Araneibatrus pubescens, Yin, Zi-Wei, Jiang, Ri-Xin & Steiner, Helmut, 2016

Yin, Zi-Wei, Jiang, Ri-Xin & Steiner, Helmut, 2016, Revision of the genus Araneibatrus (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 4097 (4), pp. 475-494 : 492-493

Araneibatrus pubescens , new species

( Figs 3 A, 4E, 5E, 7A, 8E, 9E, 11D–F, 12)

Type material. Holotype: male: ‘Banpoya Dong, Banpo Cun, Bixi Xiang, Nanjian Xian, [Yunnan, CHINA], 中国 云南省南涧县半坡村半坡崖洞, 16.ix.2009, H. m. Chen leg.’ ( NSMT).

Diagnosis. Body length 2.61 mm. Vertex with faint mediobasal carina, lacking lateral postantennal carinae; clypeus elongate, about one-third of total head length. Pronotum lacking median longitudinal and antebasal sulci; lacking dorsal carinae, lacking discal and antebasal tubercles. Elytra lacking discal striae; anterolateral margins not emarginate. Metaventrite with narrow notch at middle of posterior margin. Tergite IV with only two basolateral foveae. Sternite IV with two mediobasal and six basolateral foveae. Male with unmodified antennal club and metaventrite, with spinose meso- and metatrochanters. Aedeagus with transverse basal capsule.

Description. Male ( Fig. 3 A). Length 2.61 mm, body extremely elongate, uniformly reddish-brown, mouth parts, tibiae and tarsi lighter in color.

Head ( Fig. 4 E) distinctly longer than wide, HL 0.54 mm, HW 0.48 mm, finely punctate; vertex with faint median carina, lacking lateral postantennal carinae; clypeus unusually long, as long as one-third of total head length; antennal clubs loosely formed by three apical elongate antennomeres, unmodified, antennomere XI asymmetrically narrowed at apical one-third. Pronotum ( Fig. 4 E) slightly narrower than head, and longer than wide, PL 0.51 mm, PW 0.45 mm; disc finely punctate, lacking median longitudinal sulcus and transverse antebasal sulcus, lacking dorsal carinae, and discal and antebasal tubercles. Elytra ( Fig. 5 E) slightly longer than wide, EL 0.85 mm, EW 0.83 mm, lacking discal striae, anterolateral margins not emarginate. Mesoventrite ( Fig. 7 A) with lateral foveae separated from forked median foveae. Metaventrite ( Fig. 7 A) unmodified; posterior margin with narrow notch at middle. Mesotrochanter with long ventral spine slightly curved at apex; metatrochanter with small, curved ventral spine. Tergite IV ( Fig. 8 E) with inner marginal carinae oblique and complete; basal impression complete, with two basolateral foveae at lateral ends of impression. Sternite IV ( Fig. 9 E) with one pair of mediobasal and three pairs of basolateral foveae. Length of aedeagus ( Fig. 11 D–F) 0.45 mm, median lobe with transverse basal bulb and large foramen, broad in lateral view, apically narrowed; dorsal lobe composed of two flat, membranous sclerites, each with numerous spine-like structures.

Female. Unknown.

Comparative notes. The new species is most similar to A. spinosus by sharing the extremely elongate body, antennae, and legs, ventrally spinose meso- and metatrochanters, and lack of median and antebasal sulci on the pronotal disc. These two species can be readily separated by the lack of pronotal antebasal spines in A. pubescens , and the different form of the aedeagus. In A. spinosus , there are two distinct antebasal spines on the pronotal disc, and the aedeagal basal bulb is much stouter.

Collecting environment. Details unknown.

Distribution. Southwestern China: Yunnan ( Fig. 12 ).

Etymology. The specific epithet refers to the long pubescence on the dorsal surface of the body.

Figures

FIGURE 3. Dorsal habitus of Araneibatrus species. A. A. pubescens, male. B. A. spinosus, male. Scales: 0.5 mm.

FIGURE 4. Head dorsum and pronotum of Araneibatrus species. A. A. callissimus. B. A. cellulanus. C. A. grossepunctatus. D. A. cf. gracilipes. E. A. pubescens. F. A. spinosus. Scales: 0.2 mm.

FIGURE 5. Right elytron of Araneibatrus species. A. A. callissimus. B. A. cellulanus. C. A. grossepunctatus. D. A. gracilipes. E. A. pubescens. F. A. spinosus. Scales: 0.2 mm.

FIGURE 7. Meso- and metaventrite of Araneibatrus species. A. A. pubescens. B. A. spinosus. Scales: 0.2 mm.

FIGURE 8. Tergite IV of Araneibatrus species. A. A. callissimus. B. A. cellulanus. C. A. grossepunctatus. D. A. gracilipes. E. A. pubescens. F. A. spinosus. Scales: 0.2 mm.

FIGURE 9. Sternites III and IV of Araneibatrus species. A. A. callissimus. B. A. cellulanus. C. A. grossepunctatus. D. A. gracilipes. E. A. pubescens. F. A. spinosus. Scales: 0.2 mm.

FIGURE 11. Aedeagus of Araneibatrus species (A, D, G. in ventral view. B, E, H. in lateral view. C, F, I. in dorsal view). A – C. A. gracilipes. D – F. A. pubescens. G – I. A. spinosus. Scales: 0.2 mm.

FIGURE 12. Distribution of Araneibatrus species.