How to Stop Carpenter Bees From Destroying Your Home

Carpenter bees are named for their ability to bore holes into wood and create galleries beneath the wood's surface. These bees drill for nesting and for shelter, and do not consume the wood they destroy. Female carpenter bees are the excavators, boring clean, ½-inch-diameter holes about 1 to 2 inches deep before taking a right-angle turn and producing a 4- to 6-inch-long gallery. One or two bees do not cause much more than cosmetic damage, but repeated excavations of galleries can result in extensive wood damage. Does this Spark an idea?

Things You'll Need

• Paint
• Paintbrush
• Caulk, wood putty or hardwood dowel and exterior wood glue
• Non-expanding foam sealant
• Insecticide dust formulated for carpenter bees
• Flexible bottle and tube

Instructions

1. Paint exposed wood surfaces with a polyurethane- or oil-based product. Carpenter bees avoid painted surfaces, but will enter where paint is chipped and worn, or along saw cuts and exposed edges. Stains do not deter attack.

2. Plug entrance holes that do not extend into a gallery. Plug the holes with caulk, wood putty or a hardwood dowel coated in exterior-grade wood glue. Carpenter bees won't chew through caulk or putty, and Eastern carpenter bees avoid hardwoods.

3. Inject a non-expanding foam sealant into the galleries to seal them and trap bees inside. Plug the entrance holes as in Step 2.

4. Spray insecticide dust into the galleries, using a flexible bottle with a long tube attached. Try to get as much dust as deep as possible into the galleries, but do the dusting on a cool night when bees are less active. Wait two to three days before sealing the entrance holes to allow bees to move about and spread the dust. As an alternative and preventative measure, dust galleries in the spring before bees are actively seeking nesting sites, again in the late summer to reach any bees not dusted in spring, and once more in the fall when a few bees are flying; then seal all the entrance holes.

Tips & Warnings

• When spraying or dusting galleries at night, place a piece of red plastic wrap or cellophane over the flashlight. Bees can't see red so they won't be attracted to the light, but you'll still see the entrance holes.

• Use caution anytime you work with pesticides. Wear the proper protective clothing, and only use the chemicals as directed on the container.

• Be careful working around bees. Male carpenter bees may threaten, but have no stinger. Females do have a stinger, but only use it on rare occasions, usually only if handled.

References

• Ohio State University Extension; Carpenter Bees; Susan C. Jones
• University of Missouri Extension; Carpenter Bees; Richard M. Houseman; August 2007
• University of Kentucky College of Agriculture; Carpenter Bees; Mike Potter
• North Carolina State University Department of Entomology; Carpenter Bees; Stephen B. Bambara and Michael Waldvogel; July 2009