Will Swallowtail Caterpillars Eat Cilantro

Swallowtail caterpillars will eat cilantro, and they often do when the plant is growing nearby.
 
If you’ve been wondering whether swallowtail caterpillars eat cilantro, the short answer is yes, but with some important details.
 
Cilantro is a host plant for certain species, especially black swallowtails, so seeing caterpillars munching on your cilantro isn’t unusual at all.
 
In this post, we’ll look at why swallowtail caterpillars eat cilantro, which species are most likely to do it, and what you should do if you find them on your herbs.
 
Let’s dig in.
 

Why Swallowtail Caterpillars Eat Cilantro

Swallowtail caterpillars eat cilantro because it belongs to the Apiaceae family, which is a group of plants these caterpillars absolutely love.
 
Here’s why cilantro ends up on the menu:
 

1. Cilantro Is a Host Plant

A host plant is the specific plant a female butterfly lays her eggs on because she knows her caterpillars will eat it.
 
For black swallowtails and anise swallowtails, cilantro is one of those host plants.
 
These butterflies seek out cilantro, parsley, dill, and fennel because they’re all in the same family.
 
So if you plant cilantro, you’re basically rolling out a welcome mat for swallowtail caterpillars.
 

2. The Leaves Are Soft and Easy to Chew

Swallowtail caterpillars eat cilantro leaves because they’re tender and packed with nutrients.
 
Young caterpillars have tiny mouths, so soft, delicate leaves like cilantro are perfect for them.
 
The feathery texture of cilantro also makes it easy for them to nibble through without much effort.
 
This is why you’ll often see caterpillars eating cilantro leaves before they move on to thicker stems.
 

3. It Contains the Right Nutrients

Cilantro gives swallowtail caterpillars the nutrients they need to grow fast.
 
Caterpillars eat almost constantly because they need to store up energy for metamorphosis.
 
Cilantro is rich in vitamins and water, which keeps them hydrated and healthy during this critical stage.
 
So when swallowtail caterpillars eat cilantro, they’re fueling their transformation into butterflies.
 

4. The Scent Attracts Egg-Laying Females

Female swallowtails use their sense of smell to find cilantro and other host plants.
 
The aromatic oils in cilantro are a strong signal that this is a safe place to lay eggs.
 
Once the eggs hatch, the caterpillars eat cilantro from the moment they emerge.
 
This is why a patch of cilantro can go from lush to laced with caterpillars in just a few days.
 

Which Swallowtail Species Eat Cilantro

Not every swallowtail caterpillar eats cilantro, but a few species definitely do.
 
Here are the ones you’re most likely to spot:
 

1. Black Swallowtail Caterpillars

Black swallowtail caterpillars eat cilantro more than almost any other swallowtail.
 
They’re the most common culprits in North American gardens.
 
You’ll recognize them by their green bodies with black and yellow bands.
 
If you see these on your cilantro, you’ve got black swallowtails in your garden.
 

2. Anise Swallowtail Caterpillars

On the West Coast, anise swallowtail caterpillars eat cilantro just as eagerly.
 
They look similar to black swallowtails and share the same taste for plants in the Apiaceae family.
 
So if you live in California or nearby, anise swallowtails are likely the ones munching your cilantro.
 

3. Giant Swallowtail Caterpillars (Occasionally)

Giant swallowtail caterpillars usually prefer citrus trees, but they’ll sometimes eat cilantro if it’s nearby.
 
It’s not their first choice, but it happens in gardens where citrus and cilantro grow close together.
 
So while they can eat cilantro, they don’t rely on it the way black and anise swallowtails do.
 

Should You Let Swallowtail Caterpillars Eat Your Cilantro?

Whether you let swallowtail caterpillars eat cilantro depends on what you want from your garden.
 
Here’s how to decide and what to do:
 

1. Plant Extra Cilantro for Them

If you love butterflies, plant extra cilantro so there’s enough for you and the caterpillars.
 
A few dedicated plants will keep the caterpillars happy without wiping out your harvest.
 
This way, swallowtail caterpillars eat cilantro while you still get plenty for your kitchen.
 

2. Move Them Gently If You Need the Herbs

If you need your cilantro for cooking, you can move the caterpillars to parsley or dill nearby.
 
Use a soft brush or your finger to gently relocate them.
 
Just make sure the new plant is also in the Apiaceae family, or they won’t eat it.
 

3. Avoid Pesticides

Never spray pesticides on cilantro if you want to keep the caterpillars safe.
 
Even organic sprays can harm swallowtail caterpillars that eat cilantro.
 
If you see chewed leaves, handpick the caterpillars instead of spraying.
 

4. Watch for Wasps and Birds

Natural predators like wasps and birds love to snack on swallowtail caterpillars.
 
If you want the caterpillars to survive, you may need to protect them with netting.
 
It’s a balancing act, but it’s worth it if you want butterflies in your garden.
 

So, Will Swallowtail Caterpillars Eat Cilantro?

Swallowtail caterpillars will eat cilantro, and it’s actually one of their favorite host plants.
 
Black swallowtails and anise swallowtails are the most common species you’ll find on cilantro.
 
They eat the leaves because cilantro is soft, nutritious, and part of the Apiaceae family they rely on.
 
So if you spot caterpillars on your cilantro, don’t panic, you’re just hosting the next generation of butterflies.
 
The key is deciding whether to share your harvest or move them to another host plant.
 
Either way, swallowtail caterpillars eat cilantro, and that’s a sign your garden is doing something right.