Bore Bee Battle

[Mrc]

We have had our home for year and have been fighting the bore bee. We bought a duststick and have put power in the existing holes and have used Bugjuice in a sealent on walls. Everything seems to work but there is conflicting advice on sealing the bore holes. Some say with cork, some say with wood and some say not at all. What say you? Mike and Jane

[Stephanie]

I say, "Isn't that a Dr. Seuss book?"

Carpenter Bees are drawn to existing holes. BUT if you fill them and there are larvae in there, they're just going to drill out again. If you dusted, probably good. I used caulk, but hey, perhaps there's something else that's better recommended, don't know.

Carpenter bees are a royal pain and borate doesn't affect them, these things will go through pressure treated wood! Problem is they don't EAT wood, so the borate doesn't bother them a bit. You can have the most bug resistant wood around and a carpenter bee will still go right for it.

There are some heavy duty chemicals out there that seem to have an affect on these creatures, but none approved for that use, that I'm aware of. I mean like a yearly application and not a weekly or monthly one.

[Joe Bartok]

Mrc, check out this Carpenter Bee link.
Plugging the holes doesn't do much good in terms of the larvae; the adults provide a supply of pollen for them in the nest.

[Mrc]

We have had great luck using Drione Dust in the existing holes and have basically stopped the cycle as those leaving get the dust and those coming back are dusted too. My concern is whether to close the holes or not. I'm sure we have eliminated most of the "clan" but don't want to hold open house for others. What are pro's and con's on closing holes. By the way, how many log homes use gutter systems? Mike in Piney Flats, Tn.

[Stephanie]

I've NEVER heard of any controversy about closing these holes. Could you send me a link to an article saying you shouldn't and why? All pest folks I've talked to say you should close them up, they attract the bees back as they reuse the holes.

[Joe Bartok]

Having browsed several websites, the consensus all around seems to be: plug the holes. Most of them recommend waiting until the bees have exited for the season. Then place dessicant dust in the holes and plug them with aluminum foil, wood fill, caulking or some combination thereof. One site suggested steel wool, but I wouldn't use steel wool unless you want rust stains on your logs.
I haven't found cork and wood suggested as a fill in the holes and to be honest it doesn't make much sense ... the bees chewed holes in wood to begin with and they can do it again.

[Stephanie]

That's what I'd heard, Joe. Thanks for posting.

[Jeff Kyger]

While some don't use gutters, most do. The below picture shows water damage that obviously didn't happen over night (and a result of total neglect), but without gutters, its an example of what can happen to the lower courses as a result of backsplash (and lack of a water repellant).

Jeff Kyger
Perma-Chink Systems

[Jeff Kyger]

Many clients having been calling about the large, black bees hovering around eaves, decks, and wood siding of their homes and outbuildings. These are probably carpenter bees searching for mates and nesting sites. Carpenter bees cause cosmetic and structural damage to wood. They can also be quite intimidating and have the potential to inflict painful stings.

The Problem: Carpenter bees are similar in appearance to bumble bees, but have different nesting habits. Bumblebees generally nest in the ground, whereas carpenter bees tunnel into wood to lay their eggs. Bare, unpainted, weathered softwoods are preferred, especially redwood, cedar, cypress and pine. Painted or pressure-treated wood is much less susceptible to attack. Common nesting sites include eaves, fascia boards, siding, wooden shake roofs, decks and outdoor furniture.

Carpenter bees over winter as adults in old nest tunnels. After mating, the fertilized females excavate galleries in wood, laying their eggs within a series of small cells. The cells are provisioned with a ball of pollen on which
the larvae feed, emerging as adults in late summer. The entrance hole and tunnels are perfectly round and about the diameter of your finger. Coarse sawdust, the color of fresh cut wood, is often seen beneath the entry hole,
and burrowing sounds may be heard within the wood. Female carpenter bees may excavate new tunnels or enlarge and reuse old ones. Serious damage can result when the same piece of wood is worked year after year.

Males are often aggressive, hovering in front of people who are around the nests. The males are harmless, however, since they lack stingers. Female carpenter bees can inflict a painful sting, but seldom will unless handled.


The Solution- The best time to control carpenter bees is before tunnels are fully excavated. For homeowners, liquid sprays of Sevin or a pyrethroid (e.g., Bayer Advanced Home/Lawn & Garden Insect Killer, Spectracide Bug Stop, Ortho Home Defense System) can be applied directly into nest openings, or broadcast sprayed as a deterrent onto wood surfaces attracting
large numbers of bees. (The broadcast spray approach is often warranted when carpenter bees are riddling siding on a barn, wood shake roofs, or similar large expanses of wood.) Residual effectiveness of such applications is
only about 7-14 days, so the treatment may need to be repeated. Tunnels that have already been excavated can also be treated with an insecticide dust (e.g., Sevin), 'puffed' into the nest opening. Wasp and hornet aerosol sprays are also effective and generally more convenient than dusts for treating individual galleries. Althoughcarpenter bees are less aggressive than wasps, female bees provisioning their nests will sting. Treatment is best performed at night or while wearing protective clothing.

Leave the holes open for a few days after treatment to allow the bees to contact and distribute the insecticide throughout the nest galleries. Then plug the entrance hole with a piece of wooden dowel coated with
carpenter's glue, wood putty, or other suitable sealant. This will protect against future use of the old tunnels, as well as moisture intrusion and wood decay.

Carpenter bees normally will not tunnel into painted wood. Therefore, a more permanent solution is to paint unfinished wood surfaces, especially those with a history of being attacked. Wood stains and preservatives are less reliable than painting, but may provide some degree of repellence versus bare wood. To further discourage nesting, garages and outbuildings should be kept closed when carpenter bees are actively searching for nesting sites. The annoying flying/nesting habit usually subsides by late May.

The product, "SEVIN" I'm told also works rather well in deterring them. You can get it in powder or liquid form at just about any hardware store or home center.

Jeff Kyger
Perma-Chink Systems