This caterpillar is the larva of the smeared dagger moth and is seen during the summer, often eating iris leaves from the top downwards. It is up to 2 inches long, is brightly colored, and has tufts of short bristly setae. A white spiracle can be seen on the lower side of the caterpillar (right-hand side of the photograph) in the center of each black spot. Not all populations of this caterpillar have the red spots. The head is black with four long, thin setae.

The spines or setae are hollow tubes connected to a gland containing irritants which is a protection against predators. The caterpillar is known to feed on willow, cottonwood, oak, elm, pine, corn, cotton, grasses and fruit trees. Young caterpillars are brown with lighter brown markings.

The adult smeared dagger moth, sometimes known as smeared gagger moth, has a wing span of about one and a half inches. The forewings are gray, the hind-wings are white and the moth has a somewhat "hairy" appearance. This moth belongs to the Noctiuidae family which includes owlet moths.