Batraxis simplex Wang and Yin

Wang, Dan, Yin, Zi-Wei & Wang, Chun-Xin, 2016, On a collection of Batraxis Reitter (Coleoptera: Staphylinidae: Pselaphinae) from Hainan Island, southern China, Zootaxa 4109 (1), pp. 1-15 : 9-10

7. Batraxis simplex Wang and Yin , new species

( Fig. 4 A–E)

Type material (5 ♂♂, 11 ♀♀). Holotype: CHINA: ♂, labeled ‘ CHINA: Hainan, Ledong Hsien, Jianfengling N.R., Mingfenggu, 18°44'30"N, 108°50'29"E, rainforest, decaying log, 995 m, 27.i.2015, Peng, Yin, Tu, Song, Shen, Zhou, Wang leg.’ Paratypes: CHINA: 1 ♂, 6 ♀♀, same label data as holotype; 3♂♂, 2♀♀, same data as previous except ‘ 23.i.2015 ’; 3 ♀♀, same data as previous material except ‘ 26.i.2015 ’.

Diagnosis of male. Body with sparse, minute pubescence in most areas; frons with complete subantennal transverse sulcus; vertex lacking median pit; antennomeres IX as long as wide; pronotum with distinct median antebasal fovea and basal impression; all tibiae thin; protibiae lacking modification, mesotibiae without apical spur; protrochanters simple; tergite IV with broad basal sulcus; discal carinae long, widely separated; with complete marginal carinae; aedeagus relatively stout.

Description. Male ( Fig. 4 A). Body reddish brown, with sparse minute pubescence, length 2.01 mm. Head rectangular, slightly longer than wide, HL 0.44 mm, HW 0.42 mm, vertex moderately convex, vertexal foveae small but distinct, with a V-shaped vertexal sulcus connecting foveae; antennal tubercles low; frons flattened, subantennal transverse sulcus complete, anterior margin of vertexal sulcus merging with subantennal transverse sulcus; each eye composed of about 30 facets; antennae relatively thick, antennomeres III–VII slightly elongate, VIII‒IX as long as wide, X transverse, XI largest, widest near base, then obliquely narrowing toward apex; median gular carina narrow, with two close small gular foveae. Pronotum slightly wider than long, PL 0.40 mm; PW 0.45 mm, with distinct median antebasal fovea and complete coarse basal impression. Elytra wider than long, EL 0.55 mm, EW 0.78 mm, with two pairs of shallow foveae at base. Protrochanters lacking spur ( Fig. 5 E). Abdomen wider than long, AL 0.62 mm, AW 0.72 mm, distinctly narrowed at base; tergite IV (first visible tergite) with broad, abrupt basal sulcus; discal carinae long, widely separated, extending to half of tergal length, width between divergent discal carinae 0.44mm at base, 0.52 mm at apices; marginal carinae complete. Aedeagus ( Fig. 4 B–D) 0.37 mm in length, relatively stout, parameres widest at middle, each with three preapical setae; endophallus complicated, with a series of symmetric sclerites, and numerous spine-like structures apicomedially.

Female. Very similar to male in general appearance; each eye composed of about 30 facets. Measurements: BL 1.89 mm; HL 0.44 mm; HW 0.42 mm; PL 0.40 mm; PW 0.44 mm; EL 0.50 mm; EW 0.76 mm; AL 0.55 mm; AW 0.69 mm; width between divergent discal carinae of tergite IV 0.52mm at base, 0.39 mm at apices.

Comparative notes. The widely separated discal carinae of tergite IV in the new species is shared with B. bicolor , B. tibialis , and B. pilosa . Batraxis simplex can be readily separated from all above congeners by the presence of a V-shaped vertexal sulcus, coarse basal collar of the pronotum, and structure of the aedeagus. Distribution. Southern China: Hainan.

Etymology. The specific epithet refers to the lack of obvious modifications in the male.

Figures

FIGURE 4. Diagnostic features of male Batraxis simplex. A. Dorsal habitus. B. Aedeagus, in dorsal view. C. Same, in later view. D. Same, in ventral view. E. Protrochanter. Scale line: A = 0.3 mm; B, C, D, E = 0.05 mm.

FIGURE 5. Diagnostic features of male Batraxis species. (A – D. Protibia. E. Mesotibia. F. Mesofemur. G – L. Protrochanter). A, G. B. bicolor. B, F, H. B. tibialis. C, I. B. pilosa. D, E, J. B. spinosas. K. B. hainanensis. L. B. minor. Scale line: 0.1 mm.