Papilio ulysses, the Ulysses butterfly (also known as the blue mountain swallowtail butterfly or Blue emperor), is a large swallowtail butterfly, in the subgenus Achillides, of Australia, Indonesia, Papua New Guinea and the Solomon Islands. Its size varies depending on subspecies, but the wingspan is about 10.5cm (04.1inches) in Queensland.[1]
This butterfly is used as an emblem for tourism in Queensland, Australia.
The Ulysses butterfly typically has a wingspan of about 14cm (06inches), but depending on subspecies has some variations in size (western subspecies largest). The upperside of the wings are an iridescent electric blue; the underside is a more subdued black and brown. The colours are produced by the microscopic structure of the scales, a phenomenon called structural colouration.[2]
The female of the species is different from the male in that she has little crescents of blue in the back, upside sections of her hindwings, where there is only black for males. When the butterfly is perched the intense blue of its wings is hidden by the plainer brown under side of its wings, helping it to blend in with its surroundings. When in flight, the butterfly can be seen hundreds of meters away as sudden bright blue flashes. Males are strongly attracted to the color blue, including blue objects which are sometimes mistaken for females.
Karl Jordan in Seitz (83-85) provides a full account of ulysses forma [3] pdf
The other members of the Papilio ulysses species group.
The Ulysses butterfly inhabits tropical rainforest areas and suburban gardens. The Australian government requires breeders to obtain permits, although the species is not endangered. In the past, this butterfly had been threatened but planting pink flowered doughwood has increased its numbers. Reduction in the number of the Euodia trees, a tree heavily used for laying eggs and for leaves eaten by caterpillars, may threaten the survival of this butterfly. Females favour small trees up to 2 metres tall to lay their eggs.
The larval food plants of this butterfly include kerosene wood, a variety of Citrus, and Euodia. In Australia, the Ulysses butterfly imago is known to feed from the blossoms of the pink flowered doughwood, a tree with clusters of small pink flowers that extrude from its branches.[4]