Triomicrus frondosus 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 : 517-518

Triomicrus frondosus Shen and Yin , new species

( Fig. 7 )

Type material (5 ♂♂, 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, 1050–1250 m, 08.vi.2012, Jia-Yao Hu & ZI-WEI Yin leg.’ ( SNUC). Paratypes: China: 1 ♂, same data as holotype ( SNUC); 1 ♂, labeled ‘ China: Zhejiang, Anji County, Longwang Shan N. R., Dongguan-Qianmutian Peak, 30°23’47’’N, 119°26’17’’E, 1250–1450 m, mixed leaf litter, sifted, 14.v.2013, Chen & Pan leg.’ ( SNUC); 2 ♂♂, labeled ‘ China: N. Zhejiang, Linan City, W. Tianmu Shan N. R. (天目山), firebreak to Xianren Peak (仙人顶), 30°20’50’’N, 119°25’58’’E, leaf litter, sifted, 1300 m, 22.x.2013, Bi, Song, Tang, Yin leg.’ ( SNUC); 6 ♀♀, also from W. Tianmu Shan ‘mixed leaf litter, sifted, 800–1150 m, 19.v.2006, Hu & Tang leg.’ ( SNUC).

Diagnosis. Antennomere XI with impression in median region surrounding disc-like median protuberance, slightly prominent. Head lacking median vertexal carina. Pronotum relatively smooth. Elytral subhumeral sulci short. Profemora simple, protrochanters and protibiae lacking spur or spine, mesotibiae lacking denticle. Apical lamina of abdominal sternite VII narrowed near base and pointed at apex. Aedeagus with right paramere curved laterally, internal sac bearing several sclerotized spines and densely hairy sclerite.

Description. Male ( Fig. 7 A). Length 2.18–2.30 mm. Head longer than wide, HL 0.50–0.51 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. 7 B–C) with median impression surrounding slightly prominent disc-like protuberance, diameter of impression about one-third of segmental length. Pronotum wider than long, PL 0.45– 0.48 mm, PW 0.53–0.55 mm, smooth. Profemora simple, protrochanters and protibiae lacking spur or spine, mesotibiae lacking denticle. Elytra wider than long, EL 0.79–0.83 mm, EW 0.89–0.93 mm, finely punctate; subhumeral sulci short, barely reaching half of elytral length. Abdomen wider than long, AL 0.44–0.48 mm, AW 0.81–0.83 mm; abdominal tergite IV (first visible tergite) with discal carinae extending to three-fifths of tergal length; abdominal sternite VII modified ( Fig. 7 D), with apical lamina narrowed near base and pointed at apex. Length of aedeagus ( Fig. 7 F) including parameres 0.37 mm, with right paramere curved laterally, internal sac bearing several sclerotized spines and densely hairy sclerite.

Female. Similar to male; antennomere XI unmodified. Each eye composed of about 18 facets. Measurements: BL 2.03–2.13 mm, HL 0.48–0.49 mm, HW 0.40–0.43 mm, PL 0.43–0.45 mm, PW 0.50–0.53 mm, EL 0.73–0.75 mm, EW 0.85–0.88 mm, AL 0.40–0.43 mm, AW 0.75–0.78 mm.

Distribution. Eastern China: Zhejiang.

Etymology. The specific epithet ‘ frondosus ’ means ‘leafy, full of leaves’, referring to the shape of the apical lamina of sternite VII.

Remarks. Populations from the Longwang Shan and Western Tianmu Shan exhibit only slight geographic variation. Sclerotized spines of the aedeagus of the population from Western Tianmu Shan ( Fig. 7 G) are slightly longer than those of the population from Longwang Shan ( Fig. 7 F). Illustrations of the sternite VII ( Fig. 7 D–E) found in each population are provided here.

Figures

FIGURE 7. Diagnostic characters of Triomicrus frondosus, male. A. Male habitus. B. Antennal club, in dorsal view. C. Same, in lateral view. D. Abdominal sternites VII – VIII (Longwang Shan). E. Same (West Tianmu Shan). F. Aedeagus, in dorsal view (Longwang Shan). G. Same (West Tianmu Shan). Scale bars: A = 0.5 mm; B, C = 0.2 mm; D – G = 0.1 mm.