Oak splendour beetle

Systematic position. The oak splendour beetle (Agrilus sulcicollis) belongs to the order Coleoptera and the family Buprestidae. It is a highly specialized wood-boring pest that primarily targets oak species, making it a subject of significant concern in silviculture and urban forestry.

Host plants and economic impact. This beetle primarily infests the pedunculate oak (Quercus robur). The pest typically attacks weakened or stressed trees, often those affected by drought, soil compaction, or previous defoliation. In outbreak conditions, it causes significant mortality among mature oaks, leading to severe economic and ecological losses.

Biology and life cycle. The life cycle usually spans one year. Adult beetles emerge in late spring and are active until mid-summer. Females lay eggs in crevices of the bark on the trunk and thick branches. Upon hatching, larvae bore into the inner bark and cambium, constructing intricate, meandering galleries that are packed with frass.

Nature of damage. The primary damage is caused by the larvae as they feed on the phloem and cambium layer. This larval feeding disrupts the translocation of nutrients and water, eventually girdling the tree. Symptoms include dieback of the crown, yellowing of leaves, and the presence of D-shaped exit holes on the bark where adult beetles have emerged.

Control measures. Management of Agrilus sulcicollis focuses on preventive forestry practices to reduce the susceptibility of stands:

• conducting timely sanitation logging to remove infested trees before beetle emergence;
• avoiding the storage of freshly cut oak logs in or near healthy forests;
• maintaining high tree vigor through proper silvicultural practices;
• monitoring populations using pheromone traps to trigger early management interventions.