Northern Prairie Wildlife Research Center
Wingspan 5.1 cm. Forewing is light brown to black-brown with a pale submarginal border and the discal spots greatly reduced; hindwing is orange to red-copper. This noctuid is common in wet conifer forests west of the Cascade Mountains. Moths fly in late summer and fall. Caterpillars are generalist feeders on the foliage of flowering trees and shrubs such as maple (Acer), alder (Alnus), manzanita (Arctostaphylos), ocean spray (Holodiscus discolor), and snowbrush (Ceanothus velutinus).
Similar species: Amphipyra tragopoginis is smaller, wings are dull brown with small black discal spots, widely distributed, caterpillars feed on herbs; Amphipyra glabella forewing is pale gray to black with a contrasting white submarginal border, widely distributed in the Rocky Mountain region, caterpillars feed on the foliage of poplar (Populus).