Hawaiian Blue

Udara blackburni, the Koa butterfly, is a butterfly in the family Lycaenidae that is endemic to Hawaiʻi. It is also known as Blackburn's butterfly, Blackburn's bluet, Hawaiian blue or green Hawaiian blue.

The wingspan is 22–29 mm.

The larvae feed on Acacia species (especially Acacia koa), Pithecellobium, Samanea saman, Perottetia sandwicensis, Dodonaea viscosa and Pipturus albidus.

Udara blackburni is one of only two butterfly species that are native to Hawai'i, the other being Vanessa tameamea. These butterflies have wings that are blue on the upper side and green on the under side.