Virginia Tech researchers have made headway on a biological-control solution that could end a pest’s devastating reign throughout practically all of sub-Saharan Africa.

The fall armyworm stays true to its ­­­­­­­­­­name – swiftly and in large numbers, it survives harsh climates, multiplies quickly, and travels great distances.

In 2017, researchers at the Feed the Future Innovation Lab for Integrated Pest Management had a hunch that the fall armyworm could be controlled using natural enemies, but they still needed to find those enemies, fast. The pest threatens 100 percent of maize yields and has the potential to cause billions of dollars of damage. Its further spread would be catastrophic to African nations.

Muni Muniappan, director of the Innovation Lab, with the help of collaborators Tadele Tefera and Peter Malusi from the International Centre of Insect Physiology and Ecology, has now identified a promising solution: two local predators of the fall armyworm.

The Innovation Lab plans to release the predators on a mass scale in Ethiopia, Kenya, and Tanzania, three of the seven countries the United States Agency for International Development (USAID) funds the Innovation Lab to work in. The release will require the collaboration of ­­­­­farmers, government officials, nonprofits, private institutions, and others.

The fall armyworm is native to the tropical and subtropical regions of the Americas. It emerged in Africa in 2016, the same year that witnessed a 24 million increase in undernourished people in the sub-Saharan Africa region.

“The fall armyworm is partial to maize, but it attacks over 80 different plant species,” Muniappan said. “Through biological control of this pest, we might be able to help stabilize food security, build better livelihoods for smallholder farmers all across Africa, and ensure that we don’t put other populations at risk in the process.”

The two natural enemies, which Muniappan predicts will attack the fall armyworm, are local to Africa, which curbs the possibility of introducing a nonnative species that could become invasive. In a second benefit of the release, the predators are expected to help keep in check the many caterpillars that threaten all food crops.

The Innovation Lab has already achieved success monitoring the pest that drills pinholes in plant leaves and feeds on ears of corn during heavy infestations. In January 2018, the team prepared a risk assessment of the fall armyworm for the USAID mission in Egypt that, based on wind currents from Sudan, modeled and predicted the pest would move into Yemen. That prediction has since been confirmed by entomologists in the West Asian nation. 

Muniappan, who counsels against the use of toxic pesticides (they are expensive in developing countries and can harm people and the environment), said the pest has developed a tolerance to many poisons. The worm is progressing so quickly that genetically modified crops are not a dependable solution either, he said.

To ensure the smooth process of mass production of the natural enemies, Muniappan turned to Malick Ba, senior scientist at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Niger, to train technicians on the multiplication process.

Ba said, “We’ve seen promising results using biological control for the pearl millet head miner, a devastating pest, in Niger. The same approach is suggested for mass multiplication of the fall armyworm natural enemies.”

While Africa braces itself for the impact of food insecurity for millions, the Innovation Lab is planning multiple workshops during the upcoming year in Africa, and now Asia (where the fall armyworm was first reported in May) to help developing countries manage the pest and potentially turn back its fast-moving army.

The Feed the Future Innovation Lab for Integrated Pest Management, housed at Virginia Tech, is managed by the Center for International Research, Education, and Development at Virginia Tech, part of Outreach and International Affairs.

Written by Sara Hendery