The caterpillar of the Old World Swallowtail is one of the easiest to identify, with its bright green body marked by black bands and orange spots. Its appearance changes noticeably through the larval stages: young caterpillars are dark, almost black, with a small white patch resembling a bird dropping, an effective form of camouflage. As they grow, they gradually acquire the characteristic green coloration. It is most often found in gardens, fallow areas, meadows and along paths. The species is present from spring to late summer, sometimes producing two generations depending on the region. When threatened, the caterpillar deploys a small orange forked organ, the osmeterium, which releases a scent to deter predators. It is completely harmless.
Found throughout Europe except England and Ireland. Up to 3000m.
Overwinters as a chrysalis.