Sighted: Most years from Oct to May. More common in summer with males appearing first usually in early to mid Oct.
Female Orchard Swallowtail feeding on Choisya ternata flowers, 25 May 2007, 4.46 pm
A male Orchard Swallowtail bred at Claire Cottage, Dorrigo Plateau, 11 Jun 2018 (Photo Phil Gilmour)
If you have a citrus tree in your garden, you will undoubtedly have the female of this large butterfly looking for tender new leaves on which to lay her eggs. The Orchard Swallowtail is common on our property where its aterpillars feed mainly on introduced Citrus and Mexican Orange and less frequently on Flindersia schottiana, F.australias and F. xanthoxyla. Although they have also laid eggs on Philotheca (Eriostemon) we have not seen the caterpillar successfully mature to pupation on that plant.
The black males are usually the first to appear in mid Spring flying lazily around nectar flowers waiting for the females to appear so mating can take place.
Male Orchard Swallowtail, 24 Jan 2016 9.51 am
Another male, 1 Mar 2015, 11.04 am
Female newly hatched Orchard Swallowtail, 28 May 2007 12.37 pm
Female Orchard Swallowtail - note difference in colour to male above 25 May 2007 4.46 pm
Female, 23 Dec 2017 2.01 pm
Female Orchard Swallowtail depositing eggs on Citrus (Lemon), 7 Nov 2018 2.47 pm
Orchard Swallowtail caterpillars when small are brown and white and look remarkably like a bird dropping as they sit motionless on top of a leaf. At this stage of their development their clever colour camouflage enables them to sit openly on the leaf.
When the caterpillar reaches its final skin (instar) it changes its colour from brown and white to become green and brown substituting the original brown for green and the white for brown. In this final instar it soon becomes too large to sit on the leaf surface and instead begins sitting on a branch where the new colours provide a better camouflage.
Egg laid on Choisya ternata (Mexican Orange) Apr 2020. Hatched 17/04/20.
A newly hatched caterpillar - note its first eating on leaf edge, Jan 2018
Early instar Orchard Swallowtail caterpillar feeding on Choisya ternata in our garden, 14 Apr 2010
Final instar Orchard Swallowtail larva feeding on Choisya ternata in our garden, 15 Mar 2011
Final instar caterpillar that has just changed its skin. Note webbing on the leaf used to ensure success in the skin changing process, 21 Mar 2007
Pupa, Dec 2015
Parasites that hatched from three pupae, Apr 2019
Young Orchard Swallowtail in defense mode, displaying its osmeterium 11 Feb 2011
If you disturb a Swallowtail caterpillar (see photo to right) you will often see them rear up and extend two red fleshy 'horns' (called osmeterium) from just above their head, these have a pungent citrus smell.
This is a defense mechanism which all Swallowtail caterpillars have to reduce the risk of attack by predators who find the smell given-off offensive.
Let's hope this mature larva is not considering making its chrysalis on the lime!
ELSEWHERE:(as for Dorrigo Plateau plus) RUTACEAE - Other native Citrus and introduced Citrus*. Additional Flindersias and many plants in QLD.
Last annual autumn sighting - Dorrigo Plateau: Male-18/03/18, m-12/04/20; Female-10/04/18
Status Dorrigo Plateau: common
Flight habit: Throughout the day.
Habitat: Rainforest - subtropical.
Items of Interest: Of the larval food plants at Claire Cottage females prefer to lay their eggs on introduced Citrus but occasionally the other food-plants shown above are used.
We usually leave wild larva in situ but following heavy losses to birds (?) in summer 2016/2017 we chose to collect many of our Orchard Swallowtail larvae this summer 2017/2018 and allow them to reach maturity in security within the house. Adults started to hatch in early February 2018 emerging from their pupa around 06.00-07.00 early in the morning as the day lightens. Released butterflies to date 2 males / 1 female.