Key to subspecies of H. viridanus

1. Pronotum (Figs 7–8) with relatively narrower base (WPmax/WPmin = 1.07–1.15) and with sides notably converging posteriad. Pronotal basal angle obtuse, narrowly rounded at apex. Elytra with superficial striae and flat intervals even apically. Terminal lamella of aedeagus comparatively long, with sides more or less notably sinuate before apex (Fig. 13). Specimens from southern Qinghai, eastern Tibet and northeastern Sichuan, China ....................................................................................................... H. v. angustibasis ssp. n.

- Pronotum (Figs 9–10) with relatively wider base (WPmax/WPmin = 1.03–1.09) and with sides more or less parallel basally, at most only slightly converging posteriad. Pronotal basal angle right-angled or slightly obtuse, usually with sharper apex. Elytra with striae deepened or almost superficial and intervals convex or flat. Shape of terminal lamella rather variable, often not sinuate at sides .................................. 2

2. Larger: body length 8.7–11.0 (usually above 10.0) mm. Elytral striae clearly deepened and elytral intervals more or less convex at least apically. Terminal lamella of aedeagus comparatively long, with sides more or less notably sinuate before apex, sometimes nearly parallel (Fig. 14). Specimens from southernmost Gansu, China ....................................................................................................... H. v. staudingerianus

- Smaller: body length 7.6–9.8 (usually under 9.5) mm. Convexity of elytral intervals variable. Terminal lamella of aedeagus usually shorter and with sides parallel or slightly converging apicad. Specimens from Russia, Mongolia, Kyrgyzstan and northern China (including Gansu to north of Minxian). H. v. viridanus