Northern Prairie Wildlife Research Center
Wingspan 3.4 cm. Wings are white with no other markings; abdomen yellow-white; ventral side of prothorax and femur of foreleg with orange hairs. This arctiid is widely distributed in western North America and is at times considered a pest. Moths fly in midsummer. Caterpillars are generalist feeders on foliage of flowering trees, including many ornamental species, where they live within silken tents and have the common name of fall webworm.
Similar species: Spilosoma virginica wings without spots, yellow bands on the abdomen; femur of foreleg with yellow-orange hairs; Spilosoma vestalis wings immaculate, femur of foreleg with red; Leucoma salicis wings immaculate and satin white, abdomen gray-black, legs with alternating black and white marks.