Soil Fungus Could End African Armyworm Crop Devastation

Fields full of dead caterpillars covered in mysterious white fuzz led scientist Letodi Luki Mathulwe to a discovery that could save millions of African farmers from devastating crop losses.

The South African entomologist was responding to panicked calls from farmers in KwaZulu-Natal during a 2025 armyworm outbreak when she noticed something remarkable. In some fields, the dreaded caterpillars were thriving and destroying crops, but in others, they lay dead and wrapped in white fungus.

Mathulwe immediately collected samples and rushed them to her laboratory in Pietermaritzburg. Her hunch was correct: a naturally occurring soil fungus was killing the pests.

The African armyworm earns its name from its march-like advance through crop fields, devouring staple foods like maize and sorghum. The caterpillars also release chemicals in grass that sicken cattle, hitting farmers with a double blow.

The numbers tell a devastating story. A 2017 outbreak wiped out 40% of Zambia's entire maize production. Last year's invasion struck countries already struggling with economic crises, including Zimbabwe where inflation reached 736%.

Current chemical treatments only work on young caterpillars, leaving farmers helpless against mature populations. When the pests develop into moths, they migrate freely to new areas, spreading destruction across entire regions.

The Ripple Effect

Mathulwe's peer-reviewed research shows the fungus could be developed into a practical treatment for farmers facing mature armyworm populations for the first time. The natural solution addresses a gap that chemical controls have never filled.

The discovery means more than just saved crops. Controlling armyworms protects food security across east and southern Africa, stabilizes food prices during economic hardship, and prevents livestock losses that devastate farming families.

Mathulwe said her team needs more testing before creating a product farmers can use. But the breakthrough offers something precious to communities that have lived with armyworm terror for generations: real hope.

"It will eventually eliminate the fear for farmers that the insect creates," she said, imagining a future where the next outbreak doesn't mean panic, hunger, and loss.