- Family: Swallowtail Butterflies – Papilionidae
- Subfamily: Swallowtails – Papilioninae
- Wing span: Very large, 60–85 mm (2.36–3.34 in.).
- Wing upper side: Yellowish white, black stripes. Margin of hind wing with row of blue blotches and one red blotch.
- Wing underside: Like upper surface.
- Habitat: Wandering species, found in various habitats.
- Flying time: May–August.
- Overwintering form: Cocoon.
- Larval foodplant: Blackthorn (Prunus spinosa) and its relatives, e.g. plum (P. domestica).
The scarce swallowtail is not established in Finland and has only been observed on a few occasions. Most of these sightings have been of individuals that have been imported by people, e.g. as caterpillars hidden among young garden plants. The scarce swallowtail has only wandered as far as Finland once, when a second-generation male was found in Turku in 1984.
The scarce swallowtail has very long spurs on its hind wings, and it is easy to differentiate from old world swallowtail (which has shorter spurs and checkered forewings) by the tiger stripes on its forewings.