Pakistatyrus schmidti, Yin, 2023

Yin, Zi-Wei, 2023, A third species of Pakistatyrus Hlaváč (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 5244 (6), pp. 595-599 : 596-598

Pakistatyrus schmidti sp. nov.

( Figs 1 , 2 )

Type material. HOLOTYPE: NEPAL: J, four labels: ‘NEPAL, Manaslu Mts. , SW Merne Pokhari, 3200–3300 m, leg. Schmidt, 11.v.2005 / 28°21'41"N, 84°30'42"E, Quellgebiet, mittl., Nebenfluss des Ngadi Khola / Coll. SENM in MHNG, loan 23.x.2015 / HOLOTYPE (handwritten) J, Pakistatyrus schmidti sp. n., det. Z.-W. Yin 2023, SENM’ (in SENM). (Note: right foreleg of holotype broken at base of femur, and missing)

Diagnosis. Male. Body length approximately 3.5 mm, color reddish-brown. Foveae of pronotum and elytra large and setose. Maxillary palpomere 3 2.6 times as long as broad. Antenna approximately 1.7 mm long; antennomere 1 approximately 1.7 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. Elytra greatly transverse, length/width 0.46. Protrochanter with distinct spine on ventral margin; mesocoxa lacking tubercle; hind leg simple. Aedeagus with broad median lobe narrowing toward apex; parameres asymmetric, much shorter than median lobe, each paramere with four apical setae; lacking obvious endophallus armature. Female. Unknown.

Description. Male. Body ( Fig. 1A ) length (from anterior margin of clypeus to apex of abdomen) 3.49 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body shining, covered with short pubescence.

Head ( Fig. 1B ) elongate-hexagonal, truncate at apex, slightly longer than wide, length from anterior margin of clypeus to posterior margin (excluding occipital constriction) 0.71 mm, width across eyes 0.62 mm; vertex rough, small asetose vertexal foveae (dorsal tentorial pits) at level posterior to middle of eyes; frons strongly impressed around setose frontal fovea, antennal tubercle weakly convex, forming distinct rostrum, area between tubercles moderately impressed; ocular canthus short, broadly triangular. Gular deeply impressed at middle to form transversely oval depression, where widely separated foveae (posterior tentorial pits) are located. Compound eyes small, each composed of approximately 22 ommatidia. Antenna moderately elongate, length 1.73 mm, indistinct club formed by three apical moderately enlarged antennomeres, lacking modifications; antennomere 1 shorter than 2 and 3 combined, 1.73 times as long as wide, 2 slightly wider than 3–8, 3–8 each elongate, successively shorter, 9 and 10 subequal in length, 10 slightly wider than 9, 11 suboval, truncate at base, as long as 9 and 10 combined. Maxillary palpus ( Fig. 1C ) with palpomere 1 small, 2 long and strongly curved, 3 and 4 basally pedunculate and apically broadened, 4 densely setose, with short, translucent palpal cone at apex; length/ width of palpomere 2 0.32/ 0.07 mm, 3 0.18/ 0.07 mm, 4 0.21/ 0.09 mm.

Pronotum ( Fig. 1B ) slightly longer than wide, length along middle 0.77 mm, maximum width 0.72 mm, widest at 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, with large, setose median and lateral antebasal foveae, lacking transverse antebasal impression or mediobasal carina. Prosternum with anterior part as long as coxal part, lateral procoxal foveae in densely setose impression; margin of coxal cavity weakly carinate.

Elytra greatly shortened, subtrapezoidal, truncate at bases, much wider than long, length along suture 0.59 mm, maximum width 1.29 mm, length/width 0.46, broadest shortly anterior to posterior margin; each elytron with two large, setose basal foveae and broad, deep discal stria; lacking humeral tubercle; subhumeral fovea and marginal stria absent.

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

Legs elongate; protibia with two perpendicular rows of spinose setae along mesal margin, protrochanter ( Fig. 1D ) with blunt ventral spine, two spines on ventral surface of profemur ( Fig. 1D ) supposedly large and long, as in P. ater and P. inconspicuus (both spines of left profemur broken in holotype, as indicated by yellow arrowheads in figure); mesocoxa simple, mesotrochanter ( Fig. 1E ) with small ventral spine, mesofemur swollen, mesotibia with short tubercle at apex; hind leg simple, lacking spines or projections.

Abdomen much broader than elytra, approximately as long as wide, widest at lateral margins of tergite 1 (IV), length 1.42 mm, width 1.49 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 and slightly sinuate, with two small basolateral foveae. Sternites 2–4 (IV–VI) subequal in length along middle, 5 (VII) shorter than 4, 2–5 each with setose basal sulcus and two basolateral at lateral margins of sulcus, 6 (VIII) transverse, posterior margin roundly emarginate at middle, 7 (IX) ( Fig. 1F ) moderately sclerotized, composed of one middle and two lateral plates, middle sclerite with many setae along apical margin.

Aedeagus ( Fig. 1G, H ) 0.59 mm long, dorso-ventrally asymmetric; median lobe broad at base, narrowing from below middle to apex, with bulbous basal capsule and small foramen, dorsal diaphragm distinct, apical area curved to left (position as in figure); parameres greatly asymmetric, left paramere much longer than right one, apical margin of each paramere with four long setae; endophallus armature absent.

Female. Unknown.

Comparative notes. This species, exhibiting the greatest degree of elytral reduction (elytral length/width 0.46 vs. 0.52 in P. ater , and 0.63 in P. inconspicuus ), differs from P. ater by the reddish-brown body and simple male antennal clubs; and from P. inconspicuus by the rough vertex, relatively much shorter antennomeres 1 in relation to 2 and 3, and much larger foveae of the pronotum and elytra. The greatly asymmetric aedeagus alone of the new species is characteristic. Geographically, P. schmidti is only 80 km east to Pakistatyrus sp. distributed in southern Tibet ( Fig. 2 ), but the single female apparently represents another distinct species with smooth vertex, smaller pronotal and elytral foveae, and longer elytra (length/width 0.57). The three known species of the genus can also be quickly separated by using the key provided above.

Bionomics. Unknown.

Distribution. Nepal: Gandaki ( Fig. 2 ).

Etymology. The new species is named after German carabidologist Joachim Schmidt (University of Rostock, Rostock, Germany), who collected the single male.

Figures

FIGURE 1. Pakistatyrus schmidti sp. nov., male. A. Dorsal Habitus; B. Head and pronotum; C. Left maxillary palpus, ventral; D. Protrochanter and profemur; E. Mesotrochanter and mesofemur; F. Sternite IX; G, H. Aedeagus, lateral (G) and ventral (H). Scale bars: 1.0 mm in A; 0.5 mm in B, D, E; 0.2 mm in C, F–H.

FIGURE 2. Distribution of Pakistatyrus species along the Himalaya, with the aedeagi compared.