The spicebush swallowtail (Papilio troilus) is the state butterfly of Mississippi.
Our chosen butterfly is predominantly black with a 3″ to 4″ wingspan. The wings are marked with ivory spots along the margins and a diagonal swipe of tie-died blue. The undersides of the wings have orange spots.
Like all swallowtails, this one has finger like projections on its back wings.
Several other types of swallowtail butterflies are primarily black in color. I had pretty much been identifying all the black colored swallowtails as spicebush swallowtails until I went to Texas and got things straight.
On a field trip to a hillside bog led by Joe Liggio, I had the opportunity to study this butterfly at close range. It was greedily slurping nectar from red milkweed (Asclepia rubra) so I was able to get several good pictures with my low end point & shoot camera. I was then able to show my photos to a smarter person who explained it all to me.
The butterflies weren’t just there to give me a photo op. The males were busily scouring the woods, roadsides and woodland edges to find receptive females.
The plan is that after mating, females lay single eggs on the underside of a host plant’s leaves. Caterpillars hatch from the eggs and live inside the folded leaves – coming out to feed at night.
The heads of the caterpillars are marked with unique dots that look like the eyes and mouth of a cartoon snake. The scary markings are thought to be a survival mechanism. Check out this Wikipedia link for a good picture of the wanky caterpillar. The adults, by the way, look very similar to the unpalatable Pipevine Swallowtail.
So… this species survives due to mimicry. The larva has a scary clown face and the grownups look like they wouldn’t taste very good.
The caterpillars are hosted mainly by spicebush (Lindera benzoin), and sassafras (Sassafras albidum). Sometimes prickly ash (Zanthoxylum americanum), tulip poplar (Liriodendron tulipifera), sweetbay (Magnolia virginiana), and redbay (Persea borbonia) also serve as hosts.
Adults are likely to be found in deciduous woodlands, fields, roadsides, yards, pine barrens, wooded swamps, and parks from southern Canada to Florida and west to Oklahoma.
I was happy to see this butterfly in abundance in Texas because several of its host plants are susceptible to the laurel wilt disease that is invading Mississippi. In the part of Texas that I visited, the spicebush, sassafras, and redbay do not seem to be succumbing to the disease.
Hopefully it will stay that way and the spicebush swallowtail will continue to prosper.