Crop-destroying armyworms on the march through Africa and will hit Asia soon, scientists say

Scientists tracking a crop-destroying caterpillar known as armyworm say it is now spreading rapidly across mainland Africa and could reach tropical Asia and the Mediterranean in the next few years, threatening agricultural trade.

In research released on Monday, scientists at the Britain-based Centre for Agriculture and Biosciences International (CABI) said the pest, which had not previously been established outside the Americas, is now expected to spread “to the limits of suitable African habitat” within a few years.

The caterpillar destroys young maize plants, attacking their growing points and burrowing into the cobs.

“It likely travelled to Africa as adults or egg masses on direct commercial flights and has since been spread within Africa by its own strong flight ability and carried as a contaminant on crop produce,” said CABI’s chief scientist Matthew Cock.

Armyworm, known as “fall armyworm” in the United States due to its tendency to migrate there in autumn, or fall, is native to North and South America and can devastate maize, a staple crop crucial to food security in large parts of Africa.

Suspected outbreaks have already erupted in Zambia, Zimbabwe, Malawi and South Africa and the UN Food and Agriculture Organisation said last week it had spread to Namibia and Mozambique.