which to lay their eggs by leaf shape, which can lead to mistakes in egg laying and thus compromising the eggs' survival rates. Aristolochic acid presence may also act as an oviposition chemical stimulant. Natural enemies The pipevine swallowtail larva has few natural predators but there have been observed cases of other butterfly larvae feeding on swallowtail larva. Parasites can also threaten larvae, with certain fly and wasp species being the most dangerous. Birds are the greatest threat to larvae, as many species will eat them whenever they can. As a result of bird predation, this butterfly has evolved a chemical defense using the aristolochic acids found in their host plants. Defense All host plants for the pipevine swallowtail have some form of aristolochic acids, which the larva sequesters while they feed. These acids are passed on to future eggs, pupa, and adult butterflies, so over generations, the level of acid in the body of the butterflies rises as the acid accumulates. High levels of acid make the larvae and adults unpalatable to bird predation. The bright orange spots present on larvae and adult butterflies are thought to serve as warnings to predators, alerting them to the potential bad taste, should the predator decide to make a meal out of the swallowtail. Mimicry As a result of the pipevine swallowtails' natural defense through acid sequestering, many other species of butterflies, like the red-spotted purple butterfly, female eastern tiger swallowtail and eastern black swallowtail butterflies, promothea silkmoth males and the spicebush swallowtail use the pipevine swallowtail as a template for mimicry. Several other swallowtail subspecies have similar coloring to the pipevine swallowtail so that predators may also associate them with distaste. This is called Batesian mimicry. Pipevine swallowtails may also be involved with Müllerian mimicry, in which two distasteful species resemble each other, and thus act as a mimic and model; certain millipede species look like pipevine larvae and release hydrogen cyanide when in danger. References Further reading Edwin Möhn, 1999 Schmetterlinge der Erde, Butterflies of the World Part VIII (8), Papilionidae V. New and rare Neotropical Papilionidae. Edited by Erich Bauer and Thomas Frankenbach Keltern : Goecke & Evers ; Canterbury : Hillside Books. , plate 2, f. 3-4, pl. 16, f. 1-2 External links Pipevine Swallowtail, Butterflies of North Carolina Pipevine Swallowtail Butterfly: Reference large format photographs Cirrus Digital Imaging Pipevine Swallowtail, Butterflies and Moths of North America Pipevine