Giant Swallowtails have a distinct yellow band across their forewings, a yellow band along margins, with a long wingspan, up to four inches. Giant Swallowtails are common in the southern California, Arizona, Mexico, Central America, Columbia, Jamaica, and Cuba. They are distinct by their large size, from 3.9 to 6.3 inches (10-16 cm). Giant Swallowtails are one of the largest Swallowtails in North America. The caterpillars feed on citrus and garden plants, they are considered a pest in citrus groves.