How To Get Rid Of Carpenter Bees

By Walt Cline

Getting rid of Carpenter Bees depends on the timing of the year. You can prevent carpenter bee infestations if you tackle the situation early enough. If you have an active Carpenter Bee infestation, we can also advise you on how to get rid of carpenter ants and exterminate them.

A. How To Prevent Carpenter Bee Infestations

Prevention is the operative word for carpenter bee control. Prevent them before you have to get rid of them.
Carpenter Bees attack unfinished wood under decks, sills, and decks first. Varnish or paint these wood surfaces to make them less attractive to these bees. A fresh coat of paint is unattractive to a Carpenter Bee.
Seal as many exterior openings as possible. The Carpenter Bees are looking for cracks that will protect entrances. Seal and caulk these cracks and crevices.
Carpenter Bees will reuse holes from the previous season. Cauk these holes in the fall, after the carpenter bees have emerged.
Carpenter Bee prevention and extermination is usually best done before nesting activity gets started. If you do not have a chance to paint or varnish the unfinished wood, before they begin to bore into the wood, spray the unfinished wood in these vulnerable areas (under rail sidings, under decks, around window sills, etc) with a good residual spray such as the ones listed below. The best time to spray preventively for carpenter bee control is spring time. Nesting and the rearing of young carpenter bees occur in the late spring or early summer . These residual insecticides will last 2-3 months, then retreat until the fall season.

Recommended Residual Insecticide Concentrates for Carpenter Bee Prevention

Optimate CS - Will not leave a visible residue.
Cyper WP - Will leave a visible residue seen against dark surfaces
These residual insecticides will make several gallons of finished product and can also be used to treat a broad variety of insects. A suggested tank sprayer that is durable and economical, is a pump sprayer such as, B&G Dura Sprayer.

**B. How To Get Rid Of Carpenter Bees- Active Carpenter Bee Infestations**

If you do have an active carpenter bee infestation, following these steps below would ensure success and exterminate carpenter ants.

Step 1

Step 2 - Spray with a residual insecticide such as Optimate CS or Cyper WP .
Step 3 - Dust a residual dust such as D Fense Dust in all the new openings. We suggest B&G Duster 1150 (the carpenter bee kit has an additional curved tip to dust into the galleries)The tip is not sold outside of this kit.
Step 4 - After all is done, plug up the holes during the fall months. If you plug up the holes too soon, the carpenter bees may make another hole to exit.

Steps 1-4 products found in Carpenter Bee Kits

How to use the Carpenter Bee Kits

Aerosols To Spray

Only the female carpenter bee will sting if provoked.The sting may be painful, and a cool ice pack can sooth the sting. Males (the ones with the yellow faces) cannot sting (they do not have stingers), but can be bothersome . You can kill the hovering males with a contact aerosol such as, Bonide' s Wasp and Hornet Killer. The only reason for killing the males is their nuisance factor, since they can't sting.

Residual Liquid Treaments To Spray

Spray the areas where carpenter bees are boring in any unpainted or unvarnished wood with Optimate CS or Cyper WP. Sometimes they may be boring in painted or varnished wood. Their holes are usually located on the underside of any wood surface including siding, soffits, overhangs, decks, fence posts, fascia boards and window frames. We recommend spraying during the spring twice at intervals of 3-4 weeks.

For severe infestations of carpenter bees on cedar and log structures, you may need to repeat the treatments more than twice. We suggest a interval of two weeks for spray treatments. After each spray treatment, apply D-Dust, Delta Dust or Drione Dust to all possible carpenter bee holes or entry points.

Optimate CS or Cyper WP will last 2 to 3 months, leaving a residual for that long, taking it through most of their season.

Using Dust In Carpenter Bee Holes

If you have a current infestation, dust with D Fense Dust or Drione Dust as many carpenter bee holes as possible. Fill the B&G Dust-R Duster 1/2 with dust and dust into the openings. Although their holes appear to be only an inch or two deep, it usually extends at a 90 degree angle.This duster comes with a curved tip thtat will fit into the 90 degree angles easier. The female will turn 90 degrees and bore a channel from 6 inches to as long as 4 feet. This channel serves as a main corridor from which she will drill small chambers a few inches deep. These chambers become egg holders. She will deposit an egg, bring in some food, and then seal it off to ensure the egg's development.

It may be difficult to treat each individual gallery with a dust , aerosol or liquid residual insecticide, as you can see by the carpenter gallery picture, but is important if you have a current infestation.

Plugging up carpenter bee entrances

You can plug up the entrances with plugs or cork, putty or use caulking compound after all the bees are killed. A safe time to plug entrances would be in the early fall months.
If you plug up the entrances too early, you would not allow the carpenter bees to pass thru the insecticide dust to pass freely and they may chew new openings in other locations.

The following year, by all means, spray early to prevent further boring.

Carpenter Bees

Carpenter Bees can look like Bumble Bees; large, with yellow and black patterns. They are about one inch and may have some metallic reflections ranging from a dark blue, yellow, green or purple tints. Their abdomens are shiny, which are different from Bumble Bees, which have more hair. They are commonly sighted in the spring hovering like a helicopter around eaves, porch rails, and under decks. Some times, they are called "wood bees", because of the way they bore into wood. Carpenter Bees do not eat the wood for nutrition.Carpenter bees, as pollinators eat nectar and pollen from flowering plants.

The female carpenter bee will bore a channel or main corridor in the wood from 6 " to as long as 4 feet to lay their eggs in "galleries". She will deposit an egg, bring in a mass of pollen for the newly hatched larvae to feed on, and then seal it all off to ensure it's development before she repeats the process for the next egg.

Although, they are a wood boring insect, they are not considered a true structural pest. They do not spread through out the entire structure, but prefer unpainted or finished wood.

For More Information : Carpenter Bees

Signs of Carpenter Bee Infestations

Carpenter Bees make holes about 1/2 inch in diameter. They prefer unfinished wood and can drill and create tunnels in seasoned hardwoods, softwoods and decaying woods. Look for "frass", that looks like sawdust from these drilling areas.

For More Information : Carpenter Bee Identification and Signs