Alien Armyworm Invading Africa May Reach Asia, Mediterranean

  • Pest that threatens corn fields already in Ghana, South Africa
  • Invasion imperils southern Africa’s recovery from drought

A fall armyworm, right.

Photographer: Taonga Clifford Mitimingi/Bloomberg

The fall armyworms that have ravaged corn fields from Ghana to South Africa since arriving on the continent last year could spread to Asia and the Mediterranean, a research body said.

Infestations of the pest that arrived from the Americas last year have been confirmed in Ghana, the Oxfordshire, U.K.-based Centre for Agriculture and Biosciences International said. South Africa also verified Feb. 3 that the caterpillars have arrived in the continent’s biggest producer of corn, a staple, after they traveled from Zambia through Zimbabwe. There are reports that they’ve also reach Malawi, Mozambique and Namibia, according to the Food and Agriculture Organization of the United Nations.

“It can be expected to spread to the limits of suitable African habitat within a few years,” the organization said in an e-mailed statement Monday. The fall armyworm “could spread to tropical Asia and the Mediterranean in the next few years, becoming a major threat to agricultural trade worldwide.”

The caterpillars that get their name from the large numbers that invade fields and eat the leaves and stems are probably more dangerous than the native African armyworm, and their introduction will pose a lasting threat to crops on the continent, according to a paper published in October by scientists including Georg Goergen. The pest can devastate corn fields, risking production of the staple food in a region that’s emerging from its worst drought in more than 35 years.

Control Difficult

“If the pest damage aggravates, it could dampen prospects for good crop harvests that are anticipated in the current farming season,” the FAO said Feb. 3 in an e-mailed statement. “The pest is known to cause extensive crop losses of up to 73 percent depending on existing conditions and is difficult to control with a single type of pesticide.”

South Africa is yet to determine the extent of crop damage, Senzeni Zokwana, the minister for agriculture, forestry and fisheries, told reporters Monday in the capital, Pretoria. The Agricultural Business Chamber said last month that the country could increase its corn crop to at least 11.9 million metric tons this year from 7.5 million tons in 2016.

In Zambia, the caterpillars affected more than 10 percent of the planted area, according to the government.

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