There’s a Papilio on my Petroselinum! I didn’t actually make such a dramatic (not to mention tongue-twisting) proclamation when I saw it. My daughter was weeding the garden with me and I think I said something much less grand like, “Oh, oh, oh, cool, a baby swallowtail!” And, baby is not even the right term. It is a larval stage and actually pretty far along – meaning about a week old. It is the larval stage of the Eastern Black Swallowtail (Papilio polyxenes), and it’s eating my parsley (Petroselinum crispum).
I have always enjoyed caterpillars. As a child I loved the fuzzy black and brown larva fondly called wooly bears that we pretended could predict the severity of winter’s chill. I don’t remember ever being curious about its adult stage when it becomes the Isabella Tiger Moth. I just had fun making little beds with Parkay® Margarine containers and downy milkweed seed.
Fast forward to years later when we lived in Houston. I planted Asclepia (milkweed) plants and enjoyed the monarch caterpillar larvae so much that my son, Kevin, caught my enthusiasm. He would emerge from bed in the morning, march downstairs and straight outside, often without saying good morning. He would come back inside a few minutes later and announce, “There are five callies on the Asclepia.” I loved this kind of morning news. We once brought a caterpillar inside and raised it to adult stage just so we could see its intricate and stunning chrysalis: spring green with gold décor.
At Halcyon, I have ample opportunity to see butterflies and moths, and to find caterpillars. I have enjoyed photographing and identifying the larvae and have made PowerPoint videos for my students. The main reason that we planted Paw Paw trees was for butterflies. We don’t really like the fruit. Paw Paws are native and are the only host plant for the Zebra Swallowtail (Eurytides marcellus). Host species are where adults lay eggs for the larvae to feed. I find such a specific trophic relationship an intricate dance between species, a give and take between host and guest. I think this is one reason only one or a few eggs are laid on each plant. It is a beautiful example of the co-evolution of species within a community. This same obligate host relationship occurs with monarchs. They use milkweed plants as the only host species for their larvae, though there are many kinds of milkweed.
The Eastern Black Swallowtail does not have an obligate host, but it does have favorites such as dill, parsley, and Queen Anne’s lace. When the larva is very young it looks more like a bird dropping. This is a great camouflaged adaptation. My parsley plant has two larvae, one very young and one further along in its development. A nearby parsley plant also has a larva that still looks like a bird dropping. I am excited to have these Papilio larvae to watch, each at different stages of development. Since the parsley plant is right inside the garden gate, I am sure I will get to see the chrysalis of at least one of them. But if I’m really good – by which I mean if I check constantly – I could get the chance to see it form its chrysalis and then to see it emerge as an adult butterfly.
By the way, I am happy to share my parsley with the Papilio larvae. It’s a small contribution for the chance to observe such a magical transformation of life.