A plague of rare forest beetles is believed to have damaged 1,000 hectares of fruit trees in Longquan District, a fruit-growing area in Southwest China's Sichuan Province.

The local plant protection research centre, under the Sichuan Academy of Agricultural Sciences, is taking emergency measures to control the pest's further spread in the province but no effective way has yet been found to kill the pest.

Yao Ge, a botanical expert with the academy, said: "We do not fully understand the pest, and an entirely satisfactory solution has not yet been found.''

He said the method used so far to get rid of the pest was to cut down and thoroughly burn all the affected trees.

It has already been established that the pest belongs to the Scolytidae family of beetles and is highly harmful to several kinds of fruit, including grapes, oranges and pears. The pest's larva and imago (the final and fully developed stage of an insect) bore into tree branches and trunks and eat them until the tree is hollow.

Chen Xiaomi, whose family has been the worst affected in Longquan District, said not even one grape tree survived the pest in her 4 mu (0.267 hectare) plot of land.

Chen Jiacai, Chen Xiaomi's father, said his family found the pest when picking the grapes last year but neither his family nor the village paid any particular attention to the problem. Now other fruit growers in the district have discovered the same pest.

It remains to be confirmed whether the beetle is an alien or indigenous species but the epidemic is certainly quite serious.

Liu Xun, another researcher with Yao's academy, said: "Many of the affected trees will provide some harvest this year but they will face a fatal blow next year as there are no efficient preventive measures or treatment and it's hard to imagine what would happen if the epidemic spread to other areas.''

A study on the pest was prepared by the scientists Liu, Yao, Shi Wancheng and Xia Xianquan.

Yao said the pear gall midge, a kind of dangerous insect that has never been seen in the province before, has also been discovered in Sichuan. It has harmed nearly 200,000 mu (13,300 hectares) of pear trees.

Experts said they hoped the relevant authorities could establish as soon as possible an emergency system to improve the responses to outbreaks of dangerous pests.

(China Daily July 5, 2003)