Straneostichus ganqingensis, 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 : 258-259

Straneostichus ganqingensis sp. nov.

Chinese vernacular name: ffûḃ步ffl

( Figures 18–20 , 21G )

Type material. Holotype male ( IZAS), “ Qinghai, Xunhua County, Mengda Tianchi forestry park; mixed forest; 2357 m, N35.7982, E102.6821. 2017.VII.22, under stone, Shi H.L. et al. lgt.”/ “ HOLOTYPE Straneostichus ganqingensis sp. nov., det. Chen & Shi. 2022” [red label] . Paratypes: 1 male and 5 females ( IZAS), “ Qinghai, Xunhua County, Mengda Tianchi forestry park; mixed forest; 2357 m, N35.7982, E102.6821. 2017.VII.22, under stone, Shi H.L. et al. lgt.” ; 1 male ( IZAS), “ Gansu, Dangchang, Daheba , 1998.V.8, Chen Deniu leg.” .

Diagnostic characters. Anterior margin of pronotum much wider than posterior margin ( PPW / APW 0.88– 0.91); lateral margins strongly sinuate before posterior angles, which are nearly rectangular, usually with weakly prominent denticle; basal fovea strongly punctate, mid-basal area between two basal foveae evidently punctate; mid-anterior area without puncture. Elytral striae deep, with fine punctures before middle. Median lobe of aedeagus relatively slender; in dorsal view, the apical lamella slightly bent rightward, apex distinctly widened; endophallic piece small and well chitinized, invisible in dorsal or lateral view.

Comparison. This new species is most similar to S. puetzi and S. liupanensis sp. nov. These three species are recognizable among the fischeri -group by: (1) anterior margin of pronotum evidently wider than posterior margin, PPW / APW 0.85–0.95; (2) median lobe of aedeagus more or less thickened, with the endophallic piece on ventral surface of apical orifice more chitinized than other species. Comparing to S. puetzi , the new species is different in: (1) anterior margin of pronotum weakly curved inward at middle, anterior angles very faintly prominent (versus anterior margin evidently curved inward at middle, anterior angles slightly prominent in S. puetzi ); (2) elytral striae with fine punctures on basal third (versus completely impunctate in S. puetzi ); (3) pronotal posterior angles usually with a small denticle, more evident than in S. puetzi ; (4) in lateral view, the apical lamella of aedeagus thinner and gradually bent downward (versus abruptly bent downward in S. puetzi ); (5) in dorsal view, the apical lamella of aedeagus with left margin smoothly curved (versus distinctly sinuate in S. puetzi ); (6) the endophallic piece less sclerotized, invisible in dorsal or lateral view (strongly sclerotized and visible in both dorsal and lateral views in S. puetzi ).

The new species is externally similar to its sympatric species S. fischeri but can be distinguished by: (1) pronotum much more constricted to the base, anterior margin distinctly wider than posterior margin, PPW / APW 0.88–0.91 (versus 0.97–1.01 in S. fischeri ); (2) median lobe of aedeagus stouter, the apical lamella of aedeagus more evidently bent downward in lateral view, more bent rightward in ventral view, and the endophallic piece much more chitinized.

Description. A medium-sized Straneostichus species (BL 10.6‒13.2 mm) ( Fig. 18 ). Dorsal surface copper green with metallic reflections; appendages dark brown. Head impunctate; vertex distinctly punctate; eyes of moderate size, frontal grooves deep, smooth and nearly straight, extending toward posterior margin of eyes. Pronotum sub-cordiform (PW/PL 1.19–1.22), lateral margins evenly curved from anterior angles to the middle, widest near anterior third (APL/PL 0.34–0.38), strongly sinuate before posterior angles; anterior margin weakly curved inward at middle, slightly wider than posterior margin (PPW/APW 0.88–0.91); anterior angles obtuse and rounded, faintly projecting, posterior angles nearly rectangular, apex sharp with weakly prominent denticle; discal area glabrous; basal foveae deep and densely punctate, mid-basal area between basal foveae with punctures and transverse microwrinkles. Elytra oviform, EL/EW = 1.43–1.47, maximum width near middle (AEL/EL 0.48–0.51); shoulders rounded, humeral teeth small but obviously prominent; basal ridge complete, forming a distinct obtuse angle with elytral lateral margin; intervals weakly convex, striae deep, with fine punctures on anterior third; microsculpture isodiametric, similar in both sexes; umbilicate series on interval IX composed of approximately 22–24 pores, sparse in the middle and dense in anterior and posterior areas. Male genitalia ( Figs. 19–20 ) Median lobe of aedeagus relatively thick MW/ML = 0.19–0.22; in lateral view, basal portion slightly expanded, apex gradually attenuate and bent downwards, the apical lamella not thickened; in dorsal view, the apical lamella slightly longer than maximum width, slightly bent rightward, left margin smoothly curved and hardly sinuate, apex rounded and a little widened; endophallic piece present on ventral surface of apical orifice, narrow but well chitinized on its central area, invisible in dorsal or lateral view.

Etymology. The specific epithet is a combination of Gan (short for Gansu Province) and Qing (short for Qinghai Province), referring that the type materials were collected in two provinces.

Remarks. The specimen from Dangchang in southern Gansu is externally identical to other ones from Qinghai, but slightly different in the male genitalia, with the apical lamella less widened and more elongated. The length of the apical lamella is about 1.5 times its maxim width ( Fig. 20 ), while this proportion is about 1.2 in the two males from the type locality ( Fig. 19 ).

Distribution. Known from two localities in eastern Qinghai (Xunhua) and southern Gansu (Dangchang).

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 18‒20. Straneostichus ganqingensis sp. nov.. 18. dorsal habitus, holotype; 19‒20. median lobe of aedeagus: dorsal (A), ventral (B) and right lateral view (C). 19. holotype; 20. Paratype (Dangchang, Gansu). Scale: 5.0 mm for 18; 0.5 mm for other.