Gyrongita uniformis, 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 : 110-111

Gyrongita uniformis sp. nov.

( Figs 48 , 82A , 90 )

Chinese common name: 同型小吉Pà甲

Type material (2 exx.). HOLOTYPE: CHINA: ♂ , ‘ China: Xizang, Gyirong County, Gyirong Valley , slope nr. Jifu Vill., 28°22’37”N, 85°19’41”E, 2400–2700 m, 22.vi.2021, Z. Peng, Z. Yin & W. Zhang leg., ƱẪU喀NJ吉PW吉 ė村ṉữ山坡 ’ ( SNUC) . PARATYPE: CHINA: 1 ♂, same data as that of holotype’ ( SNUC) .

Diagnosis. Male. Body length less than 1.7 mm; dorsal surface of body with dense, moderately long pubescence. Head subtriangular, transverse, slightly broader than pronotum, tempus moderately long, angulate at posterolateral angle, vertex with reversed U-shaped sulcus connecting small, asetose foveae, with short mediobasal carina extending from near head base anteriorly to point posterior to middle of eyes, with two pairs of distinct lateral carinae from base to posterior margin of weakly raised antennal tubercles; antenna moderately short, lacking modifications, club loosely formed by apical three moderately enlarged antennomeres. Pronotum with thin median and lateral longitudinal sulci, with pair of short discal carinae, with small antebasal and marginal tubercles. Discal stria of elytron indistinct, short; disc finely punctate. Legs lacking modifications. Aedeagus in dorsal view symmetric, flattened; median lobe with large, rounded triangular foramen, ventral stalk laterally narrowed, dorsal lobe embracing ventral stalk, lobe plate-like, parameres reduced to single membranous structure.

Description. Male. Body ( Fig. 48A ) length 1.59–1.66 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with relatively dense pubescence.

Head ( Fig. 48B ) subtriangular, wider than long, length 0.30–0.32 mm, width across eyes 0.39–0.40 mm; vertex smooth, markedly raised at middle, with reversed U-shaped sulcus connecting asetose, widely separated vertexal foveae (dorsal tentorial pits), mediobasal carina short, extending from near head base anteriorly to extend past posterior margin of eyes, with two pairs of distinct lateral carinae, both extending from near head base anteriorly to base of antennal tubercle; posterolateral angle angulate; frons anteriorly demarcated from clypeus by oblique frontalclypeal ridge, weakly impressed between weakly raised antennal tubercles; clypeus with smooth surface, its entire anterior margin strongly carinate and moderately raised; ocular-mandibular carina complete, carina branched below eye, extended ventrally and then anteriorly to posteroventral articulation of mandible. Venter with smooth surface; small gular foveae (posterior tentorial pits) originating from shared oval opening, with faint median carina present for short distance posterior to mouthparts. Compound eyes prominent, conical, each composed of approximately 45 ommatidia. Antenna relatively short, length 0.79 mm, club ( Fig. 48C ) loosely formed by moderately enlarged apical three antennomeres; antennomere 1 thick, subcylindrical, 2–8 each moniliform, 9 much larger than 8, 10 much longer than 9, 11 largest, as long as 9 and 10 combined, sub-conical.

Pronotum ( Fig. 48B ) approximately as long as wide, length 0.34–0.35 mm, width 0.35–0.37 mm, widest at middle; lateral margins rounded, convergent apically and basally; disc slightly convex, finely punctate, with thin median longitudinal sulcus and short mediobasal carina, with pair of short, indistinct discal carinae and lateral longitudinal impressions, with small antebasal, discal and marginal tubercles; with small, asetose lateral antebasal and outer and inner pair of basolateral foveae; collar region roughened. Prosternum with anterior part slightly longer than coxal part, with small lateral procoxal foveae; hypomeral ridge extending from base to middle of anterior part, with punctiform lateral antebasal hypomeral pit; margin of coxal cavity slightly carinate.

Elytra much wider than long, length 0.44–0.46 mm, width 0.55–0.59 mm; each elytron with three moderately small, widely separated asetose basal foveae; indistinct discal stria extending posteriorly from outer basal fovea to slightly less than half of elytral length; humerus denticulate, subhumeral fovea present, marginal stria extending from fovea to posterior margin of elytron.

Mesoventrite short, demarcated from metaventrite by transverse carinae; median mesoventral foveae moderately widely separated, originating from shared opening, large lateral mesoventral foveae deeply forked internally, with broad anterior mesoventral process, with complete marginal stria. Metaventrite prominent admesally, inclined towards middle, with well-developed lateral mesocoxal foveae, two lateral metaventral foveae widely separated; posterior margin weakly emarginate at middle, with narrow split.

Legs moderately elongate, lacking modifications.

Abdomen widest at lateral margins of tergite 1 (IV), length 0.52–0.53 mm, width 0.51–0.55 mm. Tergite 1 (IV) more than twice as long as 2 (V), with one pair of mediobasal and two pairs of basolateral foveae, lacking discal carinae, inner marginal carina oblique, complete, outer marginal carina lacking; tergite 2 (V) slightly longer than 3 (VI), 4 (VII) shorter than tergites 2 and 3 combined; tergites 2–4 (V–VII) each with one pair of small basolateral foveae and pair of thin lateral carinae, tergite 5 (VIII) semicircular, posterior margin weakly emarginate at middle. Sternite 2 (IV) with one pair of mediobasal and three pairs of basolateral foveae, with pair of lateral carinae; midlength of sternites 2–5 (IV–VVI) gradually shorter, sternites 3–5 lacking foveae, sternite 6 (VIII) short, strongly transverse, posterior margin broadly emarginate, sternite 7 (IX) ( Fig. 48D ) membranous, consisting of pair of subtriangular lateral plates and one elongately oval central plate.

Aedeagus ( Fig. 48E, F ) 0.25 mm long, in dorsal view flattened; median lobe with broad basal capsule and large foramen, with curved basoventral projection, ventral stalk laterally narrowed and with rounded apex, with two apical setae; dorsal lobe broad, plate-like, embracing median lobe; parameres membranous, reduced to single membranous structure.

Female. Unknown

Distribution. Gyirong County, Tibet, SW China ( Figs 82A , 90 ).

Etymology. The specific epithet ‘ uniformis , - e ’ is a Latin adjective meaning ‘uniform’, referring to the lack of observable male secondary sexual characters of the new species.

Figures

FIGURE 48. Morphology of Gyrongita uniformis sp. nov., male. A. Dorsal habitus. B. Head and pronotum. C. Antennomeres 9–11. D. Sternite 7 (IX). E–F. Aedeagus, lateral (E) and ventral (F). Scale bars: 0.5 mm in A; 0.2 mm in B; 0.1 mm in C–F.

FIGURE 82. Distribution of Tibetan Batrisini. A. Gyrongita uniformis sp. nov. B. Hingstoniella lata, Jeannel C. Myrmicophila motuoensis Yin.

FIGURE 90. Environment of and collecting sites at Gyirong Valley. A. General environment of the valley. B. A slope dominated by conifers along the valley. C. Zhong Peng searching pselaphines under the bark of a fallen trunk.