Several days ago I wrote about the adult Spicebush Swallowtail (Papilio troilus). The caterpillar of that beautiful butterfly has an impressive set of eyespots giving the caterpillar the look of a small snake which protects it from predators. The actual eyes are quite small, about the size of a pinpoint, located down the head, close to the mouth.

The Spicebush Swallowtail goes through five instars, or caterpillar stages, taking three to four weeks. In the first four of those instars the caterpillar looks much like bird poop with small false eyespots that get larger as each instar emerges. Like those eyespots, the bird poop camouflage works well as a protection against predators.

An element on the eyespot really impresses me. There is a white spot on the black pupil, a faux reflection! As the fifth instar ages, it goes from bright green to rich sunshine yellow leaning toward orange. Once the Spicebush Swallowtail reaches the adult and butterfly stage, it lives for just six to fourteen days nectaring on many flowers including jewelweed, milkweed, and thistle.