Old House Borer Beetle Old house borers or woodborers as they are often referred to, can cause major damage in structural wood such as pine, fir, hemlock and other soft woods commonly used in building construction. |
. The larva do the damage while feeding on the wood. They digest the wood and their excrement is a fine powdery frass about the consistency of talcum powder. Their name "old house borer" is somewhat misleading as they are most often found in structures less than ten years old. The creamy white larva can live in wood from three to fifteen years. They prefer wood with moisture content between 10% and 20%. The larva will mature at a faster rate in wood with a higher moisture content and temperatures above 65 degrees. As the larva feed they make a rasping or ticking noise in the wood. The larva are usually over four years old before they can be heard eating in the wood. The larva pictured would be large enough to be heard feeding which sounds similar to a toothpick breaking. |
As they feed they make oblong holes about 1/4 inch in diameter. Many times their powdery frass can be seen streaming from their exit holes. |
In the above pictures we are viewing the bottom of a floor joist that had been infested by old house borers. As the larva eat they leave a fine powdery frass behind in the wood. |
Notice the "groove marks" near the top of the picture left in the wood by the strong mouthparts of the "old house borer beetle larva".. |
