Click beetle

Systematic position: The genus Hemicrepidius belongs to the order Coleoptera and the family Elateridae, commonly known as click beetles. In an agronomic context, the primary concern is the larval stage, known globally as the wireworm. These pests are notorious for their persistence in soil and their ability to cause significant economic losses in various cropping systems worldwide.

Target crops: Hemicrepidius larvae are polyphagous, meaning they feed on a vast range of cultivated plants. They frequently attack cereal crops such as wheat and barley, industrial crops like maize and sunflowers, and root crops such as potatoes and carrots. Because they inhabit the soil, they often target the seeds and roots of newly planted crops, significantly impacting crop establishment.

Biology and life cycle: The life cycle of the click beetle is characterized by a prolonged larval stage, lasting several years. During this time, the larvae develop within the soil, feeding on organic matter and plant roots. Pupation typically occurs in late summer within a soil cell, followed by the emergence of adults. Their complex life cycle makes them difficult to eradicate, requiring long-term field management strategies.

Damage and severity: The damage caused by wireworms is often hidden beneath the soil surface. Larvae chew on seeds, destroy roots, and bore into the crowns of seedlings, which leads to thinning stands and stunted plant growth. In severe cases, the damage is irreversible, resulting in total crop failure and the need for expensive replanting. Their presence is often identified only after significant damage has already occurred.

Protection measures: Management of Hemicrepidius requires an integrated approach that includes:

• Cultural control: crop rotation and timely cultivation to expose larvae to natural predators or desiccation.
• Chemical control: treating seeds with systemic insecticides to protect the plant during early germination stages.
• Monitoring: using bait traps in the soil to estimate population density before deciding on the planting strategy.
• Field sanitation: reducing weed populations that provide alternative food sources for the larvae.