About Papilio aegeus Donovan, 1805
Both male and female Papilio aegeus have black forewings marked with a white stripe, with females having more white covering their forewings overall. Their hindwings are also black, with a broad white band crossing the middle. Markings differ between sexes here: females have chains of red to orange and blue crescent-shaped markings toward the edge of the hindwings. Underside wing markings are similar to the markings on the upper side of the wings. The body of the butterfly is black. Females have a wingspan of around 140 millimetres (5.5 in), while males have a wingspan of around 120 millimetres (4.7 in), making the species overall quite large, and the largest butterfly commonly seen in at least part of its range. Although Papilio aegeus is a swallowtail butterfly, a group named for the distinctive tails on their hindwings, this characteristic tail feature is completely absent in this species. Karl Jordan describes forma of Papilio aegeus on pages 65–67 in Seitz. Papilio aegeus can be found in every Australian state except Tasmania. It has well-established colonies in the Albany region of Western Australia, and is generally found across eastern Australia, with some groups promoting controlled propagation of its eggs and caterpillars in Western Australia. It is especially common in Queensland, and is the largest butterfly commonly found in Brisbane, where many citrus trees grow; citrus trees are the food source for the species' larvae. During summer, the species' distribution temporarily extends into Victoria. In New South Wales, adults are more abundant during late summer and autumn. The subspecies P. a. ormenus is found on Thursday Island and in Papua New Guinea. Other subspecies occur on islands in the Banda Sea and the Bismarck Sea. A distinguishing feature between males of the nominate subspecies P. a. aegeus and males of P. a. ormenus is that nominate males have a red spot on the upper side of each hindwing, and this spot is absent in P. a. ormenus males.
