Desert locusts are once again on the move across North and West Africa in what experts warn could be an even more devastating invasion than the one earlier this year, renewing fears of a regional food crisis. Swarms of immature locusts invaded southwestern Libya near the Algerian border last week, and continued to form in southern Mauritania, the country worst hit by this year's infestation, according to the UN Food and Agriculture Organization (FAO).

Northern Senegal, Mali, and northern Burkina Faso are also fertile breeding grounds for the young locusts, which have formed the worst swarms in more than a decade, able to cover a square kilometer (less than half a square mile) with up to 80 million finger-length insects, which change color from pink to yellow as they mature.

A series of good rains during the past year have created favorable conditions for locust development, allowing at least four generations to breed in quick succession.

Jan Egeland, United Nations Under Secretary-General for Humanitarian Affairs, paints a dark picture for the region: "If we lose the battle in the next five weeks, we will have a tenfold increase in the locust swarms and they will go north," Egeland said in Geneva. "Tens of millions of people in the poorest countries in the world will have no food, no livelihood, because locusts will have eaten everything in that area," he said, renewing pleas for international aid to battle the swarms. "This is a much greater danger to livelihoods than any of the wars in the African region at the moment, Darfur included."

Level: B2