Thank you for your question. I believe this is an early instar caterpillar of the Eastern Tiger Swallowtail butterfly, but I have forwarded your photo on to an Extension entomologist to verify the identity. The early instars, or stages, are brown. As the caterpillar gets older it become green. I will be back in touch as soon as I hear back from them.
Thank you for your patience.
Hello again. I heard back from the Extension entomologist. I was correct on the species, Eastern Tiger Swallowtail, scientific name Papilio glaucus, but the instar is a later stage, not an early one. The caterpillar in your photo will be pupating soon to transform into a butterfly.
This species occurs from the lower half of Minnesota, Michigan and central New England south to Florida and Texas.
The caterpillar feeds on magnolia, sweetbay, tulip trees, cherry, ash and other species.
I hope this answers your question, and thank you for contacting Ask an Expert.
Thank you so much for getting back with me so quickly. I have no idea how it made it onto my porch. I’m happy I could rescue it and help it complete it’s journey.
You're welcome! Contact us any time.