Sathytes virupaksa, Yin, 2022

Yin, Zi-Wei, 2022, The Batrisini of Tibet: unveiling an enigmatic ant-loving beetle diversity at Earth’s “ Third Pole ” (Coleoptera, Staphylinidae, Pselaphinae), Zootaxa 5111 (1), pp. 1-211 : 138-140

Sathytes virupaksa sp. nov.

( Figs 60 , 84C , 97D )

Chinese common name: 广ƃḛà甲

Type material (3 exx.). HOLOTYPE: CHINA: ♂ , ‘ China: Xizang, Nyingchi City, Tongmai Town, pass nr. 102 Tunnel , 30°04’15”N, 95°08’07”E, 2150–2400 m, 12.vii.2021, Peng, Yin & Zhang, Ʊ Ẫȃ 9 102 Ṁdz ’ ( SNUC) . PARATYPES: CHINA: 2 ♀♀, same data as that of holotype ( SNUC) .

Diagnosis. Male. Body length approximately 2.6 mm; ratio (length/width) of head 1.07, pronotum 1.03, elytra 0.78, length of eye/tempus 0.88. Antennomere 9 as long as wide (length/width excluding apophysis 0.90), with hyaline apophysis at basal 2/5 of strongly oblique mesal margin, antennomere 11 elongate (length/width 1.89), with distinct protuberance at base, apex of protuberance with tuft of curved setae. Aedeagus dilated at apex, apical margin moderately emarginate at middle. Female. Body length approximately 2.7–2.9 mm; antenna lacking modifications, genitalia as in Fig. 60G .

Description. Male. Body ( Fig. 60A ) length 2.64 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with short pubescence.

Head ( Fig. 60B ) sub-rectangular at base, slightly longer than wide, length 0.59 mm, width across eyes 0.55 mm, length/width 1.07; vertex weakly raised, with small asetose foveae (dorsal tentorial pits) located posterior to level of posterior margin of eyes; frons anteriorly confluent with strongly declining clypeus, shallowly impressed medially; clypeus with smooth surface, anterior margin carinate and moderately raised; ocular-mandibular carina short; postgenal region strongly projecting. Venter with small, broadly separated gular foveae (posterior tentorial pits), with faint carina posterior mouthparts. Compound eyes prominent, composed of approximately 20 large ommatidia, length of eye/tempus 0.88. Antenna elongate, length 1.31 mm, distinct club ( Fig. 60C ) formed by enlarged apical three antennomeres; antennomere 1 thick, subcylindrical, 2–8 each transverse, subequal in width, 9 ( Fig. 60D ) strongly enlarged, approximately as long as wide, length/width excluding apophysis 0.90, mesal margin expanded mesally, anteriorly strongly oblique, hyaline apophysis located at approximately basal 2/5 of mesal margin, 10 transverse, length/width 0.90, 11 largest, much longer than 9 and 10 combined, length/width 1.89, with short, distinct protuberance at base, apex of protuberance with curved tuft of golden setae.

Pronotum ( Fig. 60B ) approximately as long as wide, length 0.62 mm, width 0.60 mm, length/width 1.03, widest at middle; lateral margins rounded, convergent apically and basally; disc weakly convex; asetose lateral antebasal foveae distinct. Prosternum with anterior part slightly longer than coxal part, with small lateral procoxal foveae; hypomeral ridge absent; margin of coxal cavity moderately carinate.

Elytra much wider than long, length 0.82 mm, width 1.05 mm, length/width 0.78; each elytron with four large, asetose basal foveae; lacking discal stria; humerus weakly angulate, subhumeral fovea present, marginal stria extending from fovea to posterior margin of elytron.

Mesoventrite short, demarcated from metaventrite by strongly curved carinae; median mesoventral foveae fused, large lateral mesoventral foveae forked internally, mesoventral process short. Metaventrite moderately prominent admesally, inclined towards middle, with well-developed lateral mesocoxal and two lateral metaventral foveae, lacking median pit anterior to posterior margin, posterior margin broadly emarginate, slightly convex at middle, with thin marginal carina.

