Crawl Space Powder Post Beetles Control

Powder post beetles

Powder post beetles

What are Powder Post Beetles, Do they cause Wood Damage?

Powder post beetles (PPBs) get their name from their ability to feed while in the larval stage from inside the wood and reduce it to powder. They are a wood destroyer and they can do sever damage to the structural integrity of your home. Homes with crawl spaces are generally inspected for the presence of a powder post beetle infestation during a real estate inspection and by exterminators when doing a crawl space termite inspection.

During my years as a termite inspector, I found hundreds of homes infested with powder post beetles. While we were looking for signs of termites we were, of course, examining the wooden beams. Small holes in the wood, a common size for PPB holes are about the size of a ball-point pen point. If the beetles are active they will have signs of frass falling out of the hole and streaming down the wood’s surface was the tell-tale signs of active powder post beetles. The above picture is a most excellent example of active powder post beetles from an article written by Dariusz Rudnicki, a retired  Illinois home inspector, founder, and editor of

The key to avoiding serious problems is early detection. Just because something is going on in your crawl space doesn’t mean you will actually notice it. It’s a good idea to have your crawl space inspected about once each year.

Active or Inactive?

Powder Post Beetles with frass streaming out of the holes.

Infestations of powder post beetles sometimes die out on their own. Therefore, it is important to be able to determine whether the infestation is active or inactive. When you use a saw on a piece of lumber the new end looks orange or brighter. Therefore when you look into a PPB hole if it’s bright or orange it may be active. As powder post beetles tunnel in the wood they eat or chew their way through. Then when they clean out their newly excavated tunnel they push the sawdust or frass out of the opening.  That’s why we know a hole that looks bright inside and has streaming saw dust is most likely active. Under some conditions, frass can cling to the wood for long periods of time so make sure the hole looks bright too.

Powder Post Beetle Control

Eliminate Moisture in the crawl space

Start by doing everything you can to eliminate moisture in your crawl space. As the moisture evaporates the water vapor rises and condenses on the wood members then moves into the wood of your substructure. Moisture or standing water in the crawl space is considered an invitation to various bug infestations. So keep the crawl space area dry.

  1. You can interrupt rising ground evaporation moisture by placing a vapor barrier on top of the soil in the crawl space. Cover 70% to 80% of the surface. Don’t cover it all, your structure needs a little keep it from drying out.
  2. Make sure your home’s crawl space has proper ventilation. At least one foundation vent on each side. would do. More is better, especially if your home is large. If not add them or get a contractor to do the job.

Homeowners should know that there are various options for controlling powder post beetles. Selecting that which is best depends on a number of factors including the severity of infestation, the area being attacked, potential for re-infestation and treatment expense the customer is willing to bear. In crawl space areas a borate treatment will surely do the job.

  1. Use Timbor Professional or Bora-Care Professional, my favorite, to kill the beetles. Both formulations are Borax based with other agents that cause the liquid particles to form so small they penetrate into the wood and are drawn to the moisture inside. that Both formulations are almost nontoxic, odorless, and remain effective for as long as 40 years.
  2. If you find one board that can be removed with little trouble, remove it and replace it.
  3. One final point to remember when applying borates or other liquid surface treatments is that the application will only control infestations which are accessible, i.e., wood that is exposed and can be reached for treatment.
  4. Infestations which have spread into walls or between floors are candidates for more drastic measures  such as fumigation.

If you want more details, read this article by Michael F. Potter, Extension Entomologist University of Kentucky College of Agriculture::

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About Mike Dukes 42 Articles
Founder and Chief editor of Termite MD, Pest, Columbus Georgia Online, Visit Historic Columbus and Stock Car Certified WDO Georgia and Alabama 1985-2013. When I'm not working on the Internet I love working in my yard.

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