Stalkborer

About this pest

In South Africa, the term “stalkborer” encompasses several different moth species that share the undesirable habit of boring into plant stems, causing significant damage. Here’s a breakdown of the three major culprits:

1. African Maize Stalk Borer (Busseola fusca):

• Common South African name: Mieliebolwurmp (Afrikaans)
• Characteristics: Adults are brown moths with dark stripes, larvae are yellow with black stripes, reaching up to 40mm.
• Hosts: Primarily maize and sorghum, but can also attack sugarcane and wild grasses.
• Damage: Tunneling in stalks weakens plants, leading to lodging (falling over), yield loss, and increased susceptibility to fungal diseases.

2. Chilo Stalkborer (Chilo partellus):

• Common South African name: Mieliestengelboorder (Afrikaans)
• Characteristics: Adults are smaller than African Maize Stalk Borer, with light brown wings and darker markings, larvae are white with brown spots.
• Hosts: Primarily maize and sorghum, but can also attack millet and sugarcane.
• Damage: Similar to African Maize Stalk Borer, but generally less severe.

3. Pink Stalk Borer (Sesamia calamistis):

• Common South African name: Pienk mieliestengelboorder (Afrikaans)
• Characteristics: Adults are pink moths with dark markings, larvae are pinkish-white with dark spots.
• Hosts: Maize, sorghum, and various millet species.
• Damage: Similar to the other two, but with a wider host range and potential for attacking younger plants.

Why are Stalkborers Pests?

• Yield losses: Damage to stems can significantly reduce crop yields, impacting farmers’ livelihoods.
• Increased susceptibility to disease: Weakened plants are more prone to fungal infections, further impacting production.
• Wide range of hosts: All three species attack vital South African crops, causing widespread economic concerns.

Combatting Stalkborers:

Integrated Pest Management (IPM): Combining multiple methods for a sustainable approach.

• • • Monitoring: Use pheromone traps and field scouting to track moth activity and larval infestation.
    • Biological control: Introduce parasitic wasps or nematodes specific to stalkborers.
    • Cultural practices: Early planting, crop rotation, and destruction of infested plant residues can disrupt their lifecycle.
    • Chemical control: Use registered insecticides as a last resort, targeting egg-laying moths or young larvae before they bore into stems.

Remember:

• Identifying the specific stalkborer species affecting your crops is crucial for targeted control measures.
• Consulting with agricultural extension services or pest control professionals can provide tailored recommendations based on local conditions and severity of infestation.
• Prioritizing natural and organic methods helps protect the environment and beneficial insects.

By understanding the different stalkborers and implementing proactive measures, South African farmers can protect their valuable crops and secure a sustainable future for their agricultural endeavors.