Carpenter Bee Repair and Prevention

• Size:  Carpenter Bees are larger than standard bees and most wasps.  They are generally 3/4 to 1 inch long with a thick build.

• Color – They have a yellow/orange fuzzy thorax sometimes with white hairs.  Their abdomen [bottom section] is a highly reflective black or sometimes metallic blue all the way round.

• Noise - Carpenter Bees can often make a frantic buzzing sound that can be heard inside the wood they have taken residence in.  

• Impostor – The Bumblebee looks very much like the Carpenter Bee as they are similar in size and color.  Simply look at the abdomen as Bumblebees are entirely fuzzy including their abdomen.  

• Hole Size - Holes are easy to identify as they are about the size of a dime [generally 1/2 inch diameter] and look as if they were professionally drilled as they are near-perfectly circular.  Perhaps what is most impressive, and frustrating, is that the female carpenter bee can drill this entrance in just a couple of hours!

• Location - Carpenter Bees prefer to make their entrances upward on the underside of wood.  This helps prevent rain and other weather from disturbing their new nest.  While it is possible they will make an entrance horizontally, it will still generally be in an area that has protection overhead.  Sometimes this is higher in the air like an overhang or low to the ground like the underside of decking.

• The Evidence - Holes can often be found by identifying piles of "frass", basically sawdust, that is created and dropped during the process of the bee chewing the wood.  These piles are telltale signs of Carpenter Bee, or sometimes Carpenter Ant, infestation.  If you believe you have Carpenter Ants, see our blog on their prevention.

Lack of Treatment and Repair results in more Damage and more Bees

• Weakened Structures – Carpenter Bee holes aren't a simple one-way cavity.  After making a 1-2 inch deep hole into the wood, the bee will make a 90 degree angle and tunnel along the wood grain at a slower rate of about one inch every 5-6 days.  This means your wood isn't damaged just where you see the hole, but horizontally along the wood ranging about 6 to 12 inches.  If these holes are not fixed, they are often reused each season and can eventually eat into the wood between 3 to 10 feet!  This can result in structural weakness and potential collapse.

• The Next Generation – These tunnels are not only a home to the Carpenter Bee, but the storage area for their eggs.  The female carpenter bee seals off these eggs into about 6 to 8 water-proof chambers with their own food supply of pollen and nectar.  Near the end of the summer, these "babies" have hatched, eaten and grown to new adults and emerge from these holes.  Where do they sleep for the winter? Right back inside your wood where they were born. 

• Treatment - if the nest is active, it is imperative that pest control treatment is utilized to eliminate the pest first.  If the hole is plugged or something is sprayed inside, this will push the bees to burrow further into your wood.

NEVER SPRAY ACTIVE HOLES!

• Repair - Push steel wool into the cavity as far as you are able.  Then use a wooden dowel appropriate for the 1/2 inch entrance and coat the dowel in exterior-grade wood glue and tap it into the hole snugly.  After the glue dries, you can sand down any part of the dowel that is not flush with the surface.  Paint or stain the area to match the surrounding wood.  

Prevention

• Paint, Stain and treated wood is your friend!  Carpenter Bees can chew through semi-hard wood, vinyl and even plaster.  However, they  prefer easier targets such as unfinished wood, wood with cracks or weaknesses, and previously used Carpenter Bee holes.  Maintain the paint or stain on your wood, use treated hardwoods or best of all synthetic building materials.  NOTE: Oil-based products work best but any paint or stain will greatly help.
• Detterents such as liquid dish soap mixed with essential oils like tea tree, citrus or peppermint can be made into a spray to naturally repel these pests.  Citrus spray can also be made from boiling chopped oranges and lemons in water.  Spray vulnerable areas to discourage Carpenter Bees from beginning.
• Trap Wood is another prevention trick where you can put out a "sacrificial" block of untreated soft wood in your lawn such as white pine, cedar or cypress.  Not only will this provide an easy distraction for Carpenter Bees, but they are territorial and will often chase off other Bees in the area!