Udara blackburni, the Koa butterfly, is a butterfly in the family Lycaenidae that is endemic to Hawaii.  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. These butterflies have wings that are blue on the upper side and green on the under side.

Description and Biology 
These butterflies have a wingspan of about an inch. The upper sides of their wings are blue and they often perch with their wings folded which reveals the under sides of the wings which are green. The adults feed on flower nectar with their long coiled up proboscis.  The caterpillars are primarily found feeding on the Koa tree but occasionally on aalii, olomea, and māmaki plants.

Distribution and Habitat 
This species is endemic to Hawaii and has been recorded on the islands of Kauai, Oahu, Maui, Molakai, Lanai, and Hawaii Island. Of the main Hawaiian Islands, the only two that have no records of these butterflies are Niihau and Kahoolawe.

Cultural significance 
Native insects developed a lot of cultural meaning to Polynesians in the Hawaiian Islands.

References

External links
Images of Udara blackburni
Butterflies and Moths of North America: Udara blackburni

Udara
Endemic fauna of Hawaii
Butterflies of Oceania
Insects of Hawaii