Triomicrus cochlis 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 : 588-589

Triomicrus cochlis Shen and Yin , new species

( Fig. 3 )

Type material (4 ♂♂, 1 ♀). Holotype: China: ♂, labeled ‘ China: Guangxi, Guilin City, Xing’an County (※aeA), Mao'er Shan (aAM), 25°51’28’’N, 110°29’04’’E, 450–650 m, mixed litter, sifted, 25.vii.2012, Hu & Song leg.’ ( SNUC). Paratypes: China: 1 ♂, labeled ‘ China: Guangdong Province, Ruyuan Hsien (viiAEA), Nanling N. R. (*≷), Laopengkeng (+*W), 24°56’29’’N, 113°00’27’’E, mixed forest, leaf litter, wood, sifted, 1360 m, 29.iv.2015, Peng, Tu, Zhou leg.’ ( SNUC); 2 ♂♂, 1 ♀, labeled ‘ China: Hunan, Chenzhou, Yizhang Hsien (ZAA), Mangshan N. R. (WM), 24°56’26’’N, 112°59’18’’E, mixed forest, leaf litter, wood, sifted & beating, 1400 m, 26.iv.2015, Peng, Tu, Zhou leg.’ ( SNUC).

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

Description. Male ( Fig. 3 A). Length 1.81–1.90 mm. Head slightly longer than wide, HL 0.36–0.38 mm, HW 0.40–0.43 mm, lacking median vertexal carina; lateral portions of frons coarsely punctate; each eye composed of about 32 facets. Antennomere XI ( Fig. 3 B, 3C) with strongly prominent disc-like protuberance near middle, diameter of protuberance about one-fourth of segmental length. Pronotum wider than long, PL 0.38–0.42 mm, PW 0.45–0.48 mm, entirely covered with dense and coarse punctation. Profemora simple, protrochanters and protibiae lacking protuberance, mesotibiae with large triangular apical spur ( Fig. 3 D). Elytra wider than long, EL 0.70–0.74 mm, EW 0.74–0.78 mm, smooth; subhumeral sulci absent. Abdomen wider than long, AL 0.36–0.38 mm, AW 0.73–0.74 mm; abdominal tergite IV (first visible tergite) with discal carinae extending to four-fifths of tergal length; abdominal sternite VII modified ( Fig. 3 E), with apical lamina narrowed near base, widest at apex. Length of aedeagus ( Fig. 3 F) 0.27 mm, right paramere long, curved mesally, internal sac bearing several sclerotized spines, lacking hairy sclerite.

Female. Similar to male; antennomere XI and mesotibiae unmodified. Each eye composed of about 15 facets. Measurements: BL 1.89 mm, HL 0.38 mm, HW 0.41 mm, PL 0.41 mm, PW 0.46 mm, EL 0.73 mm, EW 0.75 mm, AL 0.37 mm, AW 0.73 mm.

Distribution. Southern China: Guangdong, southern Hunan and Guangxi.

Etymology. The specific epithet ‘ cochlis ’ in Latin means ‘a spiral shell or conch’, referring to the shape of the apical lamina of sternite VII.

Remarks. Populations from the Nanling and Mangshan show a slight geographic variation. The right paramere of the aedeagus in the population from Mangshan ( Fig. 3 H) is longer than that in the population from Nanling ( Fig. 3 G). The sternite VII of specimens from each population are shown in Fig. 3 E, 3F.

Figures

FIGURE 3. Diagnostic characters of Triomicrus cochlis, male. A. Habitus. B. Antennal club, in dorsal view. C. Same, in lateral view. D. Mesotibia in dorsal view. E. Abdominal sternites VII – VIII (population from Mao'er Shan). F. Same (population from Nanling). G. Aedeagus, in dorsal view (population from Mao'er Shan). H. Same (population from Nanling). Scale bars: A = 0.5 mm; B, C = 0.2 mm; D – H = 0.1 mm.