Armyworms are caterpillars that eat staple crops throughout sub-Saharan Africa, such as maize, wheat, sorghum, millet and rice. Large numbers of extensive outbreaks of the pest ravaged Zambia throughout December and caused a national emergency, as hundreds of resource-poor farmers lost their entire crops.

One of the farmers affected by the invasion of caterpillars was Annie Mututu, who lost all of her maize in one field to armyworms.

“They entered the field at night-time when we were asleep. The next day it was all gone.”

In response to the current crisis, Vice-President Dr Guy Scott, who chairs the Zambian Government's Disasters and Mitigation Committee, released 2,000 tonnes of free maize seed worth $5 million, so that as many farmers as possible could replant their ravaged fields in the hope of recovering the situation.

He said: "These days we have good early-maturing varieties of maize, so if we can get this in the ground now then the losses may not be bad".

Annie Mututu was one of the lucky farmers who was able to secure new seed for replanting but was unsure of what the future holds.

“I don’t know whether this maize that we planted here today will mature, as we are three weeks late in planting and the rains may not last”.

Professor Wilson met the Zambian Vice-President, Dr Scott, at his official residence in Lusaka. He advised on further measures to mitigate the crisis and discussed current efforts to tackle armyworms using an environmentally-safe biopesticide called SpexNPV.

SpexNPV is a natural disease of the armyworms, which is being developed by Crop Biosciences Ltd, a private enterprise in Tanzania, in collaboration with Professor Wilson and colleagues at the University of Greenwich. The ongoing research and development project, funded by the Department for International Development (DfID) and the UK’s Biotechnology and Biological Sciences Research Council (BBSRC), has recently culminated in the construction of a state-of-the-art biopesticide processing facility in Arusha, Northern Tanzanian. Production of SpexNPV should begin in early 2013, with a registered product for sale following soon after. The Zambian Vice President and his team were eager to acquire the new technology when it is available and has urged his government to ensure that SpexNPV is registered in Zambia as soon as it is available.

Professor Wilson said: "The situation in Zambia is very serious. Swift action by the Vice-President to provide farmers with maize seed to replant the stricken crops means that if the rains hold out, and the armyworm situation does not worsen, then the cost to the Zambian economy, and to hard-working farmers, will be minimised. However, my fear is that if the rains do not persist, then the re-planted maize will not mature, resulting in crop failure and food insecurity”.

The situation is exacerbated by the fact that the armyworm caterpillars infesting the fields now will soon develop into highly migratory adult moths that will fly from their current locations to destinations downwind hundreds of kilometres away. This makes it extremely difficult to know where the next wave of armyworm outbreaks will hit or how extensive those outbreaks will be. The armyworm may attack the crops of other farmers elsewhere in Zambia or they may migrate to vulnerable neighbouring countries such as Malawi and Zimbabwe. Armyworm outbreaks have already been reported in Kenya and Tanzania and all the signs are that the situation will get much worse before it gets better, causing a major food security crisis.