The head and thorax are white, and the abdomen is yellow orange with a row of black spots.

[4] The yellowish eggs are laid in clusters on the host plant leaves.

The larva, known as the salt marsh caterpillar, which grows to about 5 cm (2 in) in length, is highly variable in color, ranging from pale yellow to rusty orange brown to dark brownish black.

It pupates in a cocoon, made in part from its own hair, usually by wrapping itself in a leaf or other debris.

Host plants used by the caterpillar include dandelions, cabbage, cotton, walnuts, apple, tobacco, pea, potato, clovers, and maize.