Q: What’s the best way to get rid of carpenter bees? I’ve heard products with borax in them are effective, but no one can tell me for sure.
— E.J., Salem
A: Borax is a stomach poison. Treating wood with borax will have a limited effect on carpenter bees because they don’t eat the wood they bore into to create their nesting tunnels, said Susan C. Jones, an entomologist with Ohio State University.
Pyrethroid insecticides labeled for use on carpenter bees can be effective, especially if they’re applied when the bees are nesting in spring and summer, she wrote in a fact sheet for the OSU Extension. She suggested injecting an insecticide dust into the bees’ tunnels and applying it to the adjacent wood surface. Wait a few days to give the bees a chance to distribute the insecticide within the nest, and then plug the entry hole with steel wool and wood putty so other bees won’t take over the nest.
Painting the surface will help deter bees from making new holes, she said.
Although carpenter bees can damage wood structures, they’re also important pollinators. Some people hang nesting blocks — predrilled blocks of soft wood — near the places where carpenter bees have become a nuisance, in hopes of giving them an alternative place to nest and spend the winter.
Jones’ fact sheet on carpenter bees can be found at http://ohioline.osu.edu/lines/pests.html. Another good resource is a fact sheet from Penn State, available at http://ento.psu.edu/extension/factsheets/carpenter-bees.
Have a question about home maintenance, decorating or gardening? Akron Beacon Journal home writer Mary Beth Breckenridge will find answers for the queries that are chosen to appear in the paper. To submit a question, call her at 330-996-3756, or send email to firstname.lastname@example.org. Be sure to include your full name, your town and your phone number or email address.