How to Get Rid of Carpenter Bees
Injecting nests with liquid or dust insecticide formulations are the most effective ways to eliminate bees, eggs and larvae. Currently permethrin and cyfluthrin in liquid formulations and dusts with boric acid are approved and effective in use against carpenter bee infestations. For a lower-toxicity and longer-lasting option, desiccant dusts may be combined with diatomaceous earth or boric acid powders and applied to the problem area.
If carpenter bee infestations are a recurrent problem, insecticide treatments should be carried out in the spring, mid-summer and early fall months. In general, prevention is the best treatment method and can be achieved by filling potential nesting holes with wood putty or steel wool.