Powderpost Beetle
This site gets a lot of e-mails from people who see one of the common signs of
drywood termites - sawdust-looking material that you find around wooden
parts of your house or furniture. Most people immediately suspect termites,
because they're the most common wood-damaging insect in the U.S. and
definitely the most well-known. This page is about another type of bug that
also eats wood and creates little piles of sawdust-material - the powder post
beetle.
Powder-post beetles are a kind of insect that eats wood, much like termites.
They eat certain kinds of hardwoods, including mahogany, oak, and hickory.
They can infest much, much smaller pieces of wood than a termite colony can,
because they're individual insects that don't need each other to function.
Even things as small as a fishing pole with a wooden handle have been reported
to have infestations. Most of the damage to the wood is done by larva of the
beetles and not the adults, as they burrow around inside the wood. They aren't
really one kind of beetle - they are several different species that usually
get lumped together under the same name.
People often get them from importing wood products from other countries. They
are very common in tropical areas, so bamboo or tropical hardwoods are key
suspects. Infestations are primarily in newer wood (if it's older than about
five years, they usually avoid it). The biggest cause of an infestation is not
storing or drying the wood correctly. You can also get them by storing
furniture someplace such as a barn, a shed, etc. where it can get exposed to
them.
How do I tell the difference between powder-post beetles and termites?
There are a couple of ways:
1) They don't look anything alike, so if you've actually seen flying insects
that look like termites (the swarmers), it's not the beetles.
2) The big thing to look for with powderpost beetles is holes in the wood.
Both eject the "sawdust" out of wood from little tiny holes. Drywood termites,
however, will fill the holes back up with a mud-like material, which dries and
is often indistinguishable from the wood itself. If you have powder-post
beetles, you will usually see visible holes all around where there was
"sawdust."
3) If you have powder-post beetles, you will often hear strange ticking noises
in the wood at night when the beetles are active.
Do I have an active infestation?
Just because you see sawdust doesn't mean you have an active infestation of
the beetles. A lot of times they'll go away on their own. The best way to tell
is to tape over all of the holes and see if any new ones show up. However,
keep in mind that the beetles usually don't make new holes except during
Spring and Summer.
What should I do?
If you have powder-post beetles, and not termites, the damage will be a lot
slower. At some point, though, you need to get the wood treated. Often this
can be done with borate-based treatments (there are a few listed on the main
page of this site), but if the infestation is deep in the interior of your
house it may need to be fumigated. As a general rule, if it's furniture that
is infested, you may be able to do it yourself by replacing boards or treating
them. If it's the structure of your house, I would at a minimum have it
inspected before attempting to apply borate treatment on your own. Other
things that can help are reducing the moisture in the air and varnish on the
surface of wood (which will discourage adults from laying eggs there).
What do the beetles look like?
You can see pictures of powder-post beetles online
here,
here, and pictures of the damage
here.
Sources and Useful Links:
http://ohioline.osu.edu/hyg
http://www.ca.uky.edu/entomolog
http://en.wikipedia.org/wiki
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