Insects Planet

Are Swallowtail Caterpillars Poisonous?


If you’ve ever seen a swallowtail caterpillar, you know that they are some of the most beautiful, and strangest-looking, insects in the world. But, can such a beautiful creature be poisonous?

Yes! Swallowtail caterpillars are very poisonous! this is because they consume large amounts of “aristolochic acids” directly from Aristolochia plants commonly known as the woolly Dutchman’s-pipe.

In fact, the toxic components of the Aristolochia species, are known to be nephrotoxic, carcinogenic, and mutagenic which can cause severe illness and even death in animals such as birds or lizards if they consume the caterpillar!

Types Of Swallowtail Caterpillars That Are Poisonous

There are over 550 species of swallowtail caterpillars found all over the world, however, not all of them are poisonous. In fact, there are only two swallowtail caterpillars that are known to be poisonous.

The most common and well-known types of poisonous swallowtail caterpillars include:

  • Pipevine Swallowtail Caterpillar
  • Tiger Swallowtail Caterpillar

Pipevine Swallowtail Caterpillar

The Pipevine Swallowtail Caterpillar “Battus Philenor” are commonly found in North America and Central America. These caterpillars are usually black in color with reddish spots and long, black spines sticking out of its body.

Pipevine Swallowtail Caterpillars will often feed on plants of the genus Aristolochia and are usually found in habitats such as forests and woodland areas where these plants grow.

The long black spines covering their body is what contains the poison that can cause an allergic reaction if touched. 

(Pipevine Swallowtail Caterpillar)

These caterpillars are known for sequestering acids from the Aristolochia plants they consume. Making them very poisonous to both predators and humans.

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Tiger Swallowtail Caterpillar

The Tiger Swallowtail Caterpillar “Papilio glaucus” are usually found in the eastern parts of North America and feeds on the plant leaves. These caterpillars are usually brown in color until they molt.

After this, they become completely green with two black, and yellow eyespots that they use to warn off predators!

They can reach a length of 5.5 centimeters (2.2 in) and along their body, they will have yellow and black transverse stripes “like a tiger” getting the name the tiger swallowtail caterpillar.

Although these caterpillars are not as poisonous as the pipevine swallowtail, if eaten they can cause server stomach issues.

(Tiger Swallowtail Caterpillar)

These caterpillars can also cause a skin rash if they crawl over an open wound ” like a small cut to the hand” or if held for a long period of time! So if you do decide to handle one it’s a good idea to wear gloves.

Are Swallowtail Caterpillars Poisonous To Handle?

Most swallowtail caterpillars are ok to handle! However, the Pipevine Swallowtail Caterpillar cannot be handled without wearing gloves as their poison can cause an allergic reaction on the skin.

Symptoms Can Include:

  • Constant Itching
  • Redness On The Skin

The Tiger Swallowtail Caterpillar can also cause a skin rash if exposed to a wound or held for too long, but the symptoms are not as potent as the pipevine swallowtail, and just simply washing your hands with soap and water can solve the problem.

Are Swallowtail Caterpillars Poisonous To Pets?

Swallowtail caterpillars can cause severe health problems for pets if ingested. In fact, the toxin in pipevine swallowtails can be so potent that it can kill predators like lizards, rodents, and even birds.

If the pipevine caterpillars were to make skin contact with one of your pets then they would most like just get a skin rash. However, if they eat one it could cause them to have severe vomiting and excessive drooling among other things which could be fatal.

Symptoms can Include:

  • Seizures
  • Vomiting
  • Diarrhea
  • Weakness
  • Muscle Tremors
  • Excessive Drooling

Important: If you suspect that your pet has come in contact or ingested one of these caterpillars, or is showing any of these symptoms, then it’s important to seek medical attention right away! Don’t delay!

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Are Swallowtail Caterpillars Poisonous To Eat?

The answer to this question is yes! While most Swallowtail Caterpillars are not poisonous, those that are safe to eat, will not taste good at all.

However, keep in mind, that the Pipevine Swallowtail Caterpillar, are very poisonous and if consumed by a child or adult can cause server health problems.

Symptoms of caterpillar poisoning in humans can include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Dehydration
  • Weakness
  • Muscle Tremors

Are Swallowtail Caterpillars Poisonous To Vegetation?

Swallowtail Caterpillars are not necessarily poisonous to your plants and Vegetation but they can severely damage your crops or plants to the point where they are not edible.

The best way to avoid your plant being damaged by these caterpillars is to remove them or use some kind of netting to surround and protect your plants. Although this won’t give you the most appealing look it will save them from being eaten alive!

How To Safely Remove Swallowtail Caterpillars?

If you find a Swallowtail Caterpillar on your plants or in your home the best and safest way to remove them is by using gloves. This will protect them from any toxins that might be on their skin.

Once you have your gloves on gently pick up the caterpillar and place them in a container. Then release them into the wild away from your home or plants.

Some people like to use a pesticide to kill the caterpillars but this is not recommended as it can be harmful to other animals, and children, if ingested.


So as you can see! Not every swallowtail Caterpillar is poisonous, but those that are can cause serious health problems. Although it’s rare to find one of these caterpillars in your garden if you do remember to remove it as soon as possible and wear gloves.

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