Northern Prairie Wildlife Research Center
Variable color depending on age. Early instars are mostly black with some white markings and have the appearance of bird droppings. Later instars, as shown here, are green with black streaks between orange spots on T1-A8; midabdominal prolegs with black spots. Prothorax with a forked eversible gland (not seen here). This species is common on cowparsnip and other species of umbelliferous plants from May to September.