A plague of locusts is threatening Melbourne’s Cup race and experts are predicting mass damage to crops. The locust plague is thought to be the worst in 75 years and farmers are preparing to tackle huge swarms across Victoria, NSW and South Australia. The Victorian government has already invested $43 million in fighting the plague, which threatens $2 billion worth of crops. “This is a war on locusts, I want to be absolutely clear about this,” Premier John Brumby said on Thursday. “We’re doing everything we can to get on top of this.”

A quarter of Victoria’s crops are in danger of being eaten by the locusts as is the Flemington track, where the prestigious Melbourne Cup is held each year. Brumby said: “[The locust plague] has got the potential to close events like Melbourne Cup Day and country race carnivals so we are doing everything we can to get on top of this.” Farmers are being reimbursed for the full cost of locust spraying, and two incident control centres will be opened next week.

Conditions have been prime for locusts this year, with summer rainfall in Queensland and NSW allowed native grasses to flourish, providing perfect breeding conditions for locusts. Swarms then moved south, laying eggs over an area of Australia about the size of Spain. Russell Amery, president of the Victorian Farmers Federation’s grain group, predicted that “all hell will break loose” in a few weeks. “They can take a paddock from green to bare dust in a matter of hours,” he said.