Annual outbreaks of African armyworms have become the norm in much of sub-Saharan Africa. By comparison, the fall armyworm — just one of at least 30 other armyworm species — has been known to destroy up to 73 percent of crops in previous outbreaks in the Western Hemisphere. The pest made its first appearance in Africa last year, and it has since been reported in South Africa, Zimbabwe, Zambia, Malawi, Namibia, Ghana and Mozambique. In each of these countries, agriculture has already been suffering from severe drought related to the El Nino weather pattern over the past couple years. Extended drought also makes crops more susceptible to armyworms. The emergence of a new pest has the potential to devastate crop production at a time when the threat to food security in the region is already high.
An unimpeded recovery no longer appears likely. Estimates vary, but roughly 130,000 hectares (about 321,000 acres) of Zambian crops have been affected thus far. In Zimbabwe, the pest has been detected in all 10 of its provinces. Some 2,000 hectares of crops have reportedly been destroyed in Malawi.
Pesticides and pheromone traps are the most common methods used to control both the African and fall armyworms. The African armyworm is easier to contain than its cousin, in part because its hatches typically occur only six times per year (compared to 10-12 times for the fall armyworm). But combating the fall armyworm is actually fairly easy for better-funded commercial farmers, so long as they have access to the necessary tools and technologies. Individual and subsistence farmers will have more difficulty bringing the pest under control.
South Africa is already making strides toward controlling the caterpillar by prioritizing the approval of two new pesticides. The use of genetically modified maize in South Africa will also help limit the outbreak. Monitoring the problem, educating farmers and spreading technical information will also be key to any effective effort to fight the pests. But each of these steps requires substantial sums of money and sectorwide coordination to be effective, meaning many subsistence farmers will remain more vulnerable than their commercial counterparts.
This makes the risks of the outbreak bigger in poorer sub-Saharan countries such as Zambia and Zimbabwe. Zambia has spent $3 million in an attempt to control the pest, but roughly three quarters of its farming activities are small-scale subsistence operations. In Zimbabwe, where the agricultural sector employs most of the population, many people rely on subsistence farming for their own food supply. Threats to such supplies are cause for humanitarian concern.