Wrinkled bark beetle

Systematic position. The wrinkled bark beetle (lat. Hylesinus porcatus) belongs to the order Coleoptera, the family Curculionidae, and the subfamily Scolytinae. It is a specialized wood-boring insect that primarily targets stressed deciduous trees.

Host plants and damage. The primary host is the common ash (Fraxinus excelsior). The pest typically colonizes stressed, dying, or freshly cut trees, but during outbreaks, it can infest relatively healthy trees, causing them to weaken significantly and eventually die due to interrupted sap flow.

Biology and life cycle. The life cycle of this beetle is strictly tied to the tree bark. Adults bore entry holes and construct maternal galleries where they lay eggs. Larvae emerge and bore individual galleries perpendicular to the maternal ones, feeding on the phloem and cambium layers. Pupation takes place in small chambers created under the bark.

Symptoms of infestation. The primary indicator of an infestation is the presence of numerous small entry holes on the trunks and thick branches, combined with distinct gallery patterns found under the bark. Severe damage to the cambium layer results in crown dieback, leaf yellowing, and the gradual death of the entire tree.

Protection measures. Preventive measures are the most effective way to manage this pest. These include regular forest sanitary monitoring, the rapid removal and destruction of infested or dead trees, and proper forest hygiene. It is essential to remove logging debris promptly, as it provides an ideal breeding ground for the beetle population.