Triomicrus longus 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 : 589-590

Triomicrus longus Shen and Yin , new species

( Fig. 4 )

Type material (5 ♂♂, 8 ♀♀). Holotype: China: ♂, labeled ‘ China: Guangxi, Xing’an County (※aeA), Mao'er Shan (aAM), 25°52’27’’N, 110°24’44’’E, beech forest, mixed leaf litter, humus, sifted, 1940 m, 29.vii.2014, Peng, Song, Yu & Yan leg.’ ( SNUC). Paratypes: China: 7 ♀♀, same data as holotype ( SNUC); 1 ♂, labeled ‘ China: Guangxi, Guilin City, Xing’an County, Mao'er Shan, 25°54’52’’N, 110°27’14’’E, 1550–1750 m, mixed litter, sifted, 24.vii.2012, Hu & Song leg.’ ( SNUC); 2 ♂♂, 1 ♀, also from Mao'er Shan, ‘ 25°53’20’’N, 110°25’53’’E, 2000–2100 m, mixed litter, sifted, 22.vii.2012, Hu & Song leg.’ ( SNUC); 1 ♂, also from Mao'er Shan, ‘ 10.vii.2011, 2100 m, W.J. He & L. Tang leg.’ ( SNUC).

Diagnosis. Antennomere XI with large, disc-like protuberance near base. Head lacking median vertexal carina. Pronotum very finely punctate. Elytral subhumeral sulci long, reaching level of metacoxae. Profemora swollen, protrochanters and protibiae lacking protuberance, mesotibiae lacking spur. Apical lamina of abdominal sternite VII composed of two sclerites. Aedeagus with right paramere slender and long, curved mesally, internal sac bearing several sclerotized spines, lacking hairy sclerite.

Description. Male ( Fig. 4 A). Length 2.05–2.08 mm. Head longer than wide, HL 0.40–0.43 mm, HW 0.43– 0.44 mm, lacking median vertexal carina; lateral portions of frons relatively smooth; each eye composed of about 29 facets. Antennomere XI ( Fig. 4 B, 4C) with large, disc-like protuberance near base, diameter of protuberance about two-fifths of segmental length. Pronotum wider than long, PL 0.43–0.44 mm, PW 0.53–0.55 mm, very finely punctuate. Profemora swollen ( Fig. 4 A), protrochanters and protibiae lacking protuberance, mesotibiae lacking spur. Elytra wider than long, EL 0.78–0.81 mm, EW 0.83–0.85 mm, smooth; subhumeral sulci long, reaching level of metacoxae. Abdomen wider than long, AL 0.43–0.45 mm, AW 0.73–0.75 mm; abdominal tergite IV (first visible tergite) with discal carinae extending to two-fifths of tergal length; abdominal sternite VII modified ( Fig. 4 D), with apical lamina composed of two sclerites, each curved mesally. Length of aedeagus ( Fig. 4 E) 0.41 mm, right paramere slender and long, curved mesally, internal sac bearing several sclerotized spines, lacking hairy sclerite.

Female. Similar to male; antennomere XI and profemora unmodified. Each eye composed of about 15 facets. Measurements: BL 1.96–2.05 mm, HL 0.41–0.43 mm, HW 0.41–0.43 mm, PL 0.40–0.41 mm, PW 0.49–0. 50 mm, EL 0.71–0.73 mm, EW 0.80–0.83 mm, AL 0.43–0.45 mm, AW 0.73–0.75 mm.

Discussion. The new spices is morphologically close to T. inaequalis Shen, Yin & Li, 2015 in a similar general habitus ( Fig. 4 A), the form of the protuberance on antennomere XI ( Fig. 4 B, 4C), the structure of abdominal sternite VII ( Fig. 4 D), and the aedeagus ( Fig. 4 E). Males of these two species can be most readily separated by the presence of a long apical spine of the protrochanter in T. inaequalis , whereas T. longus lacks such a spine.

Distribution. Southern China: Guangxi.

Etymology. The specific epithet ‘ longus ’ in Latin refers to the long right paramere of the aedeagus.

Figures

FIGURE 4. Diagnostic characters of Triomicrus longus, 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.