Native Australian fungi and bacteria found to stop unstoppable fall armyworm
Fall armyworm has swept across the country since it was detected in 2020. (Supplied: DPIRD)
In short:
New biological control methods targeting fall armyworm have been found by Queensland's DPI and the CSIRO after years of research.
The naturally-occurring biocontrols act better than insecticides with some killing the pest within 24 hours.
What's next?
Research from the DPI is close to commercialisation and could be available to farmers soon.
Fall armyworm's relentless march across the globe has threatened the food security of 600 million people in more than 80 countries, but it may have finally met its match in native Australian flora and fauna.
Feeding mainly on corn but also devastating wheat, sorghum, millet, sugarcane, and vegetable and cotton crops, the Food and Agriculture Organisation of the United Nations (FAO) estimates the flying insect can reduce yields by up to 73 per cent.
Originating in the Americas it was first detected in Africa in 2016, and has also been found in the Middle East, Asia, the Pacific, and Europe. It arrived here in 2020.
But breakthroughs by two separate Australian research projects may have finally found a way to halt the destruction of the "impossible to eradicate or control" pest.
And it is all thanks to native fungi and bacteria.
A naturally-occurring white fungus can be cultured and used as a biopesticide against fall armyworm. (ABC Rural: Charlie McKillop)
Resisting control
Using chemicals like insecticide sprays to control fall armyworm has proven difficult due to a number of natural advantages the insect possesses.
It spreads far and fast — managing to move from the Torres Strait to Tasmania in a little over a year, is difficult to detect, and develops resistance to most chemical products on the market quickly.
But a new biological defence against the destructive pest labelled by some farmers as the "coronavirus of agriculture" could soon be commercially available.
This image shows two fall armyworms infested with the fungus Nomuraea rileyi in a corn crop. (Supplied: Georgia Rodgers)
As many as five strands of fungi have already been identified to be able to kill the pest within 24 hours and without it developing resistance.
Among them is a pathogenic fungus Nomuraea rileyi which Queensland's Department of Primary Industries (DPI) has been researching since 2021.
DPI principal entomologist Dr Ian Newton said the naturally-occurring biocontrol acts similarly to insecticides, essentially coating the worm and eating it from the inside out over a number of days.
Ian Newton said a biocontrol product for fall armyworm is ready to be used but requires approval. (ABC Far North: Brendan Mounter)
"There's almost no chance of resistance to these biologicals," he said.
"It's almost never occurred."
He said, pending approvals, the product could be available to buy soon.
"I think we're pretty close. We could basically commercialise the product now and get it in the field,"Dr Newton said.
"If we can get a biological product out to market sooner rather than later it basically means that growers can rely more on the biological product.
"That should increase the longevity of the chemicals so that [the worm] won't develop resistance as quickly."
Faster acting fungi found
Simultaneously, Australia's chief science agency CSIRO has been undertaking research into different native Australian fungi and bacteria to those being examined by DPI that kills fall armyworm.
A four-year study published in the peer-reviewed journal Agriculture in January found some of its varieties killed the insect within 24 hours of exposure.
Fall armyworm caterpillars are treated with the fungus and assessed to determine which strains were fatal. (Supplied: CSIRO)
Researcher Dr Bea Apirajkamol said it was unusual for the fungi to be effective so quickly.
"It normally takes quite a few days," Dr Apirajkamol said.
It is not yet understood exactly how the fungi and bacteria kill the pest insect but Dr Apirajkamol said they believe both produce a toxin.
"The Australian fungi that we found work really rapidly I think could change the way we go about biocontrol in Australia,"she said.
The team treated fall armyworm with the fungi and bacteria at different stages of the life cycle.
Dr Apirajkamol said they were most effective when the insect was a caterpillar but also worked when it was a moth.
Research from the CSIRO has found five strains of fungi that can kill the invasive fall armyworm. (Supplied: CSIRO)
Unlike the work of the DPI, Dr Apirajkamol said the CSIRO research was still in its early stages and would not be commercially available for at least a few years.
"There's a lot more research that needs to be done," she said.
Relief for impacted farmers
Entomologist Dr Melina Miles inspects a fungus-infested fall armyworm under a microscope. (ABC Rural: Amy Phillips)
On the frontline of helping farmers manage the insect, another DPI principal entomologist Dr Melina Miles said there was "enormous relief" damage was down after an outbreak year in 2024.
"It reinforces that the really horrendous year we had last year is more likely to be an anomaly,"Dr Miles said.
One of the growers seeing a rebound is Rhys Daniels whose farm near Capella in central Queensland was hard hit last season.
He said current control measures were not cost effective, meaning he had little choice but to watch the pest devour his crop.
"One paddock's a bit worse than another, but nothing like last year," Mr Daniels said.
"We're sort of just turning a blind eye this year.
"The impact's not too bad for the cost of doing something about it."