Papilio zelicaon
Anise Swallowtail

Family Description:
Caterpillar: The caterpillar is typically green to bluish green and marked with alternating thick and thin black bands. The thick bands are dotted with yellow to orange spots, and each segment is marked with one or two black spots on the bottom of each side, right above the "leg." It can reach a maximum length of two inches.
Adult: The butterfly is large, with a wingspan 2 to 3 inches, and tailed. The upperside is yellow marked with black. Specifically, the black occurs near the body, in a thick band spotted with yellow on the front leading edge of the forewing, and in a thick border, dotted with yellow, from the forewing tip to the rear. The yellow occurs as a straight band spanning the wings, curving down towards the abdomen on the hindwing. The hindwing is marked with several patches of blue and at the rear with an orange eyespot that has an isolated black center. Underneath, the butterfly is similarly marked. Both the fore- and the hindwing have more blue than on the upperside, and the hindwing has several hazy spots of orange on both sides of the blue patches. The butterfly’s abdomen is black and marked with a wide yellow stripe on the side. Note that a rare, black form of the species can occur.

This species ranges from central British Columbia and Alberta south through the western half of the U.S. to southern California and northern Arizona and New Mexico. It ranges east as far as the western edge of the Dakotas and Nebraska and central Colorado. In Idaho, it occurs throughout most of the state.

It utilizes almost every type of habitat except within forests.


Caterpillar: Caterpillars feed on the leaves, buds, and flowers of a variety of plant species, primarily from the parsley family (Apiaceae) and several from the citrus family (Rutaceae).
Adult: Butterflies drink flower nectar.

There are two generations of caterpillars each year in most of the range. There may be only one generation in higher elevations and there are many each year in California. Younger caterpillars feed on leaves and switch to flowers when older. They may cause damage to citrus groves in California. Pupae present when temperatures drop will overwinter in a physiological state called diapause, and can remain in diapause for several seasons. Adults generally fly from April through July inmost of its range.

Males both perch and actively patrol in search of receptive females. Courting males and females will often congregate at high points in the landscape in order to find potential mates. This behavior is called "hill topping." Females lay eggs on the leaves and flowers of host plants.

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.