Araneibatrus cellulanus, 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 : 485-487

Araneibatrus cellulanus , new species

( Figs 1 B, 4B, 5B, 6B, 8B, 9B, 10D–F, 12)

Type material. Holotype: male: ‘ China: Guangdong, Yangshan Hsien, Chengjia Town, Dabei Vill., Mine station, cave, 24°46′27.85″N, 112°48′15.60″E, 138 m, 28.xii.2014, M.-Y. Tian et al. leg. [广东阳山县秤架村大陂村矿站 岩洞]’ ( SNUC).

Diagnosis. Body length 2.01 mm. Vertex with short mediobasal carina, lateral postantennal carinae present; clypeus short, less than one-third of total head length. Pronotum with shallow median longitudinal and transverse antebasal sulci, lacking dorsal carinae and discal and antebasal spines. Elytra with shallow, indistinct discal striae; anterolateral margins emarginate. Metaventrite with relatively wide notch at middle of posterior margin. Tergite IV with two mediobasal and four basolateral foveae. Sternite IV with two mediobasal and six basolateral foveae. Male with simple antennal club and modified metaventrite, with spinose mesotibia and projecting metatrochanter. Aedeagus with transverse basal capsule.

Description. Male ( Fig. 1 B). Length 2.01 mm. Body uniformly yellowish-brown, mouth parts, tibiae and tarsi lighter in color.

Head ( Fig. 4 B) almost as long as wide, HL 0.42 mm, HW 0.40 mm, finely punctate; vertex with short median carina extending from posterior margin of head toward level of mid-length of eyes; pair of lateral postantennal carinae extending from posterior margins of antennal tubercles to near postocular margins; clypeus relatively short, about one-fifth of total head length; antennal clubs loosely formed by three apical elongate antennomeres, antennomere XI unmodified, asymmetrically narrowed at apical half. Pronotum ( Fig. 4 B) as wider as head, almost as long as wide, PL 0.42 mm, PW 0.40 mm; disc finely punctate, with wide median longitudinal sulcus and distinct transverse antebasal sulcus, lacking dorsal carinae and discal and antebasal tubercles. Elytra ( Fig. 5 B) slightly longer than wide, EL 0.66 mm, EW 0.60 mm, with shallow discal striae and emarginate anterolateral margins. Mesoventrite ( Fig. 6 B) with posterior pair of forks of lateral foveae overlapping median foveae. Metaventrite with pair of distinct submedian protuberances ( Fig. 6 B, indicated by arrow); posterior margin with relatively wide notch at middle. Mesotibia with small apical spine; metatrochanter with apically broad ventral projection. Tergite IV ( Fig. 8 B) with complete and oblique inner marginal carinae; basal impression subdivided into three parts by one pair of mediobasal and two pairs of basolateral foveae. Sternite IV ( Fig. 9 B) with one pair of mediobasal and three pairs of basolateral foveae. Length of aedeagus ( Fig. 10 D–F) 0.28 mm, median lobe with transverse basal bulb and large foramen; apex of median lobe broad and curved; dorsal lobe composed of two elongate sclerites.

Female. Unknown.

Comparative notes. Araneibatrus cellulanus shares with A. callissimus and A. grossepunctatus (described below) the median and postantennal carinae on the vertex, the apically spinose male mesotibiae, and a relatively broad notch at the middle of the posterior margin of the metaventrite. The new species can be readily separated from A. callissimus by the unmodified antennal clubs, and stouter pronotum, and from A. grossepunctatus by the much more slender antennomeres IX–X, and the finely punctate pronotal disc.

Collecting environment. Individuals were collected beside a pool inside a cave about 130 m from the entrance.

Distribution. Southern China: Guangdong ( Fig. 12 ).

Etymology. The specific epithet means ‘a hermit, a recluse’, referring to the collection of this species in a cave.

Figures

FIGURE 1. Dorsal habitus of Araneibatrus species. A. A. callissimus, male. B. A. cellulanus, 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 6. Meso- and metaventrite of Araneibatrus species. A. A. callissimus. B. A. cellulanus. C. A. grossepunctatus. D. A. gracilipes. 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 10. 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. callissimus. D – F. A. cellulanus. G – I. A. grossepunctatus. Scales: 0.2 mm.

FIGURE 12. Distribution of Araneibatrus species.