As a follow up to my guide about how to raise monarch butterflies, here is a step-by-step guide about how to raise swallowtail butterflies – from finding the butterfly eggs to raising the caterpillars and releasing the adult butterflies.
We started out raising monarch butterflies, which is probably a pretty typical way to get started. But once you join the butterfly world, it is inevitable that you will want to collect and raise ALL the butterflies you can find. And unlike other types of raising wildlife in captivity, raising butterflies inside your home is actually beneficial for them.
In the wild, the survival rate for butterflies is quite low. Only one or two butterfly eggs out of every 100 laid survives long enough to become a butterfly. Caterpillars have a few defenses, but overall, they’re very susceptible to predators, disease, parasites and even the weather. And that’s just what nature throws at them. Add in humans and pesticides and insecticides, and it’s not easy out there for a caterpillar.
However, raising swallowtail butterflies inside is fun and easier than you might think. You just need a few basic things to get started and a food source, and you’ll have everything you need to help boost the butterfly population.
Types of swallowtails
One of the coolest parts of raising swallowtails is the variety of swallowtail species. There are several different types of swallowtails, and they’re all beautiful. Swallowtail butterflies are large butterflies in the family Papilionidae and include more than 550 different species worldwide. Less than 30 species live in North America.
A common characteristic of most swallowtail butterflies is a tail on their hind wings that looks like a swallow bird tail, although not all swallowtail butterflies have them.
There are four general groups of swallowtail butterflies in North America:
- Black swallowtails
- Giant swallowtails
- Tiger swallowtails
- Pipevine swallowtails
We live in Missouri where we have the following swallowtail butterflies:
- Pipevine Swallowtail
- Polydamas Swallowtail
- Zebra Swallowtail
- Ozark Swallowtail
- Black Swallowtail
- Eastern Tiger Swallowtail
- Pale Swallowtail
- Spicebush Swallowtail
- Palamedes Swallowtail
- Giant Swallowtail
Google the swallowtails in your area to see which species you can find near you.
What do swallowtail caterpillars eat?
The first step to finding your swallowtail eggs and caterpillars is to identify the host plants they eat. Most caterpillars only feed on one specific kind of host plant. For example, monarchs caterpillars only eat milkweed, although there are several types of milkweed they will feed on.
Swallowtails tend to have a more broad array of plants they will eat, which makes it easy to keep them fed as they eat a lot and grow quickly during their few short weeks as a caterpillar. However, the host plant also depends on the species of swallowtail caterpillar.
Here are the host plants for the most common swallowtail caterpillars in Missouri:
Black Swallowtail caterpillars eat plants from the carrot family like parsley, dill, fennel, and rue, along with common roadside wildflowers like Queen Anne’s lace.
Zebra Swallowtail caterpillars‘ only host plant is the pawpaw tree. You can find pawpaw trees on the bank of a river or creek, and they are also small enough to plant as an ornamental tree in your yard. Zebra swallowtails are some of our favorite butterflies and I have yet to raise one successfully to a butterfly. But I do have a potted pawpaw tree waiting to find its forever home soon.
Giant Swallowtail caterpillars eat plants in the citrus family like orange, grapefruit, kumkuat, etc. They also feed on Hercules’ Club, Hop Tree, and Prickly Ash trees. But the easiest way to collect giant swallowtails eggs and caterpillars is on rue, which is also a host plant for the black swallowtail.
Eastern Tiger Swallowtail caterpillars feed on a large variety of host plants, mostly trees like cottonwood, ash, birch, wild black cherry, tulip tree, sweet bay (magnolia), and willow. We also have a potted tulip tree waiting for its forever home. We are addicted.
The host plant for the Spicebush Swallowtail caterpillar is the spicebush, along with sweet bay, sassafras and the tulip tree.
Pipevine Swallowtail caterpillars eat Virginia snakeroot, Dutchman’s pipe, and other members of genus Aristolochia (pipevines).
As you can see, there are plenty of host plant options for your garden to help you attract swallowtails butterflies to lay eggs.
How to find swallowtail caterpillars and eggs
Once you have identified an appropriate host plant for swallowtails, check the leaves for a white-ish yellow-ish sphere. As the caterpillar is closer to hatching out of the egg, it may turn a darker color. While monarch eggs are usually laid on the underside of milkweed leaves, swallowtail eggs can be found on the top or bottom of the leaf depending of the species.
