WA’s regions have been hit by thousands of mice. Will stronger baits help turn the tide?

There are hopes stronger baits will help turn the tide on a plague of rodents that has taken hold in Western Australia’s regions, with farmers optimistic after weeks of campaigning.

Landholders in towns including Northampton, Mullewa and Ravensthorpe were recording more than 8000 mice per hectare in April; a plague is typically declared at levels above 5000 mice per hectare.

The issue is also affecting areas in South Australia, with the plague spread across Western and central Australia.

However, a decision handed down by the Australian Pesticides and Veterinary Medicines Authority on Monday means bait production will ramp up in the hopes of quashing the outbreak.

Access to stronger baits will also now be available to grain farmers in a bid to protect their crop, after Grain Producers Australia secured a national ZP50 emergency permit.

Australian grain producers have been desperately calling for permits for stronger mouse baits to tackle the growing problem, with the standard available bait proving inadequate.

Grain Producers Australia research development and extension spokesperson Andrew Weidemann said while grain producers had ongoing access to 25g/kg zinc phosphide (ZP25) mouse bait, it wasn’t strong enough to tackle the level of mice farmers were seeing.

“Mouse plagues can obviously cause massive crop and financial losses in the absence of adequate management tools, as well as significant psychological stress for farmers, their families and those living in affected areas,” he said.

APVMA chief executive Scott Hansen said the emergency permit had been approved in line with strong safety and environmental standards.

“This prioritisation does not mean taking shortcuts in examination of the product and the way in which it is proposed to be used, including its potential impacts on human health, wildlife and the environment,” he said.

WA’s Agriculture and Food Minister Jackie Jarvis had been advocating for the change for some time.

“I’m pleased this decision will provide a way forward for landholders and communities to undertake effective mice control,” she said.

“The state government is also supporting affected communities with additional funding to local government for baits and clean up measures to help alleviate the cost and stress of dealing with this issue.”

The CSIRO has thrown its support behind the changes, as has the Department of Primary Industries and Regional Development.

DPIRD primary industries development deputy director general Cec McConnell said restricted access to the high-strength baits would be a valuable addition to support landholders’ control efforts.

“Mice control has been extremely challenging this season, which is particularly concerning now crops are emerging, and ZP50 baits will be another tool to help landholders to get on top of this issue at a crucial time,” she said.

The department is liaising with industry, scientists and regulators as a member of the National Mouse Group, hosted by CSIRO.

On Monday, the Shire of Morawa posted a warning to its Facebook page, urging the community to stay safe while handling dead mice.

They advised people to wear disposable gloves, closed shoes, long sleeves and a face mask when dealing with dead mice, seal them in a bag or wrap them in newspaper before placing them in red bins, then wash your hands, and remove droppings, wipe away urine and disinfect surfaces carefully.