Desert locusts in Africa: a disaster?

Migrating locusts, especially the desert locust (Schistocerca gregaria), have been feared in Africa for thousands of years as famine-inducing pests. Instead of simply waiting for outbreaks to occur, attempts are being made to take preventive action against these pests. Since the breeding areas of the desert locust are distributed across the entire Sahel region, the Arabian peninsula, Pakistan and India, a gigantic logistical and organizational effort is required. Every year, millions of dollars are spent on these preventive control measures, which are still unable to prevent locust plagues completely. The outbreaks in 1987/88 and 1993/94 are the most recent examples. Exactly how large potential disasters caused by gigantic locust swarms may be and whether the effort and expense involved in preventing them pays off economically has never been systematically investigated. The Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) project, 'Integrated Biological Control of Grasshoppers and Locusts', has attempted to assess, on the basis of the available data, what the costs and potential benefits are and to identify the difficulties involved in developing an effective strategy.