You can also bring small caterpillars inside to raise, however it is recommended you keep larger caterpillars quarantined from the rest of your caterpillar population. Most caterpillar eggs are free of parasites and disease, but caterpillars may not be so lucky. A tip for finding freshly hatched caterpillars is to look for the tiny tracks on the leaves where they have started eating.
What to expect: Life cycle of a swallowtail caterpillar
The life cycle of the swallowtail caterpillar varies by species, but they generally follow this outline. There are four phases: egg, larva, pupal and adult – the butterfly. A caterpillar will hatch from its egg about 3-5 days after being laid.
As a caterpillar, the swallowtail eat as much as it can for two to four weeks and shed its skin several times as it grows. These stages are called instars, and the swallowtail caterpillar will go through five instars before it sheds its skin one final time and pupates into its chrysalis.
When its ready to pupate, the caterpillar will purge itself (a final elimination of liquidy frass) and find the perfect spot to prepare for its chrysalis. Then it will form a silk button to attach to and curl into an upside down J shape while it creates a silk thread called a saddle to wrap around itself. Within the next day or so, it will shed its final skin and harden into a chrysalis.
The pupal stage – when the caterpillar undergoes metamorphosis in its chrysalis – is the stage of the lifecycle that varies the most with different species. Some swallowtails will emerge from their chrysalises (a process called eclosing) as butterflies within 2-3 weeks, and others will take longer, sometimes several months. Unlike monarchs, swallowtails are also able to overwinter in their chrysalises in colder climates and eclose in the spring when the weather is more favorable.
After the butterfly ecloses, it will hang onto its chrysalis for a few hours while its wings dry. Then it can fly off an enjoy life as a butterfly for the next 10-45 days. Black swallowtails, one of the most common species in Missouri, only live an average of 10-12 days as a butterfly.
What you need to raise swallowtail butterflies
Beyond a steady supply of food, there are a few things that make raising butterflies easier.
You’ll want some type of container to keep the caterpillars in. We use rubbermaid containers with holes poked in the lids. As long as you keep it well stocked with host plants, most caterpillars won’t wander too far unless they are shedding their skin or pupating. But for those reasons, you will want to use the lids. You can reuse the containers by periodically washing them well with bleach water and letting them dry completely before reintroducing eggs or caterpillars.
You’ll also need a butterfly enclosure so your butterflies have a safe space to let their wings dry before you release them. If butterfly wings are damaged before they’re dry, it can often be fatal for the butterfly. Mostly because it won’t be able to fly to find food.
Another thing that is beneficial, though not required, is a watering tube. You can collect stems of the host plant with multiple leaves attached and use this watering tube to keep your leaves fresher longer. This is beneficial when caterpillars are quite big and go through a lot of food in short periods of time.
How to find swallowtail eggs and caterpillars
Look for caterpillars on their host plants. You can most certainly search naturally growing host plants, or plant your own! The Black Swallowtail is an easy one to start with because its host plants are readily available at most garden centers. Parsley, rue, dill and fennel all make great starter plants that attract swallowtail butterflies.
So plant them and they will come! Add some nectar plants to your garden and you’ll be even more successful.
Even if you don’t have a large garden or yard to plant all the things in, you can still attract and raise butterflies. Container gardening works just as well! Plant those herbs in a planter and set it in a sunny spot, and the swallowtails will find your plants to lay eggs. Check them once or twice a day, and bring in any eggs or small caterpillars that you find!
How to care for swallowtail caterpillars inside
Once you collect your swallowtail eggs, place them in your clean container, and wait for them to hatch. If you watch closely you’ll see a tiny caterpillar within a day or two. Replace the leaves as the caterpillar eats them, or as they begin to wither. You’ll need to keep a fresh supply of food in the container at all times.
At first your tiny caterpillar will eat slowly, but as he grows he will consume his food much more quickly .You’ll be surprised at how much you’re feeding him toward the end of the two weeks. Fun fact: you won’t know if your caterpillar is male or female until its a butterfly. And some species are difficult to identify.
As your caterpillar eats more, it will also poop more. Caterpillar poop is called frass. You’ll want to clean the frass out of the container at least once a day in the beginning, and probably twice a day by the second week.
As long as you provide a clean and well stocked home for your caterpillars, they’ll be growing and turning into butterflies in no time! Then you are ready for the most fun part of all, releasing your butterfly back into the wild, where hopefully they’ll choose to return to you and lay more eggs!