... mimics of the poisonous and distasteful pipevine swallowtail, Battus philenor (L.) (Brower 1958). Some butterflies such as the Monarch and Pipevine Swallowtail eat poisonous plants as caterpillars and are poisonous themselves as adult butterflies. All the host plants that the pipevine swallowtail larvae eat have something in common: they contain a toxin that is harmful or distasteful to many animals but not to the pipevine swallowtail larvae! This chemical protection even survives metamorphosis and extends to the adult butterfly. Other good-tasting butterflies (called "mimics") come to resemble them and thus benefit from this "umbrella" of protection. But the caterpillars are immune and gratefully accept the toxicity as they feed. There are also butterflies like Monarch and Pipevine Swallowtail that eat poisonous plants when they are caterpillars and grow up to become poisonous butterflies. This rash is not life threatening but it will definitely be unpleasant and a painful experience. However, tropical pipevine plants are too toxic for pipevine swallowtails. The Pipevine Swallowtail’s nefarious plot begins after it hatches out of its egg. Dear Mother and daughter nature enthusiasts, You caterpillar is quite distinctive and we recognized it immediately as the caterpillar of a Pipevine Swallowtail.. Females lay batches of eggs on underside of host plant leaves. According to BugGuide: “Larvae feed on Aristolochia species. Some gardeners choose the exotic tropical varieties for their showy flowers, but this can be counter-productive to a … How so? Life History: Adult males patrol likely habitat in search of receptive females. The caterpillar incorporates this toxin into its body to use as a defense against predators. However as soon as they grow big they get poisonous pipevine. 7:32 AM on Aug 26, 2010. Caterpillars feed in small groups when young but become solitary when older. The Aristolochea contain the poisonous aristolochic acid, a renal toxin and probable carcinogen. It will also tell you which caterpillar is not to be tampered with since some of them are poisonous… David L. Wagner, author of Caterpillars of Eastern North America, notes that a sting he received from a buck moth caterpillar was still visible 10 days later, with hemorrhages at the sites where spines had penetrated his skin. Not every pipevine is an acceptable food choice and, unfortunately, the one species of pipevine that is most commonly sold in nurseries is deadly to the caterpillars of the pipevine swallowtail. You caterpillar is quite distinctive and we recognized it immediately as the caterpillar of a Pipevine Swallowtail. They feed on the poisonous pipevine plants they’re named after. There are several species of caterpillars all around you. In an article by the Napa Valley Master Gardeners, we picked up this information on the toxicity of the plant to the pipevine swallowtail. Like the monarch, milkweed tiger moth caterpillars eat nothing but milkweed and spend all of their time on the plant, living and moving in small groups of up to ten. There are relatively few Lepidoptera species that feed on milkweed, which has poisonous sap that may make the caterpillars themselves poisonous to birds. Generally in life, when we see butterflies the common knowledge is to not touch them as they are fragile and our body’s oils can harm them in addition to our strong fingers smushing-up their bodies (which is just a shame). Are there other stinging caterpillars in the southeast you think our readers should watch for in their gardens? Virginia snakeroot, Dutchman’s pipe are good choices for these caterpillars. Some butterfly species are known to cause skin lesions or conjunctivitis too. These butterflies start their life as a dark velvety brown or black and bright orange spotted caterpillar. Yes, even as a baby the Pipevine Swallowtail is out to get you. To protect itself from being eaten, Dutchman’s Pipevine has evolved with chemicals that are at minimum distasteful to those who would eat it, and if a sufficient amount is ingested, they are toxic. Pipevine swallowtail caterpillars eat only the leaves of plants from the Pipevine Family, that’s what their name comes from. "All parts of the pipevine plant, including the seed pods, are toxic to humans.