Geonigidius sinensis Xin, Gong, Zhong & Qi, 2025

Geonigidius sinensis Xin, Gong, Zhong & Qi , sp. nov.

Chinese common name: 中华üaēạṁş http://zoobank.org/ urn:lsid:zoobank.org:act:

( Figs. 1–10 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 )

Type material. Holotype, ♂ ( NACRC: IOZ (E) 224806), CHINA, Xizang Autonomous Region, Nyingchi City , Medog County ( 墨º县), Derkog Village ( Ễ尔ūť), near Degang Temple ( DZÑŵ) ( 29.178471°N, 95.123986°E), 2003 m, 9.VII.2025, Jia-Xian Gong, Hai-Bin Zhang & Yun-Jie Zhang leg. GoogleMaps

Diagnosis. As for the genus.

Description of the holotype. Male, body length 24.3 mm. Length of particular body parts: head ( 4.7 mm), mandible (horizontal length: 2.8 mm; right dorsal appendage: 6.9 mm; left dorsal appendage: 4.0 mm), pronotum ( 6.4 mm), elytra ( 10.5 mm); width: head ( 10.3 mm), pronotum ( 9.5 mm), elytra ( 9.7 mm).

Habitus ( Figs. 1–2 View FIGURE 1 View FIGURE 2 ). Body stubby with a length only 2.1 times the width; black, punctate, with distinct luster, and without conspicuous vestiture on surface except for the base of mandibles and the dorsal side of the apical part of protibiae.

Head ( Figs. 3–4 View FIGURE 3 View FIGURE 4 ) large, subtrapezoidal, length approximately over 1/5 of the entire body, weakly wider than the pronotum but slightly shorter in length relative to the latter, with its surfaces bearing dense, deep punctures; a pair of short longitudinal carinae occur on the dorsal surface behind the anterior margin of head, with distinct elevation and posterolateral orientation; two conspicuous punctate tubercles symmetrically positioned lateral to the midline of the·basal 1/3. Eyes small located on the outer margins of the median length of the head. Canthus thin and just completely dividing the eye; the postocular margin connected to canthus to cover the entire eye, and exhibiting an obvious subtriangular expansion, with the lateral angles rounded; the length of the postocular margin significantly longer than the preocular margin. Clypeolabrum transverse, rectangular, with flat apical margin. Mandibles robust and asymmetrical; inner margin of left mandible with two blunt teeth, while the inner margin of the right mandible with one blunt tooth; apices of mandibles obtusely acute. The dorsal appendages of mandibles distinctly asymmetrical, strongly upturned, nearly perpendicular to the head; the left one shorter slightly curved with three small rounded teeth apically, while the right one strongly curved at apical half and with two small rounded teeth; apices of appendages rounded. Mentum wide, surface flat and moderately punctate, and an M-shaped apical margin. Ventral side of apical half of the scape covered with deep and irregular punctures. Antennal club with 3 antennomeres, antennomeres VIII–IX subtriangular, antennomere X semi-elliptic.

Pronotum ( Fig. 5A View FIGURE 5 ) transverse, 1.5 times wider than long, widest behind the anterior angles, narrower and slightly shorter than head. Dorsal surface relatively smooth without central depression, shiny parts occur on both sides near the midline, the remaining areas bear dense and distinct punctures. Anterior margin bisinuate; lateral margins relatively straight and slightly serrated in the middle; posterior margin slightly curved and exhibits a smooth contour. Anterior angles obtuse, lateral lobes almost absent, posterior angles rounded.

Prosternum ( Fig. 5B View FIGURE 5 ) covered with deep punctures, and most of these punctures with a short yellowish-brown seta in the center. A significant distance between the prothorax and metathorax results in incomplete closure of the segments.

Elytra ( Fig. 5C View FIGURE 5 ; 6C–E View FIGURE 6 ) short and broad, widest at the middle, length less than the sum of the head length (excluding the mandible) and the pronotum length. Distinctly arched in lateral view, with dense deep punctures at the base, and dense rows of punctures varying in size; 7 longitudinal carinae obviously elevated, extend from the base to the region before the apex, the outermost longitudinal carina (carina VII) exhibits the strongest elevation, and completely obscures the lateral margin of the elytron in dorsal view.

Metasternum and visible abdominal ventrites ( Fig. 5D View FIGURE 5 ) covered with punctures; the former exhibit larger and deeper punctures, while the latter show denser ones, and most of the punctures on the abdomen with a short seta.

Scutellum ( Fig. 5E View FIGURE 5 ) tiny and trapezoidal, length and width nearly equal; with 8 deep punctures on the surface.

Legs. Protibia with 5 conspicuous sharp teeth (excluding apical fork) along outer margin, the tooth near base tiny; apex bifurcate with branches sharp at tip. Outer margin of the meso- and metatibia with 3–4 lateral spines, apically with three spines. Tarsi short with a single seta between pair of claws ( Fig. 5F View FIGURE 5 ); protarsus approximately 1/2 the length of the protibia; mesotarsus approximately 4/5 the length of the mesotibia; metatarsus approximately 1/2 the length of the metatibia.

Hindwings ( Fig. 6A–B View FIGURE 6 ) strongly atrophied into a strip-like shape, length slightly shorter than the elytra, with venation degenerated and structure simplified.

Abdomen and aedeagus. Abdominal tergite VIII ( Fig. 7A View FIGURE 7 ) without lateral angles, with a broad central membranous area. Abdominal ventrite VIII ( Fig. 7B View FIGURE 7 ) transverse, structure-simplified with sclerotic outer margin. Ventral plate of the abdominal segment IX ( Fig. 7C–E View FIGURE 7 ) without membranous stripe, and widens strongly near the apical 1/3. Aedeagus ( Fig. 8A–D View FIGURE 8 ) about 2.2 times longer than wide in dorsal view. Basal piece elongated, distinctly constricted in basal part, nearly 1.6 times longer than parameres in dorsal view; pair of dorsal plates strip-shaped, with sclerotized and membranous parts in roughly equal proportions; ventral plate ( Fig. 8D View FIGURE 8 ) at apical end of basal piece slightly sclerotized. Paramere ( Fig. 8E View FIGURE 8 ) distinctly curved inward apically, with a relatively large triangular projection present on the ventral side. Base of the median lobe ( Fig. 8E View FIGURE 8 ) membranous in dorsal side; extends laterally toward both sides at apex on ventral side. Flagellum ( Fig. 8A, F View FIGURE 8 ) extremely long, length exceeding 5 times that of aedeagus, coiled spirally, tapering from base to apex, apex sharp.

Female. Unknown.

Etymology. The specific epithet sinensis refers to China, the country of origin of the new taxon.

Notes. The habitat of Geonigidius sinensis Xin, Gong, Zhong & Qi , gen. nov. and sp. nov. including a living individual is shown in Fig. 9 View FIGURE 9 .

Distribution. China ( Xizang) ( Fig. 10 View FIGURE 10 ).