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Thread: Powder Post beetle

  1. #1
    Join Date
    Jul 2005
    Location
    Cincinnati Ohio
    Posts
    4,731

    Powder Post beetle

    Can you get Powder Post beetles AFTER your lumber has been kiln dried or do they only infest green wood?
    "Remember back in the day, when things were made by hand, and people took pride in their work?"
    - Rick Dale

  2. #2
    Yes you can get PPB after the wood has been dried although in my experience it is not all that common unless the material is stored in a spot that the critters could easily make their way into.

  3. #3
    Join Date
    Mar 2010
    Location
    Williamsburg, Virginia
    Posts
    112

    Powder Post Beetle Primer

    Often much confusion on wood beetles. Powder post beetles will only attack and reside in dry wood (air dried or kiln dried). The holes of the power post beetle are small (approx. 1/16") and will leave the tell tale sign of the "powder or fine dust" behind as evidence. The dust is actually a mixture of bug poop and fine wood dust. When you find the dust, the critter is long gone - hatched and off to mate and lay eggs elsewhere to produce future generations.

    The powder post beetle gestation period is fairly long, often 18 - 24 months so you shouldn't find evidence of powder post beetles in newly dried lumber as any eggs and larva that might have been layed in the lumber in the latter stages of air drying on the lumber yard would be destroyed in the kiln drying process from the high kiln temperature. If the lumber is properly kiln dried any powder post beetle infestation will occure after the lumber has left the kiln (and in most cases after the lumber has left the sawmill / kiln drying facility). Most powder post beetles have species preference and white ash and hickory/pecan are regional favorites. Powder post beetles are unlikely to lay eggs in wood that has wood finish but lumber that has gestating eggs or larva can easily be crafted into projects only to have the beetles emerge many months later as the nursey was set up and populated prior to crafting & applying the finish.

    I haven't seen very much powder post infestation in walnut but I have seen a lot of walnut that is sold that has never been properly kiln dried (such as air dried in an out building for 20 years).

    Powder post beetles damage shouldn't be confused with lumber that has ambrosia beetle holes. Ambrosia beetles infest live trees and produce a larger hole (usually around 1/8" in diameter) but are killed during the kiln drying process. Ambrosia beetles will not reinfest dry lumber.

    A good rule of thumb - the longer the wood has been out of the kiln, the higher the probability that the wood could be infestated with powder post beetles. Buying lumber from a source that sells only kiln dried lumber and has high turnover of their lumber inventory is the safest preventative. Most powder post infestations that I've seen originated in shops that had some stock (again, usually ash or pecan/hickory) in storage for years that becomes infested. All it would take is one or two boards of old infested stock sitting in the shop corner mixed in with 200 bd ft. of newly purchased fresh stock to cause major problems for the customer, craftsman, the lumber retailer and down the line to the sawmill / dry kiln operation, all pointing fingers at each other. It is can be a nightmare that is very hard to pin point the actual point of infestation.

    I've had a customer that had to foot the bill for fumigating an entire home and replace a set of very expensive ash cabinates that were installed only months earlier due to a few emergence holes in a couple of boards that powder post beetles emerged from after construction and installation. Ironically, the newly produced beetles likely died prior to fumigatioin in the home without raising a family as a suitable site for rearing is not likely to be found in a home of properly finished wood products.

  4. #4
    Join Date
    Jan 2010
    Location
    Bellingham, Washington
    Posts
    1,149
    Lyctids (ppb) feed on starch in hardwoods such as oak, walnut or ash. They also infest bamboo (a grass). Ten species of Lyctids are known in the US and six are considered economic pests. Tropical woods from Central and South America, left in storage in the SE US prior to manufacture and distribution, are often attacked by Lyctids. They have a 1-year life cycle, but as wood ages less nutrition is available so the lifecycle may be extended. Adults are active at night and readily fly to lights. Eggs are laid in the pores of hardwoods and take 1 to 3 weeks to develop. Larvae (the damage stage) mature over 8 to 10 months. When you see holes and frass, that does not mean the infestation is over. There are usually many generations in the wood. Control usually necessitates removal of infested wood, or in extreme cases, tent fumigation. Much of this information was taken from the Washington Department of Agriculture Structural Pest Inspector Training Manual. I happen to be a licensed structural pest inspector and often find Lyctid infestations in hardwood floors. Her in Washington (West of the mountains-maritime area) we have another beetle known as the Anobiid. It is often mistaken for Lyctids but is quite different. It infests softwood (framing lumber), has a much longer lifecycle, requires a moisture level between 13 and 18 percent and can do severe structural damage to homes (usually in crawlspaces).

  5. #5
    Join Date
    Apr 2007
    Location
    Stephenville, TX
    Posts
    914
    My favorite rant. One of them, anyway. A lot of people think because wood has been kiln dried (and properly dried) it's then beetle proof. Wood kiln dried to 6-10% moisture will not get powder post. But let it sit outside the kiln and take up moisture from the air and when it reaches about 12-13% it's like a dinner bell has rung for the little critters. As a matter of fact, although I don't know for sure their working range for moisture I don't think powder post beetles will get in green wood.....at least not like borers.
    And now for something completely different....

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