Carpenter bees are often seen hovering about wooden eaves and porch railings during the summer months. These large bees, which derive their name from the ability to bore tunnels into wood, are a great benefit to the environment, pollinating a wide variety of crops and flowering plants. Carpenter bees, however, can become a nuisance. Although they are solitary and do not swarm or live in hives, their repeated tunneling in wood can cause structural damage. Individual bees can be killed quickly, though long-term treatment offers the best results.
Kill individual carpenter bees fast by using a bee and hornet killer spray. These aerosol sprays can be purchased at almost every department, grocery and/or hardware store. Get as close to the bees as possible when spraying them. Try to stay upwind and wear the proper protective clothing. The spray should knock the bees down and kill them almost immediately.
Apply the insecticide dust directly into the tunnels using a duster or applicator of your choice. This will kill any female bees that are inside the tunnel. The residual effect of the poison will also destroy any larvae that exists within the tunnel.
Wait a few days and then plug the hole with cork or a rolled-up ball of aluminum foil. If you wish, you can coat the plug with wood glue to ensure that it stays in place. It is important that you wait a few days, as this allows any remaining bees to distribute the insecticide dust throughout the network of tunnels.