Ynghylch

The UK's largest butterfly, the swallowtail is striking and exotic-looking. Adults fly between May and July when they can often be seen over reedbeds, or feeding on ragged-robin or flowering thistles. Swallowtails are restricted to reedbeds and marshlands in the Norfolk Broads; very rarely, migrants from the Continent appear on downland in southern England. The foodplant of the caterpillars of our native race is Milk-parsley, whereas migrants may feed on wild carrot.