A creeping crisis has struck the heart of South Africa’s agricultural belt, as swarms of African armyworms storm through fields in Gauteng, Mpumalanga and Limpopo. Farmers across these provinces were left reeling after the discovery of the destructive pests in February this year, following a spell of late summer rains that swept in after months of dry weather.

The African armyworm, a small but relentless caterpillar, is infamous for its ability to strip fields bare almost overnight. Recent sightings show the worms in overwhelming numbers, targeting pasture grasses like tef and eragrostis, and encroaching dangerously on maize lands. For many, this invasion has sparked memories of previous infestations, but the current scale appears more intense.

“This is not just a pest problem – it is a disaster,” said Dr Honest Machekano, a specialist in insect ecology and a senior lecturer in UP’s Department of Zoology and Entomology. “We’ve seen similar outbreaks elsewhere in Southern Africa, but this one is particularly aggressive. The recent climate swings provided the perfect conditions for armyworm eggs to hatch en masse.”

In response, farmers have scrambled to protect their land. On a smallholding near Bronkhorstspruit, quick-thinking and old-school ingenuity paid off. 

“They came like a marching band,” said farmer Thinus Herbst, who watched the worms advancing across his crops. “We used Cypermethrin and diatomite lime as a barrier. Within hours, they were stuck. Then we ploughed them under before they could go further.”

Herbst, who documented the infestation, shared a now-viral TikTok video of the event, showing the worms crawling in eerie unison across the soil. His farm narrowly escaped major damage, but others were not so lucky. Fields planted with traditional maize varieties have taken a heavy hit, while those using pest-resistant or genetically modified strains saw far less damage.

Informal and small-scale farmers, who often cannot afford pest-resistant seed, have been the most vulnerable. Their losses are not just economic; they affect food security and household survival. Local authorities and agricultural support bodies have since stepped in to distribute emergency pesticides and offer advice to affected farmers.

A key concern now is livestock safety. While armyworms do not directly target animals, experts warn that grazing livestock on contaminated pastures can lead to illness if the worms are ingested in large quantities.

With support from the Gauteng Department of Agriculture and Rural Development, Grain SA and the Agricultural Research Council, containment efforts are in full swing. Officials remain hopeful the infestation can be curbed before it spreads further into other provinces.

Still, the event has raised pressing questions. Are local farmers prepared for future outbreaks? Can early warning systems be improved? And how can rural and small-scale growers be better supported in the face of climate-fuelled pest crises?

“This outbreak is a stark reminder that nature does not wait for us to catch up,” said Dr Machekano. “We need to adapt our farming methods, invest in education and ensure everyone, not just large-scale farmers, have the tools to fight back.”

As the pests continue their march, one thing is clear: the battle for the fields is far from over.