Papilio Aegeus

''Papilio aegeus'', the orchard swallowtail butterfly or large citrus butterfly is a species of butterfly from the family Papilionidae, that is found in eastern Australia and Papua New Guinea.

The larvae of this species are sometimes considered a pest, due to their feeding on citrus leaves in suburban gardens.

Description

Both male and female have black forewings with a white stripe, though there is more white overall on the female forewing. The hindwing is again black, and there is a white swath through the middle. Here the markings differ in that the female has chains of red to orange and blue crescents toward the edge. The markings on the underside are similar to those on top. The body is black. The wingspan is about in females and in males, making it rather large overall and the largest butterfly commonly seen in at least part of its range.

Despite being a swallowtail, which group derives its name from the distinctive tails on the hindwing, this characteristic is entirely absent.

Distribution

''Papilio aegeus'' can be found in every state in Australia except Tasmania. Western Australia has well established colonies in the Albany region. Some people are promoting the controlled propagation of eggs and caterpillars in Western Australia, but it is generally found in eastern Australia. It is especially common in Queensland and is the largest butterfly commonly found in Brisbane where there are many citrus trees, on which the larvae feed. During summer, the distribution is temporarily extended to Victoria. Adults are more abundant during late summer and autumn in cc. NSW.

The subspecies ''P. a. ormenus'' is found on Papua New Guinea and Thursday Island.

A differentiating feature between males of ''P. a. aegeus'' and ''P. a. ormenus'' is that ''P. a. aegeus'' males have a red spot on the above side of each hindwing, which is absent in the males of ''P. a. ormenus''.

Other subspecies occur on islands in the Banda Sea and the Bismarck Sea.

Variation

Subspecies

* ''Papilio aegeus aegeus'' — Cape York - East Victoria, South Australia
* ''Papilio aegeus adrastus'' C. & R. Felder, 864/small> — Banda Group
* ''Papilio aegeus aegatinus'' Rothschild, 1908 — Noemfoor Island
* ''Papilio aegeus goramensis'' Rothschild, 1908 — Goram Island
* ''Papilio aegeus keianus'' Rothschild, 1896 — Kai Island
* ''Papilio aegeus kissuanus'' Rothschild, 1908 — Watubela Island, Goram Island
* ''Papilio aegeus oritas'' Godman & Salvin, 1879 — New Ireland, New Hanover
* ''Papilio aegeus ormenulus'' Fruhstorfer, 1902 — Fergusson Island
* ''Papilio aegeus ormenus'' Guérin-Méneville, 831/small> — Aru, Missol, Salawari, Jobi, Waigen, West Irian, Papua, New Guinea, Trobriand, D'Entrecastreaux, Woodlark, Lousiades, Torres Straits Is
* ''Papilio aegeus othello'' Grose-Smith, 1894 — Biak
* ''Papilio aegeus websteri'' Grose-Smith, 1894 — New Britain

Forms

Females of both ''P. a. aegeus'' and ''P. a. ormenus'' have three forms; regular, pale and dark. The pale form has yellow spots on the hindwings, compared to the usual red spots. The forewings are almost completely white. The front wings of the dark form are almost completely black and the hindwings have a smaller white patch.

File:Papilio aegeus 2.jpg, ''P. a. aegeus'' (male)
File:Papilioaegeus ormenus.JPG, ''P. a. ormenus'' (male)
File:Papiliooberon.JPG, Dark form (female)

Life cycle

Egg

The female lays creamy white, smooth, spherical eggs with an approximate diameter of 0.5 millimetres individually on the upper surface of the leaves and shoots of host plants, primarily tropical to subtropical members of the family Rutaceae, which includes introduced and native citrus. The eggs will hatch about one week later.

Larva

The early instars are brown with three white patches, one the: thorax, above the first pair of prolegs, and one on 8th and 9th segment of the abdomen. It is lined with black and white tubercles. The larva only feed on their food plants, citrus. Feeding usually takes place during the day and resting on the upperside of leaves during the night, resembling fresh bird droppings.

The later instars are green with irregular white, yellow or brown markings that run diagonally up/back from the bottom edge of the thorax to the 4th and 6th segments. After about four weeks, the larva may have reached a length of and be ready to pupate.

The larvae are sometimes parasitised by other parasitic insects. Like other swallowtail butterflies, when disturbed, the caterpillar erects its bright red osmeterium from behind the head, releasing the smell of citrus, to drive predators away.

Pupa

The pupa is coloured in cryptic grey, green or brown, depending on the colour of the stem it is attached to. The chrysalis is fastened to a stem of the host plant by means of a cremaster. A thin girdle of silk keeps the head end of the chrysalis uppermost during pupation. Depending on the season, an imago will emerge from the chrysalis, approximately one to six months later.

Images of life cycle

Image:Papilio_aegeus_early_instar1.jpg, An early instar caterpillar
Image:Papilio_aegeus.jpg, A later instar caterpillar
File:Papilio aegeus copulation.JPG, Copulating ''P. a. aegeus'' in Melbourne Zoo - female above, male below

Larval food plants

Native

The larvae are known to naturally use species the following Australian-native taxa as food plants: ''Boronia'', ''Citrus'', '' Clausena'', ''Dinosperma'', '' Eriostemon'', '' Flindersia'', '' Geijera'', ''Halfordia'', ''Leionema'', ''Micromelum'', '' Philotheca'', '' Zanthoxylum'' and ''Zieria''

Introduced

In addition, larvae have also been recorded using introduced species of the following taxa as food plants: '' Choisya'', ''Citrus'', '' Murraya'', '' Poncirus'' and '' Zanthoxylum''

Caterpillars also accept leaves from Parsley and Cryptocarya glauscens however female butterflies do not appear to lay eggs on these plants.

Taxonomy

''Papilio aegeus'' is the nominal member of the ''aegeus'' species group. The clade members are:

*''Papilio aegeus'' Donovan, 1805
*'' Papilio bridgei'' Mathew, 1886
** ? '' Papilio erskinei'' Mathew, 1886
*'' Papilio gambrisius'' Cramer, 777/small>
*'' Papilio inopinatus'' Butler, 1883
*'' Papilio ptolychus'' Godman & Salvin, 1888
*'' Papilio tydeus'' C. & R. Felder, 1860
*'' Papilio weymeri'' Niepelt, 1914
*'' Papilio woodfordi'' Godman & Salvin, 1888

References

Cited texts

*Braby, Michael F. ''The Complete Guide to Butterflies of Australia''. Corrected edition. Collingwood, Victoria: CSIRO Publishing
8.Harden, Gwen J.(Ed.) "Flora of New South Wales, Volume 1" New South Wales University Press, 1989.

External links

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Brisbane InsectsButterflies and other Invertebrates Club
Images from Naturhistorisches Museum Wien

{{Taxonbar, from=Q136158

aegeus
Butterflies of Australia
Butterflies described in 1805