Large ground beetle

The Large ground beetle (Curtonotus aulicus) belongs to the Carabidae family. Unlike most predatory ground beetles, this species is known for its phytophagous habits, causing damage to crops.

Adults reach 12–16 mm in length and have a robust, convex body shape. Their color ranges from dark brown to black, often with a subtle metallic sheen on the elytra.

The larvae are campodeiform, white or yellowish, and possess strong legs. They spend their entire developmental period in the soil, feeding on organic matter and plant roots.

Adult beetles are strictly nocturnal. During the day, they remain inactive in soil crevices or under plant debris, which makes them difficult to spot during standard field inspections.

The life cycle involves overwintering as either adults or larvae in the soil, with reproduction occurring during the warmer summer months when eggs are laid in the ground.

This beetle primarily affects cereal crops, including wheat, rye, barley, and oats. Both the adult stage and the larval stage contribute to agricultural losses.

Adults consume grains during the milky and waxy ripeness stages. They often eat the contents of the kernel, leaving the husk behind, which significantly impacts yield quality.

Larvae cause damage by feeding on the root systems and the underground stems of young seedlings, which can lead to stunted growth or the total death of the plant.

Fields with high infestations show visible thinning of the crop stand, especially if the beetles and larvae are present during the critical seedling emergence period.

The economic impact is particularly high during years with favorable climate conditions for the beetle's reproduction, potentially requiring chemical intervention.

The most distinctive sign of adult damage is the presence of hollowed-out grains in the ear, where the outer skin of the seed remains intact but the inside is gone.

Early-stage infestations appear as missing or damaged seedlings with shredded leaves, often causing gaps in the rows of the crop field.

Field inspection using a flashlight at night is the most effective way to detect active adults feeding on the ears or stems of the crop.

Yellowing of young plants or irregular wilting patches in the field may indicate the presence of larvae feeding on roots underneath the soil surface.

Scouting for these beetles should focus on the edges of the field and areas near uncultivated borders, where they often hide during the day.

Effective management begins with integrated pest management (IPM) practices, emphasizing crop rotation and field hygiene to break the beetle's life cycle.

Deep autumn plowing is a highly recommended practice, as it exposes overwintering larvae and adults to harsh environmental conditions and natural predators.

Seed treatment with systemic insecticides can provide early protection against larval feeding, ensuring a higher plant survival rate during germination.

If the adult population exceeds the economic threshold during the grain filling stage, targeted insecticide applications are necessary to prevent further grain damage.

• Maintain proper crop rotation with non-host plants.
• Perform deep soil cultivation to disrupt larval habitats.
• Use seed dressings to protect young seedlings.
• Monitor adult activity using nighttime visual checks.
• Apply registered insecticides based on scouting thresholds.