Farmers are being urged to help create a more accurate national picture of resistance to rodenticides in rats and mice.
The call from the Campaign for Responsible Rodenticide Use UK (CRRU) comes in response to the ‘surprising and troubling’ spread of resistance to rodenticides found by its latest surveillance.
It found not only that three-quarters of rats analysed carried a resistance gene but one-in-five had two different genes, known as ‘hybrid-resistance’.
This poses potentially unknown difficulties for rodent control, according to CRRU chairman Dr Alan Buckle.
“A critical practicality is that, where resistant rodents are present, farmers could be using products that are ineffective," he said.
"And where resistance genes are still absent, others may be using resistance-breaking products unnecessarily."
The appeal involves collecting 2-3cm tail ends from freshly deceased rats or mice and sending by post in free packaging kits.
These are available with detailed instructions from CRRU's website, and in return, producers will get a free indication of their farm’s status.
Resistance testing is a formal component of the CRRU-operated UK Rodenticide Stewardship Regime.
