The Arcas Cattleheart is found from Mexico to northern South America. It is similar to other Cattleheart Swallowtail butterflies and has several subspecies including the Mylotes Cattleheart. It looks similar to the Transandean or Pink Cattleheart,
Parides iphidamas, but the Arcas has pink edging rather than white and has five pink spots on the underside hind wing rather than six.
The male has broader, shorter white patches on the topside and may have a bluish sheen by the body. The female, above, may have a more salmon-coloured red bar. Although part of the larger Swallowtail group, many of the Cattleheart (Parides genus) butterflies, including the Arcas, do not have tails.
Arcas butterfly attracted to a picture of an Arcas
Caterpillars feed mainly on pipevines, making them and the adult butterfly toxic to predators -- hence the warning red spots on the body.