Northern Prairie Wildlife Research Center
Wingspan 2.8 cm. Forewing is a dark mottled gray to black with a narrow wavy black median line and a curved black basal line. This geometrid is common and widely distributed in western North America. Moths fly in midsummer. Caterpillars feed on the foliage of conifers, particularly grand fir (Abies grandis), Douglas-fir (Pseudotsuga menziesii), and western hemlock (Tsuga heterophylla).