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Pest Control/powder post beetles


I have an old barn,30' x 50' post and beam construction, build a 100 years ago. 30 years ago I replaced the center haymow floor section, 18' x 30', with 3x6 green cut  beams and a plywood floor.  While I was gone from the area for a time the roof developed a serious leak problem.  When I returned I found that there was fine sawdust covering anything that was under mow floor. I had a new metal roof installed on the barn which stopped the leak problem.  The dust problem is not as bad as it was but it has continued.  I have also found some dust on top of materials under other sections of the orginal haymow floors, which had been whitewashed years ago.
What can I do with this?
Is this a danger to other buildings that are attached?
Thanks for your help.

Dear Bob,

To answer your last question first - since most of the insects that produce a powdery kind of frass are known to reinfest nearby wood, I'd have to say Yes, this is PROBABLY a threat to the existing wood of both this, and any attached buildings.

Knowing exactly which insect is causing the damage is critical so, if you haven't yet done so, get about three different pest control companies to come out and do a FREE inspection of the barn - with the goal being to identify the pest. They'll also offer solutions to the problem, and I can tell you this - the control measures are pretty much the same, no matter which critter it is.

If the area(s) of infestation can be determined, and if it is accessible, then you have two choices. You can replace the wood (and destroy the old wood) or if the wood is too hard to replace (e.g., a heavy beam), then a localized treatment (application of an insecticide to the surface of the wood or injected into the wood) might do the trick. Using contemporary insecticides for these treatments will provide residual protection in the areas treated, thus reducing the potential for reinfestation.

However, if the infestation is rampant, or if the infested area is inaccessible, then you will have to consider looking at fumigation - which WILL be expensive. Also, with fumigation, although everything will be killed, there is no residual protection against future infestations.

So, my wish is that the problem can be localized - so that the treatment will be more affordable.  

Hope the info is helpful when dealing with the pest management firms...


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George E Serdes


My knowledge is in the areas of structural insect or rodent pest problems. I do not know enough about lawn and garden pests to be of any help there...


I've retired from the pest control industry in Central Florida. I spent 15 years in all areas of the industry (sales, night technician, integrated pest management specialist, service manager, and branch manager for both National and local companies.

Formerly sat on the Florida Pest Management Association's Board of Directors (Region IV)

Retired Florida State Certified Pest Control Operator -

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