SUMMER RAINFALL AREA MUST BRACE ITSELF FOR CUTWORM INFESTATION
CropLife SA received a large number of calls from small and commercial farmers about cutworm outbreaks over the past two weeks. KwaZulu-Natal, Limpopo, western parts of Mpumalanga, northern and eastern parts of Gauteng, the Free State and parts of the Eastern Cape seem to have the largest infestation of cutworms. This widespread and very common plant pest is a typical Lepidoptera pest that starts with moth clouds that invade crop areas. Once they have mated and laid their eggs, the pest proliferates, and the huge larvae begin to attack any young plants.

Maize farmers in KwaZulu-Natal reported large-scale damage to newly planted maize while Free State farmers noticed massive numbers of different cutworm species while preparing seedbeds for planting. Small farmers in KwaMhlanga, northern KwaZulu-Natal, the Mpumalanga Lowveld, Eastern Cape and Polokwane in Limpopo also reported serious cutworm damage to vegetable crops and maize.

Early indications show that the cutworm population may have developed a certain degree of resistance to the pyrethroid insecticides that are registered to control cutworms. Farmers must apply these insecticides at the highest dosage rate as indicated on the labels, and as early as possible after the cutworms have hatched. Cutworms develop over as many as nine instars and like other Lepidoptera pests, they become increasingly difficult to control with most insecticides as they grow older.

Cutworms are normally large, fat larvae ranging from pale grey to virtually black, depending on the species and region. They live just beneath the soil surface and emerge at night to forage. Moths are non-descript grey-brown.

Farmers are encouraged to take good quality photos with smartphones and send them via WhatsApp to the CropLife SA emergency number 082 446 8946 for verification by the specialist entomologists who assist CropLife SA with plant pest identification.

Insecticides that are registered for the control of cutworms are listed on the CropLife SA Agri-Intel database on www.agri-intel.com.  

For more information please contact:
Dr Gerhard Verdoorn, Operations and Stewardship Manager, CropLife South Africa
gerhard@croplife.co.za, 082 446 8946

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