Armyworm war needs new tactic
Africa should turn to lower risk solutions to fight the pest which is endangering food security and livelihoods
THE CATERPILLARS of the fall armyworm (Spodoptera frugiperda), an invasive moth, can potentially feed on more than 350 species of plants. In the Americas it’s known as a serious pest.
It destroys crops of maize, rice, sorghum, sugar cane, peanuts, soybean and non-food crops such as cotton. In maize, fall armyworm feeds on the developing leaves and then the grains, damaging the plant and reducing yield.
It was found only in the Americas. But in 2016 it appeared in West Africa and is in more than 40 countries in tropical and southern Africa. It has also recently been reported in India.
Research mapping environmental suitability shows that large areas of Asia are suitable for fall armyworm, including parts of India and China, the world’s second-largest maize producer.
The pest presents a threat to food security and its impact on maize alone could devastate the livelihoods of tens of millions of farmers. Estimates suggest that the potential yield loss due to fall armyworm in 12 countries would be huge. The data show that between 4 million and 18 million tons annually out of an expected production of 39 million tons could be lost.
The economic cost is estimated to be from $1 billion (R14bn) to $4.6bn a year.
To protect their food supplies, African countries are putting in place large-scale emergency measures. Many of these focus on the widespread distribution and use of pesticides. But this isn’t the ideal solution for a number of reasons. First, some pesticides are harmful and toxic. Second, pesticides put many smallholder farmers at risk – many aren’t familiar with the products and might lack the protective equipment to prepare and apply them safely.
There are other lower risk alternatives. One of these is biopesticides – naturally occurring substances or organisms that kill pests. In a recently published study we show that biopesticides present safe, low-risk options which can serve as viable alternatives.
Biopesticide products to control fall armyworm are commercially available in the Americas and are used by farmers in North and South America. Some African countries are also moving in this direction. For example, South Africa has provisionally registered