Swallowtail Butterfly

Swallowtail butterflies belong to the family Papilionidae, and the genus Papilio contains some of the largest and most recognizable butterflies in the world, including species like the eastern tiger swallowtail, Papilio glaucus, one of the most widespread and familiar in North America. The group is named for the distinctive tail projections extending from the hindwings of most species.

Swallowtails are considered among the most visually striking butterflies due to their large size, bold coloring, and graceful, gliding flight. As adults they are important pollinators of a wide range of wildflowers and garden plants, while their caterpillars often display remarkable defensive adaptations, including camouflage and false eyespots that make them resemble small snakes.

• Large butterfly with a wingspan typically ranging from 3 to 5.5 inches, among the biggest butterflies in many regions.
• Distinctive tail-like extensions projecting from the base of each hindwing.
• Wing colors and patterns vary by species, ranging from yellow with bold black tiger-stripes to solid black with blue and orange hindwing markings.
• Strong, broad wings and a graceful, often unhurried gliding flight pattern.
• Lookalike: different swallowtail species can resemble one another closely; look at the specific stripe pattern, hindwing spot colors, and tail length to distinguish species.

Swallowtail species are found on every continent except Antarctica, with many species common across North America in gardens, meadows, woodland edges, and along stream corridors. Adults are most active on warm, sunny days from spring through late summer, frequently visiting nectar-rich flowers.

Adult swallowtails feed on nectar from a wide variety of flowers, using a long proboscis to reach deep into blossoms, making them valuable pollinators. Males of many species patrol favored areas or hilltops in search of mates, while females seek out specific host plants on which to lay eggs. Their caterpillars often rely on camouflage, resembling bird droppings when young, and later develop eyespot markings and, in some species, a retractable orange forked gland used as a startle defense against predators.

Swallowtail butterflies undergo complete metamorphosis. Eggs are laid singly on the leaves of specific host plants and hatch within about a week into caterpillars that feed and molt through five stages over several weeks. The mature caterpillar forms a chrysalis attached to a stem or nearby structure by silk threads, from which the adult emerges after one to two weeks in summer generations; northern populations typically produce one to three generations per year, overwintering as a chrysalis.