Raising Black Swallowtail Caterpillars: A Complete Guide

Nov 30, 2025 by Tom Lembong 57 views

Hey there, fellow butterfly enthusiasts! Ever stumbled upon a striking black swallowtail caterpillar munching away on your parsley or dill? These little guys are a treat to watch, and raising them can be a super rewarding experience. In this guide, we'll dive into everything you need to know about caring for these cool caterpillars, from finding them to releasing a beautiful butterfly. Let's get started!

Spotting and Identifying Black Swallowtail Caterpillars

First things first, how do you even find these awesome caterpillars? Well, black swallowtail caterpillars are pretty easy to spot if you know where to look. They're typically found in the eastern and midwestern United States, Canada, and parts of Mexico, though they've been spotted as far west as Arizona. They love to munch on plants in the Apiaceae family, which includes parsley, dill, fennel, Queen Anne's lace, and even carrots. So, if you've got these plants in your garden, keep an eye out!

Identifying them is also pretty straightforward. Young caterpillars start out looking like tiny birds droppings, which helps them camouflage from predators. As they grow, they develop a vibrant look, with green bodies and black bands with yellow or orange spots. They also have an osmeterium, a forked, orange, fleshy gland behind their head that they pop out when threatened. It smells pretty nasty, like a mix of rotting oranges and something even worse. Trust me, you'll know it when you smell it! Keep in mind that there are other caterpillars that look similar, such as the Anise Swallowtail caterpillar, so make sure you've correctly identified the species before you start your project. You can check the pattern or food that it eats to identify the exact species.

Now, if you don't have these plants, or if you just want to get started, you can also often find them on plants that are for sale at local nurseries or in the gardens of friends and neighbors. Just make sure the plants haven't been treated with any pesticides, as these can be harmful to the caterpillars.

Where to Find Them

Your Garden: Check your parsley, dill, fennel, and carrot plants. They are the favorite plant food for the caterpillars.
Local Nurseries: You might find them on plants for sale.
Parks and Fields: Keep an eye out when you are strolling or hiking.

Setting Up a Caterpillar Habitat

Alright, you've found your caterpillars – now what? You'll need to create a cozy habitat for them. The goal is to provide a safe space where they can eat, grow, and eventually pupate into a chrysalis. A suitable habitat is easy to build, and you may find everything you need at home!

Container: A clear plastic container, a large jar, or even a fish tank works great. The size depends on how many caterpillars you have, but you'll want enough space for them to move around and for their food to last. Make sure the container is big enough to accommodate the caterpillars when they are fully grown and also allow enough room for the chrysalis.
Ventilation: Caterpillars need fresh air, so make sure your container has good ventilation. You can use a lid with air holes, a mesh lid, or even cover the top with cheesecloth or netting secured with a rubber band. This will also prevent the caterpillars from escaping!
Substrate: Line the bottom of your container with paper towels. This will make it easier to clean up caterpillar droppings (called frass) and keep the habitat clean and hygienic. Replace the paper towels regularly to maintain a healthy environment.
Food: This is super important! The caterpillars will need a constant supply of their host plants. If you're keeping them in a container, you can provide them with fresh sprigs of parsley, dill, fennel, or whatever they're eating, placing the stems in a small jar or water-filled container (covered with a lid with holes) to keep them fresh. Change the plant every day or two, or whenever the leaves are eaten or start to wilt. Make sure to remove any old food or droppings to keep the environment clean. This is also a good time to check on the caterpillars and see how they are doing.

Habitat Essentials

Container: Clear plastic container, jar, or fish tank.
Ventilation: Lid with air holes, mesh lid, or cheesecloth.
Substrate: Paper towels on the bottom.
Food: Fresh parsley, dill, fennel, or other host plants.

Feeding and Caring for Your Caterpillars

Now that you've got your habitat set up, let's talk about the good stuff: feeding! Black swallowtail caterpillars are voracious eaters, so you'll need to make sure they have a constant supply of food. The type of plant food depends on your caterpillars, so identify what they are eating. If you adopted the caterpillars from your garden, then feed them with the plants that they are eating.

