Northern Prairie Wildlife Research Center
Wingspan 3.8 cm. Forewing with a varying mix of colors of pale lavender, purple-gray, and dark red-brown with large round discal spots: hindwing is gray. This noctuid is abundant and widely distributed in western North America. Moths fly in early spring. Caterpillars feed on the foliage of flowering trees and shrubs such as maple (Acer), alder (Alnus), oak (Quercus), cherry (Prunus), buckthorn (Rhamnus purshiana), willow (Salix), and elderberry (Sambucus). This species may be a pest in fruit orchards.
Similar species: Orthosia revicta forewing is pale gray-lavender with red shades and a red submarginal line, widely distributed in wet conifer forests, caterpillars are generalist feeders on the foliage of flowering trees and shrubs, particularly cherry (Prunus); Orthosia pacifica forewing is yellow-brown with a narrow dark reniform spot.