Australia's lucrative wine industry is threatened

Cereal crops in South Australia have already been damaged, and the region's lucrative wine industry is also under threat. It could be the worst such plague in the state for nearly 50 years.

The authorities are trying to control infestations by spraying insecticide from aircraft. But they say the young locusts - banding together in vast swarms - are being protected from the sprays under the lush growth produced by summer rains.

Plague in east and west

The infestation coincides with the worst plague of locusts in 10 years in western Australia, which is currently ravaging the state's wheat belt.

"It's most unusual for us to have both sides of the continent having major outbreaks at the same time," said Plague Locust Commission director Graeme Hamilton, quoted by the AFP news agency.

By November the number of locusts could reach 1,000 billion, and the commission estimates that damage to crops and the wine industry in the eastern states could total $120m.

A member of the grasshopper family, locusts cluster together when young and form swarms of up to 15,000 per square metre, often travelling at night.