The term “powderpost beetle” applies to any one of three beetles found in the super family Bostrichidae. The larvae of these beetles reduce wood timbers to a mass of powder-like material. The adults do not normally damage the wood – they simply use the wood for reproductive means. Powderpost beetles infest flooring, studs and other parts of buildings, lumber, furniture, and many other wood products. Infestations in buildings are often a result of using wood that is infested. Powderpost beetles are often brought into homes in firewood. The first sign of infestation is piles of very fine sawdust and the presence of small holes in wood.
True Powderpost Beetles (Family Lyctidae)
Adult lyctid beetles lay their long, cylindrical eggs in the surface pores of wood. The larvae bore into the wood as soon as they hatch. Lyctid larvae are white with dark brown heads and mandibles. The front end of the body is larger than the back. These larvae can be easily identified by examining the last pair of spiracles; they are much larger than the rest. Larvae live in and eat the wood. At time of pupation, they bore near the surface of the wood and pupate. Adults bore out through the surface, pushing out a pile of fine sawdust. The adults are flattened and reddish-brown to black in colour. They are small beetles.
False Powderpost Beetle (Family Bostrichidae)
This beetle, since it rarely attacks wood commonly used people, does not cause as much problems as other powderpost beetles. As well, this beetle does not reinfest wood so dam-age is limited to one generation. These beetles however can work quickly and thoroughly on wood with a high starch content. Adult bostichid beetles bore into the wood to lay their eggs. Mature larvae are curved and wrinkled, lack hairs and have 3 pairs of short legs. As these beetles tend to be larger than other powderpost beetles, they cause larger holes in wood and produce more sawdust. After pupation, the adults emerge and are dark brown or black in color. The adults have a cylindrical body with the exception of their thorax which is rough. The antenna has three distinct segments. Bostichid beetles are dependent upon starch and other nutrients from the wood – they are unable to digest cellulose. Bostichids commonly infest hardwoods but have been known to infest some softwoods.
Furniture Beetles (Family Anobiidae)
The furniture beetle not only attacks furniture as its name applies but structural timbers as well. Anobiid beetles lay their eggs in cracks and crevices of seasoned wood. The eggs hatch into larvae and the larvae burrow into the wood. Here the larvae will live and tunnel for a year or more. When it is time to pupate, the beetles burrow towards the surface and then pupate. The Anobiid larvae are slightly curved, wrinkled and have tiny hairs on their bodies. They have three short pairs of legs. Adults are small and vary in colour from red to blackish-brown. Anobiids infest all seasoned woods, however their preference is the sapwoods of softwoods. Because of this, anobiids commonly infest areas that contain a high amount of pine.