Forest cockchafer

The forest cockchafer (Melolontha hippocastani) is a beetle belonging to the order Coleoptera and the family Scarabaeidae. This species is widely distributed in forest and forest-steppe zones. It is biologically similar to the common cockchafer, but can be distinguished by specific morphological features, particularly the shape of its pygidium, which is short and slightly club-shaped at the tip.

The adult beetles feed on the leaves of deciduous trees, which can lead to significant defoliation during mass outbreak years. However, the most damaging stage is the larval stage, commonly known as a white grub. These larvae live underground for several years, feeding on the roots of various plants, including vegetables, strawberries, and young tree seedlings.

The development cycle of the forest cockchafer is long, typically ranging from three to five years depending on the environmental temperature and soil conditions. The female beetle lays eggs in the soil, and the larvae go through several instars. The later instars (second and third year) are the most voracious, causing the most severe damage to agricultural production.

Root damage is the primary cause of economic loss. As larvae chew through the root system, plants begin to wilt suddenly, turn yellow, and eventually die. In nurseries or intensive berry production, the presence of these larvae can result in total crop failure if the density of the pest population exceeds economic thresholds.

Integrated pest management (IPM) is essential for controlling this beetle. This includes physical disruption of the soil cycle through deep autumn plowing, which exposes larvae to birds and drying. Chemical control options involve applying granular soil insecticides during planting. Biological control, using entomopathogenic nematodes or fungi like Metarhizium anisopliae, is also an increasingly popular and effective sustainable solution.