Triomicrus gutianensis Shen and Yin

Shen, Jia-Wei, Yin, Zi-Wei & Li, Li-Zhen, 2015, Triomicrus Sharp of Eastern China (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 4007 (4), pp. 509-528 : 518-520

Triomicrus gutianensis Shen and Yin , new species

( Figs 8–9 )

Type material (14 ♂♂, 13 ♀♀). Holotype: China: ♂, labeled ‘ China: N. Zhejiang, Quzhou City, Gutian Shan N. R. (古 田山), 29°14’45’’N, 118°06’52’’E, mixed leaf litter, sifted, 400–500 m, 19.vi.2013, Zheng & Li leg.’ ( SNUC). Paratypes: China: 4 ♂♂, 6 ♀♀, same data as holotype; 1 ♂, 2 ♀♀, labeled ‘ China: N. Zhejiang, Quzhou City, Gutian Shan N. R., 29°16’04’’N, 118°07’28’’E, mixed leaf litter, sifted, 1200–1240 m, 18.vi.2013, Hu leg.’ ( SNUC); 1 ♂, 2 ♀♀, labeled ‘ China: C. Zhejiang, Zhuji (诸暨), Dongbai Shan (东 白山), 29°29’11’’N, 120°23’54’’E, leaf litter, sifted, 300 m, 20.x.2012, Tie-Xiong Zhao leg.’ ( SNUC); 1 ♂, 1 ♀, labeled ‘ China: S. Zhejiang, Lishui City, Fengyang Shan N. R. (凤阳山), forest nr. Datianping (大田坪), 27°54’33’’-55’18’’N, 119°10’20’’-17’’E, mixed litter, moss, sifted, 1170–1300 m, 06.x.2013, Feng, Peng, Yu & Yin leg.’ ( SNUC); 2 ♂♂, 1 ♀, labeled ‘ China: Zhejiang, Linan City, Qingliangfeng N. R. (清凉峰), 30°06’04’’N, 118°51’45’’E, alt. 1300 m, mixed litter, sifted, 09.viii.2011, Jian-Qing Zhu leg.’ ( SNUC); 4 ♂♂, 1 ♀, labeled ‘ China: Zhejiang, Ningbo City, Tiantong Shan (天童山), 29°47’N, 121°48’E, leaf litter, sifted, 350 m, 26.iv.2009, Ting Feng leg.’ ( SNUC).

Diagnosis. Antennomere XI with impression in median region. Head lacking median vertexal carina. Pronotum finely and sparsely punctate. Elytral subhumeral sulci absent. Profemora simple, protrochanters lacking spine, protibiae with apical protuberance, mesotibiae with apical denticle. Apical lamina of abdominal sternite VII stout, widest near middle, posterior margin obliquely narrowed. Aedeagus with right paramere slightly curved laterally, internal sac bearing several sclerotized spines and a densely hairy sclerite.

Description. Male ( Fig. 8 A). Length 2.18–2.27 mm. Head longer than wide, HL 0.48–0.49 mm, HW 0.43– 0.44 mm, lacking median vertexal carina; lateral portions of frons finely and sparsely punctate; each eye composed of about 34 facets. Antennomere XI ( Fig. 8 B–C) with median impression, diameter of impression about half of segmental length. Pronotum wider than long, PL 0.45–0.48 mm, PW 0.50–0.52 mm, relatively smooth. Profemora simple, protrochanters lacking spur, protibiae with apical protuberance ( Fig. 8 E), mesotibiae with apical denticle ( Fig. 8 F). Elytra wider than long, EL 0.79–0.80 mm, EW 0.85–0.88 mm, finely punctate; subhumeral sulci absent. Abdomen wider than long, AL 0.48–0.52 mm, AW 0.75–0.78 mm; abdominal tergite IV (first visible tergite) with discal carinae extending to three-fifths of tergal length; abdominal sternite VII modified ( Fig. 8 D), with apical lamina stout, widest near middle, posterior margin obliquely narrowed. Length of aedeagus ( Fig. 8 G) including parameres 0.33 mm, with right paramere slightly curved laterally, internal sac bearing several sclerotized spines and densely hairy sclerite.

Female. Similar to male; antennomere XI, protibiae and mesotibiae unmodified. Each eye composed of about 23 facets. Measurements: BL 2.01–2.13 mm, HL 0.46–0.48 mm, HW 0.41–0.43 mm, PL 0.39–0.43 mm, PW 0.49– 0.51 mm, EL 0.73–0.74 mm, EW 0.82–0.85 mm, AL 0.43–0.48 mm, AW 0.75–0.78 mm.

Distribution. Eastern China: Zhejiang.

Etymology. This species is named after the type locality, Gutian Mountain.

Remarks. Although populations from various localities exhibit slight variation in the male sternite VII ( Figs 8 D, 9A–D) and aedeagus ( Figs 8 G, 9E–H), the presence of a large impression on the Antennomere XI, and the apical spur of the protibiae and mesotibiae are stable. Therefore all populations are treated as belonging to the same species.

Figures

FIGURE 8. Diagnostic characters of Triomicrus gutianensis, male. A. Male habitus. B. Antennal club, in dorsal view. C. Same, in lateral view. D. Abdominal sternites VII – VIII. E. Protibia in dorsal view. F. Mesotibia in dorsal view. G. Aedeagus, in dorsal view. Scale bars: A = 0.5 mm; B, C = 0.2 mm; D – G = 0.1 mm.

FIGURE 9. Diagnostic characters of Triomicrus gutianensis, male. from various localities. A. Abdominal sternites VII – VIII (Dongbai Shan). B. Same (Fengyang Shan). C. Same (Tiantong Shan). D. Same (Qingliangfeng). E. Aedeagus, in dorsal view (Dongbai Shan). F. Same (Fengyang Shan). G. Same (Tiantong Shan). H. Same (Qingliangfeng). Scale bars: 0.1 mm.