Erymus paramerum Bordoni, 2005

Zhou, Yu-Lingzi & Zhou, Hong-Zhang, 2014, Taxonomy of the genus Erymus Bordoni (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) in China with descriptions of two new species, Zootaxa 3814 (4), pp. 521-536 : 533-534

5. Erymus paramerum Bordoni, 2005

( Fig. 2 B)

Bordoni, 2005a: 10

(Type locality: China, Sichuan, Bao Xing Co., Tibet Autonl Unit. Yaoji, QingYi River).

Material examined: “ HOLOTYPUS, Erymus , paramerum sp. n., Bordoni det. 2004 ”/ “‘ CHINA, Sichuan Prov.,’ Bao, xing ‘Co. ,’ Tibet Auton Unit .,/ Yaoji ; Qing Yi River 1750m, elev.; 16.viii.1995. R.E., Roughley coll.” ( NMW).

Description. Measurements. BL= 7.53 mm, FL= 4.50 mm, HL= 1.29 mm, HW= 1.08 mm, PL= 1.60 mm, PW= 0.92 mm, EL= 1.38 mm, EW= 1.31 mm.

Body nearly cylindrical, medium sized. Body entirely brown, except elytra darker and apical 1/3 of last antennomere yellowish. Maxillary and labial palpi light brown.

Head ( Fig. 2 B). Elongate (HL to HW ratio 1.2), tempora not parentheses-like, widened posteriorly, posterior angles rounded. Dorsal integument extensively bearing obvious transverse microstriae, and densely punctate except a narrow median longitudinal strip impunctate, distance between punctures about a puncture’s diameter; deflexed portion of tempora with 2–3 rows of tiny punctures. Anterolateral puncture (near antennal insertion) and midlateral puncture (adjacent to dorsal margin of eye) missing. Frontal furrows deep and long, fused with two paired tiny punctures, overpassing line connecting midth of each eye. Anteocular furrows long and visible. Eyes small, nearly 1/4 of tempora length (eye: tempora = 0.23: 0.92 mm), slightly protruding laterad. Epistoma relatively broad and subrectangular, surface flattened. Distance between antennal insertions 0.39 mm, longer than distance from antenna to eye (0.23 mm).

Antennae. Scape stout, thickened apically, shorter than length of four subsequent antennomeres combined, 0.58 mm; antennomere II elongate, 0.18 mm; III elongate, distinctly longer than II, 0.23 mm; IV and V wider and shorter than III, subequal in length of 0.05 mm; last antennomere medium in length, 0.23 mm, subequal to length of two preceding antennomeres combined.

Neck. Medium width (0.39 mm), slightly wider than 1/3 of head width.

Pronotum ( Fig. 2 B). Subrectangular, distinctly elongate (PL to PW ratio 1.7), distinctly longer and narrower than head. Not widened anteriad, lateral margins straight, anterior angles rounded, posterior angles broadly rounded. Dorsal surface extensively bearing micropunctures, without any microsculpture. Each side bearing 5–6 rows of punctures, interspace between rows nearly the diameter of 2–3 punctures.

Mesoscutellum. Glossy, without any microsculpture, and with a pair of small punctures at apical 1/3.

Elytra ( Fig. 2 B). Subquadrate (EL to EW ratio 1.1), distinctly shorter and wider than pronotum. Humeri welldeveloped, lateral margins distinctly dilated outwards, hind margin distinctly rounded. Integument glossy, flattened, without microsculpture, each side bearing numerous rows of punctures, interspace between rows nearly a puncture’s diameter, and also with 3–4 rows on deflexed portion.

Abdomen. Cylindrical, broadest at segment VI. Tergites III–VII glossy, each segment covered with distinct transverse microstriae, also with small scattered punctures, interspaces between punctures approximately the diameter of 2–3 punctures, and punctures distinctly denser on tergites VI and VII. Each tergite with a shallow basal impression near anterior margin; surface between two basal transverse carinae glossy, covered with transverse microstriae and sparsely-scattered punctures. All abdominal sternites glossy, with microstriae and punctures as those on tergites.

Distribution. China (Sichuan).

Remarks. Although the stout and long parameres conform to the type of the genus Erymus , it is yet very special one compared to its congerners and may form an isolated group in the future, for its following characteristics: 1) body brown; 2) irregular- and dense-distributed punctuation on body surface; 3) antennomere II distinctly shorter than III; 4) head with microsculpture; 5) male sternite IX more developed; 6) basal bulb not ovoid-shaped, with well-developed pressure plate (cf. Bordoni, 2005: 10).

Figures

FIGURE 2. Forebody: A. Erymus gracilis (Fauvel); B. E. paramerum Bordoni; C. E. sinicus Bordoni. Scale bars 0.30 mm.