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How to Raise Swallowtail Butterfly Caterpillars

Raising a caterpillar with your kids is a great learning experience, and swallowtails are some of the most beautiful and biggest butterflies in North America. These butterflies can be identified by the back end of their wings that looks like a forked tail, reminiscent of swallow tails. The caterpillars are large and have what looks like a horn under the skin, in the thoracic region.

Attract the butterflies to your garden by growing plants they like to feed on, such as milkweed, purple coneflower, bee balm, butterfly weed, butterfly plant, zinnias and lantana. Check with your local gardening center for plants that grow well in your area.

Grow host plants for the butterflies to lay its eggs on. Swallowtail butterflies use host plants like dill, fennel, carrots, parsley or rue. The female butterfly will lay a small, white-yellow egg on the host plant.

Plant some host plants in the aquarium because caterpillars need a lot of fresh food. Use some organic potting soil and place the dill or fennel in your aquarium. If you do not want to plant anything, make sure you provide lots of fresh food.

Collect the eggs if you find them or wait until the caterpillars hatch and collect them at that point. The young caterpillars are less than 1/2 inch long and are black with white spots.

When the caterpillar has gotten large, around 3 to 4 inches, it begins looking for a place to form its chrysalis. Provide some sticks in the aquarium for this purpose. The caterpillar will select a spot and remain still for a time before forming its chrysalis.

Once it has attached itself to the stick, it will remain in that position for 24 hours or so before it sheds its skin and forms the chrysalis. The chrysalis is either brown or green in color, depending on what its attached to. The butterfly emerges from the chrysalis in around nine to 11 days. Once the butterfly has emerged, its wings are wrinkled and it needs to hang upside down for a couple of hours. The wings are very delicate during this time so it is best not to touch the butterfly.

Keep the butterfly in the aquarium until it starts flapping its wings, then release it back into the yard. Take the whole aquarium outside and remove the lid. At this time you can try to get the butterfly to walk onto your hand so that your children can hold the butterfly before it flies away. If you let it go by a nectar source in your yard, it may hang around for a while.


If you do not want to be collecting food, leave the caterpillar on the host plant until it is 3 to 4 inches and then remove it to the aquarium so it can form its chrysalis.


Do not touch the wings of the butterfly. They are extremely fragile and can be damaged easily. Supervise your kids around the caterpillars and chrysalis, which can also be damaged if squeezed or dropped.

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