Papilio anactus

Papilio anactus W.S. Macleay, 1826
Dainty Swallowtail
(previously known as Elleppone anactus)
PAPILIONIDAE, PAPILIONOIDEA

Don Herbison-Evans
(donherbisonevans@yahoo.com)
and
Stella Crossley

Papilio anactus

These Caterpillars are commonly found on cultivated Citrus, such as :

Kaffir Lime ( Citrus hystrix ),

Lemon ( Citrus limon ),

Grapefruit ( Citrus paradisi ),

Madarin ( Citrus reticulata ),

Orange ( Citrus sinensis ),

Wood Apple ( Limonia acidissima ), and

Hardy Orange ( Poncirus trifoliata ).

(Photo: courtesy of Neil Horner, Canberra, Australian Capital Territory)

The caterpillar will also feed on the Australian native plants:

Australian Lime ( Citrus australis ),

Large Leaf Lime ( Citrus inodora ),

Desert Lime ( Eremocitrus glauca ),

Australian Willow ( Geijera parviflora ),

Finger Lime ( Microcitrus australasica ), and

all in RUTACEAE.

last instar
(Photo: courtesy of Fred Swindley, West Ryde, Sydney, New South Wales)

The early instars are kite shaped, and coloured dark blue with orange spots. The body surface is covered by small fleshy spikes.

(Photo: courtesy of Robert Whyte, The Gap, Brisbane, Queensland)

The later instars are cylindrical with short knob-like spines. They reach a length of 4 centimetres, and are coloured brown or dark blue, with yellow, white and orange spots.

(Photo: courtesy of Alex Peters and Heath Dillon)

(Photo: courtesy of Bruce Anstee)

When disturbed, all instars evert an orange osmeterium from just behind the head producing a decaying citrus smell. The smell is produced by a fluid secreted from glands near the base of the osmeterium. The caterpillar aims the osmeterium towards the disturbance, and the secretion may be more effective when applied directly to a predators skin. It appears to be harmless to human skin.

caterpillar about to pupate
(Photo: courtesy of Jan Lile, North Ipswich, Queensland)

healthy pupa
(Photo: courtesy of Jan Lile, North Ipswich, Queensland)

sick or parasitized pupa
(Photo: courtesy of Trevor Jinks, North Burnett, Queensland)

The pupa is slim with a bifurcated head rather like a pair of horns. It is a patchy green colour, and secured to a stem of the foodplant head up, by a cremaster and girdle. If the pupa is brown or has brown markings, it is probably dead or parasitised. Pupae formed in summer mature in about four weeks, but those formed in March or April may stay dormant for 6 months throughout the whole winter, or indeed sometimes for 18 months, being dormant through a whole extra year. The pupa has a length of about 3 cms.

(Photo: courtesy of Patricia Maree, Capalaba, Queensland)

The adult butterflies have a wing span around 7 cms. They are black and white, with red and smaller blue spots on the margin of each hindwing. These spots appear to mimic those on other Australian Swallowtails. There is no obvious difference between the sexes.

underside
(Photo: courtesy of Patricia Maree, Capalaba, Queensland)

The males establish territories which are strenuously defended, an interesting spectacle to watch. The unusual thing is the same territories will be used year after year.

(Photo: courtesy of Trevor Jinks, North Burnett, Queensland)

The eggs are pale yellow and spherical. They are laid singly on the undersides near the edge of young leaves of a foodplant.

The species is commonly found all over mainland Australia, including

Northern Territory,

Queensland,

New South Wales,

Australian Capital Territory,

Victoria,

South Australia, and

Western Australia.

Butterflies of this species may be purchased for release at weddings etc.

(Photo: courtesy of Trevor Jinks, North Burnett, Queensland)