The miniaturised electronic tags, which can be fitted to the bodies of live insects, have been developed by the biological sciences department at the University of Wales Aberystwyth.

Dr John Gee: "The tag will reflect the signal from the hand-held detector"

The idea is scaled down version of a device used to track skiers caught in avalances.

Project leader Dr John Gee said the tagging device would illuminate scientists on the all-important adult life stage of insects such as the cadis fly.

"We know quite a lot about the early life stages of these insects," he said.

Dr John Gee: "The adult is a very important stage of the life cycle"

"What we want to know is how far the females get with their eggs, whether they are impeded by trees, how they are affected by the weather and how far they go."

The project team at the university has created tiny diodes which are attached to tags and placed on the stomachs of the cadis flies.

The diodes themselves are made from very fine wire, which is thinner than human hair, and acts as an aerial.

These then reflect the signals from a hand-held detector, explained Dr Gee.

The scale of the tags mean that scientists could theoretically track the movements of the insect world, discovering unknown data.