What type of holes does a true powderpost beetle leave in wood?

A true powderpost beetle leaves small holes in wood as it emerges from the infested material. These holes are typically very small, often less than 1/8 inch in diameter. They are the result of adult beetles boring out of the wood after completing their development. The small size of these exit holes distinguishes powderpost beetle damage from that caused by other wood-boring insects which may leave larger openings.

Additionally, the presence of these small holes is indicative of an infestation, as they suggest that larvae have been feeding inside the wood, creating fine powder-like frass as they do so. This fine powder is a characteristic sign of powderpost beetle activity and helps pest control professionals identify current or past infestations in wooden structures.