Battus philenor

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Geographic Range

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).

Habitat

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).

Physical Description

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

Reproduction

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)

Behavior

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)

Food Habits

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).

Conservation Status

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.

Other Comments

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).

Contributors

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

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

References

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 http://www.sciencenews.org/sn_arc98/4_11_98/bob1.htm.

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 http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm.

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.