African armyworm makes its way to Porterville

An outbreak of African armyworm (Spodoptera exempta) has been confirmed on farms near Porterville in the Western Cape, marking a shift in the pest’s usual pattern of migration.

- Octavia Avesca Spandiel

Speaking to Farmer's Weekly, Dr Godfrey Kgatle, research coordinator at Grain SA, said the outbreak is linked to climatic conditions that made the region more favourable for the pest this year.

“We started receiving reports in early April 2025 from areas around Porterville, Riebeek West, Wellington and Philadelphia. This region is not usually affected, so it came as a surprise,” Kgatle said.

He added that the pest’s arrival was likely to have been influenced by a combination of early rain, a dry period, and then heavy rainfall from January, which supported fresh grass growth, ideal conditions for larvae.