Every spring we plant a lot of parsley, dill and fennel in hopes of luring the Eastern Black Swallowtail (Papilio polyxenes) to lay her eggs in our garden. Last year we released over 25 EBS butterflies, which we raised from larva to adult. This year we haven’t found nearly as many, but we do have some. Just today I found this beauty on a a Queen Anne’s Lace (another host plant of the EBS and another reason to let a patch of QAL grow wild in your yard).
Eastern Black Swallowtail caterpillars look different at different stages; those stages are called instars, and the caterpillars shed their skin between each. I was so surprised when I first learned this and then saw it with my own eyes.
We like to give our caterpillars lots of room to move and lots of the fresh food to eat. Our EBS habitat is an aquarium with parsley planted directly in garden soil. Parsley grows really well this way, fennel and dill usually get too big so if an EBS prefers fennel, dill or Queen Anne’s Lace then I have to replace it daily. I just place the fennel and dill in the tank mingled in with the parsley in hopes that the caterpillar will go for the parsley (usually they do if they are young enough when placed in the tank). I am not a fan of the plant in a vase of water method because I have seen caterpillars fall into the water and drown. My sister Katrina (a butterfly expert at a local arboretum), recommends putting the stems of freshly picked larval host plants in green oasis that has been soaked with water, this keeps the plants fresh longer and doesn’t endanger the caterpillars. We put sticks in the habitat for the caterpillars to form their chrysalises on when they are ready. We have a screen top made to fit on this aquarium to keep the caterpillars in and the predators out. Sometimes the caterpillars like to make their chrysalises on the top, which is fine, but we have to be careful when we move the lid to put fresh food in, water or release butterflies.
The Eastern Black Swallowtail will overwinter in a chrysalis if it hatches from an egg in the fall. If it is kept in a safe place outdoors for the winter, a beautiful welcome of spring is in store come May. With good care and a little patience the beautiful caterpillars will become beautiful butterflies!
*Jump over to 5 Orange Potatoes at Wodpress for a better look of the photos.