Key to species of Onega

1) Forewings without supernumerary crossveins ............................................................. 2

1’) Forewings with supernumerary crossveins on corium and clavus ............................... 3

2) Crown­frons transition with carina only on median portion, not continuous with carina on antennal ledges; forewings light brown maculate with translucent white (Fig. 1 D); male pygofer with posterior margin forming a lobe bearing short stout macrosetae (Fig. 2 A); subgenital plates much shorter than pygofer (Fig. 2 A); aedeagus with single apical process (Fig. 2 D); female unknown...................................... O. freytagi sp. nov.

2’) Crown­frons transition with carina complete, continuous with carina on antennal ledges; forewings translucent yellow with few small lighter yellow spots at base (Fig. 1 B); male pygofer without setigerous lobe (Young 1977: Fig. 232c); subgenital plates extending posteriorly beyond pygofer apex (Young 1977: Fig. 232c); aedeagus with pair of apical processes (Young 1977: Figs 232f, p); female sternite VII with very elongate lateral margins (Cavichioli & Wyler 1992: Fig. 4).......... O. bracteata Young

3) Forewings mostly dark with large unpigmented oblique area on basal half of clavus (usually covered with brochosomes) (Figs 1 F, G) ...................................................... 4

3’) Forewings variably colored, but without large unpigmented area on basal half of clavus (Figs 1 A, C, E, H) .................................................................................................. 5

4) Females smaller, 12.3–13.3 mm; forewings dark brown to black (Fig. 1 F); male pygofer with apical margin serrate (Fig. 4 A); aedeagus with dorsal robust elongate process extending from base posteriorly beyond apex of shaft (Fig. 4 D); female sternite VII with posterior margin broadly round and without median projection (Fig. 4 G); female pygofer with macrosetae along most of posteroventral margin (Fig. 4 I) ........... .......................................................................................................... O. orphne sp. nov.

4’) Females larger, approximately 14.9 mm; forewings dark red (Fig. 1 G); male unknown; female sternite VII with small median projection on posterior margin (Fig. 5 A); female pygofer with few macrosetae restricted to dorsal anteapical region (Fig. 5 C) ... ............................................................................................... O. sanguinicollis Latreille

5) Forewings with costal margin bordered with red and clavus never red (Figs 1 C, E); males with paraphysis present as median sclerite (Fig. 3 D, Young 1977: Fig. 233f); female sternite VII abruptly narrowed on apical portion (Fig. 3 E, Young 1977: Fig. 233i) ....................................................................................................................................... 6

5’) Forewings with costal margin usually not bordered with red (Figs 1 A, H), if costal margin is red then clavus is red; males without paraphysis (Young 1977: Figs 234f, 235f, 236f); female sternite not abruptly narrowed distally (female of O. stella unknown) (Young 1977: Figs 234i, 235i) .................................................................... 7

6) Forewings with small translucent white speckles (Fig. 1 F); male pygofer with apex broadly round (Fig. 3 A); aedeagus without dorsal elongate process (Fig. 3 D) ............. .......................................................................................................... O. krameri sp. nov.

6’) Forewings without speckles (Fig. 1 C); male pygofer with apex modified into a narrow

lobe extending posterodorsally (Young 1977: Fig. 233c); aedeagus with dorsal elongate process arising near base, extending posteriorly almost to apex of median ventral process (Young 1977: Fig. 233f)........................................................... O. fassli Young 7) Male pygofer produced apically into an acute process (Young 1977: Figs 235c, p, 236c); styles with apex broadened and foot­shaped (Young 1977: Figs 235e, 236e)... 8

7’) Male pygofer with apex broadly round (Young 1977: Fig. 234c); styles with apex round, not foot­shaped (Young 1977: Fig. 234e) ............................. O. stipata (Walker)

8) Forewings with broad black subcostal stripe extending from near base to just beyond middle (Fig. 1 A); claval crossveins limited posteriorly and laterally by outer claval vein .............................................................................................................. O. avella Distant

8’) Forewings without black subcostal stripe; claval crossveins occurring more extensively ............................................................................................................... O. stella Distant