Wisconsin Native Caterpillars
Viceroy Caterpillar
Genus-Species: Leminitis archippus
Description: Resembles bird droppings in all stages.
May be mottled brown or green; has creamy blotches and two knobby horns on thorax. Partially
grown caterpillars from the third brood spend the winter in a specially rolled leaf called a
hibernaculum that they silk to a branch. Feeding and development resumes that following spring.
Note: To distinguish Viceroy caterpillars from Red-Spotted Purple caterpillars, look for spiked
rather than rounded projections behind the head.
Chrysalis: Shiny brown and white. Abdomen is paler.
Thorax has a a large, knob-like projection. Also resembles a bird dropping.
Host Plants: Trees in the willow family (Salicaceae)
including Willows (Salix species), and Poplars and Cottonwoods (Populus species)
Habitat: Wetland areas, especially along streams, where
willows, its host plants are found.
Comments: The Viceroy is a mimic of the Monarch and
can easily be confused with it, especially in flight. The Viceroy is smaller, is found along wetland
areas where its host plants, willows, are found, and has a dark postmedian line on the hindwing
that can be seen from above or below. This butterfly, like the Monarch, is also found commonly
throughout Wisconsin.