South African scientist finds fungus that could curb destructive armyworm infestations

A surge of African armyworms in 2025 moved from northern South Africa into the eastern province of KwaZulu-Natal, prompting frantic calls from local growers. While inspecting Kikuyu grass fields, entomologist Letodi Luki Mathulwe noticed dead caterpillars encrusted in a white substance, which laboratory tests later identified as a naturally occurring fungus capable of killing the insects. Her findings, now published in a peer-reviewed journal, represent a major advance because chemical controls are ineffective against mature armyworms, which also release toxins that can sick cattle.

Past infestations have devastated maize production, such as a 2017 outbreak that destroyed up to 40% of Zambia’s crop and triggered price spikes across the region. Mathulwe believes the fungus could be formulated into a product for rapid deployment during future outbreaks, easing farmer anxiety and protecting livestock health. She cautioned that additional research and field trials are still needed before commercial use. If successful, the biocontrol could lessen food insecurity and economic strain in affected African nations.