Erymus dalianus Bordoni, 2006

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 : 529-532

3. Erymus dalianus Bordoni, 2006

( Fig. 1 C; 5A–G)

Bordoni, 2006: 19

(Type locality: China, N-Yunnan, Dali Bai Nat. Aut. Pref, 1 km W Dali old town, creek valley at toothill of Diancang Shan, 25.41N, 100.08E); Bordoni, 2011: 429 (Yunnan); Bordoni, 2012a: 429 (Dali Bai Aut. Pref., Mao Jiao Shan).

Material examined: “ PARATYPUS, Erymus , dalianus sp. n., Bordoni det. 2004”/ “ CHINA (N-Yunnan) Dali Bai Nat., Aut. ‘Pref., 1 km W Dali old town,’, creek valley at foothill of Dian-, cang ‘Shan, 2170m, ‘25°41.9´N/’, 100°08.4´E (ruderal place), 28.VIII. / 1.IX. / 3.IX.2003 Wrase [18].” (CS) ; CHINA: Hainan: Ledong co.: Jianfeng Ling (E 108.8792, N 18.7211), 3 males, 6 females, 1 ex., 970 m, 16.VII.2004, Wu Jie & Chen Yongjie collectors ; one male, 6 females, same data as above, except 940 m ; one female, same locality as above, except 800 m, 24.VII.2004 ; 3 males, 8 females, same data as above, except 900 m, 16.VII.2004 ; one male, 1 ex., same data as above, except 700 m, 24.VII.2004 ; 4 males, 6 females, same data as above, except 1000 m, 17.VII.2004 ; one male, 2 females, same data as above, except 1050 m, 18.VII.2004 ; 7 males, one female, same data as above, except 1010 m, 18.VII.2004 ; Wuzhishan City (E 109.5169, N 18.7751), one female, 790 m, 11.VII.2004, Wu Jie & Chen Yongjie collectors ; Sichuan: Baoxing co.: Longdong town, Ganyang Gou (E 102.1366, N 29.6727), one male, 1796 m, 12.VIII.2003, Yu Xiaodong collector ; 2 females, same data as above, except 1795 m ; Dengchi Gou (E 102.9294, N 30.5262), one female, 1700 m, 22.VIII.2003, Zhou Hongzhang collector ; Genda co.(E 103.3070, N 31.0913), one female, 1630 m, 5–8.V.2004, Yu Xiaodong collector ; one female, same data as above, except 8–11.V.2004 ; Zhejiang: Lanao co.: Fengyang Shan: Datianpin (E 119.1725, N 27.9066), one female, 1290 m, 04.VIII.2008, Zhou Yulingzi collector ; Fengyang Shan: Daxiagu, one female, 1400 m, 28.VII.2007 ; 2 females, same locality as above, 1400 m, 28–31.VIII.2007, Zhao Zongyi collector ; 2 males, one female, same data as above, except Zhao Zongyi & Yang Zhuo collectors ; Pingyang co.: Linan: Shunxi (E 118.9425, N 30.0507), one female, 400 m, 09.VIII.2008, Zhou Yulingzi collector ; Guangxi: Napo co.: Nianjin Village (E 105.8816, N 22.9474), one male, 910 m, 11.IV.1998, Zhou Haisheng collector ; Yunnan: Mengla co.: Longmen village: Xiaoniupeng (E 101.3252, N 21.3095), one male, 1010 m, 07.X.2010, Zhou Yulingzi collector ; Hubei: Muyu co.: Shennongjia (E 110.6804, N 31.7435), one female, 20.IX.2005, Chen Yongjie collector (IZ-CAS).

Description. Measurements. BL= 3.80–4.04 mm, FL= 2.06–2.29 mm, HL= 0.60–0.66 mm, HW= 0.47–0.51 mm, PL= 0.68–0.76 mm, PW= 0.44–0.47 mm, EL= 0.68–0.78 mm, EW= 0.58–0.75 mm.

