Helius Lepeletier & Serville, 1828

Key to Korean species of the genus Helius Lepeletier & Serville, 1828 View in CoL

1. Wing cord surrounded by distinctly darkened area······

················ Helius ( Helius) gracillimus Alexander, 1938 View in CoL

- Wing cord surrounded by indistinct darkening at most, usually not darkened ·················································· 2

2. Thorax gray. Radial sector ( Rs) straight ······················· ················· Helius ( Helius) polionotus Alexander, 1938

- Thorax light brown or yellowish. Radial sector ( Rs) angulated or arched at base ········································ 3

3. Radial sector ( Rs) angulated and short­spured at base, cross­vein r­m less than its own length beyond branching point of Rs. Gonocoxite of male genitalia with extra lobes on dorsal surface············································ ············ Helius ( Helius) obliteratus ( Alexander, 1920b)

- Radial sector ( Rs) arched at base, cross­vein r­m far beyond branching point of Rs ( Fig. 6D View Fig ). Gonocoxite of male genitalia simple, without extra lobes on dorsal surface ( Fig. 6E View Fig ) ··························································· ············ Helius ( Helius) nipponensis ( Alexander, 1913)