Batrisiella zhujianqingi, 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 : 87-89

Batrisiella zhujianqingi sp. nov.

( Figs 37 , 80C , 92C )

Chinese common name: 朱氏小毛唇à甲

Type material ( 9 exx.). HOLOTYPE: CHINA: ♂, ‘China: Xizang, Nyalam County, Zhangmu Town , 27°59’15”N, 85°58’59”E, 2200 m, 17.vii.2010, leaf litter, sifted, J.-Q. Zhu leg., [ƱẪỄŃ木县樟木W]’ ( SNUC). PARATYPES: CHINA: 1 ♂, 6 ♀♀, same data as that of holotype; 1 ♀, also from Zhangmu, except ‘ Lixin Vill. (ĒẾ村), 27°57’21”N, 85°58’41”E, 2400–2600 m, 27.vii.2010 ’ (all paratypes in SNUC).

Diagnosis. Male. Body length 1.81–1.87 mm. Head sub-rectangular at base; vertexal foveae small and asetose, with transverse sulcus disappearing just before foveae; antenna long, antennomeres each slightly elongate, lacking modifications. Discal stria of elytron extending to apical 1/7 of elytral length. Legs almost simple, only mesotibia with small apical spur. Abdomen with large tergite 1 (IV) and vertical tergites 2–5 (V–VIII); tergite 1 with large posteromedial cavity and setose lateral patches. Aedeagus strongly asymmetric; ventral stalk narrowing apically and with rounded apex; dorsal lobe strongly curved at base, broad apically; parameres reduced and forming single semi-membranous structure. Female. Body length 1.73–1.75 mm; mesotibia lacking apical spur, tergite 1 lacking modifications, genitalia as in Fig. 37H .

Description. Male. Body ( Fig. 37A ) length 1.81–1.87 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with moderately long pubescence.

Head ( Fig. 37B ) sub-rectangular at base, much broader than long, length 0.37–0.38 mm, width across eyes 0.44–0.45 mm; vertex smooth, sparsely pubescent, with large, asetose vertexal foveae (dorsal tentorial pits), with transverse sulcus posterior to antennal tubercles, disappearing before vertexal foveae, mediobasal carina absent; antennal tubercles weakly raised; frons slightly impressed between antennal tubercles, roughly punctate, confluent with clypeus; clypeus with roughly punctate surface, its anterior margin moderately carinate and raised; ocular-mandibular carina present. Venter with two small gular foveae (posterior tentorial pits) originating from shared transverse slit, with distinct median carina extending from foveae anteriorly to mouthparts. Compound eyes prominent, composed of approximately 20 ommatidia. Antenna elongate, length 0.90–0.95 mm, apical three antennomeres loosely forming club; antennomere 1 thick, subcylindrical, apicolateral portion ( Fig. 37C ) with inner glandular structure and small trichome composed of short, thickened setae, 2–8 each elongate, 8 smallest, 9 much longer and broader than 8, 10 slightly broad than and as long as 9, 11 largest, much shorter than 9 and 10 combined, sub-fusiform.

Pronotum ( Fig. 37B ) approximately as long as broad, length 0.44–0.47 mm, width 0.46–0.47 mm, widest at middle; lateral margins rounded; disc slightly convex, finely punctate and sparsely pubescent; median longitudinal sulcus slightly longer than semicircular lateral sulci in dorsal view, the latter extending from dorsal surface laterally and posteriorly and then fusing with lateral ends of antebasal sulcus; lacking median antebasal fovea, lateral antebasal foveae connected by deep antebasal sulcus; outer and inner pair of basolateral foveae distinct. Prosternum with anterior part as long as coxal part, with large lateral procoxal foveae; thin hypomeral ridge extending from base to middle of anterior part, with two pairs of small hypomeral foveae; margin of coxal cavity weakly carinate.

Elytra much wider than long, length 0.50–0.52 mm, width 0.71–0.72 mm; each elytron with two large, asetose basal foveae, lacking subbasal fovea; discal stria extending from outer basal fovea to apical 1/7 of elytral length; humerus denticulate, with small subhumeral fovea, with marginal stria extending from fovea to posterior margin of elytron, with thin, curved carina extending from fovea to humerus.

Mesoventrite short, demarcated from metaventrite by ridged anterior edges of impressed areas where lateral mesocoxal foveae situated at mesal margins, with pair of strongly raised admesal carinae; setose median mesoventral foveae widely separated, lateral mesoventral foveae large and setose, broadly forked internally; intercoxal process short. Metaventrite weakly impressed medially, with large, setose lateral mesocoxal foveae and pair of smaller, setose lateral metaventral foveae, posterior margin broadly and shallowly emarginate at middle, lacking split.