Legs elongate, simple.

Abdomen widest at lateral margins of tergite 1 (IV), length 0.77 mm, width 0.92 mm. Tergite 1 (IV) more than twice as long as 2 (V), lacking basal sulcus, with one pair of mediobasal and two pairs of basolateral foveae, lacking discal and marginal carina; tergite 2 (V) slightly longer than 3 (VI), 4 (VII) longer than 3 but much shorter than 2 and 3 combined; tergites 2–3 (IV–VI) each with one pair of mediobasal and two pairs of basolateral foveae, 4 with one pair of basolateral foveae and marginal tubercles, tergite 5 (VIII) semicircular, transverse, posterior margin roundly emarginate at middle. Sternite 2 (IV) with one pair of mediobasal and three pairs of basolateral foveae, lateral carina absent; midlength of sternites 2–5 (IV–VII) gradually shorter, sternites 3–4 (IV–VI) each with three pairs and 5 (VII) with one pair of small basolateral foveae, sternite 6 (VIII) transverse, posterior margin broadly emarginate, sternite 7 (IX) ( Fig. 60E ) moderately sclerotized, stout, apex with three long setae.

Aedeagus ( Fig. 60F ) 0.32 mm long, slightly asymmetric, plate-like; median lobe with large foramen, apex dilated, much broader than base, apical margin moderately emarginate at middle.

Female. Similar to male in external morphology; antenna slightly shorter, lacking modifications; each compound eye composed of approximately 13 ommatidia; humerus weakly angulate. Measurements (as for male): body length 2.67–2.91 mm; length/width of head 0.62/ 0.53–0.55 mm, pronotum 0.62–0.63/ 0.61–0.62 mm, elytra 0.80/ 1.01–1.04 mm; abdomen 0.85–0.91/ 0.94–0.98 mm; length of antenna 1.28–1.37 mm; maximum width of genitalia ( Fig. 60G ) 0.28 mm.

Comparative notes. This species resembles S. chayuensis which is found in Zayü County and S. aequalis by the relatively long antennomeres 11 and he markedly oblique mesal margins of antennomeres 9. Sathytes virupaksa can be distinguished from both of these species by the smaller body size (2.64 mm vs. 2.80–2.99 mm for S. chayuensis , 2.87–2.95 mm for S. aequalis ), the relatively much shorter basal protuberances of antennomeres 11, the more posteriorly placed apophyses of antennomeres 9, as well as the dilated apex of the aedeagus.

Distribution. Bomê County, Tibet, SW China ( Figs 84C , 97D ).

Etymology. This species is named after Virűpâkṣa (广ƃƙƚ), who is one of the Four Great Heavenly Kings of Buddhism.

Figures

FIGURE 60. Morphology of Sathytes virupaksa sp. nov. (A–F. Male. G. Female). A. Dorsal habitus. B. Head and pronotum. C. Antennomeres 9–11. D. Antennomere 9. E. Sternite 7 (IX). F. Aedeagus, ventral. G. Genitalia. Scale bars: 0.5 mm in A; 0.3 mm in B; 0.2 mm in C; 0.1 mm in D–G.

FIGURE 84. Distribution of Tibetan Batrisini. A. Sathytes magnus Yin & Li (circle), S. panzhaohuii Yin & Shen (triangle) and S. pengzhongi sp. nov. (square). B. S. proclivis sp. nov. (circle), S. pseudograndis sp. nov. (triangle) and S. simplex Löbl (square). C. S. sympatricus sp. nov. (circle), S. transversus Yin & Shen (triangle) and S. virupaksa sp. nov. (square).

FIGURE 97. Environment of and collecting sites at Nyingchi area. A. Sign of Yigong Tea Farm (ƌŭē厂). B. Forest near Yigong. C. Forest at Pailong Township (ḦË乡). D. Forest near Tongmai Town (ȃ9W).