What is the primary evidence of powder post beetle activity?

The primary evidence of powder post beetle activity is frass, which is a fine, powdery substance produced as the beetles tunnel through wood. This frass is comprised of wood particles that have been digested by the larvae and excreted in their tunneling process. The presence of frass indicates active feeding and boring, which are characteristic behaviors of powder post beetles as they damage hardwoods and softwoods.

Other indications of insect activity in wood, such as wood shavings, may be present, but they are not as definitive as frass. Wood shavings are more commonly associated with other wood-boring insects and can be left behind by various species. Mud tubes are primarily associated with termites, not powder post beetles, and egg casings would indicate the presence of larvae rather than active tunneling and feeding. The distinctive nature of frass makes it a clear sign of powder post beetle infestation, signifying ongoing damage to the wood structure.