What method is recommended to control carpenter bees?

Injecting an insecticide into exit holes is the recommended method for controlling carpenter bees because it directly targets the insects where they are active and nesting. Carpenter bees bore into wood to create nesting sites, and by applying insecticide into these exit holes, the treatment effectively reaches the adult bees inside the tunnels. This method not only kills the existing bees but can also help prevent future infestations by addressing the problem at its source.

In contrast, other methods may not be as effective. For instance, using traps with bait typically works better for species that are attracted to specific lures, but carpenter bees are not as easily lured to traps. Applying a repellent spray may deter some insects temporarily but does not eliminate existing infestations. Lastly, using natural predators could help in some scenarios, but it lacks the immediacy and direct effectiveness of treating the nests with insecticides. Therefore, the method of injecting insecticide directly into the exit holes provides a targeted approach to managing carpenter bee populations effectively.