Pselaphodes femoralis, Huang & Li & Yin, 2018

Huang, Meng-Chi, Li, Li-Zhen & Yin, Zi-Wei, 2018, Four new species of Pselaphodes Westwood (Coleoptera: Staphylinidae: Pselaphinae) from Thailand, Laos, and China, Zootaxa 4472 (1), pp. 100-110 : 101-103

Pselaphodes femoralis , new species

( Figs 1A , 2–3 )

Type material (14 exs). Holotype: CHINA: ♂, ‘ China: N. Guizhou, Daozhen Co. (道真仡佬族苗族自治县), Dashahe (大沙河), (29°10′12″N, 107°33′36″E), mixed leaf litter, sifted, 1730 m, 07.VII.2015, Jiang, Peng, Tu & Zhou leg.’ ( SNUC) . Paratypes: CHINA: 1 ♂, same label data as the holotype ( SNUC) ; 1 ♂, also from N. Guizhou (28°30′01″N, 106°24′12″E), except ‘ Xishui Co. (习水县), Sanchahe (三岔河), 890 m, 12.VII.2015.’ ( SNUC) ; 1 ♂, ‘ China: S. Zhejiang, Qingyuan Baishanzu N.R. (庆元百山祖自然保护区), path nr. hotel, (27°44′42″N, 119°10′19″E), leaf litter, sifted, 30.iv.2014, 1060- 1130 m, Peng, Song, Yan & Yu’ ( SNUC) ; 1 ♂, 2 ♀♀, ‘ China: Fujian Province, Wuyishan City (武夷山市), Tongmu Village (桐木村), Guadun (挂墩), (27°44′01”N, 117°38′13″E), mixed forest, leaf litter, wood, sifted, 1242 m, 4.x.2015, Yan, Tu, Shen, Jiang & Zhou leg.’ ( SNUC) ; 1 ♂, ‘ China: Guangdong Province, Ruyuan Hsien (乳源瑶族自治县), Nanling N.R. (南岭自然保护区), Hamashi (蛤蟆石), (24°55′37″N, 112°59′21″E), mixed forest, leaf litter, sifted, 1750 m, 01.v.2015, Peng, Tu, Zhou leg.’ ( SNUC) ; 1 ♂, 1 ♀, ‘ China: Guangxi, Wuming County (武鸣县), Daming Shan (大明山), (23°30′57″N, 108°26′13″E), mixed leaf litter, sifted, 1150-1250 m, 31.vii.2012, Hu & Song leg.’ ( SNUC) ; 1 ♂, ‘ China: SICHUAN PROV., Emeishan Mt. , QINGYIN TEMPLE (清音阁), 700 m, (29°34′20″N, 103°23′31″E), 7.VI.2014, sift #3, around wet rocks, mixed forest near river, J. Hájek & Růžička leg.’ ( NMPC) ; THAILAND: 1 ♂, 1 ♀, ‘ Thailand, 1990. Do Chiang Dao Wildlife Sanct. Chiang Dao Dist. 510 m, 23. 11, P. Schwendinger’ ( MHNG) ; 1 ♂, ‘ THAILAND: Chiang Mai, Doi Ang Khang, 10 km, W Fang , 1500 m, 20.III.87, P. Schwendinger. ’ ( MHNG).

Diagnosis of male. Length 2.88–3.52 mm; antennomere IX with a disc-shaped process at apex; profemur with two bluntly triangular projections; protibia with a distinct acute spur near middle, and a strongly expanded projection at the apex.

