There is a new cloud on the horizon in western Queensland that is making some graziers wonder why they got into farming.
In March this year, central and western Queenslanders were hit with widespread flooding on a scale not seen since European colonisation. Stock drowned, topsoil was stripped, fences were destroyed and houses inundated. Spirits plummeted. But then came bounty from the rains, pastures springing forth in the vibrant colours of hope and new life.
Now, as graziers repair fences, watched on by cattle fattening on the fresh grass, the new cloud is drawing in. It has been described as a black blanket moving across the landscape.
It is a swarm of locusts, and graziers such as Geoff Seccombe from Kenya Station near Muttaburra, 1,200km north-west of Brisbane, are nervous.
“Over the last five years we’ve had grasshoppers four times and they’ve wiped us out three times,” Seccombe says. “We lost 100% of our pasture in 2020, 2021 and 2022 and [as a result] we did not have an animal on the place, they were all put on agistment at a massive cost.”
These grasshoppers, or locusts, are native species but three – migratory locusts, Australian plague locust and spur-throated locusts – have the potential to cause massive pasture loss. Migratory and spur-throated swarms currently have Longreach surrounded with sightings extending north to Muttaburra, west to Winton, east to Dysart and as far south as Hay in southern New South Wales.
So far, Seccombe says, the damage has been manageable – thanks to the species of locusts in question. “We’ve had a lot of locusts but we’re fortunate in that we’re having a good season and we didn’t get a big impact, mainly because they were migratory locusts that eat the leaves and don’t eat the whole plant off at ground level like the other two do,” he says.
Geoff Penton is operations manager for Desert Channels Queensland, a natural resource management organisation based in Longreach. He says dealing with locusts is a like playing Russian roulette.
“We’ve seen images of swarms that could be up to half a kilometre across, and should that blanket touch down on your property the locusts have the ability to reduce a paddock with 40-50cm grass height to bare ground in under an hour,” he says.
“If you haven’t had too much flood damage and if you haven’t had locusts, you’re probably having one of the best seasons you’ve had for 20 years.”
A taskforce has been set up in Longreach in response to the flying threat, represented by the Australian Plague Locust Commission (APLC), the Queensland Department of Primary Industries and local councils.
The federal and state governments have also redirected $20m from flood recovery funding to spray for locusts. “Heavy rainfall and flooding events cause significant disruption to our farmers and producers but also increase the risks of locust habitats migrating, which can significantly impact our food production and biosecurity,” the federal minister for agriculture, Julie Collins, said in August.
But Seccombe says the taskforce has not made a dent and is calling for increased monitoring and spraying to control locusts.
“I was walking a mob of cattle – and cattle do about 3km/h – and the mob overtook a swarm of locusts, so they don’t move very fast,” he says. “Government needs to be more organised so when we make the phone call they can be here within hours with chemical and crop dusters.”
Penton says there is little a grazier can do when swarming locusts strike and that spraying should only be used in extreme cases due to its detrimental effect on birds predating the swarms. One commonly used insecticide, fenitrothion, was recently restricted by the Australian Pesticides and Veterinary Medicines Authority after a safety review, which saw evidence of a potential negative impact on the environment, particularly birds.
But another weapon, in the form of biological control, has entered the fight. Salvation may come from spiders.
Dr Shaodong Guo works at the University of the Sunshine Coast, which houses the world’s largest collection of arachnid venom, with more than 800 species represented. With a $240,000, three-year Advance Queensland Industry Research fellowship, Guo is crafting pest-specific bio-insecticides.
“Spiders are the most successful venomous predators in the world and there are over 500,000 species, which means we have a great talent pool,” he says. “We have screened nearly 200 spider venoms and have found 11 that show high oral toxicity for locusts.”
Once the most effective venoms have been identified, they can be formulated into a spray to be applied to vegetation.
Guo says using spider venom for locust control has several advantages over current methods. “Venom can be very selective, which means it can target a pest but not affect other species, such as bees or humans, and it is biodegradable so is very eco-friendly,” he says.
Guo is in the second year of his research and hopes to be doing field trials by the middle of next year. He is also taking donations of locusts from affected farmers.
For graziers like Seccombe, a possible solution can’t come soon enough.
