About Papilio multicaudata Kirby, 1884
Scientific name: Papilio multicaudata Kirby, 1884. The two-tailed swallowtail is a large swallowtail butterfly native to western North America. It is one of multiple species that have yellow wings with black tiger-style striping. Each of its hindwings holds several blue markings on both the upper and lower surfaces. Like other striped swallowtails, it has a small orange eyespot near the lower angle of each hindwing. These eyespots trick predators into attacking the rear of the butterfly instead of its head, giving the butterfly an opportunity to escape. Its overall appearance is similar to that of the western tiger swallowtail and eastern tiger swallowtail, but it has narrower black stripes, and usually has two tails on each hindwing rather than just one. Most two-tailed swallowtails have a black "slit pupil" within the orange eyespot on each hindwing; this feature is never present in the western tiger swallowtail. It is also usually larger than similar swallowtails that share its range, though some eastern tiger swallowtails can reach the same maximum size as two-tailed swallowtails. Its wingspan ranges from 3 to 6.5 inches (7.6 to 16.5 cm), which makes it the largest swallowtail found in western North America. Like most swallowtail species, female two-tailed swallowtails are larger and more brightly colored than males. Females have more blue in the submarginal band that wraps around the orange spots on the upper side of the hindwing, and their background wing color is a deeper yellow that can shade into orange. Females also have wider black stripes on their forewings than males. Males may participate in mud-puddling, and have claspers that appear as a yellow segment at the tip of the abdomen, past the black abdominal stripes. Unlike western, eastern, and Canadian tiger swallowtails, the two-tailed swallowtail does not commonly hybridize with related species. This butterfly can be found from Guatemala, through Mexico and the western United States, to southern Canada in southern British Columbia, Alberta, and southwestern Saskatchewan. It typically inhabits areas near streams and moist valleys, but can also be found in canyons and low-elevation cities. Its known host plants are chokecherry, bitter cherry, Arizona rosewood, single-leaf ash, hoptree, and Arizona sycamore. In California, the two-tailed swallowtail mostly uses California hoptree as a host plant. In other parts of the western US, it often uses green ash planted along city roads. In California, city habitats are usually occupied by western tiger swallowtails rather than two-tailed swallowtails. The two-tailed swallowtail is the official state butterfly of Arizona. For its life cycle, adult two-tailed swallowtails fly during spring and summer, and the species produces one brood per year. Females lay eggs one at a time directly on their host plant. Once the caterpillar hatches, it folds the host plant's leaves and ties them together with silk, then feeds from within this constructed structure. Pupae overwinter, and emerge as adult butterflies in May.
