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Battus philenor

What do they look like?

Wing span: 2 3/4 - 5 inches (7-13 cm)

The eggs of a pipevine swallowtail are red-orange and circular. As larvae (caterpillars), pipevine swallowtails are black, with red projections and spots running down their backs. The color of the larvae and pupae of this species is affected by temperature, animals experiencing warmer temperatures shade from black to red. The chrysalis of this has its own shape distinct from other butterflies. The posterior end is segmented and has an inward curve; the ventral thorax of the chrysalis is raised, and the head has a pair of horns at the anterior dorsal portion.

The fore-wing of adults is coal-black above and gray below. The dorsal hind-wing is where the males and females are noticeably different. Males have smaller cream or pale spots than females, and the spots run along the fringe of the wings. Males are also a brighter metallic blue than their female counterparts, in the dorsal hind wing region. The bottom half of the ventral hind wing of males and females is metallic blue; a single row of seven orange spots and small pale, cream dots are found at the edge of the wing within the metallic blue section. (Comstock, 1927; Opler, et al., 1995; Pyle, 1981; Scott, 1986)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • Range wingspan
    7 to 13 cm
    2.76 to 5.12 in

Where do they live?

Battus philenor is found in the southern half of the United States (occasionally further north), and ranges south to southern Mexico (Opler et al. 1995; Pyle 1981; Scott 1986; Comstock 1927; Lucien 1972; Allen 1991).

What kind of habitat do they need?

B. philenor is found mostly in warm climates through out North America. The species favors open woodlands, meadows, and anywhere else an abundance of pipevine grow, including backyard gardens and nurseries. (Opler et al. 1995; Pyle 1981; Scott 1986; Comstock 1927; Lucien 1972; Allen 1991).

How do they reproduce?

Pipevine swallowtail males spend most of their time looking to breed with females. Once a male has located a female, he will quickly land and attemp to mate. Females lay clusters of eggs on or under leaves of pipevines and mostly exposed in the sun. Larva (caterpillars) hatch from the eggs and begin feeding on the host plant. Once they have eaten enough, and matured enough, the larva will metamorphose into a pupa, or chrysalis. It spends the winter as a chrysalis (or in warm regions, just a few weeks), and emerges as an adult in the spring. (Opler et al. 1995; Pyle 1981; Scott 1986; Comstock 1927; Lucien 1972; Allen 1991)

How do they behave?

The pipevine swallowtail feeds on pipevines (Aristolochia) as larvae. Pipvines are toxic to other animals, but not B. philenor. The caterpillars and later stages retain the toxins from the plant and use them to discourage predators. Many other buttterflies mimic B. philenor as a form of defense, because B. philenor has a bad taste and releases a toxic chemical. (Opler et al. 1995; Pyle 1981; Scott 1986; Comstock 1927; Lucien 1972; Allen 1991)

What do they eat?

As larvae, pipevine swallowtails feed only on plants in the genus Aristolochia (known as pipevines). As a butterfly, B. philenor feeds soley on nectar from flowers, including thistles (Cirsium), bergamot, lilac, viper's bugloss, common azaleas, phlox, teasel, dame's rocket, lantana, petunias, verbenas, lupines, yellow start thistle, California buckeye, yerba santa, brodiaceas, and gilias (Opler et al. 1995; Pyle 1981; Scott 1986; Comstock 1927; Lucien 1972; Allen 1991).

Are they endangered?

Pipevine swallowtails are, for now, secure globally. In Michigan, where they reach the northern limit of their range, they are listed as a species of special concern.

Some more information...

Pipevine swallowtails can quickly learn to associate certain flower colors with nectar supplies. They may be as intelligent as honeybees in this regard (Milius 1998).


Imron Gregory Ramos (author), Fresno City College, Jerry Kirkhart (editor), Fresno City College.


Bailowitz, R. 1991. Butterflies of Southeastern Arizona. Tucson, Arizona: Sonoran Arthropod Studies.

Comstock, J. 1927. Butterflies of California: a popular guide to a knowledge of the butterflies of California, embracing all of the 477 species and varieties at present recorded for the state. Los Angeles, California: J.A. Comstock.

Harris, L. 1972. Butterflies of Georgia. Norman, Oklahoma, USA: University of Oklahoma Press.

Milius, S. 1998. "How Bright Is a Butterfly?" (On-line). Science News Online. Accessed 01/29/2008 at

Nice, C., J. Fordyce. 2006. How caterpillars avoid overheating: behavioral and phenotypic plasticity of pipevine swallowtail larvae. Oecologia, 146: 541-548.

Opler, P., R. Stanford, H. Pavulaan. 1995. "Butterflies of North America" (On-line). Accessed October 25, 2000 at

Pyle, R. 1981. The Audubon Society Field Guide to North American Butterflies. New York: Alfred A. Knopf, Inc..

Scott, J. 1986. The Butterflies of North America. Stanford, California, USA: Stanford University Press.

University of Michigan Museum of ZoologyNational Science Foundation

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Ramos, I. 2001. "Battus philenor" (On-line), Animal Diversity Web. Accessed April 15, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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