A new growing season brings new alerts for potential pests across Australian farms.

Mice are just one pest which multiply or wane, depending on seasonal factors. The flooding of two years ago actually helped in controlling numbers of these rodents as farm infrastructure and drowned crops, appeared to have stopped them in their tracks.

Now, with weather patterns more normalised, the threat of growing mouse numbers has prompted a call to check and record mouse numbers on broadacre farms.

A major player in the agricultural industry, the Grains Research and Development Corporation (GRDC) are urging farmers to report mouse number to aid in early detection and effective control. GRDC has invested in the National Mouse Group (NMG) which aims to co-ordinate action against any possible mouse plague.

GRDC supported mouse researcher Steve Henry from CSIRO, is encouraging growers to monitor and log mouse activity this season through the free MouseAlert website, via X (formerly Twitter) using @MouseAlert or though the FeralScan Pest Mapping app.

These tools will help track and manage the populations of these pests.

"We are urging growers to get out of their utes and check their paddocks. Even if you think mouse numbers may be low, get out, walk through paddocks and look closely for any signs of current mouse activity. High stubble loads can hide the signs of mouse activity," Mr Henry said.

“While mouse numbers varied across cropping zones, if present in high numbers, they could have devastating impacts on crops being sown in the coming months.”

Most recent reports from our area show patchy mouse activity west of Dubbo, near Trangie, in Warrumbungle and between Coolabah and Byrock. However, these reports were in the first half of 2023. Mr Henry urged growers to monitor paddocks regularly with new reports needed to help with research.

“This year, we are seeing localised and patchy mouse activity. In some areas, good summer rains could lead to increased mouse numbers, but conversely, flood events may have helped to keep mouse populations low. The key message is to monitor,” Mr Henry said.

Growers who do record high numbers are advised to apply control measures when background food is at its lowest, which is generally at sowing, to give mice the best chance of finding and eating the bait and to protect germinating crops. 

Growers should be aware that the emergency permit for ZnP50 expired at the at the end of December 2023, so 25g/kg zinc phosphide baits (ZnP25) are currently the only registered bait available. Zinc phosphide bait must be spread according to the label rate of one kilogram per hectare.

While correct use of bait products is critical, GRDC Pest Manager Leigh Nelson said chemical control was only part of the solution.

"It's not just about putting the bait out and hoping for the best, growers need to continue checking paddocks, assess the situation and decide if additional actions are necessary,” Dr Nelson said.

There are over 3000 recorded mouse sites recorded on Mouse Alert with hopes for many more to be recorded this year.