Key to species of the Schinia tertia complex
1. Forewing with broad white medial band (Figs. 1–11) ................................................ 2
1’. Forewing with white medial band narrow (Figs. 12–16) or absent (Figs. 17–18)....... 5
2. Hindwing with large black discal spot; wide black marginal band (Figs. 7–16); uncus short (Figs. 27, 29, 31, 33); female papillae anales broadly triangulate with apex pointed to narrowly rounded (Figs. 36–37, 39–40, 41–44) .......................................... 3
2’. Hindwing discal spot faint, pale gray, or absent; marginal band pale gray and narrow to absent (Figs. 1–6); uncus elongate (Fig. 25); female papillae anales elongate triangular, apex curved, pointed (Figs. 35, 38) ............................................................ tertia
3. Forewing ground color dark brown; white medial band narrow (Figs. 13–16); southern California ................................................................................................. brunnea (part)
3’. Forewing ground color brown; white medial band wide (Figs. 7–11); Colorado to California ............................................................................................................................ 4
4. Second sternite of male with large hair pencils (Fig. 21); Colorado to California ......... ........................................................................................................................ albafascia
4’. Second sternite of male lacking hair pencils (Fig. 22); Arizona and southwestern New Mexico .......................................................................................... ........................ ferrisi
5. Forewing ground color cream to rufous (Figs. 17–18); second sternite in male with a vestigial hair pencil (Fig. 23) ...................................................................... erosa (part)
5’. Forewing ground color reddishbrown to dark brown (Figs. 12–16); second sternite in male with a well developed hair pencil (Fig. 24) ..................................... brunnea (part)