A breakthrough in the dung beetle laboratory at CSIRO involving fungi is expected to help scientists with their mission of keeping the little soldiers on the job of burying cow pats year round.
Dung beetles are crucial to the control of buffalo and bush flies, which breed in cow dung. Some species of dung beetles are able to bury dung 250 times their own mass in one night, eliminating the breeding ground for the serious pest to cattle producers.
They also help recycle nutrients and increase the amount of pasture in a paddock as the grass that grows through a cow pat is unpalatable.
However, despite Australia's dung beetle program having released 44 species from Europe and Africa since the 1960s, only 23 have established and we are still not in a position where dung beetles are active across all environments all of the time.
The discovery that the pathogenic fungus, Beauveria australis, may have played a role in the failure of some imported species to establish means scientists can now focus on eliminating that hurdle and plugging a lot more of the gap.
Interestingly, Beauveria are related to the Cordyceps fungi made famous in post-apocalyptic TV series The Last of Us.
Their spores infect insect hosts, spread through their bodies and eventually kill them.
Scientists also found Beauveria bassiana, which is sometimes called the 'icing sugar fungus' as it looks like the insect has been dusted with thick patches of icing sugar where the fungus is growing.
CSIRO entomologist Dr Valerie Caron said this was the first time this fungus had been found in the scarab beetle family, although scientists already knew it was here and could infect grasshoppers, ants, wasps and other beetles.
She said the next move would be to investigate how prevalent the fungus was is in dung beetle populations.
"Then we will need to build up the beetles' immunity as a population to the fungi and release beetles where there is less of the fungi," she said.
Dung beetles are very fussy - they are quite particular in their dung choices, Dr Caron explained.
"We have amazing dung beetles in Australia because they co-evolved with the fauna here - but kangaroo dung is very different to cow dung and most of the native beetles don't like cow dung," she said.
"That's why we need to import various species but even with all the work that has been done since the 1960s we still don't have yearly activity.
"Australia has so many different climates, with livestock in all areas. Dung beetles tend to have a peak period when they use most of the dung.
"We are finding gaps in activity all the time and would like to not only introduce more species but ensure all the species establish."
That's where this new discovery comes in, and Dr Caron said because fungi like humid soils it was possible that there was more of it around now after the good rains in most parts of the past few years.
She said if producers find a dung beetle with a fluffy white look, they should contact CSIRO.
Shan Goodwin
Shan Goodwin steers ACM’s national coverage of the beef industry. Shan has worked as a journalist for 30 years, the majority of that with agricultural publications. She spent many years as The Land’s North Coast reporter and has visited beef properties and stations throughout the country and overseas. She treats all breeds equally. Contact 0427686187. E: s.goodwin@austcommunitymedia.com.au
Shan Goodwin steers ACM’s national coverage of the beef industry. Shan has worked as a journalist for 30 years, the majority of that with agricultural publications. She spent many years as The Land’s North Coast reporter and has visited beef properties and stations throughout the country and overseas. She treats all breeds equally. Contact 0427686187. E: s.goodwin@austcommunitymedia.com.au
