Two alien invaders -- the American white moth and the red turpentine beetle--are threatening plants and crops in areas around Beijing. They could bring disaster if not controlled, said forestry officials.

The pests have not yet found their way into Beijing and city departments are prepared to prevent them from entering the capital, Beijing forestry officials said.

American white moth pupae have been found in Qinhuangdao, Langfang, Tangshan and Cangzhou, in Hebei Province, and in parts of Tianjin Municipality.

The American white moth has strong reproductive ability, with each moth laying 2,000 to 3,000 eggs. A family of larva can eat all the leaves of a healthy tree in a few days.

Meanwhile, China Central Television reports that red turpentine beetles have killed several million Chinese pines in the Taihang Mountains in north China's Shanxi Province, not far from the capital.

The beetles eat the bark from the lower part of the tree, eventually causing its death.

An official with the Beijing forestry bureau who refused to be identified said on Monday that the two pests have not yet been found in the capital.

Strict control and prevention measures against invasive alien forest pests have been in place in the city for the past few years, he said.

Extensive inspections are carried out across Beijing each May and October, and each year nearly 200 planes spray pesticide in places where such pests may thrive.

The official added that efforts are under way in Hebei, Tianjin and Beijing to prevent American white moths from entering the city.

Invasive alien pests are causing great losses to China in terms of biodiversity, forestry and agriculture. Chinese experts have called for strengthened control over such species.

Alien pests have been found in all the provinces, autonomous regions and municipalities in China, as well as into nearly all the nature reserves in the country.

Once introduced, alien species adapt to the environment and become difficult to eliminate, said Cai Lei, an expert with the State Environmental Protection Administration.

The impact of such invasions can be devastating.

Each year, 1.5 million hectares of forest are damaged by invading pests such as the American white moth.

A proposal report submitted at the recent session of the 10th Chinese People's Political Consultative Conference, China's top political advisory body, says that invasive alien pests cause losses of more than 57 billion yuan (US$6.9 billion) to China's agriculture and forestry each year.

The proposal offered suggestions for controlling such pests, including the implementation of an invasive alien species control law and strengthening research.

(China Daily March 30, 2004)