Titanic chafer

The titanic chafer (Holotrichia titanus) belongs to the order Coleoptera and the family Scarabaeidae. It is a large beetle that is primarily crepuscular in its activity.

Adult individuals have a characteristic body structure typical of the Melolonthinae subfamily, with a strong chitinous shell of brown or dark brown color.

The larvae of this species, like those of other representatives of the genus Holotrichia, have a C-shaped body, a whitish-cream color, and developed thoracic legs.

The larva's head is well-defined, equipped with powerful mouthparts adapted for gnawing through the underground parts of plants.

The dimensions of the adult insect reach impressive figures for this genus, which is reflected in the specific epithet "titanus".

The pest is a dangerous polyphage, damaging a wide range of agricultural, forest, and ornamental crops in the regions where it occurs.

The main damage is caused by larvae living in the soil layer, where they feed on the roots of young trees, shrubs, and field crops.

Among the most vulnerable crops are corn, sugar beet, potatoes, as well as fruit and forest tree nurseries.

Adult beetles can damage the aerial part of plants, eating leaves and buds, which reduces the total area of the photosynthesizing surface.

The greatest damage is recorded in young plantations, where damage to the root system often leads to complete plant death in a short time.

The life cycle of Holotrichia titanus is multi-annual, with a significant part of it spent in the soil at various stages of development.

Adult emergence usually coincides with the warm season, most often observed in late spring or early summer, when the soil is sufficiently warmed.

Mating and egg-laying occur in surface soil layers rich in organic matter, which provides food for the larvae immediately after hatching.

Larval activity in the soil depends directly on humidity and temperature, reaching a peak during the growing seasons of agricultural crops.

Hibernation of older larvae and adults occurs in deep soil horizons, below the freezing line, which ensures high survival rates.

The first sign of infestation in a plot is often the sudden wilting of plants despite sufficient soil moisture.

Inspection of the root system of affected crops reveals characteristic gnawed roots, often with traces of deep furrows.

In the soil next to damaged plants, larvae of different ages can be found curled up in a characteristic "resting pose".

Adult beetles can be noticed in the evening when they fly and actively feed on tree leaves, sometimes exhibiting phototaxis towards light sources.

• Focal dying of seedlings in the field.
• Appearance of holes in underground potato tubers.
• Presence of large larvae during soil excavations.

The main control method includes agrotechnical measures: deep autumn plowing, which brings larvae to the surface to be preyed upon by birds and exposed to frost.

The application of soil insecticides during sowing or planting of crops in foci of mass multiplication of the pest is effective.

The use of biological control agents, based on entomopathogenic fungi and nematodes, allows for reducing population density without environmental harm.

Crop rotation using repellent crops, such as mustard or rapeseed, contributes to reducing larval density in the soil by changing feeding conditions.

Monitoring adult numbers using light traps during the flight period allows for timely decisions on protective treatments.