dorsal view; J—aedeagus, lateral view; K—aedeagus, ventral view. Scale bar 0.5 mm.