Black Swallowtail Butterfly

Papilio polyxenes asterius

The Black swallowtail butterfly is common through much of the United States except the Rocky mountains and west coast. It can also be found in extreme southern Canada.

Like the Anise swallowtail, its favorite host plants are of the carrot family, making this butterfly a frequent visitor to many vegetable gardens.

Black Swallowtail

A butterfly that is usually on the wing from spring to fall, but may be seen a while longer in warmer climates.

To avoid predators, the female is similar in appearance and movement to the Pipe Vine Swallowtail.

Black Swallowtail Butterfly Description:

This Swallowtail is mostly black with patches of yellow.

The male has a narrow yellow band on both wings.

The female has a series of small yellow spots.

From wing tip to wing tip this butterfly measures 2 and 1/2 inches to 3 and 1/2".


This Swallowtail butterfly has a more lilting flight than the Pipe vine, but it also flutters its wings when taking nectar from flowers and feeders.

During cool weather, members of the species can be found basking close to the ground with their wings spread.

This practice is common among many butterfly species and is known as dorsal basking.

Larvae and host plants:

Larvae feed on various members of the carrot family, including carrots, parsley, dill and celery.

Young larvae are mostly black with a white saddle. The white saddle is due to uric acid deposits that may function as antioxidant to protect larvae from photo-toxic chemicals in the diet. Older larvae are green with black transverse bands containing yellow or orange spots.

Markings that resemble bird droppings.

Be sure to plant some for the butterflies and protect the rest of your garden plants with netting.

Larvae pupate in the typical swallowtail "head-up" position attached at the posterior end to a silk pad and supported by a silk girdle.

Pupae of the overwintering generation (short photoperiod pupae) are brown, but those of other generations may be either green with yellow markings or brown depending on the pupation substrate

Nectar plants:

Black swallowtail larvae

Butterfly weed, butterfly bush, phlox, thistle, clover and others.

Planting a butterfly garden or a bed of flowers and host plants will almost insure this haunting beauty to visit.

Don't forget to add a source of water.

Mud puddles are ideal hangouts for butterflies.

Not only do they get water, but they also feed on trace minerals that seep up from the surrounding ground.

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