The largest locust infestation in 40 years is sweeping across Australia’s croplands and pastures like a hailstorm—devastating tens of thousands of acres and costing farmers millions of dollars.

The quick-breeding locusts, which multiply after periods of severe drought followed by intense rains, have stripped clean crops, pastures, orchards, gardens and sports fields from Queensland (northeast Australia) to Melbourne and Adelaide. In some cases, the insects can destroy an entire area in a single day.

“You’ve got to see it to believe it,” an owner of one of Australia’s largest carrot producers told The Age. ‘‘One centre pivot [plantation] got destroyed completely. We had about 25 million carrots in there. That gives you an idea of how many locusts there are.’’

Some swarms cover areas as large as 186 square miles. The highly mobile insects can travel over 300 miles a day in search of food. According to the Australian Plague Locust Commission (APLC), a swarm of 0.4 miles can contain over 50 million locusts with the ability to devour 11 tons of forage in a 24-hour period.

Experts do not believe the infestation will end with the season. “Come the middle of September through to October across that entire inland area...we expect there to be some very large infestations again,” APLC head Chris Adriaansen told AFP.

This explosion of spring locust hatchlings has farmers and the agricultural industry bracing for disaster. Millions of locusts have already migrated into Victoria and destroyed canola, carrot and oat crops—and they do not evidence signs of stopping.

“This is potentially one of the worst seasons, because we had that rain around Christmas time and the floods out in the Channel Country,” Graham Hartwick, an officer with government agency Biosecurity Queensland, told ABC News Australia. “Mostly when they breed up in the Channel Country they go south into New South Wales, Victoria and South Australia; however, there is the risk that they can come into the cropping areas in the east and that is what we are concerned about at this stage.”