Species: Papilio aegeus
Common names: Orchard Swallowtail Butterfly
After the bushcare working bee in early October I spent a couple of hours walking around the Fort and observed some interesting butterfly behaviour. There were several Orchard Swallowtails flying – these are one of the largest butterflies found in SEQ. The female commonly lays her eggs on citrus leaves including backyard lemon, lime and mandarin trees. Some gardeners are familiar with the large, fat larvae with their multi-coloured markings, which apparently are meant to mimic a large bird dropping and therefore provide camouflage from potential predators. The larvae also have another defence mechanism – smell. When disturbed, the larvae project two red antennae-looking structures, called osmeterium, from the top of their heads (or correctly, the prothorax). When the osmeterium appear, so does a rank smelling odour.
I watched both male and female Orchard Swallowtails feed on the flowers of the Banana Bush (Tabernaemontana pandacaqui). The females were also laying eggs (ovipositing) on the leaves of Bumpy Ash (Flindersia schottiana), one of their native host plants. One poor female was being chased incessantly by two males. Her hindwings were quite damaged, possibly as a result of such behaviour. (Deborah Metters)
This large butterfly is very common and can usually be seen somewhere in the Reserve at this time of year. The typical larval host plants in the Reserve are the Flindersia species and Citrus australis. The larvae also feed on introduced citrus trees. The photo shows their courtship activity with the male hovering and fluttering around the female who has settled on a leaf. Note the colour differences between the male and female.
You’ve probably seen the beautiful large Orchard Swallowtail butterflies flitting through the reserve. Their native host plants include Flindersia species and Citrus australis but are most frequently seen on garden citrus trees. This young caterpillar (below) has put out its two red “horns” in a defensive display.