Northern Prairie Wildlife Research Center
Violet to gray brown with numerous fine, wavy stripes edged with black. Addorsal stripes often orange. Dorsum of first 8 abdominal segments with shiny black warts bearing prominent black setae, longer and more conspicuous than those of small phigalia. Head tan with black mottling. Spiracular areas often swollen and warted, and flushed with orange. Food: common on many hardwoods, especially apples, oaks, maples, basswoods, hickories, and elms. Caterpillar: May to July; 1 generation.