Identification: Forewing light brown with white-edged dark brown lines; subterminal line with three prominent pointed teeth near costa and short horizontal dash at costa; a total of five distinct lines cross the wing (as opposed to eight lines in Operophtera bruceata); no noticeable terminal line; fringe checkered with dark and pale patches of about equal width; hindwing brownish-gray with small discal spot and checkered fringe
Wing Span: 3.0 cm
Flight: March to June
Caterpillar Hosts: Primarily leaves of Western Hemlock and Sitka Spruce; other hosts include Amabilis Fir, Subalpine Fir, Engelmann Spruce, White Spruce, Douglas-fir, Mountain Hemlock, Western Larch.
Habitat: coniferous forests
Range: British Columbia to northern California; common to uncommon along the coast; rare inland
Taxonomy Notes: Formerly in the genus Epirrita, Zootaxa, 4258(2): 145–156.