Black Swallowtail
Paired rows of yellow spots and an orange-centered hindwing eye distinguish a butterfly whose striped caterpillar feeds on carrots’ wild relatives.
Artwork inspired by Doel Reed
Male black swallowtails usually show broad yellow spot bands; females often appear darker with stronger blue on the hindwings. Both carry an orange-red spot containing a black center near each hindwing tail. Caterpillars change from bird-dropping mimicry to green, black, yellow, and white bands as they grow.
Larvae use parsley-family plants including native golden alexanders as well as garden dill, fennel, and parsley. Share some foliage instead of moving every caterpillar indoors. When disturbed, a larva may extend an orange forked osmeterium and release a strong odor—an effective defense that should not be provoked for entertainment.
- Host family
- Carrot or parsley family
- Hindwing mark
- Orange spot with black center
- Oklahoma link
- Official state butterfly
Quick guide
- Check both spot rows
- Yellow markings cross forewing and hindwing.
- Find the host
- Search dill, parsley, fennel, and native umbels.
Recognize and observe
- Check both spot rows
- Yellow markings cross forewing and hindwing.
- Find the host
- Search dill, parsley, fennel, and native umbels.
- Respect the defense
- Do not squeeze a larva to force the osmeterium out.
- Leave enough food
- Move plants or share stems rather than starving caterpillars.
Good to know
The similar pipevine swallowtail lacks the same yellow spot pattern and uses toxic pipevines, not parsley-family hosts.
Notice these
- Carrot or parsley family
- Orange spot with black center
- Official state butterfly