Family: Papilionidae, Swallowtails view all from this family

Description 3 3/8-5 1/8" (86-130 mm). Large; 2 tails on each wing. Yellow with narrow black stripes. HW edge above and below lined with bright blue patches; black border spotted with yellow and orange; between border-spots each wing points outward in a series of partial tails, and 1 long and 1 medium tail. Female has broader stripes, more blue on HW, and orange cast.

Similar Species Western Tiger and Pale Tiger swallowtails have only 1 tail and broader stripes; Pale Tiger creamier overall.

Life Cycle Yellow-green egg. Apple-green caterpillar has yellow, black-rimmed eyespots on black-banded hump; becomes reddish before pupating. Feeds on various cherries (Prunus) and ashes (Fraxinus) and on common hoptree (Ptelea trifoliata) in Texas; folds leaves into protective tent while feeding.

Flight February-November in Texas; spring and fall broods in California; single June-July brood in Rockies and Cascades.

Habitat Semiarid canyonland, mid-level mountains, and gardens; also moister parts of dry areas, especially canyon bottoms.

Range E. British Columbia and e. Washington along Canadian borders to Dakotas, south to Oklahoma, Texas and through California to Baja; also Mexico and Guatemala.

Discussion The largest western tiger, this species is equally at home in the wild canyons of the Colorado Desert or in a Denver suburban garden. The smaller Three-tailed Tiger Swallowtail (P. pilumnis), a Mexican species, appears rarely in the lower Rio Grande Valley of Texas and in southern Arizona. It is yellow with broad black stripes; the corner projection of the hing wing is developed into a third tail. Its caterpillars feed on laurels (Lauraceae).