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Black Swallowtail (Papilio polyxenes)

The black swallowtail is found in the tri-county area around Titusville, Pennsylvania and throughout Pennsylvania. In North America it is found east of the Rocky Mountains.

Associated Plants

These butterflies select their host plants based on the odor they put out.

Common Rue (Ruta graveolens) — photo credit: Daderot, Public domain, via Wikimedia Commons

Host Plants

  • Queen Anne’s Lace (Daucus carota)
  • Common Rue (Ruta graveolens)
  • Water hemlock (Cicuta maculata)
  • Herbwilliam (Ptilimnium capillaceum)
  • Canby’s cowbane (Tiedemannia canbyi)
Flower of Showy Milkweed (Asclepias speciosa)
Showy Milkweed (Asclepias speciosa) — Matt Lavin from Bozeman, Montana, USA, CC BY-SA 2.0, via Wikimedia Commons

Nectar Plants

  • Phlox (Phlox sp.)
  • Milkweed (Asclepias
  • Clover (Trifolium sp.)
  • Thistle (Cirsium sp.)

Range and Habitat

Black swallowtail butterflies are found in the tri-county region around Titusville, Pa, throughout Pennsylvania, and east of the Rocky Mountains.

Field at Cedar Creek Battlefield in Virginia
Field at Cedar Creek Battlefield in Virginia — Photo credit: Wikimedia Commons, public domain


These butterflies are found in open areas such as gardens, fields, dunes, farmland, meadows, open riverbanks, and seldom are located in woodlands.

Life Cycle

Green and black caterpillar of the Black Swallowtail
Black Swallowtail caterpillar — Photo credit: NCBioTeacher, CC0, via Wikimedia Commo


The caterpillar grows to 2″ and varies from white to leaf green with black stripes and red or orange coloring. Two broods can be produced in a year depending on the location.

Black Swallowtail butterfly on a purple coneflower
Black Swallowtail on a Purple Coneflower — Photo credit: Ltshears, Public domain, via Wikimedia Commons


The adult butterflies grow to 7 to 9 cm in size and can have a wingspan of around 11 cm. The females of the species resemble the Pipevine Swallowtail in order to have protection from predators, since the Pipevine Swallowtail is poisonous to predators. This is called Batesian mimicry. It can have 2-3 broods a year, depending on the location.

Interesting Facts about Black Swallowtails

  • This is the state butterfly of Oklahoma and New Jersey.
  • The species name, polyxene, is for the youngest daughter of King Priam of Troy.

References and External Links

Monroe, James L. and David M. Wright. 2017. Butterflies of Pennsylvania. University of Pittsburgh Press. 304 pp.

Pyle, Robert Michael. 1981. National Audubon Society Field Guide to Butterflies. Chanticleer Press. 924 pp.

Papilio polyxenes. 2021-12-30. In Wikipedia.

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