Sathytes asura, 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 : 116-118

Sathytes asura sp. nov.

( Figs 50 , 83A , 97A, B, D )

Chinese common name: Nj修Ɓḛà甲

Type material (18 exx.). HOLOTYPE: CHINA: ♂ , ‘ China: Xizang, Nyingchi City, pass nr. Yigong Tea Farm , 30°10’14”N, 94°55’51”E, 2200–2400 m, 11.vii.2021, Peng, Yin & Zhang, Ʊ Ẫffż 波ṁ县ƌŭē厂 ’ ( SNUC) . PARATYPES: CHINA: 1 ♂, 3 ♀♀, same data as that of holotype; 5 ♂♂, 8 ♀♀ , ‘ 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 ’ (all paratypes in SNUC) .

Diagnosis. Male. Body length approximately 2.70–2.8 mm; ratio (length/width) of head 1.11–1.18, pronotum 1.00–1.07, elytra 0.78, length of eye/tempus 0.78. Antennomere 9 approximately as long as wide (length/width excluding apophysis 1.04), with hyaline apophysis at basal 1/3 of mesal margin, antennomere 11 elongate (length/ width 1.70), with large protuberance at base, apex of protuberance with thin tuft of curved setae. Aedeagus broad throughout length, apical margin slightly emarginate. Female. Body length approximately 2.7–2.9 mm; antenna lacking modifications, genitalia as in Fig. 50G .

Description. Male. Body ( Fig. 50A ) length 2.70–2.76 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with short pubescence.

Head ( Fig. 50B ) sub-rectangular at base, slightly longer than wide, length 0.61–0.63 mm, width across eyes 0.55 mm, length/width 1.11–1.18; 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, flat; 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), median carina shortly present near foveae. Compound eyes prominent, composed of approximately 19 large ommatidia, length of eye/tempus 0.78. Antenna elongate, length 1.39–1.43 mm, distinct club ( Fig. 50C ) formed by enlarged apical three antennomeres; antennomere 1 thick, subcylindrical, 2–8 each transverse, 2 slightly wider, 3–8 subequal in width, 9 ( Fig. 50D ) enlarged, approximately as long as wide, length/width excluding apophysis 1.04, mesal margin moderately oblique, hyaline apophysis located approximately basal 1/3 of mesal margin, 10 transverse, length/width 0.68, 11 largest, as long as 9 and 10 combined, length/width 1.70, with large protuberance at base, apex of protuberance with curved tuft of thin golden setae.

Pronotum ( Fig. 50B ) approximately as long as wide, length 0.62 mm, width 0.58–0.62 mm, length/width 1.00– 1.07, 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 0.82–0.83 mm, width 1.05–1.06 mm, length/width 0.78; each elytron with four large, asetose basal foveae; lacking discal stria; humerus weakly prominent, 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 medially, large lateral mesoventral foveae forked internally, mesoventral process short, with complete marginal stria. Metaventrite slightly raised admesally, inclined towards middle, with well-developed lateral mesocoxal and two lateral metaventral foveae, with small, round median pit shortly anterior to posterior margin, posterior margin broadly emarginate, slightly convex at middle.

Legs elongate, simple.

Abdomen widest at lateral margins of tergite 1 (IV), length 0.80–0.81 mm, width 0.91–0.94 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 or 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. Sternites depressed along 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. 50E ) moderately sclerotized, elongate, apex with three long setae.

Aedeagus ( Fig. 50F ) 0.30 mm long, slightly asymmetric, plate-like; median lobe with large foramen, slightly constricted at apical 2/5 and then slightly broadened, apical margin slightly emarginate at middle.

Female. Similar to male in external morphology; antenna slightly shorter, lacking modifications; each compound eye composed of approximately 13 ommatidia; humerus angulate. Measurements (as for male): body length 2.72–2.87 mm; length/width of head 0.60–0.61/ 0.55–0.56 mm, pronotum 0.60–0.63/ 0.60–0.65 mm, elytra 0.71– 0.87/ 0.99–1.07 mm; abdomen 0.88–0.92/ 0.93–0.99 mm; length of antenna 1.27–1.33 mm; maximum width of genitalia ( Fig. 50G ) 0.27 mm.

Comparative notes. This species morphologically resembles S. alpicola found in Mêdog, in the similar form of antennomere 9 and location of the hypophysis on it (at limit of approximately basal 1/3). These two species may be separated only by subtle differences: Sathytes asura is slightly smaller in all body parts and has shorter antennae, antennomeres 9 are relatively slightly more elongate and antennomeres 11 stouter, and the apical margin of the aedeagus is not expanded on left side.

Distribution. Bomê County, Tibet, SW China ( Figs 83A , 97A, B, D ).

Etymology. The new species is named after Asuras, demigods of the desire realm of Buddhism.

Figures

FIGURE 50. Morphology of Sathytes asura 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 83. Distribution of Tibetan Batrisini. A. Sathytes aequalis sp. nov. (circle), S. alpicola Yin & Shen (triangle) and S. asura sp. nov. (square). B. S. caichenyangi sp. nov. (circle), S. chayuensis Yin & Shen (triangle) and S. dawai sp. nov. (square). C. S. duojii sp. nov. (circle), S. laticornis sp. nov. (triangle) and S. linzhiensis Yin & Shen (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).