Batraxis antennata, 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 : 447-449

Batraxis antennata , new species

( Figs 3 A, 10G‒I, 15)

Type material (2 ƋƋ, 4 ♀♀). Holotype: CHINA: Ƌ, labeled ‘ CHINA: Yunnan, Baoshan City (保山市), Tengchong County (腾冲县), Mingguang Town (明光镇), Zizhi Village (自治村), 25°43'46"N, 98°34'17"E, 1900 m, 26.iv.2013, Dai, Song & Peng leg.’ ( SNUC) . Paratypes: CHINA: 1 Ƌ, 3 ♀♀, same label data as holotype ( SNUC) ; 1 ♀, labeled ‘ China: Yunnan, Baoshan City, Baihualing (百花岭), alt. 1700 m, 25°17'42"N, 98°47'49"E, 20.iv.2013, Song, Peng & Dai leg.’ ( SNUC) .

Diagnosis of male. Body almost glabrous, elytra with sparse, short setae; frons with abrupt subantennal transverse sulcus; antennomeres IX slightly elongate, XI concaved at apicolateral margins; pronotum with distinct median antebasal fovea and basal impression; all legs simple, tibiae slender; tergite IV with narrow basal sulcus, discal carinae relatively short, moderately close, with relatively short marginal carinae; aedeagus stout.

Description. Male ( Fig. 3 A). Body dark-brown, length 2.03 mm. Head rectangular, slightly wider than long, HL 0.45 mm, HW 0.47 mm, vertex glabrous, apical margin of frons and clypeus sparsely pubescent; vertex moderately convex, with pair of small but distinct vertexal foveae; antennal tubercles low; frons flattened, subantennal transverse sulcus abrupt, vertexal sulcus short; each eye composed of about 30 facets; antennae thin, antennomeres III–IX elongate, X about as long as wide, XI largest, widest at middle, distinctly concaved at anterolateral margins; median gular carina narrow, with two separated nude gular foveae. Pronotum slightly wider than long, PL 0.37 mm, PW 0.43 mm, with distinct median antebasal fovea and complete V-shaped basal impression. Elytra wider than long, EL 0.59 mm, EW 0.86 mm, dorsal surface with sparse, minute setae, each elytron with two distinct foveae at base. All legs simple. Abdomen slightly wider than long, AL 0.62 mm, AW 0.77 mm, slightly narrowed at base; tergite IV (first visible tergite) with narrow basal sulcus; discal carinae relatively short, close, extending to one-fourth of tergal length, width between carinae 0.23 mm at apices; marginal carinae extending to apical one-third of tergal length. Aedeagus ( Fig. 10 G‒I) 0.36 mm in length, stout, parameres slightly shorter than median lobe, each with two short apical setae; endophallus without distinct sclerites, comprising a series of symmetric, weakly-sclerotized setae-like structures.

Female. Similar to male in general appearance; each eye composed of about 30 facets. Measurements: BL 1.94‒2.03 mm; HL 0.4 3‒ 0.45 mm; HW 0.43‒0.44 mm; PL 0.34‒0.37 mm; PW 0.40‒0.43 mm; EL 0.54‒0.59 mm; EW 0.77‒0.84 mm; AL 0.62‒0.68 mm; AW 0.72‒0.79 mm; width between discal carinae of tergite IV 0.21‒0.23 mm at apices.

Comparative notes. Batraxis antennata is a very distinct species among its Chinese congeners. It can be readily separated from all other species by the antennomeres XI distinctly concaved at the apicolateral margins, the presence of a V-shaped sulcus on the pronotal base, and the aedeagal endophallus has numerous weakly-sclerotized setae-like structures.

Distribution. China: Yunnan ( Fig. 15 ).

Etymology. The specific epithet refers to the concaved antennomeres XI.

Figures

FIGURE 3. Dorsal habitus of Batraxis males. A. B. antennata. B. B. longicornis. Scale bars: 0.5 mm.

FIGURE 10. Aedeagi of Batraxis species. (A, B, D, E, G, H. in ventral view. C, F, I. in lateral view). A – C. B. gloriosa, population from Jiangxi. D – F. B. gloriosa, population from Guangxi. G – I. B. antennata. Scale bars: 0.1 mm.

FIGURE 15. Distribution of Batraxis species in China.