Northern Prairie Wildlife Research Center
Wingspan 2.1 cm. Forewing is pale gray with rows of narrow black lines. This geometrid is abundant and widely distributed in wet conifer forests of western North America. Moths fly in spring. Caterpillars feed on the foliage of alder (Alnus), chinquapin (Chrysolepis chrysophylla), and oak (Quercus).
Similar species: Venusia duodecemlineata is smaller, forewing is dark gray, widely distributed, moths fly in spring; Venusia cambrica is larger, wing mostly white, occurs in wet conifer forests in the Pacific West, moths fly from mid to late summer; species of Operophtera and Epirrita are larger with a more elongate forewing, moths fly in fall and winter; Perizoma curvilinea forewing elongate with thicker black lines, moths fly in midsummer; Spargania magnoliata (Geometridae) hindwing pink, widely distributed, caterpillars feed on fireweed (Epilobium).