Mediterranean corn stalk borer

Systematic position: The Mediterranean corn stalk borer (Sesamia nonagrioides) is a member of the Noctuidae family within the order Lepidoptera. It is a highly significant agricultural pest that primarily affects grain crops in the Mediterranean region, posing a continuous threat to maize production throughout the growing season.

Host crops: While maize is the preferred host, this insect is capable of feeding on a variety of plants, including sorghum, millet, and sugar cane. The adaptability of the larvae to various graminaceous plants allows the pest to survive in field margins and weeds before migrating into cultivated fields, making eradication difficult.

Biology and life cycle: The life cycle is typically multivoltine, with the number of generations per year depending on the regional climate. The pest overwinters as mature larvae inside the stems or stubble of the host plants. In the spring, these larvae pupate, and the emerged adults begin the reproductive cycle, laying eggs in clusters beneath the leaf sheaths of host plants.

Damage symptoms: The larvae are responsible for the damage. Upon hatching, they bore into the plant stem, moving towards the center. This tunneling weakens the stalk, leading to "dead hearts" in younger plants and susceptibility to lodging in mature ones. Furthermore, the damage to the ear shanks can result in direct grain loss and lower quality due to mycotoxin contamination.

Management strategies: Effective management relies on Integrated Pest Management (IPM) practices.

• Cultural control: Destructing crop residues after harvest is crucial to reduce the overwintering population.
• Biological control: The use of natural enemies like parasitoid wasps.
• Chemical control: Precise timing of insecticide applications based on moth flight monitoring.
• Resistant cultivars: Choosing maize varieties with natural resistance mechanisms.