Borer bees, also known as carpenter bees, are found throughout the U.S. There are several species of borer bees, all of which have similar characteristics and habits. Control methods are the same for any type of borer bees.
You can identify a borer bee infestation by the half-inch or slightly larger round hole that will appear in exposed structural wood or wood siding. This is the entrance hole the bees chewed, and they will create a chamber, or gallery, inside the wood. You can often see yellowish staining from their feces on the wood surrounding the holes. Sometimes you can hear borer bees buzzing inside the wall, and you may notice sawdust droppings when the borer bees are actively chewing the wood.
Get Rid of Borer Bees
Locate the borer bee holes during the daytime. Look for the staining or sawdust, checking in hidden areas such as under facia boards and in cracks around windows or corners.
Wait until evening, when the bees are less active, to treat the holes. Male borer bees have no stingers, and females are not very aggressive, so getting stung is not usually a problem.
Insert a wire into the entrance hole of a large, more developed gallery, and probe inside to kill larvae and pupae.
Plug and fill the borer bee holes. Use a small bit of crumpled aluminum foil or a piece of steel wool to stuff into the hole, and then patch over it with a weatherproof wood patch putty. Paint over the patch when it is dry.
Borer bees rarely try to burrow out by making a new tunnel. Their chewing process is a slow one, about one inch in six days, so plugging the hole effectively kills the bees and their offspring.
Caulk all cracks. Female borer bees can crawl through very tiny cracks and create galleries in support timber inside walls.
Keep your house paint in good shape. Borer bees will not chew through paint. Wood stain is not a deterrent.
Things You Will Need
- Ladder (optional)
- Steel wool or aluminum foil
- Wood putty
- Putty knife
- Diatomaceous earth (optional)
- Wasp insect spray (optional)
- Sevin insecticide (optional)
- Caulk (optional)
- An organic method of killing the bees is to dust the hole with diatomaceous earth. When a bee contacts the dust, the exoskeleton is etched, causing the insect to dehydrate and die. Place the dust at the entrance, and the bees will crawl through it and distribute it throughout the gallery.
- If you are not comfortable on a ladder, you can kill carpenter bees by spraying a commercial wasp/bee spray into the hole in the evening. These spray cans have long-reach jets so you can reach most bee holes while standing on the ground. Another chemical that is effective is Sevin dust. Use it at the entrance and let the bees crawl through it. This method does not seal the hole, however.
- Woodpeckers will open the holes in search of the borer bee larvae and pupae, which are incubating in the gallery. Borer bee tunneling can extend long distances, and woodpeckers can do lots of damage in their search for food.