A South African scientist, Letodi Luki Mathulwe, has discovered a naturally occurring soil fungus that effectively kills the African armyworm, a notoriously destructive crop pest. The breakthrough research offers a potential natural cure for farmers struggling with the pest, which has caused significant damage across east and southern Africa.

The African armyworm, known for its rapid, march-like advance through fields, poses a major threat to agriculture in the region, consuming vast quantities of crops and grazing land. An outbreak in 2025 saw the pest spread from northern South Africa to the eastern province of KwaZulu-Natal, prompting urgent calls from affected farmers.

Mathulwe, an entomologist working for the agriculture department, was alerted to the presence of dead armyworms covered in a white, fungal substance in the fields of Kikuyu grass. "Something was killing the insects naturally. I was intrigued because in other areas the insects were alive and destroying the grass but as soon as they come here, there’s something that is killing them," she stated.

Gathering samples of the dead caterpillars and the fungus, Mathulwe and her team conducted laboratory tests. Their findings, published in a peer-reviewed research paper, confirmed that the fungus could indeed be a potent biological agent against the armyworm, potentially reducing reliance on chemical pesticides.

This discovery comes at a critical time when chemical controls for the African armyworm have proven increasingly ineffective, and their environmental impact is a growing concern. The use of a naturally occurring fungus could provide a more sustainable and environmentally friendly solution for pest management.

Further research is expected to focus on the scalability of using this fungus as a biocontrol agent. Scientists will investigate methods for cultivating the fungus and applying it effectively in agricultural settings to protect crops and livestock grazing land.

Experts in entomology and agriculture are hailing the discovery as a significant step forward in pest management strategies for Africa. The potential for a natural, locally sourced solution could greatly benefit smallholder farmers who are often most vulnerable to crop losses caused by pests like the armyworm.

The research aims to provide farmers with a viable alternative to chemical pesticides, which can be costly and harmful to ecosystems. The long-term goal is to develop an accessible and effective treatment that can be deployed widely to mitigate the devastating impact of the African armyworm on food security in the region.