Cupido amyntula (Boisduval, 1852)
Status: Rare/Possibly an extirpated resident.
NENHP Rank: S1 Tier 2
Range: The Western Tailed-Blue is found from Alaska southeast into Minnesota and eastern Ontario, and south in the western United States through California and New Mexico. In Nebraska it has been found in the northwestern quarter of the state.
Larval Hostplant(s): Various legumes are listed of which Slender Milkvetch (Astragalus flexuosus), Yellow Vetchling (Lathyrus ochroleucus), Purple Locoweed (Oxytropis lambertii), American Vetch (Vicia americana) are found in Nebraska.
Broods/Flight Times: There is one primary flight, mainly in early June, with a partial second flight possible in early August.
Overwintering: As full-grown caterpillars.
Habitat: Habitat: Open undisturbed areas.
Avg. Wingspan: 7/8 – 1 1/8 inches
Similar Species: Eastern Tailed-Blue has black spots boldly marked and three orange spots (also plainly visible) on the ventral hindwing while the Western Tailed-Blue has only a single distinct orange spot with the other two reduced or absent. The vhw black markings are less distinct, not as bold.
Notes: This species is possibly overlooked as the more common Eastern Tailed-Blue.