Legs moderately elongate, lacking distinct modifications; mesotibia with small apical spur.

Abdomen widest at lateral margins of tergite 1 (IV), length 0.53–0.55 mm, width 0.70 mm. Tergite 1 (IV) ( Fig. 37D ) strongly longer than tergites 2–4 (V–VII) combined, setose basal sulcus separated by mediobasal and one pair of basolateral foveae, discal carinae long, outer marginal carinae present at basal 1/3; with large, transverse central cavity at posterior end of tergite, anterior margin of cavity with one middle and two admesal tubercles, posterior margin with broad projection and setose tuft at middle, areas lateral cavity covered with dense, short setae; tergites 2–5 (V–VIII) tightly compressed, vertical, 2–4 each with one pair of basolateral foveae, tergite 4 (VII) as long as 2 and 3 combined along middle, tergite 5 (VIII) broad and slightly transverse, posterior margin roundly emarginate at middle. Sternite 2 (IV) with large mediobasal and two pairs of basolateral foveae in setose basal impression, with pair of moderately long lateral carinae; midlength of sternite 2 (IV) shorter than 3–4 (V–VI) combined, sternites 3–5 (V–VII) each with one pair of small basolateral foveae, sternite 6 (IX) ( Fig. 37E ) sub-rounded, apical 1/3 moderately sclerotized and with a few setae along anterior margin, basal 2/3 membranous.

Aedeagus ( Fig. 37F, G ) 0.31 mm long, strongly asymmetric; median lobe with large basal capsule and small, rounded triangular foramen, ventral stalk dorsoventrally broad at base, strongly narrowed for short distance at middle, and then dilated apically, with rounded apex; dorsal lobe in dorso-ventral view strongly curved at base, broad at middle, strongly broad at apical portion; parameres reduced and forming single semi-membranous structure.

Female. Similar to male in external morphology; antenna slightly shorter, apicolateral trichome of scape same as that of male; tergite 1 (IV) lacking modifications; each compound eye composed of approximately 18 ommatidia; humerus also denticulate; mesotibia lacking apical spur. Measurements (as for male): body length 1.73–1.75 mm; length/width of head 0.34–0.35/ 0.40–0.41 mm, pronotum 0.40–0.42/ 0.43 mm, elytra 0.46–0.47/ 0.65 mm; abdomen 0.53–0.54/ 0.64–0.66 mm; length of antenna 0.81–0.82 mm; maximum width of genitalia ( Fig. 37H ) 0.23 mm.

Comparative notes. The new species shares with B. concisa and B. ganma a posteriorly positioned central cavity of male tergite 1 (IV), and vertical tergites 2–5 (V–VIII). It differs from both of these species by the posterior margin of the tergal cavity with broad projection and setose tuft at middle (projection absent in B. concisa and of a different form in B. ganma ), as well as a broad, apically obliquely dilated dorsal lobe of the aedeagus.

Distribution. Nyalam County, Tibet, SW China ( Figs 80C , 92C ).

Etymology. The new species is named after Jian-Qing Zhu, a Lepidopterist and the collector of the new species.

Figures

FIGURE 37. Morphology of Batrisiella zhujianqingi sp. nov. (A–G. Male. H. Female). A. Dorsal habitus. B. Head and pronotum. C. Antennomere 1. D. Tergite 1 (IV). E. Sternite 7 (IX). F, G. Aedeagus, dorsal (F) and lateral (G). H. Genitalia. Scale bars: 0.5 mm in A; 0.3 mm in B; 0.05 mm in C, E; 0.2 mm in D, F, G; 0.1 mm in H.

FIGURE 80. Distribution of Tibetan Batrisini. A. Batriscenaulax campestris sp. nov. B. Batrisiella acclivis sp. nov. (circle), B. beibeng sp. nov. (triangle), B. bomea sp. nov. (square) and B. concisa sp. nov. (cross). C. B. curvitibialis sp. nov. (circle), B. ganma sp. nov. (triangle), B. guttata sp. nov. (square) and B. zhujianqingi (diamond).

FIGURE 92. Environment of Zhangmu Valley (樟木沟). Environment of Youyiqiao (友谊桥) (A, B), Lixin Village (ĒẾ村) (C) and Qu Township (DZ乡) (D). Photo Credit: A, B by Jian-Qing Zhu; C, D by Wen-Xuan Bi.