About Thallophaga hyperborea (Hulst, 1900)
Thallophaga hyperborea, commonly known as the northern thallophaga, is a moth species belonging to the family Geometridae. It was first described by George Duryea Hulst in 1900. This species is found in Western North America, with a range that extends from California in the United States to British Columbia in Canada, and also includes the Alaskan Panhandle. The wingspan of adult Thallophaga hyperborea ranges from 30 to 37 mm, which equals 1.2 to 1.5 inches. Adult moths emerge between the months of April and May. The larvae of this species feed on western hemlock, Douglas fir, red cedar, and other fir species. The moth has additionally been recorded on willow, alder, and a variety of other conifers.
