Dorcus liyuani Qi & Zhan, 2025

Dorcus liyuani Qi & Zhan View in CoL , new species

Chinese common name: ṃ圆大*

Figs. 1A–B View FIGURE 1 ; 2A View FIGURE 2 ; 3A–B View FIGURE 3 ; 4A–B View FIGURE 4 ; 5A–H View FIGURE 5 ; 6A–B View FIGURE 6 ; 7A–H View FIGURE 7 ; 8A–B View FIGURE 8

Type locality. China, Gansu Province, Longnan City, Tanchang County, Guanegou National Forest Park.

Type material. Holotype: ♂ ( NACRC: IOZ (E) 211515), CHINA, Gansu Province, Longnan City, Tanchang County [àȅ县], Guanegou National Forest Park [ḂẈŝ国ẍũūȓ园], alt. 2500 m, 19.IV.2023, Yuan Li & Rong-Chuan Tao leg. Paratypes: 2♂♂ ( CCCC, CCZ) same data as holotype ; 1♂ ( CZHQ) same data as holotype, but 21.III.2024, Yuan Li leg. ; 1♂ ( CYL) same data as holotype, but 20.VII.2020, Xu Liu leg.

Description of the holotype. ♂ ( Fig. 1A–B View FIGURE 1 ), body length 35.4 mm. Length of particular body parts: head (5.5 mm), mandible (7.7 mm), pronotum (6.5 mm), elytra (15.7 mm); width of: head (12.4 mm), pronotum (13.5 mm), elytra (11.7 mm).

Habitus ( Figs. 1A–B View FIGURE 1 ). Body black with glossy, generally glabrous; some distinct, recumbent, yellowish pubescence present on the middle part of the prosternum and lateral parts of the metasternum.

Head transverse, about 2.2 times wider than long, widest at eyes. Canthus thin, dividing about 1/2 of the eye. Clypeolabrum short and strongly transverse, widely and shallowly emarginate at the apical margin; lateral angles of clypeolabrum weakly acute. Mandible about 1.5 times as long as the head, distinctly incurved at the middle; a single inner tooth present at the middle, pointing entad and rounded at the apex; the tip of the mandible sharp, with a small, rounded protuberance on the dorsal surface behind the apex ( Fig. 4A View FIGURE 4 ). Postocular margin bulged into a moderate process. Mentum transverse, about 3.7 times wider than long, anterior margin widely emarginated, with lateral angles rounded. Antennal club with three antennomeres; antennomere VII slightly extended inwards; antennomeres VIII–X lamellate.

Pronotum transverse, about 2.0 times wider than long, widest between two lateral angles. Anterior margin bisinuate, anterior angles rounded; lateral angles widely produced and obtuse; posterior margin almost straight, posterior angles obtuse.

Scutellum subtriangular, punctuated, 1.2 times wider than long.

Legs. Protibia with 5 sharp teeth (excluding apical fork) along outer margin, apex bifurcate with sharp branches at tip. Except apical spurs and spines, each mesotibia and metatibia with one lateral spine, and the former is larger than the latter.

Elytra elongate, 1.3 times longer than wide, the anterior margin of elytra obviously narrower than pronotum; anterior margin with moderately large punctures, and the area beyond that densely and finely punctate ( Fig. 4B View FIGURE 4 ).

Abdomen and aedeagus. Abdominal tergite VIII ( Fig. 5A View FIGURE 5 ) with a crack membranous area at middle of basal part; abdominal ventrite VIII ( Fig. 5B View FIGURE 5 ) without membranous area at middle of basal part. Abdominal segment IX ( Figs. 5C–D View FIGURE 5 ) broad, the ventral plate ( Fig. 5D View FIGURE 5 ) narrowest near the half-length, without membranous area. Aedeagus ( Figs. 6A View FIGURE 6 ; 7A–D View FIGURE 7 ) about 3.0 times longer than wide in ventral view. Basal piece distinctly constricted in basal part, about 1.6 times as long as parameres, with a pair of well-developed sclerotized dorsal plates ( Fig. 7B View FIGURE 7 ). Paramere with unremarkable basal process, strongly upturned and apically sharp in lateral view ( Fig. 7C View FIGURE 7 ). Penis distinctly shorter than paramere, widest just behind the apex. Flagellum ( Fig. 6A View FIGURE 6 ) long, slender and trifurcate, about 3.3 times as long as aedeagus; lateral branches very short and thin, the total length of flagellum around 8.3 times longer than the length from base to fork; apex shown in Fig. 7D View FIGURE 7 .

Male paratypes. Body length 21.5–38.2 mm (n=4).

Variation. In the small sized male ( Fig. 3A–B View FIGURE 3 ), dorsal surface with relatively dense and distinct punctures. Head about 1.2 times as long as the mandible, with a small single inner tooth at basal of mandible; lateral angles of clypeolabrum obtuse; postocular margin bulged into a small process. Mentum about 3.0 times wider than long, anterior margin almost straight. Lateral angles of pronotum absent. Elytra with dense rows of punctures distinctly and several slightly longitudinal ridges; sides of elytral suture obviously broad. Flagellum about 3.7 times as long as aedeagus.

Female. Unknown.

Differential diagnosis. This new species should be assigned to the Dorcus reichei group (sensu Huang & Chen 2013). The new species is most closely related to Dorcus tianlongi Wang & Zhou, 2019 , and also resembles D. liyingbingi Huang & Chen, 2013 . However, the morphological features of the large male mandibles, elytra, and genitalia can clearly distinguish it from the latter two species, as shown in Table 1 View TABLE 1 . In addition, at first glance, this new species somewhat resembles D. antaeus Hope, 1842 , but there are significant differences between the two in terms of size and aedeagus, which can reach more than 85 mm in large males and the flagellum is short with three branches at the apex in D. antaeus .

Etymology. The new species is named after Mr. Yuan Li (ṃ圆) (Sichuan, China), who collected and provided the specimens of the new species for our research.

Distribution. China (Gansu).