What’s Causing Sawdust Piles?

By Chris Williams on April 14, 2011.
Q. I’ve been finding small piles of what looks like sawdust on the floor underneath wall-to-wall cabinets. Could this mean I have termites?
A. You might have termites but they’re not the source of the sawdust! The common subterranean termites that we have in the Northeast do not create sawdust. The sawdust could be from one of three things: It could be actual sawdust from construction of the cabinets or repairs that has since sifted out of the cabinets if they’ve been moved or banged around. Or, the sawdust could be from either carpenter ants (or sometimes other ants), or powderpost beetles.
Both carpenter ants and powderpost beetles feed on wood and can cause damage to wood in your home. Both pests push wood debris out of their galleries. A pest control expert can tell which pest is the culprit by looking for differences in the sawdust under magnification. In the case of carpenter ants, the sawdust is actually made up of tiny shreds of wood that they have torn loose with their mandibles, along with dead insects and pieces of debris. The ants push this dump material out of their gallery nest through slits in the wood.
The sawdust from powderpost beetles is actually feces, although it is very fine and looks more like talcum powder or cornmeal. The beetle larvae feed on wood inside their galleries, excreting tiny fecal pellets of digested wood (sometimes called frass). Depending on the type of powderpost beetle, the sawdust may be packed tightly in the galleries or it may be loose. After the larvae pupate and turn into adult beetles, the adults bore tiny, round exit holes in the wood. As they leave the infested wood, they push the sawdust out.
If you look closely directly above the sawdust piles, you may see the slits where carpenter ants push out their sawdust or you may see the round exit holes left by powderpost beetles. One way to help determine whether the sawdust is caused by an active insect infestation is to sweep or vacuum it up. If more appears in a few days, it likely means active insects in your wood. The other way to determine whether or not you have an active insect infestation is to call a professional. At Colonial, our trained technicians can tell you whether or not that sawdust is cause for concern. Give us a call!



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