Northern Prairie Wildlife Research Center
Wingspan 3.6 cm. The wings are gray-white with wavy dark lines. This geometrid is common and widely distributed in western North America. Moths fly in fall. Caterpillars are generalist feeders on the foliage of conifers and flowering trees and shrubs such as Douglas-fir (Pseudotsuga menziesii), true fir (Abies), larch (Larix), pine (Pinus), alder (Alnus), birch (Betula), and poplar (Populus).
Similar species: species of Venusia, such as Venusia pearsalli, are smaller and fly in spring and summer; Operophtera danbyi, forewing is dark gray with straighter dark lines, moths fly in the late fall.