Triomicrus anfractus 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 : 512-515

Triomicrus anfractus Shen and Yin , new species

( Figs 3–4 )

Type material (12 ♂♂, 6 ♀♀). Holotype: China: ♂, labeled ‘ China: Zhejiang, Anji County, Longwang Shan N. R. (龙王山), Dongguan-Qianmutian (千亩田), 30°24’17’’N, 119°26’37’’E, mixed leaf litter, sifted, alt. 1050–1250 m, 08.vi.2012, Jia-Yao Hu & Zi-Wei Yin leg.’ ( SNUC). Paratypes: China: 1 ♂, 1 ♀, same data as holotype ( SNUC); 3 ♂♂, labeled ‘ China: Zhejiang Prov, Longwang Shan N. R., Parking lot, alt. 1300 m, 27.v.2009, Yuan leg.’ ( SNUC); 2 ♀♀, labeled ‘ China: Zhejiang Prov, Longwang Shan N. R., Dongguan (东关), alt. 1300 m, 26.v.2009, Feng, Yuan & Yin leg.’ ( SNUC); 2 ♂♂, labeled ‘ China: Zhejiang Prov, Qingliangfeng N. R. (清凉峰), Guanlizhan-Baibuling (百步岭), alt. 1000 m, 15.vii.2009, Feng & Yuan leg.’ ( SNUC); 1 ♀, also from Qingliangfeng, ‘Qingsongling (青松岭), alt. 1300 m, 16.vii.2009, Feng, Yuan & Yin leg.’ ( SNUC); 5 ♂♂, 2 ♀♀, labeled ‘ China: Anhui, Yuexi County, Yaoluoping Shan N. R. (鹞落坪), Jingangling (±NJΚ), 30°00’18’’N, 116°07’14’’E, beech forest, mixed leaf litter, humus, sifted, 1273 m, 18.vi.2013, Dai & Peng leg.’ ( SNUC).

Diagnosis. Antennomere XI with disc-like protuberance, slightly prominent. Head lacking median vertexal carina. Pronotum relatively smooth. Elytral subhumeral sulci absent. Profemora simple, protrochanters and protibiae lacking spur or spine, mesotibiae lacking denticle. Apical lamina of abdominal sternite VII stout, widest near middle, apical margin obliquely narrowed. Aedeagus with right paramere curved mesally, internal sac bearing several sclerotized spines, lacking hairy sclerite.

Description. Male ( Fig. 3 A). Length 1.95–2.08 mm. Head longer than wide, HL 0.44–0.46 mm, HW 0.43– 0.45 mm, lacking median vertexal carina; lateral portions of frons sparsely punctate; each eye composed of about 32 facets. Antennomere XI ( Fig. 3 B–C) with disc-like protuberance, slightly prominent, diameter of protuberance about one-ninth of segmental length. Pronotum wider than long, PL 0.40–0.41 mm, PW 0.50–0.53 mm, relatively smooth. Profemora simple, protrochanters and protibiae lacking spur or spine, mesotibiae lacking denticle. Elytra wider than long, EL 0.68–0.73 mm, EW 0.76–0.82 mm, smooth; subhumeral sulci absent; mesotibiae lacking denticle. Abdomen wider than long, AL 0.44–0.48 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. 3 D), with apical lamina stout, widest near middle, apical margin obliquely narrowed. Length of aedeagus ( Fig. 3 E) including parameres 0.31 mm, with right paramere curved mesally, internal sac bearing many sclerotized spines, lacking hairy sclerite.

Female. Similar to male; antennomere XI unmodified. Each eye composed of about 20 facets. Measurements: BL 1.80–1.91 mm, HL 0.40–0.43 mm, HW 0.39–0.40 mm, PL 0.38–0.40 mm, PW 0.48–0.50 mm, EL 0.65–0.67 mm, EW 0.75–0.80 mm, AL 0.38–0.41 mm, AW 0.73–0.75 mm.

Distribution. Eastern China: Zhejiang and Anhui.

Etymology. The specific epithet ‘ anfractus ’ means ‘curved, bent’, referring to the shape of the apical lamina of sternite VII.

Remarks. Populations from the Longwang Shan, Qingliangfeng and Yaoluoping exhibit only slight geographic variation. Right paramere of aedeagus of the population from Longwang Shan ( Fig. 3 E) is more straight than the other two populations ( Fig. 4 C–D). Form of the sternite VII ( Figs 3 D, 4A–B) found in all populations are almost the same.

Figures

FIGURE 3. Diagnostic characters of Triomicrus anfractus, 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.

FIGURE 4. Diagnostic characters of male Triomicrus anfractus from various localities. A. Abdominal sternites VII – VIII (population from Qingliangfeng N. R.). B. Same (population from Yaoluoping). C. Aedeagus, in dorsal view (population from Qingliangfeng). D. Aedeagus, in dorsal view (population from Yaoluoping). Scale bars: 0.1 mm.