TOKYO • Across Japan's capital, delicate pink and white cherry blossoms are emerging, but the famed blooms are facing a potentially mortal enemy, experts say: an invasive foreign beetle.

The alien invader is aromia bungii, otherwise known as the red-necked longhorn beetle, which is native to China, Taiwan, the Korean peninsula and northern Vietnam.

The beetles live inside cherry and plum trees, stripping them of their bark. In serious cases, an infestation can kill a tree.

"If we don't take counter-measures, cherry trees could be damaged and we won't be able to enjoy hanami (cherry blossom viewing) in a few years' time," Dr Estuko Shoda-Kagaya, a researcher at the Forestry and Forest Products Research Institute, said yesterday.

The beetle was first spotted in 2012 in central Aichi prefecture but has now spread across the region near Tokyo, according to the Environment Ministry. Experts say it may have entered Japan with imported wood materials.

In January, the Environment Ministry designated the beetle an invasive alien species, meaning its import and transfer are banned.

"The damage will spread further if we don't do anything," said Mr Makoto Miwa at the Centre for Environmental Science in Saitama.

He said beetle larva should be killed with pesticide, and trees with serious infestations should be cut down to save others.

The centre has issued a guidebook with details on how to identify and kill the beetle, which grows up to 3cm to 4cm.

Tokyo's cherry blossom season officially started last week as forecasters watching trees at Yasukuni Shrine announced that the city's first blossoms had appeared.

AGENCE FRANCE-PRESSE