Straneostichus liupanensis, Chen & Shi & Liang, 2022

Chen, Jia-Heng, Shi, Hong-Liang & Liang, Hong-Bin, 2022, Taxonomic notes on the Chinese endemic genus Straneostichus Sciaky, 1994 (Coleoptera: Carabidae: Pterostichini), with descriptions of three new species, Zootaxa 5182 (3), pp. 247-264 : 256-258

Straneostichus liupanensis sp. nov.

Chinese vernacular name: 六Ḋḃ步ffl

( Figures 16–17 , 21F )

Type material. Holotype: male ( IZAS), “ Ningxia Hui Autonomous Region, Guyuan City , Jingyuan County, Mt. Liupanshan , 2050m ”/ “ IV-25-2021, Si-Kai Du leg.”/ “ HOLOTYPE Straneostichus liupanensis sp. nov., det. Chen & Shi. 2022” [red label] . Paratypes: 2 males ( CCJH), the same data as holotype . 1 male and 1 female ( CLYH), “ Ningxia, Guyuan, Jingyuan, Mt. Liupanshan , V-2021 ” ; 1 female ( CRS), “ China, Ningxia, Liu Pa Shan , VI.2021 ” ; 1 male and 1 female ( CRS), “ Ningxia, Helan Mts. , 07.2020” .

Diagnostic characters. Maximum width of pronotum just before middle ( APL / PL 0.42‒0.44); lateral margins shortly sinuate before posterior angles, posterior angles nearly rectangular, with faintly pointed denticle; basal fovea sparsely punctate; mid-basal area between basal foveae sporadically punctate. Elytral striae superficially but distinctly punctate. Median lobe of aedeagus moderately slender; in dorsal view, the apical lamella not widened, strongly bent rightward; endophallic piece present on ventral surface of apical orifice, large and well chitinized, but not visible in dorsal or lateral view.

Comparison. The new species is most similar to S. ganqingensis sp. nov. distributed in Gansu and Qinghai. Both species are distinguishable in the fischeri -group by the combination of: pronotum basal margin narrower than anterior margin ( PPW / APW = 0.88‒0.93); pronotum sparsely punctate between two basal foveae; median lobe of aedeagus moderately slender. Comparing to S. ganqingensis , S. liupanensis sp. nov. is different in: (1) maximum width of pronotum more close to the middle, APL / PL 0.40‒0.48 (versus 0.34‒0.38 in S. ganqingensis ); (2) pronotum lateral margins more shortly sinuate before posterior angles, and the denticle on posterior angles more distinct; (3) median lobe of aedeagus a little slenderer, the apical lamella distinctly bent rightward and apex more truncated when in dorsal view (versus hardly bent rightward and apex more rounded in S. ganqingensis ); (4) endophallic piece on apical orifice more strongly chitinized and thickened.

S. liupanensis sp. nov. can be readily distinguished from S. puetzi , distributed in adjacent area and also has similar pronotal shape, by: (1) body size much smaller, 9.4‒9.8 mm (versus 11.5‒14.9 mm in S. puetzi ); (2) maximum width of pronotum closer to the middle; (3) posterior angles of pronotum with pointed denticle; (4) elytral striae distinctly punctate; (5) median lobe of aedeagus slenderer, and endophallic piece invisible in dorsal or lateral view.

Description. A small-sized Straneostichus species (BL 9.4‒9.8mm) ( Fig. 16 ). Head, pronotum and elytra bright green with metallic coppery reflection. Mouthparts brownish yellow, antennae and legs dark brown or nearly black. Head glabrous, vertex distinctly punctate; eyes of moderate size, frontal grooves deep, smooth and nearly straight, extending toward posterior margin of eyes. Pronotum slightly transverse (PW/PL 1.25‒1.27), lateral margins rounded from anterior angles to the middle, very shortly sinuate before posterior angles; anterior and posterior margins nearly straight, anterior margin slightly wider than posterior margin (PPW/APW 0.91‒0.93); anterior angles obtuse and rounded, not projecting; posterior angles near rectangular, apex obtuse with faint denticle; discal area glabrous, with weak transverse wrinkles; basal fovea relatively short, deep and areal punctate, middle area between two basal foveae sparsely punctate, with irregular micro-wrinkles. Elytra oviform, EL/EW = 1.40‒1.44, maximum width near middle (AEL/EL 0.50‒0.54); shoulders narrow and rounded off, humeral teeth indistinct, not prominent; basal ridge complete, forming a distinctly obtuse angle with lateral margin; intervals weakly convex, striae relatively shallow, finely and distinctly punctate; microsculpture isodiametric, similar in both sexes; umbilicate series on interval IX composed of approximately 18–20 pores. Male genitalia ( Fig. 17 ). Median lobe of aedeagus relatively slender, MW/ML = 0.15‒0.17; in lateral view, basal portion strongly expanded, apex gradually narrowed and bent downwards, ventral margin a little sinuate before the apical lamella, the apical lamella short, not thickened; in dorsal view, the apical lamella slightly longer than maximum width, evidently bent rightward, left margin distinctly sinuate, apex rounded-truncated, base of the apical lamella hardly constricted; endophallic piece present on ventral surface of apical orifice, narrow, strongly chitinized and thickened, invisible in dorsal or lateral view.

Etymology. The specific epithet refers to the type locality of the new species, Liupanshan mountains ranging through the southern part of Ningxia.

Distribution. Only known from Liupanshan and Helanshan Mountains in Ningxia Hui Autonomous Region.

Figures

FIGURE 21. Pronotum hind angle and basal area of Straneostichus species (fischeri-group). A. S. ovipennis (Songpan, Sichuan); B. S. politus sp. nov. (Baoxing, Sichuan); C. S. haeckeli (Meixian, Shaanxi); D. S. fischeri (Zêkog, Qinghai); E. S. puetzi (Songxian, Henan); F. S. liupanensis sp. nov. (Jingyuan, Ningxia); G. S. ganqingensis sp. nov. (Xunhua, Qinghai). Scales: 1.0 mm.

FIGURES 16‒17. Straneostichus liupanensis sp. nov.. 16. dorsal habitus, holotype; 17. median lobe of aedeagus: dorsal (A), ventral (B) and right lateral view (C). Scale: 5.0 mm for 16; 0.5 mm for 17.