Plagues of mice and locusts are threatening huge swathes of Australia's farming heartland and could wipe out crops worth one billion dollars (880 million US), scientists warned Wednesday.
Millions of mice are currently devouring crops and will be joined within months by dense swarms of locusts, affecting southeastern regions with the combined area of Portugal.
"This is the result of what we are calling a perfect storm," said Chris Adriaansen from the Australian Plague Locust Commission. "Many millions of eggs will hatch."
High rainfall and mild temperatures have created ideal breeding conditions for the pests, which will hit parts of New South Wales, Victoria, Queensland and South Australia, experts told a briefing.
Mass locust hatching in September and October is set to create swarms of up to 15,000 per square metre (yard), devastating crops at a rate of several hundred metres a day.
Scientists said the best way to stop the plagues was to predict their movement and use pesticides, but held out hope that cannibalism by the locusts could limit the disaster.
"Locusts are constantly nibbling on each other and are more than willing to feed on each other," said Greg Sword, an Associate Professor at the University of Sydney's Molecular Ecology Lab.
"The locusts would effectively be feeding on themselves and could help limit their own populations."
Aerial tracking aircraft will be used to follow the outbreaks, allowing farmers to target the use of pesticides to protect their vegetable and grain crops.
"The problem with poisons is that they have other impacts throughout the ecosystem," said Mathew Crowther, a lecturer in wildlife management at the University of Sydney.
"They're also quite expensive, and when the farmers do put them out, often a lot of the damage is already done."
But the impact of inaction could be far worse, with Adriaansen estimating losses of up to one billion Australian dollars if the plagues are left unchecked.
And while scientists are confident they will ultimately be able to control the outbreak, it is expected to continue for several months at least.
"This will be a problem that will continue into (southern hemisphere) summer," said Adriaansen.
News of the plagues comes after a mass sabotage in Queensland wiped out seven million vegetable plants, mainly tomatoes, which cost an estimated 50 million dollars and is expected to send prices soaring.
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