Fresh Food: Provide fresh food every day, or every other day. If you are using sprigs of herbs, change them as soon as the leaves are eaten. If the food is wilted, it will not be good for the caterpillars.
Cleanliness: Remove any uneaten food, droppings, and dead leaves to keep the habitat clean. This will help prevent disease and keep your caterpillars happy and healthy.
Water: Caterpillars get their water from their food, so you don't need to provide a separate water source. However, make sure the food is clean, and wash the plants before feeding the caterpillars.
Handling: Try to avoid handling the caterpillars unless necessary. If you must move them, use a soft brush or gently move a leaf with the caterpillar on it. Caterpillars are delicate creatures, and excessive handling can stress them out.

Feeding Tips

Freshness: Ensure a constant supply of fresh food.
Cleaning: Remove uneaten food and droppings regularly.
Water: Caterpillars get water from their food.
Handling: Minimize handling to avoid stress.

The Chrysalis Stage

After several weeks of feasting and growing, your caterpillar will enter the pupa, or chrysalis, stage. This is a magical time when the caterpillar transforms into a butterfly. Here's what to expect:

Preparing for Pupation: When the caterpillar is ready to pupate, it will wander around the container, looking for a suitable spot. It will then find a spot and attach itself to a twig, the side of the container, or even the lid. Sometimes they will spin a silk girdle to support themselves.
Chrysalis Formation: The caterpillar will then shed its skin one last time, revealing the chrysalis underneath. The chrysalis can be green, brown, or a combination of both, depending on the environment. The color can change over time.
Patience: The chrysalis stage can last anywhere from a few weeks to several months, depending on the season and environmental conditions. During this time, the caterpillar undergoes a complete metamorphosis, transforming into a butterfly.

Chrysalis Care

Leave it Alone: Don't touch or disturb the chrysalis.
Humidity: Maintain moderate humidity in the habitat.
Watch and Wait: The transformation can take several weeks or months.

Releasing Your Butterfly

Once the butterfly emerges, it will need a bit of time to dry its wings and get ready for the big world. Here's how to help:

Emergence: The butterfly will emerge from the chrysalis, often in the morning. Its wings will be crumpled and wet. You can tell that the butterfly is about to emerge because the chrysalis will become translucent.
Drying Wings: Allow the butterfly to hang upside down to dry and expand its wings. This can take several hours.
Providing Nectar: You can offer the butterfly a sugar-water solution (mix one part sugar with nine parts water) on a cotton ball or sponge. This will give it energy for its first flight.
Release: Once the wings are dry and the butterfly is ready, release it into a garden with flowers, where it can find nectar and continue its life cycle. Choose a warm, sunny day with minimal wind for the release.

Releasing Tips

Patience: Allow the butterfly to dry its wings fully.
Nectar: Offer a sugar-water solution for energy.
Release Location: Release the butterfly in a garden with flowers.

Common Problems and Troubleshooting

Even with the best care, things can go wrong. Here are some common problems and how to solve them.

Diseases: Overcrowding or a dirty environment can lead to diseases. Keep the habitat clean and provide good ventilation.
Pesticides: Avoid plants treated with pesticides. These can be deadly to caterpillars.
Parasites: Sometimes, parasitic wasps or flies can lay eggs on the caterpillars. If you see tiny white eggs or larvae on your caterpillars, remove them from the habitat and seek advice from a local entomologist or experienced butterfly enthusiast. It can be hard to take care of them if they are infested.

Troubleshooting Guide

Disease: Maintain a clean habitat and good ventilation.
Pesticides: Ensure plants are pesticide-free.
Parasites: Remove infested caterpillars and seek advice.

Conclusion

Raising black swallowtail caterpillars is a fascinating and rewarding hobby. By following these simple steps, you can provide a safe and nurturing environment for these amazing creatures and witness the incredible transformation from caterpillar to butterfly. So, grab some dill, gather your supplies, and get ready for an unforgettable journey into the world of butterflies! Enjoy the process, and feel free to ask questions and share your experiences. Happy caterpillar rearing, guys!