Black swallowtail
The black swallowtail is a big black butterfly with rows of yellow spots and long tails on its back wings. Each back wing also has a red spot with a black middle, like a little target. Its stripy green caterpillar loves to eat parsley in gardens.

How big is it?
How wide are its wings?
How big is Black swallowtail compared to YOU?
Just maths in your browser. Nothing is saved or sent anywhere.
How fast is it?
Fun facts
When the caterpillar is scared, it pushes out a bright orange forked thing that looks like a snake's tongue and smells bad.
The caterpillar takes in bad-tasting stuff from its food plants, so birds do not like to eat it.
Females look like another butterfly that tastes nasty to birds, which helps keep them safe.
Its chrysalis can be green or brown, which helps most of them hide.
It is named after Polyxena, a princess from old Greek stories.
Most asked questions about Black swallowtail
?What does a black swallowtail caterpillar eat?
Parsley, carrot, parsnip and related plants. It is often found in vegetable gardens.
?How big is a black swallowtail?
Its wings are about 7 to 8.5 centimetres across. Females are bigger.
?Is the black swallowtail caterpillar poisonous?
It is harmless to touch gently, but it tastes bad to birds and can make a stinky smell.
For bug experts
- Scientific name
- Papilio polyxenes
- Group
- Butterflies
- Family
- Papilionidae
- Classification
- Insecta > Lepidoptera > Papilionidae
- Lives on
- North America, South America
- Also known as
- Eastern black swallowtail, American swallowtail, Parsnip swallowtail
Where the facts come from
- Papilio polyxenes (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
- Picture by D. Gordon E. Robertson. CC BY-SA 3.0, Wikimedia Commons. The round sticker of this bug is cut from the same picture.
If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at [email protected] and we will fix it.