Straneostichus Sciaky, 1994

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 : 248-249

Key to species of the genus Straneostichus Sciaky, 1994

1. Vertex with fine and dense punctures; pronotal basal fovea composed of two fused grooves (outer groove present); pronotum usually with only one mid-lateral seta (occasionally two, the basolateral seta not included); outer surface of metatarsomere I distinctly ridged on three-fourth or more of its length; in lateral view, apical lamella of aedeagus evenly curved to venter ( fischeri -group)...................................................................................... 2

- Vertex impunctate; pronotal basal fovea composed of single long groove (outer groove absent); pronotum usually with two or more mid-lateral setae (occasionally one); outer surface of metatarsomere I faintly ridged less than half of its length; in lateral view, apical lamella of aedeagus more or less sinuate (vignai- group)............................................ 8

2. Pronotal basal fovea sporadically punctate, mid-basal area between basal foveae completely impunctate ( Figs 21A–B ); elytral shoulders strongly narrowed; apical lamella of aedeagus much longer than maximum width, L/W = 1.55-1.75 ( Figs 3–4 , 6–7 ) ................................................................................................... 3

- Pronotal basal fovea densely punctate, mid-basal area between basal foveae more or less punctate ( Figs 21C–G ); elytral shoulders moderately narrowed; apical lamella of aedeagus longer or nearly as long as maximum width, L/W = 1.00-1.60 (usually less than 1.40) ( Figs 9 , 11–12 , 14–15 , 17 , 19–20 )..................................................... 4

3. Elytral striae near base with fine punctures ( Fig. 21A ); elytra strongly elongated, EL/EW = 1.50-1.56; basal portion of aedeagus slightly thickened, in dorsal view apical lamella strongly bent rightward ( Figs 3A, 3A ); N. Sichuan, S. Gansu ... S. ovipennis

- Elytral striae completely impunctate ( Fig. 21B ); elytra less elongated, EL/EW = 1.43-1.46; basal portion of aedeagus strongly thickened, in dorsal view apical lamella only slightly bent rightward ( Figs 6A, 7A ); C. Sichuan .......... S. politus sp. nov.

4. Pronotal anterior margin subequal to posterior margin (PPW/APW = 0.98–1.05, mean 1.02); endophallic piece hardly visible (depigmented) on ventral surface of apical orifice ( Figs 9 , 11–12 )............................................... 5

- Pronotal anterior margin slightly wider than posterior margin (PPW/APW = 0.85–0.95, mean 0.92); endophallic piece visible (well pigmented) on ventral surface of apical orifice ( Figs 14–15 , 17 , 19–20 )...................................... 6

5. Pronotum finely punctate on mid-anterior area; posterior angles forming a clear denticle ( Figs 21C ); median lobe of aedeagus very narrow on middle portion, apical lamella a little widened in dorsal view ( Fig. 9A ); Shaanxi .............. S. haeckeli

- Pronotum impunctate on mid-anterior area; posterior angles evident but usually not forming denticle ( Fig. 21D ); median lobe of aedeagus thicker on middle portion, apical lamella strongly widened in dorsal view ( Figs 11A, 12A ); Gansu, Qinghai ............................................................................................... S. fischeri

6. Pronotal posterior angles rarely forming denticle ( Fig. 21E ); elytral striae almost impunctate; middle portion of median lobe of aedeagus very thick (MW/ML = 0.23–0.27); endophallic piece on apical orifice strongly sclerotized and thickened, visible in lateral view ( Figs 14C, 15C ); Shaanxi, Henan ......................................................... S. puetzi

- Pronotal posterior angles usually forming clear denticle ( Fig. 21F‒G ); elytral striae with fine but distinct punctures; middle portion of median lobe of aedeagus thinner ( MW / ML = 0.15–0.22); endophallic piece on apical orifice moderately sclerotized, not thickened, invisible in lateral view; Gansu, Qinghai, Ningxia ............................................... 7

7. Maximum width of pronotum just before middle (APL/PL = 0.42‒0.44); elytral striae shallower; middle portion of median lobe of aedeagus thinner (MW/ML = 0.15‒0.17) ( Fig. 17C ); in dorsal view, apical lamella strongly bent rightward, apex nearly truncate ( Fig. 17A‒B ); Ningxia ................................................... ..…… S. liupanensis sp. nov.

- Maximum width of pronotum near anterior third (APL/PL = 0.34–0.38); elytral striae deeper; middle portion of median lobe of aedeagus thicker (MW/ML = 0.19–0.22) ( Figs 19C, 20C ); in dorsal view, apical lamella not bent rightward, apex rounded ( Figs 19–20 ); Gansu, Qinghai ............................................................. S. ganqingensis sp. nov.

