Araneibatrus grossepunctatus, 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 : 487-488

Araneibatrus grossepunctatus , new species

( Figs 2 A, 4C, 5C, 6C, 8C, 9C, 10G–I, 12, 13A–B)

Type material. Holotype: male: ‘ China: Hunan, Binzhou, Beihu District, Songjia Cave, 25°40′08.05″N, 112°43′59″E, 493 m, 2015. viii.25, Wang, Huang, Tang, Yang leg. [湖 南郴州市 北湖区宋 家洞]’ ( SNUC); Paratypes: 1 female: same label data as the holotype ( SNUC); 3 males, 1 female: ‘ China: Hunan, Binzhou, Beihu District, Wanhuayan, 25°41′52.05″N, 112°35′42″E, 340 m, 2015. viii.23, Wang, Huang, Tang, Yang leg. [湖南郴州 市北湖区万华岩]’ ( SNUC).

Diagnosis. Body length 2.34–2.40 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; dorsal carinae present, lacking discal and antebasal spines. Elytra lacking discal striae; anterolateral margins not 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 unmodified antennal club and metaventrite, with spinose mesotibia and protruding metatrochanter. Aedeagus with stout basal capsule.

Description. Male ( Fig. 2 A). Length 2.38–2.40 mm. Body uniformly reddish-brown, mouth parts, tibiae and tarsi lighter in color.

Head ( Fig. 4 C) slightly longer than wide, HL 0.49 mm, HW 0.46–0.47 mm, finely punctate; vertex with short median carina extending from near posterior margin of head toward level of mid-length of eyes; pair of lateral postantennal carinae extending from posterior margins of antennal tubercles toward postocular margins; clypeus relatively short, slightly more than one-fifth of total head length; antennal club formed by three apical enlarged antennomeres, antennomeres IX and X broad, XI asymmetrically narrowed at apical one-third. Pronotum ( Fig. 4 C) narrower than head, longer than wide, PL 0.50–0.52 mm, PW 0.41–0.44 mm; disc coarsely punctate, with wide median longitudinal sulcus and distinct transverse antebasal sulcus, dorsal carinae present, lacking discal and antebasal tubercles. Elytra ( Fig. 5 C) slightly longer than wide, EL 0.71–0.73 mm, EW 0.69–0.72 mm, lacking discal striae, anterolateral margins straight. Mesoventrite ( Fig. 6 C) with lateral foveae separated from median foveae. Metaventrite ( Fig. 6 C) lacking protuberances; posterior margin with relatively wide notch at middle. Mesotibia with elongate apical spine; metatrochanter with elongate, apically blunt ventral protuberance. Tergite IV ( Fig. 8 C) 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 C) with one pair of mediobasal and three pairs of basolateral foveae; sternites IV and V each with one pair of submedian tubercles. Length of aedeagus ( Fig. 10 G–I) 0.37 mm, median lobe with stout basal bulb and large foramen; apex of elongate median lobe deeply split; dorsal lobe elongate, with two short sclerites at apex.

Female. Similar to male, except for antennomeres IX and X narrower, mesotibia and metatrochanter simple; eyes smaller and elytra relatively shorter. Measurements: BL 2.34 mm, HL 0.46–0.48 mm, HW 0.43–0.44 mm, PL 0.49 mm, PW 0.40 mm, EL 0.66–0.67 mm, EW 0.66–0.67 mm, AL 0.71–0.72 mm, AW 0.63–0.64 mm.

Comparative notes. This new species is similar to A. callissimus and A. cellulanus by sharing the presence of median and postantennal carinae on the vertex, and the spinose apex of the mesotibiae. It can be readily separated from both species by the coarsely punctate pronotal disc, and a different form of the male antennal clubs.

Collecting environment. Songjia Cave is a flooded cave, the holotype and one paratype were found in a passage ca. 80 m from the entrance. Paratypes from Wanhuayan were collected from a sandy floor with bat guano ( Fig. 13 A–B).

Distribution. Central China: Hunan ( Fig. 12 ).

Etymology. The specific epithet refers to the coarse punctation of the pronotal disc.

Figures

FIGURE 2. Dorsal habitus of Araneibatrus species. A. A. grossepunctatus, male. B. A. cf. gracilipes, female. 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.

FIGURE 13. Collecting environment of Araneibatrus species. A, B. A living A. grossepunctatus wandering on the cave floor. C, D. Passages inside Tham Chom Ong (C) and Tham Houay Soy (D), where two specimens of A. spinosus were collected.