Blue Birdwing

Ornithoptera priamus urvillianus is the blue island subspecies of Priam's birdwing. Names applied to unusually green or intensely blue individuals describe variation within this taxon. [1]

Males have pointed black forewings with blue bands and rounded hindwings carrying large black spots. A median forewing stripe is normally absent. Blue tends to become deeper toward the southeastern part of the range. Females have muted brown wings with pale markings. [1]

The range extends from New Ireland and neighbouring islands through Bougainville and much of the Solomon Islands. Populations occupy coastal vegetation, river margins and secondary forest. [1][4]

In Straatman's Solomon Islands rearings, larvae pupated beneath leaves of nearby trees or shrubs, usually away from the food vine. The pupal period was 30–33 days. Older caterpillars were dark, with a conspicuous white saddle and red-based tubercles. [2]

Aristolochia tagala supported larvae on several Solomon Islands. On Malaita, larvae transferred to another local Aristolochia accepted the leaves but subsequently died, showing that feeding acceptance alone did not establish a suitable host. [2]

Females in the Solomon Islands frequently laid eggs on nearby twigs, stems or other surfaces rather than directly on the host vine. Newly hatched larvae then had to reach the food plant. [2]

Microscopy reveals layered internal structures in the blue wing scales. Optical measurements found a reflection maximum near 490 nm, while ultraviolet-absorbing pigment filters shorter wavelengths. The blue therefore results from an interaction between scale structure and pigment. [3]

Green tree ants attacked large larvae and newly formed pupae in the Solomon Islands. Hornets also captured larvae, and toads took mature caterpillars moving near the ground. [2]

The name honours the French naturalist and explorer Dumont d'Urville. The earliest material came from New Ireland during the Coquille expedition of 1822–1825. [1]