Northern Prairie Wildlife Research Center
Wingspan 5.3 cm. Forewing is mottled dark black-brown with large discal spots; hindwing is solid dark gray to black. This noctuid is common and widely distributed in high elevation conifer forests of western North America, especially abundant in the Pacific Northwest. Moths fly in midsummer. Caterpillars feed on the foliage of poplar (Populus).
Similar species: Eurois nigra hindwing is pale gray with a white submarginal border, widely distributed and abundant in the Rocky Mountains, caterpillar host plant unknown; Eurois occulta is larger, forewing mottled gray and black with a white orbicular spot, hindwing black with a prominent white fringe of hairs on the wing margin, widely distributed in high elevation conifer forests, caterpillars feed on the foliage of many flowering trees and shrubs such as willow (Salix), poplar (Populus), and alder (Alnus), and on larch (Larix).