Triomicrus hamus 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 : 520-521

Triomicrus hamus Shen and Yin , new species

( Fig. 10 )

Type material (2 ♂♂, 2 ♀♀). Holotype: China: ♂, labeled ‘ China: W. Jiangxi Province, Luxi County (芦溪县), Wugong Shan (武功山), 27°27’53’’N, 114°10’47’’E, mixed forest, leaf litter, wood sifted & beating, ca. 1570 m, 27.x.2013, Peng, Shen & Yan leg.’ ( SNUC). Paratypes: China: 1 ♂, same data as holotype ( SNUC); 2 ♀♀, also from Wugong Shan, ‘ 27°27’59’’N, 114°09’54’’E, mixed forest, leaf litter, wood sifted & beating, ca. 1050 m, 28.x.2013, Peng, Shen & Yan leg.’ ( SNUC).

Diagnosis. Antennomere XI with impression in median region surrounding disc-like protuberance, slightly prominent. Head lacking median vertexal carina. Pronotum relatively smooth. Elytral subhumeral sulci short, barely reaching half of elytral length. Profemora simple, protrochanters lacking spine, protibiae with distinct preapical denticle, mesotibiae lacking denticle. Apical lamina of abdominal sternite VII strongly transverse, pointed at apex of lateral margin. Aedeagus with right paramere curved mesally, internal sac bearing several sclerotized spines and densely hairy sclerite.

Description. Male ( Fig. 10 A). Length 2.31–2.39 mm. Head longer than wide, HL 0.54–0.55 mm, HW 0.45– 0.46 mm, lacking median vertexal carina; lateral portions of frons finely and sparsely punctate; each eye composed of about 34 facets. Antennomere XI ( Fig. 10 B–C) with impression in median region surrounding disc-like protuberance, slightly prominent, diameter of impression about three-fifths of segmental length. Pronotum wider than long, PL 0.49–0.50 mm, PW 0.53–0.55 mm, relatively smooth. Profemora simple, protrochanters lacking spur, protibiae with distinct preapical denticle ( Fig. 10 D), mesotibiae lacking denticle. Elytra wider than long, EL 0.85–0.87 mm, EW 0.88–0.90 mm, smooth; subhumeral sulci short, barely reaching half of elytral length. Abdomen wider than long, AL 0.44–0.46 mm, AW 0.79–0.81 mm; abdominal tergite IV (first visible tergite) with discal carinae extending to three-fifths of tergal length; abdominal sternite VII modified ( Fig. 10 E), with apical lamina strongly transverse, pointed at apex of lateral margin. Length of aedeagus ( Fig. 10 F) including parameres 0.37 mm, with right paramere curved mesally, internal sac bearing several sclerotized spines and densely a hairy sclerite.

Female. Similar to male; antennomere XI and protibiae unmodified. Each eye composed of about 19 facets. Measurements: BL 2.18–2.30 mm, HL 0.53–0.54 mm, HW 0.43–0.45 mm, PL 0.46–0.48 mm, PW 0.51–0.53 mm, EL 0.78–0.82 mm, EW 0.85–0.90 mm, AL 0.43–0.45 mm, AW 0.79–0.80 mm.

Distribution. Eastern China: Jiangxi.

Etymology. The specific epithet ‘ hamus ’ means ‘a hook, spike’, referring to the shape of the apical lamina of sternite VII.

Figures

FIGURE 10. Diagnostic characters of Triomicrus hamus, male. A. Habitus. B. Antennal club, in dorsal view. C. Same, in lateral view. D. Protibia in dorsal view. E. Abdominal sternites VII – VIII. F. Aedeagus, in dorsal view. Scale bars: A = 0.5 mm; B, C = 0.2 mm; D – F = 0.1 mm.