Limenitis [Basilarchia] archippus

Family Description:

Caterpillar: Caterpillars vary in color but generally are greenish to brown and dappled with white, with a whitish or beige patch on its back in the middle. They look much like a bird dropping and thus are well camouflaged from potential predators. The back has five pairs of small spines, the front end is humped, and the head has two bristly "horns."
Adult: This butterfly is the famous mimic of the well-known Monarch. It is smaller, usually measuring 2 to 3 inches across the wings, compared to the 3 to 4 inches of the Monarch. The upperside of the wings is orange and black like the Monarch’s, but the hindwings have a curved, continuous black line, forming a semicircle, a third of the way in from the edge. A black border with white spots outlines the wings. The orange may be more of a light to dark brown in certain parts of its range. The underside is similarly marked, but paler in color.

This species ranges from Alberta east to the east coast, south to central Mexico, and occurs in patches in the intermountain and southwestern states. In Idaho, it occurs in the southwest and in patches of the central and eastern parts of the state, as well as in an isolated patch of the panhandle.

It is found in open or shrubby areas, including meadows, roadsides, and water edges.


Caterpillar: Caterpillars eat the leaves and catkins of willows (Salix spp.) primarily, but may also be found feeding on poplars (Populus spp.) and on some fruit trees (Prunus spp.).
Adult: Butterflies use aphid honeydew, fungi, dung, carrion, and mud for food early in the season and feed on the nectar of flowers in the sunflower family (Asteraceae) later in the summer.

Eggs are well camouflaged on host plant leaves, as they resemble galls commonly found on them. Caterpillars eat the shells of their eggs upon hatching. The young caterpillars eat the tips of leaves while leaving the midribs, which they rest upon. They make a dangling ball of leaf material and dung held together with silk, which hangs from where they are feeding and possibly serves as a distraction to potential predators. Mature caterpillars make a "sleeping bag" (a hibernaculum) out of a rolled leaf tied with silk in which they overwinter, in a physiological state called diapause. There is one generation of caterpillars each summer in the north, two in the middle parts of its range, and four or more in the south. In the case of multiple generations in a single season, only the last generation of caterpillars overwinters. Adults generally fly from April to October. Viceroy butterflies mimic the coloration of Monarchs. Predators find Monarchs distasteful to eat and learn to avoid consuming them, and because Viceroys are similarly colored and patterned, predators avoid them as well.

Males perch on vegetation well above the ground to wait for receptive females to pass by, or they may actively patrol for them as well. Females lay eggs on the tips of host plant leaves, typically only two to three per plant.

Idaho Status: Unprotected nongame species.
Global Rank:

G5; populations are widespread, abundant, and secure.

Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.  Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.