Carpenter Bees Gotcha Ducking?

Published 5:58 pm Thursday, April 6, 2023

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One of the joys of my life has been playing sports, in particular lacrosse. While I haven’t had the opportunity to play competitively for some time, I have enjoyed coaching for nearly a decade. Not only is this the fastest sport on two feet, it is fun and rewarding and gives me a chance to give back to the sport that helped me get where I am today. If I’m being honest, I also love knowing that I get to be outside every afternoon in the spring! This week it has been pretty warm in the afternoons. As such, we have seen an uptick in the number of bugs out near sunset. As we were in our parting huddle on the field one day this week, I couldn’t help but notice those carpenter bees buzzing through the air.

They can be distinguished from bumble bees by looking at the shiny black tail section. They can often be seen hovering around porches, houses, and especially wooden sheds like the one at my house. They are yellow and black and tend to be large in size for a bee. Females have stingers but tend not to use them unless they are trapped in your hand. Males tend to be really aggressive in swarming your head but do not have stingers. So, a lot of bark but no sting in this case. Males can be distinguished by the whitish spot on the front of their face.

Also contrary to popular belief, carpenter bees do not eat wood. They excavate holes for nesting as a solitary bee species. The female will tunnel in about ½” and then follow the grain of the wood creating galleries. These galleries typically extend 6”-7” but may be as long as a foot. Inside the gallery the female deposits a mixture of pollen and nectar that will serve as food for her emerging eggs. She then deposits the eggs near this ball and seals this section off with chewed wood. The female will continue to make these cells until the tunnel is completely filled. The bees die in a matter of a few weeks. The new adults emerge and continue the cycle throughout the season.

The bees can create a bit of damage over several years, eventually harming the structural integrity of the wood and/or exposing it to the elements. Painted and salt treated wood can be deterrents but the bees will still tunnel into them. Pest resistant wood such as redwood or cypress is by no means immune to attack either. Another issue is the excrement from the bees as they enter their tunnels. It causes yellow staining to the wood on porches and homes.

So, what to do? Control is very difficult because the carpenter bees do not eat the wood. Pesticides sprayed into the holes can cause a bit of trouble for them but often they will not be exposed to enough to be lethal. Treating holes with powdery products such as those containing carbaryl (the active ingredient in Sevin and other products) can be the most effective at reducing future nesting activity. Sprays do not have a long enough residual effect to be worth the time. Seal the hole with a ball of aluminum foil for 24-36 hours and then caulk it shut. That will deter other carpenter bees from nesting in that hole and prevent water damage. Plugging holes with wire or mesh is ineffective, bees will often just tunnel another exit.

Mike Waldvogal, NCSU Entomologist, says that swatting them with a tennis racket can be just as effective and possibly therapeutic! Remember folks, these are pollinators as well, harvesting nectar and moving pollen, so try not to swat too many.

If you are having trouble with growing in your home landscape, call the Extension office to talk to a Master Gardener Volunteer on Mondays and Wednesdays from 10:00 to 12:00 at (252)946-0111. Check-out the new Beaufort County Master Gardener Facebook page to see helpful gardening tips and see the plant of the week. Save the dates, today April 8 for the “Growing Tomatoes Successfully” class led by Master Gardener Volunteers. Participants will get a presale shot at buying Master Gardener grown Tomatoes! And, the Plant Sale on April 15 from 9- 11:00 a.m. when the Extension Master GardenerSM Volunteers will be having their annual vegetable sale. Until then, Happy Gardening!