Western Tailed-Blue
(Cupido amyntula)
Blues
Appearance: Small, fine tail on hindwing. Above, male is purple-blue; female slate gray with blue at wing base. Tail spot when present is not conspicuous. Below, black spots are either indistinct or missing and one small indistinct orange tail spot. (Eastern Tailed-blue has two orange spots, one near the tail and black submarginal spots).
Wingspan: Small; 7/8 to 1 1/8 inches.
Habitat: Moist habitats, meadows, open woodland; foothills, montane.
Flight Times: April to August; one brood. Sometimes there is a partial second brood in southern Rocky Mountains. Caterpillar overwinters and pupates inside seed pod of host plant.
Larval Foodplant: Legumes, especially vetches and locoweed.
Did You Know…
Tails on this blue are an example of convergent evolution with hairstreaks (Pyle, 2002).
