Northern Prairie Wildlife Research Center
Highly variable: brown mottled with tan, black, and white; dorsum checkered with diamonds and oblique lines. Head sometimes with whitish spot to either side of midline. Spiracular stripe darkens toward back of body, often enclosing small white spots above the spiracle on first 7 abdominal segments. First pair of prolegs half-sized. Venter pale, sometimes with pinkish flush and spots anterior to prolegs. Food: oaks. Caterpillar: May to June; 1 generation.