This very inappropriately-named Dingy Swallowtail – Papilio anactus – was spreading out its over-4cm wingspan to dry on a recent evening, following 98mm of rain in Dubbo Field Naturalist member Elsie Howe's West Dubbo garden. Papilio is actually Latin for butterfly.
An endemic species, with male and females alike, it's common and widespread in eastern Australia, especially where citrus have been planted on which they can lay their small, pearl-like eggs.
In the natural environment, the resulting larvae of these eggs favour food plants which are in the same plant family as citrus trees; in our part of the world that includes the Wilga, Geijera parviflora.
The swallowtails' preference for plants in this family tend to make them unpalatable to predators. After the first unpleasant beakful, they presumably soon get to recognise this species' spectacular appearance and stay clear!
The day before the dumping of rain, this was probably the same Dingy Swallowtail which had been seen characteristically leisurely gliding around a tree-surrounded clearing in the garden – complete with nearby orange tree.
Every so often it veered off course to chase away at speed an intruding competitor – another characteristic behaviour – and thereby identifying themselves as males. It then resumed life at a slower pace, every so often settling briefly, wings outstretched, on a small bottlebrush. Thanks, Dubbo City Council, for that give-away a few years ago at your stall at a Dubbo Show.
Australia plays host to around 400 species of butterflies, and even though northern Australia has a larger number of species, because of its proximity to countries to the north, our south-east corner has the highest number of endemics, ahead of Tasmania and south-western Western Australia.
The Butterflies of Australia by Orr and Kitching (2010) is an amazingly-illustrated and fascinating book of over 300 pages about all facets of their widely-varying life cycles, as well as the plants with which they're associated. If you want to encourage butterflies to your garden, it's one book well worth having on your shelf.
- Contributed by Elsie Howe