Northern Prairie Wildlife Research Center
Wingspan 5.2 cm. Wings and abdomen white with small black spots (left photo); femur of foreleg with red hairs (right photo). This arctiid is common west of the Cascade Mountains. Moths fly in late May and June. Caterpillars are generalist feeders on foliage of flowering trees, particularly oak (Quercus).
Similar species: Spilosoma virginica has orange-yellow femur on foreleg and yellow bands on the abdomen; Hyphantria cunea has immaculate white wings; Leucoma salicis wings are immaculate and satin white, abdomen gray-black, legs with alternating black and white marks.