A medium-sized butterfly is a short black and yellow swallowtail with short tails. The butterfly has blue and red markings. Sexes are alike.
Papilio hospiton is similar to Papilio machaon, but the wings are more rounded, and the hindwing is provided with a short tooth instead of a tail. The black colour is more extended and more densely powdered with yellow than in machaon. The caterpillar is green, striped with black and dotted with small yellowish red punctures, the black colour being more extended than in the larva of machaon. Chrysalis green, the abdominal tubercles more prominent than in machaon. The Corsican swallowtail inhabits mountainous regions at 400-1,500 metres (1,300-4,900 ft) above sea level on the islands of Corsica and Sardinia.[2] The foodplants are from the family Umbelliferae, and include Fennel Foeniculum vulgare, Giant Fennel Ferula communis, Corsican Rue Ruta corsica and Peucedanum paniculatum though some of these records are disputed.[1] Papilio hospiton is bivoltine with broods in May and August. Habitat destruction and disappearance of foodplants as well as excessive collecting are the principal threats to the Corsican Swallowtail.