Termites which threatened to ruin the Forbidden City are now being controlled with high-tech devices.

Restorers renovating the ancient building in readiness for the flood of visitors the Olympic Games will bring to Beijing in 2008, warned urgent measures were needed to prevent termites burrowing through the wooden structure. And they are now using high-tech devices to detect, infect and eventually kill the burrowing bugs.

The special devices, developed by the Zhejiang-based Deqing Termite Prevention and Control Centre, have been placed along the building's walls close to areas where termites frequently appear.

The new devices are designed to lure the termites in and infect them with a special powder.

Once a termite has been infected with the powder it will pass it on to other termites when it returns to the nest, according to Guo Jianqiang, director of the centre.

Guo and three other experts were invited to Beijing last week for a five-day inspection of the Forbidden City.

"The device has already been used to kill white ants, which were discovered in a local temple in Deqing," said Guo, adding that white ants found in the Forbidden City are the same species of those in the temple.

China has more than 480 types of termite, and with the bugs migrating and reproducing in May and June, it is urgent to check their spread now, said Guo.

An experiment conducted by Guo showed that a group of white ants die within 24 hours after being infected by a termite that has been lured into the device.

In the past pesticides have been sprayed around areas where termites visit, but according to Guo it is not an effective way of killing them and can pose an environmental threat.