Locust Swarms Forming in West Africa

October 23, 2012

A locust devouring vegetation in Morocco, July 2004. ©FAO/Giampiero Diana

Four countries in West Africa have been put on alert for the likely arrival of swarms of Desert Locusts. If uncontrolled, a small swarm can eat the same amount of food in one day as 35-thousand people.

Locust swarms are currently forming in Chad, northern Mali and northern Niger. But expert Keith Cressman said they’re not expected to stay there very long.

“As we’re at the end of the rainy season, the vegetation is drying out, conditions are becoming unfavorable for Desert Locusts, the swarms will then move. And they will move in a northerly direction, and we’re expecting them to move towards Libya, Algeria, parts of southern Morocco and northwestern Mauritania” said Cressman, Senior Locust Forecasting Officer for the U.N. Food and Agriculture Organization. He described the locusts’ arrival as imminent.

Locusts can be found just about any time of the year in the world’s deserts, but usually in low numbers.

Perceived risk or threat of current desert locust infestations, October 2012.

“However,” he said, “when conditions are extremely favorable – that is, where there are good rains in the desert and there’s natural vegetation that becomes green – those locusts can increase very rapidly in numbers, some 16-fold with every generation. When these locust numbers increase, they change their behavior from that of a solitarius locust to one that becomes part of a group. And they form what we call concentrations of locusts, which is commonly known as swarms.”