Black-spotted longhorn beetle

The black-spotted longhorn beetle (Rhagium mordax) is a member of the Cerambycidae family within the order Coleoptera. It is a common species across European woodlands, known as a secondary pest that typically targets weakened, stressed, or recently fallen deciduous trees.

The beetle affects a variety of deciduous species, including birch, oak, lime, aspen, and hornbeam. It is most frequently encountered in declining forest stands, around decaying stumps, and in timber that has not been processed or stored properly, making it an important factor in forest wood degradation.

The life cycle of this beetle usually spans two to three years. Adults emerge in spring and early summer, feeding on tree sap and pollen. Females oviposit in bark crevices, and upon hatching, the larvae bore into the subcortical layers, creating extensive winding galleries filled with wood frass, which compromises the tree's vascular system.

The primary damage occurs in the cambium and sapwood layers. While healthy trees can sometimes withstand small populations, infested trees often exhibit signs of dieback. In forestry, the economic impact includes loss of timber quality and potential mortality in trees already affected by drought or primary disease outbreaks.

• Removal of infested trees during winter or early spring sanitation cuts.
• Proper management and quick removal of logging debris from the site.
• Encouraging natural predators such as woodpeckers and parasitic wasps.
• Monitoring using pheromone lures to track population trends in sensitive areas.

Control strategies emphasize forest hygiene to disrupt the beetle's life cycle. By limiting the availability of suitable breeding sites and maintaining tree vigor through appropriate silvicultural practices, forest managers can effectively minimize the impact of Rhagium mordax on commercial stands.