Northern Prairie Wildlife Research Center
Variable from nearly black to mostly cream, dappled with few to many yellowish flecks, occasionally with diffuse, whitish spiracular stripe. Body densely covered by prominent tufts of branched spines. Gregarious in early instars. Spines inflict painful sting followed by swelling. Occasionally a pest in southern forests and parks. Food: oaks, but wandering late instars on many other shrubs and trees. Caterpillar: April to July; 1 generation.