Australians fear return of winged cannibals

With beds of insects' eggs found and weather patterns favourable to breeding, farmers say billions of eating machines may ravage land

Ian Edson, a sheep and cattle farmer who lives west of Sydney, says the last outbreak of locusts reduced his land to dust.

SYDNEY // They fly in their billions in cannibalistic swarms that turn the sky black, and now locusts are threatening to inflict more pain on some of the most drought-ravaged parts of eastern Australia. Ominously, hundreds of farmers have found beds of eggs, and officials fear that many more have not yet been discovered as recent patchy rain increases the risk of ruinous locust activity later in the year. "They can be devastating to both pastures as well as agricultural fields," warned Greg Sword, a senior lecturer at the University of Sydney. "The general rule of thumb is an insect can eat more or less its body weight in green vegetation in a single day and when you have a billion of them that's obviously a lot of plant material that can be consumed."

Australia's last major locust outbreak occurred in 2004 when the voracious insects invaded central parts of the country's most populous state, New South Wales, and formed a 1,000-kilometre front that ravaged huge areas of agricultural land. The government estimates that damage during the 2004 outbreak amounted to about $11 million Australian dollars (Dh35m). Official figures also show that emergency control measures, such as spraying, saved $55m in crop losses. The government will not speculate on the potential cost of any future outbreak. Specialists say the movement of swarms is driven by a frenzy of cannibalism, where insects are either being chased or are pursuing others to devour them. "They are actually trying to attack and bite and potentially feed on nearby individuals," Mr Sword said. "Millions of these types of interactions are causing locusts to travel in the same consistent direction, so this collective motion is a forced march mediated by cannibalism."

Much of southern Australia is in the grip of the worst drought in a century, but recent rain in areas where locusts are known to breed has caused concern. The worry is that a combination of periodically damp conditions and warmer temperatures will be ideal for breeding. Islands of green have appeared in the parched landscape and colonised by locusts, which have evolved in one of nature's most efficient eating machines. At the forefront of efforts to contain the menace is the Australian Plague Locust Commission, which was established in 1970s and is charged with monitoring and controlling outbreaks. Chris Adriaansen, its director, is looking towards the start of the locust season in late September with a sense of unease.

"We had some very significant numbers of locusts congregating in the southern New South Wales and northern Victoria region," he said. "Now, those adults will have laid a number of eggs. When you combine that with the fact that that area has had some reasonable rainfall, there will be vegetation there to be able to support those emerging nymphs. So, we're actually looking at the potential of having some reasonable populations in that area." When swarms take to the skies, they usually fly downwind and tend to migrate from north to south. Where they end up, according to researchers, is completely random and such uncertainties will not do much for the nerves of farmers, whose businesses are already beset by drought and rising production costs. Ian Edson, a livestock and cereal farmer near the Outback town of Ivanhoe in New South Wales, knows only too well the damage that locusts can cause. "They just about wiped us out," he said. "[They] took all the best feed and there was nothing left. All you end up with is land that's back to dust. "We went from having a good season to having nothing. It was gone within a few days and your year had gone. So, it was more than disappointing. You've just spent thousands of dollars and all of a sudden it's gone." Confronted by such adversity, Australian farmers have had to draw on their fabled reserves of strength and perseverance. "Mother Nature dishes it up to you occasionally," said a stoic Mr Edson. "As a farmer, it's part of life." The spraying of pesticides is the favoured weapon in the fight to control the spread of locusts in Australia. It is not an easy task as the eggs are usually hidden underground and are difficult to spot. Juveniles are not easy to kill because they are so small and they too are hard to find. Most pesticides are chemically based although increasingly a biological and more environmentally- friendly alternative is being used that smothers the insect in a fungus. "The spores land on the surface of the locust and penetrate through the cuticle of the insect and they set up an infection inside the body of the insect which eventually overcomes it and the insect dies," said Richard Milner, honorary research fellow with the Australian government's Commonwealth Scientific and Industrial Research Organisation. "It does take quite a significant amount of time, that's the one negative side of this method of control." As the locust threat looms once again in Australia, early intervention is the key. "By the time you have large-scale locust outbreak, it's really too late," said Mr Sword. "It's akin to battling a fire once the house is half-burnt down. The damage has been done." @Email:[e-mail]