To Bee or Not to Bee

Many of you are hearing the buzz...the bee buzz that is. Several calls have come in recently from homeowners concerned about the carpenter bees hard at work around their homes. There is also concern about being stung by the carpenter bees that are hovering around. Carpenter bees are generally considered beneficial insects because of the wide range of plants that they pollinate. However, since they nest in wood they can become pests due to the aesthetic and structural damage they cause. So what's the deal with these little board boring bees?

Well let's first calm the fears about being stung. Unlike honeybees, carpenter bees are not stinging bees. A male carpenter bee (which is generally seen flying about) is aggressive when protecting its nesting site, but is harmless to us because it does not have a stinger. Although a female has a stinger, she will not generally sting unless she is being handled. Go figure, you shouldn't try to hold bees!

Okay, now that we are all relatively safe from being stung (except those who just can't resist the temptation to hold one) let's address the next issue of concern, those HOLES. Carpenter bees will gladly make use of man-made structures for the wood used to construct their nests. You think your home is nice and so do they. Common nesting sites include wooden house siding, eaves, window trim, fascia boards, shingles, decks, fences, and outdoor furniture.

So you know who is to blame for those perfectly round ½ inch holes in your wood, but what can you do about them? Prevention is the first step! Bare, unpainted, or weathered softwood is especially attractive to carpenter bees. In order to prevent carpenter bee infestation you can paint or varnish all wood surfaces. You should apply two coats of good exterior primer and follow up with at least one coat of finish. Of course, it may not be practical to paint every exterior surface of your home and unfortunately wood stains provide little repellent action. Sometimes standard window screening can be used to keep bees from getting into areas where there may be unpainted surfaces or other places where it might be difficult to paint. Cut strips of metal window screening; don't use the fabric or plastic type. Wedge or staple the screening into the places where the bees are working. Under most conditions carpenter bees can be successfully controlled using these preventive measures. If infestation is high or the risk of damage is great, insecticides may be used in addition to other methods of control.

Chemical management of carpenter bee populations is accomplished by treating each individual tunnel opening with an insecticide. It is best to treat in late evening or after dark when bees are calm and inside the tunnels. A pressurized can of bee/wasp spray can be used to shoot a stream of liquid into the tunnel. You can also place a longer lasting insecticide such as a dust inside the tunnel. Dusts are generally more effective and can be applied with a suction bulb. The tunnels should be filled 24 hours after treatment to discourage recolonization by other bees. Tunnels can be filled with caulking compounds, wood putty or a tight-fitting (1/2-inch) wooden dowel glued in place. Do not use the foam insulation that comes out of pressurized cans and expands to fill cavities because carpenter bees go through it easily. Again, if paint on the wooden surface is not undesirable, painting will discourage further attack by other carpenter bees.

More information on carpenter bees can be found in Extension publication ANR-1302. Publications are available at your local Extension office or can be found at the Alabama Cooperative Extension System website www.aces.edu.