The Eastern Tiger Swallowtail butterfly (Papilio glaucus) is a prevalent and stunning butterfly found in the eastern regions of North America. Its range extends from Ontario down to the Gulf Coast and northern Mexico, east of the Rocky Mountains. These butterflies are active from spring to fall, often soaring above deciduous forests, woodlands, and streams. They are also commonly seen in residential gardens, parks, and orchards.
Characteristics
Tiger Swallowtails boast an impressive wingspan of up to 6 inches (15 cm), ranking them among the largest butterflies in North America. Their hindwings feature long, pointed tail extensions, which give them their characteristic swallowtail appearance.
The color of the eastern tiger swallowtail can vary. Males are yellow or yellow-orange with black tiger stripes. Their wings are bordered in black with yellow spots, and they have black “tiger stripes” running across the top of their wings. Their long black tails have blue patches on them.
Females come in two forms. The yellow form resembles the male but has additional blue shading on the hindwings. The black form is called dimorphic coloration, which adds a level of protection by mimicking the distasteful Pipevine Swallowtail. These females often exhibit a shadow of the “tiger” stripes.
Host and Nectar Plants
The Eastern Tiger Swallowtail utilizes a large variety of host plants, mostly trees, such as cottonwood, ash, birch, wild black cherry, tulip tree, sweet bay (magnolia), and willow.
Adult Eastern Tiger Swallowtails feed on nectar from flowers. Their long proboscis allows them to access nectar deep within the flowers. They are attracted to a wide variety of flowers, including native milkweeds, phlox, lilac, ironweed, Joe Pye weed, Gayfeather, tall verbena, Mexican sunflowers, pentas, purple coneflowers, and zinnias.
Behavior
Tiger Swallowtails are solitary, preferring to spend most of their life in the canopy of deciduous trees. Recently hatched larvae spend their days resting in a silken hammock attached to a leaf. At night they will begin feeding on their host plant.
Males will form large groups is when they participate in a behavior called puddling, in which they congregate on mud, damp gravel or puddles. They extract sodium ions and amino acids from these sources which aid in reproduction. Females will occasionally puddle, but do not form congregations. Adults have also been seen feeding on dung, carrion, and urine.
Lifecycle
Egg Stage: Female eastern tiger swallowtail butterflies lay their greenish eggs singly on the upper surface their host plants. Each female can lay up to 250 eggs. The eggs are small, round, and greenish yellow.
Caterpillar Stage: After about a week, the eggs hatch into tiny caterpillars. Initially, the caterpillars are brown and white, resembling bird droppings, which helps protect them from predators. As they grow, they turn bright green with two large, false eyespots on their thorax, which can startle predators.
Like all swallowtails, the caterpillar of Papilio glaucus possesses an osmeterium, an orange, fleshy organ that emits foul-smelling odor repel predators. Normally hidden, the osmeterium is located on the first segment of the thorax and can be everted when the caterpillar feels threatened. The combination of eyespots and osmeterium makes the caterpillar resemble a snake.
Chrysalis Stage: The chrysalises can range from beige to dark brown to green which helps it to blend in the environment and protect it from predators. The larvae that experience the shortening days of late summer will enter diapause after transforming into pupae. The pupae stop developing throughout the winter and wait for increasing day length and warmer temperatures. They produce glycerol and trehalose, which act like antifreeze to protect them from freezing. These pupae emerge as the first eastern swallowtails you see in the spring.
Adult Stage: The adult butterfly has a lifespan of 2 weeks.
Once considered a single butterfly with a vast range, there are four other distinct species of tiger swallowtails:
Western Tiger Swallowtail (Papilio rutulus)
Two-tailed Swallowtail (Papilio multicadata)
Canadian Tiger Swallowtail (Papilio canadensis)
Appalachian Tiger Swallowtail (Papilio appalachiensis)
The tiger swallowtail butterfly is not considered to be a threatened or endangered species. However, as with many other butterfly species, their populations may be declining due to habitat loss and other human activities. It is important to protect and preserve their habitats to maintain healthy populations of tiger swallowtail butterflies. Click here to learn how to create a butterfly garden that will attract these majestic butterflies.
The eastern tiger swallowtail is the state butterfly of Alabama, Delaware, Georgia, North Carolina and South Carolina, and is the state insect of Virginia.