To manage carpenter bees effectively, consider the following approaches: 1. Direct Treatment of Nesting Holes

• Use insecticide aerosols or dust formulations labeled for carpenter bee control. Apply these directly into the tunnel entrances and along exposed surfaces to kill bees inside the nests. Leave holes open for a few days after treatment to allow distribution of the insecticide, then plug the holes with wood dowels and sealant to prevent reuse and moisture intrusion

• Common insecticides include bifenthrin, cyfluthrin, deltamethrin, or lambda cyhalothrin

2. Physical Prevention and Habitat Modification

• Paint or thoroughly seal wood surfaces, especially bare or weathered softwoods like cedar and pine, since carpenter bees prefer unpainted wood. Painting is more effective than staining or preservatives

• Fill cracks and holes with caulk (preferably silicone-based) to block existing tunnels and prevent new ones

• Replace vulnerable wood with composite materials or very hard woods that bees cannot drill into, such as black locust or ipe, although this can be costly

3. Trapping and Deterrents

• Install carpenter bee traps near eaves and other areas where bees hover. Traps can be purchased or homemade and work by luring bees into a container where they cannot escape

• Use natural repellents like citrus sprays made from boiled citrus peels or apply citrus oil solutions to deter bees without harming them. Spray after bees emerge in spring or before they return to nests in fall, avoiding application during active nesting

4. Alternative Nesting Sites and Coexistence

• Provide alternative nesting spots away from your home, such as untreated softwood blocks or piles of fallen branches, to encourage bees to nest elsewhere

• Recognize that carpenter bees cause minimal structural damage and are important pollinators. If possible, coexistence with them is beneficial for the environment

5. Persistent Monitoring and Maintenance

• Regularly inspect for new holes and treat or seal them promptly. It may take several seasons to fully reduce carpenter bee populations

• Swatting bees away is a simple but labor-intensive way to discourage them

By combining these methods-chemical treatment, physical barriers, traps, repellents, and habitat management-you can effectively control carpenter bees and protect your wooden structures while minimizing harm to these valuable pollinators.