Pipevine Swallowtail Caterpillar

The Pipevine Swallowtail Caterpiller, Battus Philenor is one menacing looking dude. As long as two inches across, he features large horns on his head and spiky growths branching from a lumpy body that starts life bright red and then matures into a black with scarlet protuberances.

He lives in a variety of environments, including meadows, fields and brush, parks, and stream-side, but he loves the mountains best. The Pipevine Swallowtail is widely dispersed, ranging from Southern Canada to as far South as Guatemala and Costa Rica. In the United States, he is found on both coasts, ranging in the East from New Mexico through Florida and in the West from Southern Ontario, Canada through Nebraska, Texas, Arizona, California and New Mexico.

The Pipevine Swallowtail Caterpillar feeds exclusively on plants in the Aristolochia Genus which are known as Pipevines or Dutchman's Pipes in plain English. These plants are native to the woods, meadows and fields and all share the same trait-toxicity. These are the plants that insects leave alone, all except for the Pipevine Swallowtail who scarfs up the poison within and becomes toxic himself.

The bright colors of the caterpillar serve as fair warning to predators and they continue to be both gaudy and toxic as butterflies. Male butterflies are a metallic black and blueish. Female butterflies add a row of yellowish white dots to the blue-black color scheme. Both sport orange dots on their undersides which are revealed when the wings are folded upright.

Since the sight is unforgettable, those fortunate enough to survive an attempt to eat this insect never do so again. The insect is a living hot stove. Once burned, predators will not quickly approach anything even remotely like him-a defense adopted by lookalike non-poisonous cousins such as the Spicebrush Swallowtail, Eastern Tiger Swallowtail, Eastern Black Swallowtail, and Red Spotted Purple.

He is usually happy with his wild home where he finds shelter among the poison ivy and greenbriars to later become a useful pollinator of a variety of plants including azalea, butterfly bush, and honeysuckle. He may sometimes be seen in some numbers lighting on puddles of mud or animal excrement where he seeks water and moisture. Even as an adult, he remains highly toxic due to his childhood diet and finds few predators. Only the bald-faced hornet is bold enough to take him on and win.

This widely-dispersed, common species is a beautiful and useful visitor to your garden who, though menacing-looking, rarely merits concern.

Sources:
http://www.fcps.edu/islandcreekes/ecology/pipevine_swallowtail.htm