Mice on the March: Why We Need Action Now

ESCALATING mice numbers have been reported on cropping properties in the Maranoa, Downs, Macintyre and Burnett regions – between January and April 2025 – after a big winter-crop harvest left more feed in paddocks.

“The increased mouse numbers could pose a higher risk to crops during planting in April and May, according to CSIRO researcher Steve Henry, when mice could dig up rows of seeds up before they germinated”, an article published this week said HERE

GPA Northern Region Director Brendan Taylor produces grain on Queensland's Darling Downs at Warra, north-west of Dalby, and is also, as Queensland AgForce Grains President, a grower representative on the National Mouse Group (NMG).

Brendan has published a strong article this week raising his serious concerns HERE about the need for growers to access double-strength ZP50 mouse bait, which requires APVMA approval, to get ahead of a potential disaster. Here are some of his most pertinent comments and calls for action, in the opinion piece.

“Currently we only have ZP25 strength bait available. The CSIRO have proven time and time again that the ZP25 bait results in sub-lethal doses - meaning mice have to find multiple grains of bait to get a lethal dose.

“Previous emergency permits allowed access to the ZP50 bait which is double the strength, meaning that each grain of bait has a lethal dose for a mouse - making the ZP50 bait consistently more effective than ZP25. So why do they persist in insisting we use the less effective version?

“Even worse, those mice that eat the toxin and don’t die because of the sub-lethal dose, actually become bait averse. Making this battle even harder.

“It is critical that baiting takes place when background food is at its lowest level, that is, at sowing or post grazing.

“Given what we know, and how this has been proven time and time again by the CSIRO Rodent Research Team with support for the GRDC, we ask why does APVMA not allow access to the ZP50?

“We originally had an emergency use permit for ZP50 (PER90799), but that expired in December 2023.

“We urge the APVMA to make this a priority not only for Queensland but for all of Australia’s grain production districts. The economic cost we face is enormous, and increasing along with the burgeoning numbers of mice devastating our primary production.”

The latest NMG meeting also heard reports of moderate to high mouse activity in major cropping regions, as reported in GRDC Ground Cover HERE

“Grain growers are advised to remain vigilant by monitoring mouse numbers locally in the lead up to sowing”, it said.

In following through on these matters, GPA has also made consistent submissions to various consultation processes, in representing the view of growers HERE including most recently the ‘Have your say’ process on the APVMA draft Strategic Plan 2025–30 HERE

GPA STATEMENT ON ZP50 PERMIT APPLICATION HERE February 2024.