The Black Polycaon Is The Most Common False Powderpost Beetle Pest In The Southwest, And They Are Known For Infesting Wood In Furniture And Structural Lumber In Homes
More than 700 species make up the Bostrichidae family of beetles, and a small minority of these species are known pests of structural wood within homes and buildings. Beetle species in this family are commonly referred to as “false powderpost beetles,” and the most common species that infest and damage homes in the southwest are known as the leadcable borer (Scobicia declivis) and the black Polycaon (Polycaon stoutii). The other two families of wood-boring beetles known as powderpost and deathwatch beetles, see female adults deposit their eggs within crevices on the surface of wood. Once these eggs hatch, the emerging larvae bore into wood where they excavate interior tunnels, resulting in significant and costly structural damage. Unlike powderpost and deathwatch beetles, female adults in the false powderpost beetle family deposit their eggs within a tunnel that they themselves excavate. From there, emerging larvae continue to excavate tunnels and feed on wood, just like powderpost and deathwatch beetles.
The black polycaon is a relatively large species, as adults are between ½ and 1 inch in body length, and they are shiny black with front legs that stick out at right angles from the body. This species usually attacks softwoods, particularly plywood, but they have been found infesting hardwoods as well, such as oak furniture. Larvae rely on nutrients in wood for sustenance during their development, and once they reach adulthood, they carve out an exit hole around ¼ of an inch wide on the surface of infested wood. Maturation from egg to adult may take one year, or several years depending on conditions, and they are abundant in the natural environment in the southwest. Infestations are often initiated in structural wood after adult females gravitate toward porch lights and indoor lights. These beetles usually infest processed woods before they are used to construct furniture and other wooden items. Infested items can be treated with high heat, freezing temperatures, or fumigation, and heavy infestations within structural wood components in homes may require full-structure fumigation.
Have you ever purchased a wooden furniture item that had been infested with wood-boring beetles?