8. Pronotum nearly trapezoidal ( Figs 22‒23, 25‒26 ), posterior angles more or less evident, forming rectangular or obtuse angles; elytral basal pores present; frontal grooves moderately deep................................................... 9

- Pronotum nearly rounded ( Figs 24 , 27 ), posterior angles obtuse-rounded; elytral basal pores absent; frontal grooves very faint .................................................................................................. 10

9. Dorsal surface metallic purple or coppery ( Figs 22‒23 ); pronotal lateral margins strongly sinuate before posterior angles, which are nearly rectangular or a little pointed; median lobe of aedeagus slenderer with longer apical lamella, in dorsal view, apical lamella a little longer than maximum width; Central and North Sichuan, Gansu, Shaanxi, Ningxia .............. S. vignai

- Dorsal surface metallic green or dark blue ( Figs 25‒26 ); pronotal lateral margins faintly sinuate or nearly straight before posterior angles, which are obtuse or slightly pointed; median lobe of aedeagus stouter with shorter apical lamella, in dorsal view, apical lamella evidently longer than maximum width; North Yunnan, South Sichuan ............. S. kirschenhoferi

10. Elytral odd intervals much wider and with shallower microsculpture than even ones ( Fig. 27A‒C ); lateral margins evenly curved in their full length; in lateral view, apical lamella of aedeagus longer and more strongly curved ventrally.................................................................................................... S. rotundatus

- Elytral odd intervals a little wider than and with similar microsculpture as even ones ( Fig. 24 ); lateral margins nearly straight before posterior angles; in lateral view, apical lamella of aedeagus shorter and slightly curved ventrally.......... S. farkaci

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.

FIGURE 27. Straneostichus rotundatus (Yu, 1992).A‒B. dorsal habitus, male (Hongshan, Yunnan); C. dorsal habitus, holotype; D‒F. median lobe of aedeagus: right lateral (D), ventral (E) and dorsal (F) view. Scale: 5.0 mm for A‒C; 0.5 mm for D‒F.

FIGURES 2‒4. Straneostichus ovipennis Sciaky, 1994. 2. dorsal habitus, male (Songpan, Sichuan); 3‒4. median lobe of aedeagus: dorsal (A), ventral (B) and right lateral view (C); 3. Songpan, Sichuan; 4. Zhouqu, Gansu. Scale: 5.0 mm for 2; 0.5 mm for other.

FIGURES 5‒7. Straneostichus politus sp. nov. 5. dorsal habitus, a male paratype (Baoxing, Sichuan); 6‒7. median lobe of aedeagus: dorsal (A), ventral (B) and right lateral view (C); 6. Paratype (Baoxing, Sichuan); 7. holotype. Scale: 5.0 mm for 5; 0.5 mm for other.

FIGURES 8‒9. Straneostichus haeckeli Sciaky & Wrase, 1997. 8. dorsal habitus, male (Meixian, Shaanxi); 9. median lobe of aedeagus (Meixian, Shaanxi): dorsal (A), ventral (B) and right lateral view (C). Scale: 5.0 mm for 8; 0.5 mm for 9.

FIGURES 10‒12. Straneostichus fischeri Sciaky, 1994. 10. dorsal habitus, male (Zêkog, Qinghai); 11‒12. median lobe of aedeagus: dorsal (A), ventral (B) and right lateral view (C); 11. Xiahe, Gansu; 12. Zêkog, Qinghai. Scale: 5.0 mm for 10; 0.5 mm for other.

FIGURES 13‒15. Straneostichus puetzi Sciaky & Wrase, 1997. 13. dorsal habitus, male (Songxian, Henan); 14‒15. median lobe of aedeagus: dorsal (A), ventral (B) and right lateral view (C); 14. Songxian, Henan; 15. Zhouzhi, Shaanxi. Scale: 5.0 mm for 13; 0.5 mm for other.

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.

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.

FIGURES 22‒26. Dorsal habitus of Straneostichus species (vignai-group). 22‒23. S. vignai Sciaky, 1994; 24. S. farkaci Sciaky, 1996; 25‒26. S. kirschenhoferi Sciaky, 1994; 22. Jingyuan, Ningxia; 23. Meixian, Shaanxi; 24. Shangri-La, Yunnan; 25. Weixi, Yunnan; 26. Muli, Sichuan. Scale: 5.0 mm.