Numbers
common in the north; rare south of New York
Identification
Adult: forewing brown with white or pale yellowish spots and bars (but not continuous lines); hindwing bright yellow with black PM band joined at one or more places to large black basal patch
Range
Newfoundland and Labrador to the tundra of Northwest Territories, Yukon, and Alaska, south in the east to Michigan (and in the Appalachians to North Carolina), and south in the Rockies to Arizona and New Mexico
Habitat
boreal mixed woods and parklands, moist shrubby arctic tundra, mountains in the south
Season
adults fly from June to August (peak numbers from mid-June to early July in the north)
larvae take two years to complete development, and are active during the short northern summer, but dormant under the snow for much of each year
Food
larvae feed on leaves of alder, aspen, birch, and willow in the wild, and have been reared in captivity on bedstraw, dandelion, lettuce, and snowberry
Life Cycle
semivoltine: one generation every two years; spends the first winter as a fifth-instar larva, and the second winter as an eighth-instar larva
See Also
Great Tiger Moth (
Arctia caja) forewing has continuous white lines, and hindwing has large dark blue spots outlined in black (
compare images of both species at CBIF)
Internet References
live and pinned adult images by various photographers, plus common name reference (Moth Photographers Group)
pinned adult image plus habitat, flight season, description, biology, foodplants, distribution (Strickland Entomological Museum, U. of Alberta)
pinned adult image by Paul Opler, plus US distribution map (butterfliesandmoths.org)
distribution in Canada list of provinces and territories (U. of Alberta, using CBIF data)