Description. Male ( Fig. 1A ). Body reddish brown, BL 2.88–3.52 mm. Head about as long as wide, HL 0.54– 0.69 mm, HW 0.59–0.64 mm; each eye composed of about 40 facets; ocular canthus well-developed. Antennomeres ( Fig. 2A ) IX–XI forming distinct club, antennomere IX slightly modified, with disc-shaped process at apex. Pronotum ( Fig. 2B ) longer than wide, PL 0.66–0.71 mm, PW 0.59–0.66 mm, coarsely punctate and regularly pubescent, with lateral margins rounded. Elytra wider than long, EL 0.79–0.92 mm, EW 1.05–1.20 mm. Metaventral processes ( Fig. 2C ) short, curved ventrally at apices. Protrochanter simple, profemur ( Fig. 2D ) with two large, bluntly triangular projections; protibia ( Fig. 2E ) with small spine near middle and large triangular projection at apex; mesotrochanter and mesofemur ( Fig. 2F ) simple, mesotibia ( Fig. 2G ) with distinct apical spur; hind legs ( Fig. 2H ) simple. Abdomen broad at base and narrowed apically, AL 0.86–0.96 mm, AW 1.02–1.13 mm. Sternite IX ( Fig. 2I ) semi-membranous. Length of aedeagus 0.64–0.83 mm, median lobe broad and asymmetric, parameres elongate, endophallus usually composed of two elongate sclerites and one sclerite of numerous ‘spinelike’ structures. ( Fig. 2J–L , Fig. 3 ).

Female. Similar to male in general; each eye composed of about 30 facets; antennae and legs simple. Measurements: BL 2.87–3.11 mm, HL 0.63–0.68 mm, HW 0.61–0.64 mm, PL 0.59–0.66 mm, PW 0.59–0.66 mm, EL 0.79–0.86 mm, EW 1.05–1.17 mm, AL 0.86–0.95 mm, AW 1.17–1.34 mm.

Distribution. China: Zhejiang, Fujian, Guangdong, Guangxi, Sichuan, Guizhou; Thailand: Chiang Mai.

Comparative notes. Males of the new species can be readily separated from all known congener by the enlarged antennomere IX with a disc-like process, the profemur with two blunt, triangular spines, and the protibia with an acute spur near middle and a large projection at the apex.

Intraspecific variation. Pselaphodes femoralis is one of the most widely distributed Pselaphodes species in Asia. The known range of this species extends from the southwestern part of Zhejiang in eastern China to northern Thailand, from 510 m (Chiang Dao, Thailand) up to 1,750 m (Guangdong, China) above sea level. The degree of variability in the shape of the aedeagus among different populations is remarkable. The apical portion of the median lobe (in lateral view) can be as narrow as in the population from Sichuan, China ( Fig. 2L ), or as broad as in the population from Chiang Dao, Thailand ( Fig. 3I –J ). The endophallus generally comprises one to two elongate sclerites, and a broad and less strongly sclerotized plate with numerous ‘spine-like’ structures, despite the position, length and shape of these sclerites are highly variable. However, all these populations exhibit a quite stable combinations of male external features, especially the uniquely modified profemur ( Fig. 2D ), protibia ( Fig. 2E ), and antennomeres IX ( Fig. 2A ) are nearly identical. The aedeagal structure from all populations in China are more or less similar, while the biggest difference in the population from Thailand ( Fig. 2I –L ) can be attributed to the greatest geographical span (there is no record in Yunnan, northern Laos, and Vietnam). It is not difficult to image that continuous variation might be found when a much broader sample becomes available. We therefore regard all these populations as representing a single species.

Etymology. The specific epithet refers to the large, blunt projections of the profemur, which are speciesspecific.

Figures

FIGURE 1. Dorsal habitus of Pselaphodes males. A. P. femoralis. B. P. incisus. Scale bars: 1 mm.

FIGURE 2. Male diagnostic features of Pselaphodes femoralis. A. Antennal club. B. Pronotum. C. Metaventral process, in lateral view. D. Protrochanter and profemur. E. Protibia. F. Mesotrochanter and mesofemur. G. Apex of mesotibia. H. Metatrochanter and metafemur. I. Sternite IX. J–L. Aedeagus, in dorsal (J), and lateral (K–L) view; J–K: population from Guizhou, L: population from Sichuan. Scale bars: 0.3 mm in A–B, D–E, F, H; 0.2 mm in C, J–L; 0.1 mm in G. I.

FIGURE 3. Aedeagus of Pselaphodes femoralis, showing intraspecific variation (A, C, E, G, I, K in dorsal view; B, D, F, H, J, L in lateral view). A–B. Population from Zhejiang, China. C–D. Population from Fujian, China. E–F. Population from Guangdong, China. G–H. Population from Guangxi, China. I–J. Population from Chiang Dao, Thailand. K–L. Population from Chiang Mai, Thailand. Scale bars: 0.2 mm.