Advertisement

Aussie fungus drilling into insects and eating them from the inside

It's the first time the pathogen has been found inside dung beetles.

Dung beetles imported into Australia have been eaten alive by a disturbing native fungus species.

CSIRO entomologist Dr Valerie Caron told Yahoo News Australia while Beauveria Australis appears “fluffy, white and cuddly”, its spores germinate inside the beetle and devour it from the inside.

The species is closely related to Cordyceps fungi, which was seen infecting human hosts in the sci-fi series The Last of Us. But Dr Caron reassured Yahoo the fungus that’s killing dung beetles doesn’t pose a danger to humans.

Two dung beetles infected with the fungus.
Beauveria Australis is infecting Australia's dung beetles. Source: CSIRO

Discovering dung beetles riddled with the fungus might be a clue as to what has wiped out 21 of the 44 species of dung beetle introduced since the 1960s. Fungi can have devastating effect on wildlife, with one introduced strain believed to have wiped out several frog species.

How does the fungus get inside the beetles?

  • Spores travel in wind, water or soil.

  • They attach to the insect's exoskeleton.

  • The spores create a tube and pierce the body.

  • The fungus then reproduces inside the beetle.

  • It’s believed it could take a few days to kill an infected beetle.

Because the closely related fungus Beauveria Bassiana is vulnerable to temperature changes, infected locusts will sun themselves to stay hot and control the fungus.

Why is Australia importing dung beetles?

While Australia has its own species of dung beetle, they aren’t able to roll the wet manure left by European herbivores that have been imported to Australia – only dry fibrous deposits dropped by marsupials. That’s why imported insects are key to keeping our paddocks healthy.

A dung beetle on a small pile of dung.
Dung beetles are imported from countries including France and Morocco. Source: Getty (File)

The fungus has been found in native grasshoppers, ants, and other beetles, just not dung beetles before. The imported insects were determined to be “squeaky clean” before they were imported, so it’s believed they became infected in Australia.

“We don't know what the impact is in nature. But we know that in our colony a quarter of them died. So that's quite high,” Dr Caron said.

She thinks sudden exposure to the Australian fungus without having built-up immunity could have led to their rapid deaths. “It’s a bit like us with Covid-19, we had to develop immunity as a population because it was a new pathogen,” she said.

If the fungus continues to harm dung beetles introduced to Australia then it could make the work of scientists working to combat our livestock manure problem harder.

Do you have a story tip? Email: newsroomau@yahoonews.com.

You can also follow us on Facebook, Instagram, TikTok and Twitter and download the Yahoo News app from the App Store or Google Play.