Several organisations around the world monitor the threat from locust plagues. They provide locust forecasts detailing regions likely to suffer from locust plagues in the near future. In Australia this service is provided by the Australian Plague Locust Commission, in Northern and Sahelian Africa the service is provided by the United Nations Food and Agricultural Organisation.
The migratory locust (Locusta migratoria) ranges from Europe to China, and even small swarms may cover several square miles, and weigh thousands of tons. Control by spreading poisoned food among the bands is very effective, but it is cheaper to spray concentrated insecticide solutions from aircraft over the insects or the vegetation on which they feed. They eat the equivalent of their own weight in a day, and, flying at night with the wind, may cover some 500 kilometres (310 mi). The largest known swarm covered 513,000 km², comprising approximately 12.5 trillion insects and weighing 27.5 million tons.