Northern Prairie Wildlife Research Center
Greenish or tan to dark purple-brown with conspicuously swollen second thoracic segment, marked with orange or red. Blackened protuberances on dorsum of fourth and eighth abdominal segments. Setal bases often light orange. Spiracles small, tan to orange, rimmed with black. Food: many forest species including softwoods. Caterpillar: June to October; 2 generations.