More pests and plagues to threaten Southern African grains in the future

Except for fall armyworm which has already wreaked havoc in southern Africa this year, two more migrating pests and plagues are moving south. It is only a matter of time before others reach Africa.

Dr Marinda Visser, Grain SA Manager of Research and Grain Policy, at an Agbiz Grain mini symposium in Pretoria warned specifically against MLN (Maize Lethal Necrosis ) and red locust.

MLN, capable of destroying a whole maize harvest, is moving towards East Africa and is in Tanzania already. The disease is a combination of two viruses, of which one (the mosaic virus) already occurs in South Africa.

“It would be devastating if the other disease also reaches South Africa. No one wants this terrible disease in their country,” Visser said

A survey, funded by the Maize Trust, is being done to establish which diseases are already in South Africa and aims to identify from which direction MLN will be the most threatening, e.g. in sugar producing areas also planted with maize.

With regards to red locust, outbreaks have already been recorded in Zambia and Mozambique. An uncontrolled swarm of 40 million locusts can completely destroy a maize crop.

Communication problems

Visser said poor communication between African countries is problematic. According to international agreements, countries must warn each other when new pests and plagues are recorded. This is not happening.

“The fall armyworm was already spotted in January 2014 in West Africa and if there was an early warning system, the devastation in Southern Africa would have been less. Until today, no West African country has officially declared the presence of the worm.”

She said this means South Africa – at the southern point of the continent – is on its own in monitoring the possibility that the plagues will reach the country.

“It is necessary that we cooperate with our own authorities to protect our industries.”

Slumbering alien threats

Two other slumbering threats destroying grains elsewhere, is the Khapra beetle, one of the most destructive insects to grain globally. It is also resistant to insecticide and can survive long periods without food. The other is the Western corn root worm from America. It has already reached Europe, but is not found in Africa yet.

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