A natural cure for the devastating African armyworm pest has been discovered by a South African scientist, offering hope to farmers in east and southern Africa. Letodi Luki Mathulwe, an entomologist, found a naturally occurring fungus that was killing off the caterpillars in fields of Kikuyu grass in KwaZulu-Natal. The fungus was enveloping the dead caterpillars in a mysterious white substance, sparking Mathulwe’s interest.
The African armyworm is one of the most destructive pests for farmers in the region, causing significant damage to staple crops such as maize and sorghum. It also releases a chemical compound in grass that can make cattle sick. The impact of an outbreak can be brutal, with one incident in 2017 estimated to have destroyed up to 40% of Zambia’s maize production.
Mathulwe’s discovery is a major breakthrough, as current chemical treatments are ineffective against mature populations of the armyworm. The fungus, which has been tested in Mathulwe’s laboratory, could be developed into a product for use by farmers. This could eventually eliminate the fear of the insect for farmers, who often panic when they find the caterpillars in their fields.
The African armyworm causes the most damage in its caterpillar stage but is also hard to control when it develops into a moth, allowing populations to migrate. An outbreak in 2025 had started in northern South Africa and had reached the eastern province of KwaZulu-Natal by April, prompting panicked calls from local farmers.
Mathulwe’s team is still working on developing a product for use by farmers, but the discovery has already created hope for those affected by the pest. The fungus could mean that farmers’ animals won’t get sick if they are able to control the presence of the insects within their fields.
The impact of the African armyworm is not limited to farmers, as outbreaks also send food prices soaring and put strain on government budgets. Last year’s outbreak caused problems for farmers in countries such as Zimbabwe and Malawi, where inflation had reached 736% and 35% respectively in 2024.
