An army of 700,000 specially trained ducks and chickens has been mobilised to help fight China's biggest locust plague in 25 years. The birds, which are taught to pursue and eat locusts at the sound of a whistle, are part of a national campaign that includes 280,000 people backed by crop-dusting planes and special locust-killing micro-organisms imported from Britain. Swarms of locusts have destroyed more than 1.6 million hectares of crops in 11 provinces in the north and east of China, and 3.8 million hectares of grassland in the far western region of Xinjiang. The birds are used in Xinjiang where they are raised and trained under contract to the local government.
Zhao Xinchun, deputy head of the Xinjiang Locust and Rat Control Office, says: "Farmers knew that chickens were very fond of eating locusts, so we did some tests with a few hundred birds before spreading the idea more widely." The chickens have now been reinforced with 100,000 ducks, which can each consume up to 400 locusts a day. "Farmers found that ducks can eat more than chickens, are tougher than chickens in bad weather and do not get eaten by eagles or weasels." The birds associate the sound of whistles with feeding, Mr Zhilo says.
Scientists are also planning to use a special parasite, metarhiziumflavoviride, which grows inside the locusts' bodies and prevents them from absorbing nourishment. The technique, believed to be safer than using chemical pesticides, was imported from Britain in 1996. China is suffering from an acute water shortage and locusts are thriving on dry stretches of the Yellow River. - Daily Telegraph