Pipevine Swallowtail

Pipevine Swallowtails (Battus philenor) are one of the most distinctive and commented upon butterflies that can be found in the Tampa Bay area.

Eggs of Pipevine Swallowtails are laid in clusters and are reddish-orange in color as opposed to the yellow-green clusters of eggs laid by the Polydamas Swallowtail. Larvae feed on Pipevines (Aristolochia species), including Virginia Snakeroot (Aristolochia serpentaria). Unlike the Polydamas Swallowtail (Battus polydamas) these caterpillars are unable to consume several species of ornamental Pipevines that are commonly sold in garden centers. Adult butterflies can be confused easily and will still lay eggs on Pipevines that their larvae cannot consume.

These caterpillars can tolerate eating a non-native species of Pipevine that can sometimes be found at specialty plant sales. Trilobed Pipevine (Aristolochia trilobata) is native to Belize and other neighboring areas of South America and is also known as Calico Vine or Bejuco de Santiago.

The slow and small growing nature of Virginia Snakeroot means these larvae need some walking prowess. When a caterpillar finishes a stem of Virginia Snakeroot it must go forth on foot to find new food sources. When the larvae are in a hurry, they can move very quickly. As they walk they tap their long tubercles (kind of a fleshy antennae) in front of them a bit like a cane being used by a blind person. Caterpillars have simple eyes that can perceive light and shadow but they don’t seem much of an image. Perhaps these tubercles help them to feel their way along. I recently added a video on the Lepcurious YouTube channel of these caterpillars speeding on the lab table. You can check out the turbo caterpillars at this link.

Pipevine Swallowtail larvae and adults take in the aristolochic acids in the leaves of their host plants and become distasteful to predators. Because of these acids, Pipevine Swallowtails are often avoided by predators and may be a Batesian model in the Swallowtail mimicry complex in some parts of their range. This means that other species mimic the look of the distasteful Pipevine Swallowtail to gain protection from predators by looking like something known to be distasteful.

The male adult butterfly has beautifully iridescent blue lower wings and also has blue patches on the underside of the lower wing with 7 round orange spots at the wing edge. The female Pipevine Swallowtail has a much deeper blue coloration and appears to be almost entirely black on the upper-side of the wing with a row of white dots on the edge of the hind wing.