The highly variable colors and patterns of the skiff moth are hypothesized to mimic senescent/necrotic lesions on leaf surfaces. They often have paired white spots that are thought to mimic the eggs of the tachinid fly, a parasite that enters the caterpillar after hatching. These “egg mimics” are hypothesized to work by dissuading flies that may attempt to avoid depositing eggs on victims that were previously parasitized.
These guys remind me of the tornado chasing vehicles that were on those TV shows about a decade ago.
This one was photographed on my wife, Sarah’s finger at Shaw Nature Reserve.
Finally, I was able to photograph the adult during National Moth Night this summer.
-OZB
A Thousand Acres of Silphiums 
Great shots! 🙂