Mother Nature has prowlers — even home invaders— everywhere. As a homeowner you need to police your property, keeping your eyes peeled for clues that your home may be under attack. Some bandits are easy to spot, like raccoons and woodpeckers. Others are a little more stealth.
There’s a common six-legged villain that many a log and timber homeowner dreads the most: carpenter bees. We’re not only going to help you sniff out the perp, we’ll show you how to put ’em away for life.
The Suspect
Bees come in all shapes and sizes, from small-but-pesky sweat bees to bulbous-but-good-natured bumblebees. Carpenter bees are among the brutes of the group — big, noisy and kind of intimidating; yet to humans, these bees are mostly harmless. The males have no stinger, and the females are quite docile (though it’s the quiet ones you need to watch out for, as they are the primary wood-boring perpetrators).
To wood, however, carpenter bees take their name to heart, leaving behind a trail of evidence, like half-inch-diameter holes with a pile of coarse sawdust beneath and yellowish-brown wood stains from their waste.
Carpenter bees thrive throughout the United States, though their wood species of choice varies by region. Western carpenter bees prefer to nest in oak, eucalyptus and redwood, while the east coasters target pine, redwood, fir and cedar. Many of these are common species for log and timber homes, making carpenter bees a legitimate threat.
The Crime
It’s a simple case of breaking and entering, followed by squatting. In early- to mid-spring, the bees will mate. The females then seek out a safe log, timber or other piece of wood to spawn, and once found, will use their strong jaws to drill holes into the surface. Once the entrance is complete, they take a sharp 90-degree turn and begin to tunnel — a process that may continue anywhere from 12 inches to as much as 4 feet until the females are satisfied with the location and stop to carve out a nest.
The nests themselves are a collection of small cells with chewed wood pulp in between. A female often creates six to 10 cells in a row along the main tunnel. At the end of this excavated gallery of cells she will leave a mixture of regurgitated nectar and pollen to feed her larvae. With her work complete, the female dies.
In August, new adult carpenter bees will venture from the nest, only to return for hibernation through winter. The following spring the next generation of carpenter bees begins the cycle anew. Females may reuse old nests with some modifications for their own larvae, sometimes for years at a time. Fresh sawdust along with drips of pollen and waste make tunnel entrances easy to spot.
You also may hear drilling sounds coming from within the wood as the females work on their tunnels and nests. Ironically, the males are given the job of guarding the nests though they have no stingers for protection.
In the end, these bees don’t want to devour your home like termites and other wood-eating predators do. They want to share it with you. The problem is they are not only uninvited, they’re unwelcome.
Mounting a Defense
So how do you rid your home of these intruders — or better yet — prevent them from invading your home in the first place?
“It is best to coat the wood before the bees find it because the next generation will return the following year to try again and again once the wood has been tunneled,” says Barbara Bloetscher, a retired entomologist who specialized in bee species.
A concentration of a borate-based solution applied to the wood’s surface has shown to be among the most effective pre-treatments available. Derived from the mineral sodium borate, water-based borate wood preservatives have been adapted for log homes for decades after having proved themselves as viable deterrents against pests of all sorts, including termites, beetles, carpenter ants and wood-decaying fungi. It’s easy to apply, odorless and non-corrosive.
While wood stains, themselves, will not deter carpenter bees, oil- and polyurethane-based finishes may help boost your efforts, as will a consistent insecticide-treatment regimen. In addition, there are many highly effective products made specifically for log homes and timber frames that can help deter and/or kill carpenter bees.
In the past, Borax, a specific compound also known as sodium borate, was used as a common insecticide for carpenter bees. However, a big disadvantage of Borax, which is pumped into the entrance holes, is the length of time it takes to kill the bees, giving them time to do more damage. But this isn’t the only negative.
“Borax is toxic to birds, bees and other wildlife,” cautions Barbara. “Although people refer to it as a ‘home remedy,’ when used improperly and allowed to blow and float in the air, it can be lethal to other vertebrates and invertebrates.” This can include humans, if ingested.
Once you have extinguished the bees (and make sure they’re dead, as live bees will tunnel their way out), remove the carcasses with a vacuum, plug the holes with cork or a dowel rod, seal it up with wood filler, then re-treat and stain the affected area.
The Verdict
It’s impossible to keep any home completely insect free. Sometimes, despite your best efforts, nature prevails. That said, log and timber homeowners do have a distinct advantage: Unlike conventional stick-framed houses, where the wood members are concealed within layers of drywall, siding and insulation, logs and timbers are on full display, making it easier to find evidence of carpenter bees and other insects early — and do something about it before irrevocable damage is done.
By creating your own mini neighborhood watch, keeping your eyes and ears open and taking appropriate action early, carpenter bees and other creepy-crawly marauders will soon find out it won’t be so easy to mess with your log or timber frame home.
Bee ID
Carpenter Bee
Photo: Chase D'Animulls - stock.adobe.com
Can you identify the wood-burrowing culprit when you see it? Carpenter bees are often mistaken for bumblebees. They are roughly the same size and do share quite a lot of physical traits and habits. But to ID a carpenter bee, keep your eye out for one distinguishing trait: its lower abdomen is black and shiny, unlike a bumblebee, which has a striped and fuzzy backside.
Bees Be Gone
Many log and timber owners try their hand at DIY solutions for pest control. However, wood-stain, preservative and maintenance-product manufacturers have created proven-effective formulas to take the guesswork out of pest prevention and extermination. Check out these top products designed specifically for wood homes.
- NBS 30™ by Outlast CTA Products. This all-natural additive is designed for use in both oil- and water-based exterior coatings, as well as plain water, and will inhibit insects from burrowing through. In addition to logs and timbers, you can also use it on decks and other wood components of your home. It is not an insecticide and is not intended to control wood-ingesting insects.
- Shell-Guard® RTU by Perma-Chink Systems. This ready-to-use, borate-based preservative protects wood from a host of natural enemies, including insects, fungi, mold and moisture. It’s odorless, colorless and has a very low toxicity level to people and pets, so you can apply it to interiors as well as exteriors. (This product is not available in California or Canada.)
- Tim-bor® by Sashco. Designed to prevent wood-ingesting insects and stop decay, this product is intended only for bare wood, as it won’t penetrate anything with a coating. For maximum protection, apply it before your logs and timbers are stained and sealed. It comes in both DIY and Pro formulas.
