Pakistatyrus inconspicuus, Yin, 2022

Yin, Zi-Wei, 2022, Discovery of mysterious Pakistatyrus in Tibet (Coleoptera: Staphylinidae: Pselaphinae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 62 (1), pp. 129-135 : 133-135

Pakistatyrus inconspicuus sp. nov.

( Figs 1 ; 2C ; 3A, B )

Chinese common name: NJ征Ẳ山ẅḎƤ

Type material. Hඈඅඈඍඒඉൾ: CHINA: ♂, ‘ China: Xizang, Nyingchi City, valley nr. Jiare Vill., Chongge, 30°03’19”N, 93°46’46”E, 3600-3750 m, 08.vii.2021, Peng, Yin, Zhang, MBHŻDZ热村ṗǩ ’ ( SNUC). Pൺඋൺඍඒඉൾ: CHINA: 2 ♂♂, same collection data as holotype ( SNUC).

Diagnosis. Male. Body length 3.6–3.8 mm, color reddish- -brown. Maxillary palpomere 3 2.1 times as long as broad. Antenna approximately 1.8 mm; antennomere 1 2.7 times as long as wide, 2–7 each slightly elongate, 8 smallest, as long as wide, 9–11 moderately enlarged to form indistinct club, lacking modifications. Protrochanter with tiny spine on ventral margin; mesocoxa with short, blunt ventral tubercle; hind leg simple. Aedeagus with broad median lobe shortly protruding on right side of apex; parameres elongate, ventrally curved before apices, each paramere with four apical setae; endophallus composed of two triangular and two elongate weakly sclerotized structures.

Female. Unknown.

Description. Male. Body ( Fig. 1A ) length 3.66–3.79 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body shining, covered with short pubescence.

Head ( Fig. 1B ) elongate-trapezoidal, truncate at apex, slightly broader than long, length from anterior margin of clypeus to posterior margin (excluding ‘neck’ region) 0.73–0.75 mm, width across ocular canthi 0.69–0.76 mm; vertex finely punctate, small asetose vertexal foveae (dorsal tentorial pits) at level of middle of eyes; frons strongly impressed around frontal fovea, antennal tubercle weakly convex, area between tubercles broadly sulcate; ocular canthus greatly developed, broadly triangular, with 7–8 short apical spines. Gula deeply impressed in middle to form transversely oval depression, where widely separated foveae (posterior tentorial pits) are located. Compound eyes small, each composed of approximately 16 facets.Antenna moderately elongate, length 1.77–1.79 mm, indistinct club formed by three apical moderately enlarged antennomeres, lacking modifications; antennomere 1 longer than 2 and 3 combined, 2.7 times as long as wide, 2 slightly wider than 3–8, 5 slightly longer than 4 and 6, 11 suboval, truncate at base, slightly longer than 9 and 10 combined. Maxillary palpus ( Fig. 1C ) with small palpomere 1, long and strongly curved palpomere 2, and basally pedunculate and apically broadened palpomeres 3 and 4, 4 with short, translucent palpal cone at apex.

Pronotum ( Fig. 1B ) longer than wide, length along middle 0.81–0.89 mm, maximum width 0.71–0.75 mm, widest in anterior 1/3; lateral margins rounded at widest point, convergent anteriorly and posteriorly, moderately incised at level of lateral antebasal foveae; disc slightly convex, finely punctate, with shallow median and lateral longitudinal impressions; shallow transverse antebasal impression connecting large, setose median and lateral antebasal foveae, with short mediobasal carina posterior to median fovea. Prosternum with anterior part much shorter than coxal part, with distinct lateral procoxal foveae; margin of coxal cavity weakly carinate.

Elytra markedly shortened, trapezoidal, truncate at bases, much wider than long, length along suture 0.79–0.84 mm, maximum width 1.26–1.34 mm, broadest shortly before posterior margin; each elytron with two large, setose basal foveae and broad, shallow discal stria; lacking humeral angle; subhumeral fovea and marginal stria absent.

Mesoventrite short, fused with metaventrite, with relatively long and carinate mesoventral process. Metaventrite distinctly ridged admesally, broadly impressed in middle, anterior metaventral process short, with truncate anterior margin, posterior process with short slit in middle.

Legs elongate; protibia with two rows of spinose setae along mesal margin, protrochanter ( Fig. 1D ) with tiny ventral spine, profemur ( Fig. 1D ) swollen, with two large spines on ventral surface; mesocoxa ( Fig. 1E ) with short, blunt ventral tubercle, mesotrochanter ( Fig. 1E ) with acute long ventral spine, mesofemur swollen; hind leg lacking spines or projections.

Abdomen much broader than elytra, as long as wide, widest at lateral margins of tergite 1 (IV), length 1.42–1.51 mm, width 1.42–1.50 mm. Tergites 1–3 (IV–VI) subequal in length along middle, each with broad paratergites protruding laterally, setose basal sulcus and two basolateral foveae, 4 (VII) slightly longer than 3 (VI) along middle, with triangular paratergites and pair of basolateral foveae in setose lateral impressions, 5 (VIII) transverse, posterior margin broadly truncate, two small basolateral foveae. Sternite 2–5 (IV–VII) subequal in length along middle, each with setose basal sulcus and two basolateral foveae on lateral margins of sulcus, 6 (VIII) transverse, posterior margin roundly emarginate in middle, 7 (IX) ( Fig. 1F ) moderately sclerotized, composed of one middle and two lateral plates, middle sclerite with many setae along apical margin.

Aedeagus ( Figs 1G, H ) 0.57 mm long, dorso-ventrally slightly asymmetric; median lobe broad, with bulbous basal capsule and small foramen, dorsal diaphragm distinct, apical margin protruding on right side (position as in figure); parameres evenly curved in lateral view, moderately curved near apex in ventral view, apical margin of each paramere with four thick setae; endophallus weakly developed and sclerotized, composed of two subtriangular and two elongate sclerites.

Female. Unknown.

Comparative notes. This species differs from its only congener P. ater ( Fig. 2B ) from northern Pakistan in reddish- -brown coloration of the body, simple male antennomeres 10 and 11 and metatibiae, as well as in dorsoventrally much broader median lobe of the aedeagus.

Etymology. The specific epithet ‘ incōnspicuus ’ (inconspicuous, unremarkable) is a Latin adjective indicating lack of obvious male sexual characters of this species.

Distribution and habitat. SW China: Tibet ( Fig. 2C ). All three individuals were collected by sifting fern leaf or fern leaf/shrub debris samples in a coniferous forest at an altitude of 3600–3750 m ( Figs 3A, B ).

Figures

Fig. 1. Morphology of Pakistatyrus inconspicuus sp. nov., male.A – dorsal habitus; B – head and pronotum; C – right maxillary palpus; D – protrochanter and profemur; E – mesocoxa, mesotrochanter and mesofemur; F – sternite 7 (IX); G, H – aedeagus, lateral (G) and ventral (H), with endophallus and parameres outlined. Scale bars: 1.0 mm in A; 0.3 mm in B, D, E; 0.2 mm in C, F–H.

Fig. 2. Dorsal habitus (A, B) and distribution (C) of Pakistatyrus. A – Pakistatyrus sp.; B – holotype of P. ater, with type labels (upper) and sketch of aedeagus (lower, from Hඅൺඏගඹ 2006); C – circle: P. ater, triangle: Pakistatyrus sp., square: P. inconspicuus sp. nov. Scale bars: 1.0 mm.

Fig. 3. Environment and habitat of P. inconspicuus sp. nov. (A, B) and Pakistatyrus sp. (C, D), and a living individual of Pakistatyrus sp. in situ (E).