The Viceroy is found throughout most of North America, from Southern Canada into Northern Mexico and from the east to west coasts. It inhabits floodplains, canals, riversides, marshes, meadows, wood edges, lakeshores, deltas, and roadside ditches However, they are most common east of the Rockies. They occupy areas inhabited by both the Monarch Butterfly (Danaus plexippus) and Queen Butterfly (Danaus gilippus), with which it is easily mistaken due to it's having similar color patterns.
Typical host plants include willows, poplars, aspen, cottonwood, birch, basswood, oak, hawthorn, gooseberry, deerberry, apple, cherry, plum, goldenrod, joe-pye weed, shepherd's needle, and Canada thistle.
It is listed as endangered within the Okanagan and Similkameen valleys of British Columbia, Canada.
The eggs are ovoid and flattened, and range from pale yellow to pale green. They are typically laid on the tips of host plant leaves. Caterpillars eat their egg shells after they hatch, then at night feed on the leaves of host plants. Caterpillars are typically 1-1 1/4", molted brown to olive green, with a white saddle shaped patch on the middle of the back; Fore parts are humped and two bristles are at the base of the head. Caterpillars mimic the appearance of bird droppings for camouflage as protection. The caterpillar makes a shelter by rolling a leaf tip for protection during the winter, this structure is known as hibernacula. Chrysalis are typically 1" in size and brown to cream colored. In the spring, adult males perch 1-2 meters above ground on host vegetation on the prowl for females. The males defend their established territories from other males similar to the behavioral mating tactics of the Monarch Butterflies. After mate paring, females ovaposit eggs on the leaf tips of host plants. They have 1-2 broods per year depending upon the local climate.
The Monarch, Queen, and Viceroy butterflies all have similar color patterns to deter predators from any of the three species. This is an excellent example of "Mullerian mimicry" because these species have toxic chemicals making them undesirable to predators because of the bad taste and resulting stomach disturbance that follows eating one. In South Carolina, the Monarch butterfly is more prevalent than the other species. Therefore, the Viceroy butterfly appears more orange than it's more southern populations which are more brown to mimic the Queen butterfly.
Michael Barnes, Lance Sanders, & Kimberly Green ENT 301, Fall 2001
