08/26/2026
Mothman: real or cryptid? Sadly, the legend of the mothman is merely a myth but we’re here to discuss a very real moth species found right here in our state park. 🐛🦋
Visitors to Bulls Island who looked closely enough may have spotted some fluffy, winged friends recently. One of our eastern redbud trees was host to a family of Io Moth caterpillars, Automeris io. Io moths are members of the giant silk moth family Saturniidae.
Caterpillars grow through five instars, or developmental stages between molts. During the first instar, their coloration is orange and slowly changes as the caterpillars grow. In the final instar, these caterpillars appear bright green with red and white stripes down the side and small orange spots. They also have prolegs, or legs on the underside of their body, like many other butterflies and moths. These little legs help the larval stage move around. Only the six true legs extending from their thorax, or main body, will remain when the adults emerge from their chrysalis.
Once they hatch from their eggs, the caterpillars are gregarious meaning that they live in a group. They will stick together as they eat and molt. Io moth caterpillars do a cool behavior called queuing when looking for more food. This involves lining up and travelling single file right behind one another to the new destination.
While beautiful, it’s important not to touch io moth caterpillars. They are covered with urticating hairs which are small spines tipped with points and setae. When something brushes against these spines, the tips break off and a venom is released that feels similar to a bee sting. If accidentally touched, tape can help to remove any hairs left in the skin.
The adult stage of io moths shows very clear s*xual dimorphism, meaning the males and females of the same species look vastly different. While both look like fallen leaves, the wings and body of males are bright yellow and females are reddish-brown. Their camouflage helps them avoid detection by predators including birds and bats. When mimicking a leaf doesn’t work, the large black eyespots on their hindwings can distract or disorient predators.
In summary, moths are cool, beautiful to look at, and have some pretty effective defense mechanisms in the wild. Not to mention some of the most dramatic metamorphoses in the insect world. So, the next time you’re out in nature and you see an interesting moth, remember to look but don’t touch! And if you take a good picture, tag us so we can see it and help you identify it!
