Ornithoptera aesacus

Ornithoptera aesacus, the Obi Island birdwing, is an extremely rare species of birdwing butterfly, endemic to the Island of Obira (formerly Obi), Indonesia. While being a very rare species, they are commercially bred and traded.

The specific epithet of Ornithoptera aesacus, is named after Æsacus, the eldest son of Priam.

History
The original description is: aesacus Ney, F. (Felix) 1903 as Troides priamus Form aesacus. The full reference is Ney, F. 1903 Eine neue Troides-Form von Obi. Insekten-Börse 20 (5): 36., 1903.

The depository of the four syntypes collected by J. Waterstradt in May 1902 is unknown. They were once held by Hermann Rolle, whose collection, in part, was sold to Eugène Le Moult.

Description
Ornithoptera aesacus is a member of the Ornithoptera priamus species group. The two species are very similar but the male O. aesacus has a brilliant turquoise-blue sheen.

Taxonomy
The classification of Ornithoptera aesacus as a species does not have full consensus, and is sometimes regarded as a subspecies of Ornithoptera priamus by some, such as Parsons (1996).

Synonymy

 * O. obiana (Waterstradt in litt.) Rebel, 1906
 * O. obiensis Rippon, 1906
 * O. obiana (as O. arruana obiana) Rippon, 1906-1912

Distribution
The Obi Island birdwing is endemic to the Island of Obira in Indonesia. It inhabits tropical rainforest. Due to extensive logging on the Island the conservation of the species is a concern, and has been classified as 'Vulnerable' by the IUCN Twenty years ago it was the rarest birdwing species in the world. It remains threatened, but is commercially bred.

Other sources

 * D'Abrera, B. (1975). Birdwing Butterflies of the World. Country Life Books, London.
 * Haugum, J. & Low, A.M. (1978-1985). A Monograph of the Birdwing Butterflies. 2 volumes. Scandinavian Press, Klampenborg; 663 pp.
 * Parsons, M.J. (1996). A phylogenetic reappraisal of the birdwing genus Ornithoptera (Lepidoptera: Papilionidae: Troidini) and a new theory of its evolution in relation to Gondwanan vicariance biogeography. Journal of Natural History 30(11):1707-1736.
 * Parsons, M.J. (1996). A phylogenetic reappraisal of the birdwing genus Ornithoptera (Lepidoptera: Papilionidae: Troidini) and a new theory of its evolution in relation to Gondwanan vicariance biogeography. Journal of Natural History 30(11):1707-1736.