Northern Prairie Wildlife Research Center
Highly variable, ranging from blackish to red and pinkish brown, abundantly dappled with minute whitish spotting. Dorsal scoli of second thoracic segment often darker than those that follow. Undulating subspiracular stripe variously developed, occasionally broken into oblique pale lines. Faint stripe above spiracle running through scoli which are darkened relative to those above or below. Abdominal spiracles black ringed with white. Food: especially elms, hackberries, but also hops and nettles. Caterpillar: May to November; up to 4 generations in South; 2 in North.