Question: are black swallowtail butterflies poisonous?
Answer: Both the caterpillar and the adult are poisonous. The caterpillars of the Pipevine Swallowtail feed on the poisonous host plant, Aristolochia, also known as the pipevine, Dutchman's pipe or birthwort. It contains the lethal toxin aristolochic acid. Nevertheless, the black caterpillars turn into beautiful adults.