May 2018: Ghost and Swift Moths
TARGET INSECT OF THE MONTH
The family Hepialidae, commonly known as Ghost and Swift Moths, contains some of the largest and most obvious Australian moths. In May 2018 we are asking you to report sightings of moths in two Hepialid genera - Abantiades and Oxycanus.
Little is know about the number of species in these genera, their distribution and their adult emergence times in the South East Corner. Your observations will help to shed light on those questions.
How to recognise Abantiades and Oxycanus moths
These moths settle hanging by their exposed forelegs with their wings closed, presenting an elongated dark grey or brown shape but often with a prominent white streak or two and impressively intricate underlying markings. Relative to their size, they have long, narrow wings.
Several Abantiades and Oxycanus species have been reported in the Atlas of Life region. These include: Abantiades hyalinatus, A. labryrinthicus and A. magnificus; Oxycanus australis and O. dirempta.
Abantiades hyalinatus - Mustard Ghost Moth
This is a large moth - males have a wingspan of about 10cm, females around 15cm. The forewings vary in colour from brown to orange and, in some individuals, have a pair of white slashes. The hindwing colour ranges from purple to red.
Abantiades labyrinthicus - Labyrinthine Ghost Moth
This is another large species, of a similar size to A. hyalinatus. The forewings are brown, with silver slashes of variable shapes and ornate patterns of concentric rings. The hindwings are plain brown.
Oxycanus australis and Oxycanus dirempta - Swift Moth
Oxycanus moths are smaller than Abantiades. Males have a wingspan of around 7cm, while females are larger - about 10cm. The forewings range from brown to purplish red in colour and generally have with a long white slash running from the wing hinge to the rear edge of the wing. A variety of other white shapes may be found on this slash or elsewhere on the forewing. The hindwings are pale orange to purple. The undersides of both fore- and hindwings is a plain, purplish-brown colour.
Oxycanus australis and Oxycanus dirempta both have variable wing patterns, which seem to overlap between the two species. The only sure way to tell them apart is to look closely at their antennae, so photos of the antennae will help us monitor the species individually rather than as a pair.
There are a number of Abantiades and Oxycanus species that have not yet been recorded in the Atlas of Life region, but that occur in nearby areas to the north, south or west. Sightings of any of those species would be particularly welcome.
If you find anything that is similar but somewhat different to the species described above, record a sighting. We may be able to identify it from your photos.
Where and when to look for Abantiades and Oxycanus moths
These moths fly in late Summer and Autumn and into early Winter, sometimes emerging en masse after rain. They often come to domestic lights, battering against the screen before settling and staying there till the morning. If you look for them in the morning, it is sensible to be up before the birds as the moths make a good meal.
Abantiades come from eucalyptus forest where the larvae usually feed underground on roots. Oxycanus larvae also live underground, but they come to the surface at night to feed on plants or litter. Some species are associated with wattle trees. You might be lucky to see an emergence.
The pupae work their way partly clear from a hole in the ground, the adults emerge, and then hang from nearby vegetation to spread their wings.
Many leave behind obvious empty pupal shells on the ground, as shown in this image.
What might look similar
Some members of the family Cossidae are large with similar narrow wings; adopt a similar posture when settled; and are basically dark with some silver markings superficially like Hepialidae. For example, Endoxyla encalypti is frequently seen in mid-summer in the Atlas region. Cossid moths fold their wings in a more rounded fashion than Hepialids, and their peak flying time is earlier.
Elhamma australasiae
A genus of smaller hepialid moths that might be confused with Abantiades and Oxycanus is Elhamma. Elhamma australasiae is common in urban areas in February and March and comes readily to lights as soon as it is dark. Males have a wingspan of 3-4cm, females twice that.
The largest Australian moth - as measured by wingspan - is also a hepialid. There is no official record of this species - Zelotypia stacyi - in the Atlas region. However, one was found freshly emerged on a low eucalypt branch overhanging a bush track near Bawley Point on 3 March 2010, and a wing was found at Bingie a few years before that.
If you find one, you are unlikely to confuse it for anything else - it has a wingspan of 18-23cm! Make sure you get a photo and post a sighting on NatureMapr if you do chance across one.
What to record
The date, time and location. The number of individuals. Their size (wingspan or overall length top of head to wingtip, ideally measured but otherwise estimated). The plants that the moths seem to be associated with. Any notes about their behaviour (e.g. feeding; resting; flying; mating).
Also the weather, both current and recent past, and even the following weather such as a cold front, as some moths are thought to be able to sense pressure changes and perhaps the likelihood of rain.
What to photograph
When taking photos of settled moths, it is most helpful to obtain more images than just a view from above. Wing scales are three dimensional objects, and can display different wing patterns when viewed at different angles, so photos taken from a side angle often show important information.
A photo taken from a 30-45 degree angle above the plane of the moth, and slightly forward of midway along the moth so the head and appendages can be seen, makes for an ideal main photo.
Additional photographs showing close-ups of the head with its antennae and other appendages are also valuable, as they often help identify genera and species. Take pictures of all the wing pattern variations seen, as it will not always be obvious whether there is only one species present, or more.
Now simply upload your sightings!
All sightings are recorded on the Atlas of Life NatureMapr database. This is a powerful, easy to use system that you can access from a computer or a mobile device.
Other resources
Moths of Victoria, part 6 “Hepialidae and their Allies” is the best available identification reference as it contains most of the species mentioned above and not too many others. It is available quite cheaply from the Entomological Society of Victoria.
“A Guide to Australian Moths” (Paul Zborowski and Ted Edwards, CSIRO Publishing 2010) is a readily available alternative.
The best online resources are the Common Moth pages in NatureMapr and the Hepialidae pages on the Butterfly House website.
ANY QUESTIONS?
If you have any questions about this survey, or about any Atlas of Life activities, please feel free to contact us.
LEADER: Glenn Cocking