Hemistola species

Key to Hemistola species of the Baikal region

1. Forewing antemedial line (usually present) rather long, convex, more or less parallel to postmedial transverse line and termen, terminates near 1/3 of costa (Fig. 17B). Male genitalia: stout sclerotized spine in base of valva comparatively long; posterior projections of sternite A8 usually rounded (Figs. 34A–34C). In female genitalia (Fig. 37E) lamella postvaginalis small, without distinct semicircular furrow.................................................... H. chrysoprasaria (Esper, 1795)

- Forewing antemedial line (often almost absent: Figs. 17A, 57D) markedly shorter than in H. chrysoprasaria, not convex, sharply curved inwards anteriorly, terminates closer to wing base, near ¼ of costa (Figs. 16D, 57C). Male genitalia: stout sclerotized spine in base of valva slightly shorter than in H. chrysoprasaria; posterior projections of sternite A8 tapered (Figs. 9A–G, 10 A–H, 34D–34F). In female genitalia (Figs. 37F, 37G) lamella postvaginalis considerably larger than in H. chrysoprasaria, with distinct semicircular furrow................................................ H. zimmermanni (Hedemann, 1879)