Northern Prairie Wildlife Research Center
Lime green, with white subspiracular stripe. Third thoracic segment humped, bearing white or lavender transverse ridge. Anterior of first thoracic segment reddish with dark eyespots to either side. Tails (anal prolegs) with extrusible portion yellow, tentaclelike, flailed over body when disturbed. Food: especially willows and poplars, also recorded from cherries. Caterpillar: June to September; 2 generations.