Research is ongoing to find other sources of resistance to orange wheat blossom midge to help protect the gene responsible for resistance to the pest in some wheat varieties.

While there was no suggestion that the midge had developed resistance in the UK, resistance had been identified in Canada, Lesley Smart of Rothamsted Research said. “We’re a few years behind the Canadians in use of resistant varieties.”

The varietal resistance was based on a single gene, which potentially made it more vulnerable to it being broken, she said.

But researchers had found some alternative genes that could confer some resistance to orange wheat blossom midge. “They might help protect the main gene.”