Aspen carpenterworm

The Aspen carpenterworm (Acossus terebra) is a moth belonging to the family Cossidae. This species is widely recognized as a serious wood-boring pest in forestry and urban arboriculture. With a large wingspan and cryptically colored wings, the adult moths are nocturnal and rarely seen during the day.

The primary host plants for this species include various poplar species, particularly aspen (Populus tremula), and willows (Salix spp.). The larvae act as xylophages, feeding internally on the trunk and thick branches. This behavior allows them to bypass the tree's natural external defenses against insect attack.

The biological cycle of this pest is prolonged, usually lasting two to three years depending on environmental conditions. After hatching, larvae tunnel into the wood, creating extensive galleries. These galleries disrupt the xylem and phloem, significantly stressing the host tree and making it prone to secondary pathogens.

The damage caused by the Aspen carpenterworm is significant. External indicators include fresh wood frass appearing at the base of the tree or at the site of larval entry. Over time, heavy infestation leads to severe wood degradation, branch dieback, crown thinning, and structural instability, which often necessitates the removal of infected trees.

Management strategies focus on integrated pest management (IPM). Preventive measures such as maintaining tree health and avoiding physical damage to the trunk are paramount. Once infestation is severe, mechanical control (removal and burning of infested timber) is the most effective method to reduce local populations.

• Sanitation logging and removal of infested timber.
• Avoidance of mechanical injuries to the tree bark.
• Application of systemic insecticides for valuable landscape trees.
• Monitoring of flight periods with pheromone-based traps.