Rothamsted Research is undertaking a field trial of GM wheat, which has been modified to repel aphids.

For the trial, scientists have modified Cadenza wheat so that it produces (E)-ß-farnesene, a naturally occurring ingredient found in peppermint plants, which is also an aphid alarm pheromone.

The two-year trial, which is costing £1.28m, aims to make wheat production less reliant on pesticides.

This video clip of aphids (Myzus persicae) resting on Chinese cabbage shows the dramatic effect of the release of an alarm pheromone.

During the film, by Christine Woodcock from Rothamsted Research, a colony of aphids is populating a leaf when a syringe delivers the pheromone.

Just seconds after the alarm pheromone is released, the aphids quickly detect it, become agitated and disperse.

Aphids are the main pests of wheat and they cause significant damage to crops and spread plant diseases, which without the use of insecticides, would cost the UK up to £120m a year, research shows.