Locust borer

The locust borer (Megacyllene robiniae) is a member of the order Coleoptera and the family Cerambycidae. This beetle is a serious wood-boring pest that specifically targets and damages black locust trees (Robinia pseudoacacia), causing significant structural damage to the wood.

Adult beetles are approximately 20–25 mm long, with black bodies covered in yellow pubescence, arranged in distinct transverse bands, giving them a wasp-like appearance. The larvae are cylindrical, legless, cream-colored grubs that grow up to 30 mm, equipped with strong mandibles designed for excavating wood.

The life cycle of this pest is typically completed in one year. Adults emerge in late summer and autumn. Females lay eggs in bark crevices, and upon hatching, the larvae burrow into the sapwood and eventually into the heartwood, where they spend the winter, causing internal damage throughout the growing season.

The damage caused by larvae is severe. By tunneling deep into the trunk and branches, they compromise the structural integrity of the tree, creating entry points for secondary infections and wood rot. Heavily infested trees show stunted growth, branch dieback, and are prone to breaking during high winds.

Effective management strategies against the locust borer include:

• Implementing systematic silvicultural practices to maintain healthy stands.
• Prompt removal and destruction of heavily infested trees during the winter months.
• Encouraging woodpeckers and other natural predators in the forest environment.
• Utilizing pheromone-based monitoring to track beetle population density.
• Applying targeted insecticides to trunks if the infestation is caught at an early stage.