Batraxis robusta, Wang, Dan & Yin, Zi-Wei, 2016

Wang, Dan & Yin, Zi-Wei, 2016, New species and records of Batraxis Reitter (Coleoptera: Staphylinidae: Pselaphinae) in continental China, Zootaxa 4147 (4), pp. 443-465 : 444

Batraxis robusta , new species

( Figs 1 , 2 A, 8, 15)

Type material (14 ƋƋ, 3 ♀♀). Holotype: CHINA: Ƌ, labeled ‘ CHINA: Jiangxi, Pingxiang City (萍乡市), Wugong Shan National Park (武功山国家森林公园), 27°27'39"N, 114°10'03"E, cable way station to Dian-Jiang- Tai (点将台), broad leaf, sifted, 1340–1400 m, 19.vii.2013, Song, Yin, Yu leg. ( SNUC)’ . Paratypes: CHINA: 3 ♂♂, 1 ♀, same label data as holotype ( SNUC); 6 ♂♂, 2 ♀♀, labeled ‘ China: Guangxi, Liuzhou City (柳州市), Jiuwan Shan N.R. (九万山自然保护区), Yangmei’ao (杨梅坳), 25°11'42"N, 108°38'51"E, mixed leaf litter, sifted, 1200 m, 24.VII.2015, Li & Zhao leg.’ ( SNUC) ; 4 ♂♂, labeled ‘ China: Guizhou, Libo Hsien (荔波县), Maolan N.R. (茂兰自然保护区), 25°15'49"N, 107°54'26"E, mixed leaf litter, sifted, 750–850 m, 20.VII.2015, He, Hu & Wang leg.’ ( SNUC) .

Diagnosis of male. Body covered with distinct pubescence; frons with complete subantennal transverse sulcus; antennomeres IX as long as wide, XI subconical; pronotum with distinct median antebasal fovea and basal impression; legs simple, all tibiae slender; tergite IV with narrow basal sulcus, discal carinae long, moderately close, with complete marginal carinae; aedeagus relatively stout.

Description. Male ( Fig. 1 A). Body dark-brown, pubescent, length 2.31‒2.69 mm. Head rectangular, slightly longer than wide, HL 0.49‒0.62 mm, HW 0.48‒0.54 mm, vertex moderately convex, with pair of distinct vertexal foveae; antennal tubercles slightly raised; frons flattened, transverse subantennal sulcus complete, anterior margin of U-shaped vertexal sulcus merging with subantennal sulcus and connecting foveae; each eye composed of about 30 facets; antennae relatively thin, antennomeres III–VII elongate, VIII slightly elongate, IX as long as wide, X transverse, XI largest, widest at basal 1/3; median gular carina narrow, with two nude, separated gular foveae. Pronotum slightly wider than long, PL 0.44‒0.49 mm, PW 0.52‒0.58 mm, with distinct median antebasal fovea and basal impression. Elytra wider than long, EL 0.64‒0.77 mm, EW 0.84‒0.98 mm, each elytron with two distinct foveae at base. All legs simple, tibiae slender. Abdomen wider than long, AL 0.59‒0.88 mm, AW 0.82‒0.92 mm, slightly narrowed at base; tergite IV (first visible tergite) with narrow basal sulcus, discal carinae long, relatively close, extending to apical two-thirds of tergal length, width between carinae 0.25‒0.30 mm at apices, marginal carinae complete. Aedeagus ( Fig. 8 A‒C) 0.40 mm long, relatively stout, parameres slightly exceeding apex of median lobe, rounded apically, each with three preapical setae; endophallus complicated, with series of symmetric sclerites, and numerous spine-like structures distomedially.

Female. Similar to male in general appearance; each eye composed of about 15 facets. Measurements: BL 2.27‒2.70 mm; HL 0.5 5‒ 0.60 mm; HW 0.50‒0.53 mm; PL 0.44‒0.48 mm; PW 0.52‒0.55 mm; EL 0.62‒0.71 mm; EW 0.86‒0.93 mm; AL 0.67‒0.91 mm; AW 0.87‒0.88 mm; width between discal carinae of tergite IV 0.28‒0.30 mm at apices.

Comparative notes. Batraxis robusta is similar to B. pilosa Wang & Yin by the long body pubescence. The new species can be distinguished from B. pilosa by its large body (2.61 mm), slightly raised antennal tubercles, more slender antennae, close discal carinae of tergite IV, simple protrochanters and protibiae, and complicated structures of the aedeagal endophallus. In B. pilosa , the body is smaller (2.05 mm), the antennal tubercles are distinctly raised, the antennae are thicker, the discal carinae of the tergite IV are widely separated, the ventral margin of each protrochanter is strongly protuberant, each protibia has a small preapical tooth, the aedeagus is more slender, and the aedeagal endophallus lacks distinct distomedian spine-like structures.

Comments. Males of the populations from Jiangxi ( Figs. 1 A, 8A‒C), Guizhou ( Figs. 1 B, 8D‒F) and Guangxi ( Figs. 2 A, 8G‒I) are slightly different in the form of the pronotal basal impression, in the width of the discal carinae on tergite IV, and in the lengths of the median sclerites of the aedeagal endophallus. These differences are interpreted as intraspecific variations.

Distribution. China: Jiangxi, Guizhou, Guangxi ( Fig. 15 ).

Etymology. The specific epithet refers to the robust body form.

Figures

FIGURE 1. Dorsal habitus of Batraxis robusta, male. A. Population from Jiangxi. B. Population from Guizhou. Scale bars: 0.5 mm.

FIGURE 2. Dorsal habitus of Batraxis males. A. B. robusta, population from Guangxi. B. B. gloriosa, population from Hunan. Scale bars: 0.5 mm.

FIGURE 8. Aedeagi of Batraxis robusta. (A, B, D, E, G, H. in ventral view. C, F, I. in lateral view). A – C. Population from Jiangxi. D – F. Population from Guizhou. G – I. Population from Guangxi. Scale bars: 0.1 mm.

FIGURE 15. Distribution of Batraxis species in China.