Catocala unijuga Walker, 
Range: Found in the northern half of the United States from Virginia west to Oregon north into central Canada
Larval Hostplant(s): Cottonwood, Poplar (Populus) and Willow (Salix),
NENHP Ranking: Not listed
Broods/Flight Times: A single extended summer brood, July into October.
Habitat: Deciduous woodlands.
Avg. Wingspan: Large size.,2 3/4 – 3 1/2 Inches.
Found at: Indian Cave State Park
Overwintering: As eggs on tree bark.
Identification: FW mottled pale to dark gray and white; black PM and white ST lines zigzag; orangish-red band on HW only slightly irregular; fringe mostly white (3)
Similar Species: Generally smaller than Semirelict Underwing (C. semirelicta) with FW grayer with less contrast, subreniform spot closed. HW inner band thicker, nearly reaching the inner margin (5), Meske’s Underwing (C. meskei) and Orion Underwings (C. orion) are generally smaller with their FWs giving a “dusty impression. HWs slightly paler, tending toward salmon with inner black band narrower, tapering more gradually to a point at or before the inner margin, apex often with some orange. The FW on the Joined Underwing (C. junctura) is soft brownish-gray, HW inner black band narrow and sometimes broken. (2)
Literature Cited: (2) Sargent, T. D. 1976 Legion of the Night. The Underwing Moths, Univ. Mass. Press; Amherst; 222 pp., (3) Covell, C. V. Jr. 1984 A Field Guide to the Moths of Eastern North America. Peterson Field Guide Series. Houghton Mifflin Co.; Boston. 496 pp. (5) Bill Oehlke’s North American Underwings
🔗Links: Moth Photographers Group, BugGuide.net, Bill Oehlke’s North American Underwings