Body nearly cylindrical, small-sized. Head and abdomen dark brown, except last abdominal segment brown; pronotum, elytra and antennae brown, except scape darker; maxillary and labial palpi and legs yellowish. In some specimens body entirely brown or dark brown.

Head ( Fig. 1 C). Subrectangular (HL to HW ratio 1.3), in some specimens more elongate, tempora parentheseslike, posterior angles rounded. Dorsal integument extensively bearing micropunctures, without any microsculpture; median longitudinal region (of the width ≈ 0.09 mm) smooth, without punctures, other surface (posterior half of head and temporal region) with deep and medium sized punctures, distance between punctures about the combined diameter of 3–4 punctures; deflexed portion of tempora with sparsely-scattered tiny punctures. Each side of cranium with anterolateral puncture near antennal insertion, midlateral puncture adjacent to dorsal margin of eye. Frontal furrows deep and long, fused with two paired tiny punctures, reaching line connecting midth of each eye. Anteocular furrows indistinct. Eyes large, distinctly longer than half length of tempora (eye: tempora = 0.19: 0.30 mm), distinctly protruding laterad. Epistoma subrectangular, surface elevated. Distance between antennal insertions 0.14 mm, longer than distance from antenna to eye (0.10 mm).

Antennae. Scape stout, thickened apically, subequal to length of four subsequent antennomeres combined, 0.23 mm; antennomere II elongate, 0.08 mm; III spherical, much shorter than II, 0.05 mm; IV and V wider and shorter than III, subequal in length of 0.04 mm; last antennomere medium in length, 0.14 mm, subequal to length of two preceding antennomeres combined.

Neck. Medium width (0.18 mm), slightly wider than 1/3 of head width.

Pronotum ( Fig. 1 C). Subrectangular, distinctly elongate (PL to PW ratio 1.6), longer but narrower than head. Widened anteriad, lateral margins sinuate, anterior angles rounded, posterior angles broadly rounded, with widest at anterior 1/3 and narrowest at posterior 1/3. Dorsal surface on each side with medial row of 5–7 punctures, a lateral row of 5–6 punctures, and a few irregular punctures near anterior margin.

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

Elytra ( Fig. 1 C). Subrectangular, elongate (EL to EW ratio 1.2), the same length of pronotum, but distinctly wider. Humeri well-developed, lateral margins distinctly dilated outwards, hind margin distinctly rounded. Integument glossy, flattened, without microsculpture, each side with 2–3 rows of smaller punctures along median suture, a row along midwidth, and also with 1–2 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 polygonal reticulum, but without punctures. All abdominal sternites glossy, with microstriae and punctures as those on tergites.

Male ( Fig. 5 A–G). Abdominal segment VIII entirely covered with setiferous punctures, posterior margin of both tergite and sternite subtruncated ( Fig. 5 A, B). Tergite IX symmetrical, connected mediobasally. Sternite IX asymmetrical, broadest near middle, with linear-shaped base and rounded apex ( Fig. 5 C). Tergite X symmetrical, lateral margins of varied shape, base sharp-pointed and apex slightly emarginated ( Fig. 5 D–E). Aedeagus elliptical, anterior portion missing, apical margin slightly arcuate ( Fig. 5 F–G), bulbus small, 0.24 mm long. Parameres symmetrical and curved, distinctly thinner apically and thicken basally, 0.21 mm. Internal sac entirely membranous and variably shaped, without any visible sclerotized structures.

Distribution. China (Yunnan, Hainan, Sichuan, Zhejiang, Guangxi, Hubei).

Remarks. This species is distinguished from its congeners by the combination of the following characters: body color darker, number of punctures in admedian row of pronotum, male sternite IX and aedeagus.

Figures

FIGURE 1. Forebody: A. Erymus gilvus sp. n.; B. E. wufengensis sp. n.; C. E. dalianus Bordoni. Scale bars 0.30 mm.

FIGURE 5. Erymus dalianus Bordoni: A. male tergite VIII; B. male sternite VIII; C. male sternite IX; D, E. male tergite X; F. aedeagus, dorsal view; G. aedeagus, ventral view. Scale bars 0.15 mm.