Northern Prairie Wildlife Research Center
Wingspan 3.5 cm. Forewing is falcate, pale mottled brown with a darker brown submarginal area, the subapical part of the median line extends to the wing margin in an abrupt, concave curve. This geometrid is common and widely distributed in wet conifer forests of the Pacific Northwest. Moths fly in late spring to early summer. Caterpillars are generalist feeders on the foliage of dogwood (Cornus) and huckleberry (Vaccinium).
Similar species: Probole alienaria is almost identical in distribution, host plants, and coloration, but the subapical part of the median line extends to the wing margin in a straight line.