By Mark Wourms
Recently, I discovered bird droppings on a Pawpaw tree (Asimina triloba) in my backyard. Upon closer inspection it turns out, they were young caterpillars of one of my favorites, Zebra Swallowtail butterflies. I was only momentarily torn between our native Pawpaw tree, which is the only temperate representative of an otherwise tropical plant family, and the Zebra Swallowtail (Eurytides marcellus) caterpillars that will consume the large leaves over the next few weeks. But Zebra Swallowtails are also the only temperate representatives of the kite-winged swallowtails and with their black and white stripes, one of my favorites.
The caterpillars are smelly, and like the adults, they are unpalatable to most predators due to the terpene chemicals they remove and store from the Pawpaw leaves. Typically 2 – 3 broods occur in our area, with some pupae (chrysalis) overwintering to emerge the first group of adults in the spring.
Zebra Swallowtails are much less common than the yellow and black Tiger Swallowtails, so keep watch for them when you are in open woodlands, particularly near water where they like to drink and sip salts from mud puddles.
Bernheim is proud to be a healthy forest, which provides a home to many creatures, even the smallest ones – insects. The Bugs of Bernheim is a blog series that will celebrate our six and eight-legged friends. Join us each year on the third Saturday in September at Bernheim’s annual BugFest, where you can see a variety of bugs, dance the buggy boogie, and even sample some tasty insect treats.