In the United States, carpenter bees from two genera, Ceratina and Xylocopa, are known for inflicting damage to structural wood within homes and on the exterior walls of homes. Carpenter bees belonging to the Ceratina genus are not considered significant wood-destroying insect pests, but seven species of the Xylocopa genus are well known for inflicting damage to timber-framed structures. Among these seven species, Xylocopa virginica virginica inflicts the greatest amount of structural damage to homes. This species is more commonly known as the “eastern carpenter bee,” and just as its common name suggests, this species is most abundant in the eastern half of the country, particularly in the northeast.

The eastern carpenter bee bores into painted and unpainted finished wood sources, including wood siding and structural wood, sometimes resulting in significant damage that weakens structurally important wood sources. Like other carpenter bee pest species, the eastern carpenter bee excavates tunnels within wood by first creating circular entry points on the surface of wood. These evenly rounded entry points are around a ½ inch in diameter, and are frequently spotted on wood siding, on and around eaves, wooden lawn furniture, fences, and even garden tool handles. Unlike many carpenter bee pests, eastern carpenter bees are well known for excavating particularly long tunnels within wood due to their habit of reusing old infestation sites.

Eastern carpenter bees return to old infestation sites where they lengthen tunnels to store large amounts of pollen, and they may enlarge internal cavities in wood in order to hibernate more comfortably throughout the winter season. However, eastern carpenter bees tunnel into structural wood primarily for the purpose of depositing eggs in a protected location where larvae can feed on stored pollen upon hatching. Although carpenter bees do not typically cause severe structural damage, tunnels as long as 10 feet are sometimes found in the structural wood of infested homes. A few carpenter bee infestation cases have seen structural wood become so inundated with internal galleries that houses have collapsed as a result, but these cases mostly involved homes that had remained uninhabited for long periods of time.

Have you ever spotted carpenter bee entry holes on the surface of wood items located on your property?