Bug Blog

Is It Possible To Visually Spot Signs Of Termite Damage On Structural Lumber

Arizona is home to a relatively high number of termite species, around half of which are known to be pests of structural wood within homes. Species from all three termite groups, subterranean, drywood and dampwood termites, can be found throughout Arizona. Dampwood termites are not found infesting the lumber components of structures often, as they can only feed on decayed wood that has become highly saturated with moisture. Drywood termite infestations are frequently found in Arizona homes, and unlike dampwood termites, drywood termites infest virtually all types of sound dry lumber. Subterranean termites are the most common and destructive of all wood-infesting pests in Arizona, as well as the entire US. While subterranean termites prefer to feed on moist and decayed wood, the species inhabiting Arizona are known for infesting dry structural wood of all types.

All termite species live in colonies that contain a large number of specimens divided into social castes. Subterranean termites dwell in the ground soil from where workers leave the nest to seek food sources such as dead roots, stumps, and occasionally, structural wood in homes. Drywood and dampwood termite colonies are inhabited by far fewer individual termites than can be found in subterranean termite colonies. Drywood and dampwood termite colonies are contained entirely within single wood items located above ground, such as dead trees, fallen branches, and logs. Considering their living conditions, termites are rarely, if ever, seen by homeowners, and they excavate spaces in the center of wood, leaving the surface intact. Because of this, termite infested wood often appears undamaged, but those with a sharp eye can sometimes identify wood that has sustained termite damage.

Since drywood termites never leave the wood they infest, they must carve tiny holes in the surface of wood in order to discard their fecal pellets. These tiny holes are called “kick-out holes,” and they usually appear long after infestations are initiated. Unlike drywood termites, subterranean termites only consume softwood and never the inner hardwood of structural lumber. This means that workers excavate wood just beneath the surface, often resulting in a sunken appearance on the surface of infested lumber. Subterranean termite workers excavate longitudinal cavities along the grain of wood, while drywood termites excavate wood across the grain. Structural wood that appears blistered or dark in color is indicative of subterranean termite damage.

Have you ever discovered termite damage to structural wood in your home?