WESTERN AUSTRALIA — Grain farmers in Western Australia are applying to the national pesticides regulator for emergency permits to use stronger poison against a severe mouse plague that is destroying new crops across hundreds of thousands of acres of the wheat belt state. Grain industry estimates put potential losses from the current plague in the billions of dollars, including in exports to Southeast Asia.

Mice outbreaks have also been reported in the neighboring state of South Australia. The situation in Western Australia is worse than the mouse plague that hit New South Wales five years ago, which caused an estimated $700 million in losses of crops and seed, according to an expert.

Mice can locate grain under the ground, dig burrows, eat grain, and strip rows of seeds. They also feed on new seedlings around their burrows.

Steve Henry, an expert on mice, described how infestations spread. "You get these isolated patches of mice. And then when conditions are favorable, they'll breed up and breed up and breed up. And because they have to move further to get their food, all of these isolated patches build up."

Mark Fowler, who grows barley, oats and canola on land south of Perth in a region affected by the infestation, described the damage to his crops. "We don't know yet to what extent that it'll have an impact on yield, but it's very significant. And it's stressful to watch, in difficult conditions, especially in this economic climate, areas of crop just getting bared out with nothing growing there."

The infestation has arrived as Australian grain farmers contend with fuel and fertilizer shortages linked to the Middle East war, which has cut off the flow of goods through the Strait of Hormuz. "Obviously, we're confronted with quite difficult circumstances for farming at the moment, with fuel and fertilizer and some challenging seasonal conditions in places as well and really tight terms of trade," Fowler said.

Australia is one of the world's top grain producers and exporters. The Australian government has expressed concern about the impact of the mouse plague on food supply.