Scientists discover how a group of caterpillars became poisonous
Genetic research using Smithsonian collections reveals the evolutionary path of six toxic butterfly species
The Atala butterfly (Eumaeus atala) and its five closest relatives in the genus Eumaeus like to display their toxicity. This sextet's toxicity comes from what they eat as caterpillars: plants called cycads that have been around since before dinosaurs roamed the Earth and contain a potent liver toxin called cycasin.
Because they are filled with poison, Eumaeus are big, gaudily iridescent and flap about like they have no place to go. Even their caterpillars are conspicuous, congregating in groups to munch cycad plants all while sporting flashy red and gold coloration. Their ostentatious qualities all signal to predators that they are a not a good meal; in nature, being toxic protects organisms from being attacked if their predators know it.
Now, new research led by the Smithsonian's END