Northern Prairie Wildlife Research Center
Very large, sea green, with prominent dorsal knobs: thoracic knobs orange, abdominal ones yellow. Sides of body with pale blue knobs. Columbia silkmoth (H. columbia) very similar, but thoracic knobs red, abdominal knobs yellow-pink, and exclusively on larch. Food: maples and cherries preferred, and many other broad-leaved trees and shrubs, including larch. Caterpillar: May to October; 2 or 3 generations in South, 1 in North.