Northern Prairie Wildlife Research Center
Large, cylindrical, elongate green to brown caterpillar with vertex deeply cleft. Front margin of first thoracic segment with subdorsal warts. Rounded warts, subdorsally on fifth abdominal segment and dorsally on eighth, bear numerous minute black spinules. Sparser spinules over dorsum of abdominal segments. Food: many broadleaf forest trees and shrubs. Caterpillar: June to October; 1 generation with partial second.