My good friend, Abby, introduced me to the pipevine swallowtail, also known as the blue swallowtail, Battus philenor. The pipevine swallowtail is blue, as are several other butterflies, which makes it confusing to identify. The easiest way to know you have spotted a pipevine swallowtail is how they move their wings. This movement is distinctly faster than that of the other blue butterflies. 

HOST PLANT

It’s better to refer to this blue beauty as pipevine swallow since its only host plant is the Dutchman’s pipevine, those plants in the Aristolochia family. 

ADULT

The dorsal wings of an adult male are black with vibrant iridescence on the hind wings. As is in nature, the female radiance is duller in appearance. Bright orange spots are visible on the back end of the ventral wings.

Immediately after emerging from the chrysalis, adult butterflies spend time near the pupa case and drying their wings and removing pupal waste products from their bodies. These newly emerged butterflies are at their most vulnerable state at this time.

Black with iridescent-blue hind-wings swallowtails are found mainly in forest or wooded properties. Abby has dozens of pipevine swallowtails in her yard, and yes, her lot is wooded. In the Joslin Garden, we also have a heavily wooded area with lots of pipevine swallowtails. Yet, I also have them in my garden area, primarily in open spaces. So you, too, can attract these blue jewels.

The adults feed on the nectar of various flowers, typically flat forms, so the adult can easily alight the plant to sup.

EGGS

Female adult pipevine butterflies lay their eggs on the leaves of host plants in clusters along the foliage stem. Egg colors can vary from red to orange. The eggs appear bumpy since they are covered with a firm and nourishing excretion forming large beads. 

The larvae hatch after a few weeks. Once hatched, they eat the remnants of the egg from which they emerged.

CATERPILLAR

Larvae spend almost all their time eating the leaves off their host plants, Dutchman’s pipevine. Once they remove edible matter from one plant, they move to the next one. And if ever you have watched them move, they are fast! They initially eat in groups, but as food sources deplete, they become more solitary as they search for fresh host plants.

Like the monarch butterfly, the pipevine swallowtail is known for sequestering acids from its host plant. This is a defense mechanism to defend themselves from predators by being poisonous when consumed. Critters have evolved to leave them alone.

CHRYSALIS

The pipevine swallowtail chrysalis (pupae) are colored green or brown. These pupae differ from other swallowtail butterfly chrysalis. The sides of their pupae bodies widen into a winged appearance, with distinctive purplish edges along the sides of these extensions.

Pipevine swallowtail pupation takes place many feet off the ground on tree trunks or other suitable spots. Pupation is rare on green surfaces. Pupation begins when the larva releases silk to form a support structure so that the chrysalis can hang safely. 

What’s interesting to observe is before emerging as an adult, the wing markings of the butterfly can be seen through the chrysalis.

If you want these visitors to your garden, plant nectar-rich plants where the adults can easily land. If you want residents in your garden, also plant their host plant, Dutchman’s pipevine!

Until soon,

Naturally, Helen