Triomicrus cavus Shen and Yin

Shen, Jia-Wei, Yin, Zi-Wei & Li, Li-Zhen, 2015, Six new species of Triomicrus Sharp from southern China (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 4044 (4), pp. 585-595 : 587-588

Triomicrus cavus Shen and Yin , new species

( Fig. 2 )

Type material (4 ♂♂, 3 ♀♀). Holotype: China: ♂, labeled ‘ China: Guangxi, Jinxiu County (A), ‘16 km’, 24°08’11’’N, 110°14’28’’E, Rhododendron forest, leaf litter, sifted, 960 m, 25.vii.2014, Peng, Song, Yu & Yan leg.’ ( SNUC). Paratypes: China: 1 ♂, same data as holotype ( SNUC); 2 ♂♂, 2 ♀♀, labeled ‘ China: Guangxi, Jinxiu County, ‘16 km’, 24°08’25’’N, 110°15’38’’E, beech forest, mixed leaf litter, humus, sifted, 960 m, 13.vii.2014, Peng, Song, Yu & Yan leg.’ ( SNUC); 1 ♀, labeled ‘ China: Guangxi Prov., Jinxiu County, Laoshan (+ M), 7 km, 22.vii.2011, 1200–1400 m, Zhong Peng leg.’ ( SNUC).

Diagnosis. Antennomere XI with large impression surrounding slightly prominent, disc-like protuberance near base. Head with median vertexal carina. Pronotum sparsely punctate. Elytral subhumeral sulci absent. Profemora simple, protrochanters and protibiae lacking protuberance, mesotibiae lacking spur. Apical lamina of abdominal sternite VII narrowed near base, widest near middle. Aedeagus with right paramere curved mesally, internal sac bearing several sclerotized spines and several hairy sclerites.

Description. Male ( Fig. 2 A). Length 1.84–1.93 mm. Head longer than wide, HL 0.41–0.44 mm, HW 0.40– 0.41 mm, with median vertexal carina; lateral portions of frons sparsely punctate; each eye composed of about 28 facets. Antennomere XI ( Fig. 2 B, 2C) with large impression surrounding slightly prominent disc-like protuberance located near base, diameter of impression slightly more than two-fifths of segmental length. Pronotum wider than long, PL 0.40–0.41 mm, PW 0.48–0.49 mm, finely and sparsely punctate. Profemora simple, protrochanters and protibiae lacking spur, mesotibiae lacking spur. Elytra wider than long, EL 0.65–0.68 mm, EW 0.73–0.75 mm, smooth; subhumeral sulci absent. Abdomen wider than long, AL 0.38–0.43 mm, AW 0.70–0.71 mm; abdominal tergite IV (first visible tergite) with discal carinae extending to three-fifths of tergal length; abdominal sternite VII modified ( Fig. 2 D), with apical lamina narrowed near base, widest near middle, posterior margin obliquely narrowed. Length of aedeagus ( Fig. 2 E) 0.33 mm, right paramere curved mesally, internal sac bearing several sclerotized spines and several hairy sclerites.

Female. Similar to male; antennomere XI unmodified. Each eye composed of about 16 facets. Measurements: BL 1.74–1.81 mm, HL 0.38–0.40 mm, HW 0.38–0.40 mm, PL 0.38–0.43 mm, PW 0.45–0.48 mm, EL 0.64–0.65 mm, EW 0.70–0.73 mm, AL 0.33–0.38 mm, AW 0.71–0.75 mm.

Distribution. Southern China: Guangxi.

Etymology. The specific epithet ‘ cavus ’ in Latin means ‘having a hole, depression’, referring to the relatively large impression of the antennomere XI.

Figures

FIGURE 2. Diagnostic characters of Triomicrus cavus, male. A. Habitus. B. Antennal club, in dorsal view. C. Same, in lateral view. D. Abdominal sternites VII – VIII. E. Aedeagus, in dorsal view. Scale bars: A = 0.5 mm; B, C = 0.2 mm; D, E = 0.1 mm.