Ash bark beetle

The ash bark beetle (lat. Leperisinus varius) belongs to the order Coleoptera and the family Curculionidae (subfamily Scolytinae). It is a significant pest primarily targeting ash trees, though it may occasionally infest other deciduous species such as lilac or olive trees, causing substantial damage to the vascular system of the wood.

The biological cycle involves one or two generations per year, depending on the climatic zone. Adult beetles overwinter under the bark or in soil litter. As temperatures rise in spring, they emerge to search for host trees, attracted by the specific volatile compounds released by weakened or stressed specimens.

Upon locating a suitable host, the female bores into the bark to create a maternal gallery, where she deposits eggs along the sides. The larvae subsequently tunnel outwards, feeding on the phloem and cambium layers. This feeding activity effectively girdles the tree, cutting off nutrient transport.

Symptoms of an infestation include small round exit holes in the bark, peeling bark, and thinning of the canopy. In severe cases, the entire tree may dry out and die within a few seasons. Infested trees are often prone to secondary attacks by other pests and pathogenic fungi.

Effective management requires an integrated approach. The most critical control measure is the prompt identification and sanitation removal of infested timber to prevent the emergence of a new generation. Chemical control via insecticide spraying during the peak flight period is also used in urban forestry.

• Sanitary logging and removal of infested trees from the site.
• Deployment of pheromone traps to monitor adult beetle activity.
• Silvicultural practices to enhance tree vigor and resistance to colonization.