A weapon with a sting in its tail is being developed against terrorists - the sniffer wasp.

Scientists in the US say trained wasps could one day take the place of dogs used to detect explosives.

Studies show they also have the potential to uncover hidden drugs, spot cancer and plant diseases, and even to locate buried bodies.

Wasps are better at detecting specific chemical odours than any existing "electronic nose", and much cheaper than dogs, say researchers from Georgia University and the US Department of Agriculture.

The insects are contained in a device called a "Wasp Hound" capable of triggering an alarm or flashing light when a target odour is found.

Biological engineer Dr Glen Rains said: "We've now developed a prototype device that puts the idea of using chemical-sensing wasps into a practical framework, and its possibilities are astounding."

He believes a commercial Wasp Hound could be available in five to ten years.

For their latest study the researchers used a tiny parasitic wasp which is harmless to humans and can be trained to detect certain odours by associating them with a food reward.

It takes as little as five minutes to train a single wasp, say the scientists.

The insects were trained to detect a specific chemical produced by toxic fungi that destroy corn and peanut crops.

Trained wasps reacted significantly more strongly to the target chemical than untrained wasps.

Previous research indicated that wasps could also be used to detect an explosives chemical, 2,4-dinitrotoluene.

More recently, the team has been looking at the possibility of using wasps to sniff out hidden bodies.