Western corn rootworm

The Western corn rootworm (Diabrotica virgifera) belongs to the order Coleoptera and the family Chrysomelidae. It is recognized as one of the most economically significant pests of maize globally, causing massive yield losses and requiring intensive management strategies.

While the larvae are specialized to feed on maize roots, adult beetles are polyphagous. They feed on the leaves, silks, and pollen of corn, but can also be found on soybean, pumpkin, and various wild grass species, which facilitates their survival in diverse agricultural landscapes.

The life cycle consists of one generation per year. Eggs are deposited in the soil during late summer and autumn, where they overwinter. In the spring, larvae emerge and pass through three larval instars, feeding destructively on corn roots. Pupation occurs in the soil, and adults emerge in mid-summer to feed and mate.

Root feeding by larvae is the most critical stage of damage, resulting in root pruning, reduced nutrient and water uptake, and characteristic "goose-necking" of plants due to lodging. Adult feeding on silks can prevent proper pollination, leading to incomplete ear fill and reduced grain quality.

Effective control measures include a combination of preventive and reactive strategies:

• Crop rotation remains the most effective cultural control measure to break the life cycle.
• Seed treatment with systemic insecticides to protect the early seedling stage.
• Soil-applied insecticide applications at planting for long-term root protection.
• Field scouting using yellow sticky traps to monitor adult beetle population dynamics.
• Foliar insecticide applications targeting adults to reduce egg-laying populations in high-pressure areas.