Corthylus

Corthylus is a genus of ambrosia beetles within the subfamily Scolytinae. These insects are significant pests of various woody plants, distinguished by their unique habit of boring deep into the xylem of the tree to cultivate symbiotic fungi upon which their larvae feed.

The host range of this pest includes a wide variety of deciduous trees, such as oaks, maples, and beeches, as well as several species of fruit-bearing trees. The beetles are attracted to stressed, dying, or recently cut timber, though they can also infest healthy trees when population densities are high.

The biology of the beetle revolves around the symbiotic relationship with fungi. Adult females excavate tunnels in the wood, creating chambers where they inoculate the wood with fungal spores. The developing larvae depend exclusively on the growth of this "ambrosia" fungus for their nutrition rather than the wood itself.

Damage to the plant is primarily caused by the tunneling activity, which disrupts the vascular system of the tree, specifically the flow of water and nutrients. Externally, infestation is characterized by small, circular holes on the bark and piles of frass, while internally, the galleries often cause staining and structural weakness.

Management strategies focus on sanitation and preventive care. This includes the removal and destruction of infested wood before the new generation of adults emerges. Maintaining tree vigor through proper irrigation, fertilization, and minimizing mechanical injury can significantly reduce susceptibility to Corthylus attacks.

• Sanitary removal of infested logs.
• Monitoring with chemical attractants.
• Maintaining optimal tree health.
• Targeted application of insecticides.