Three groups of wood-boring beetles—powder post, deathwatch, and false powder post invade and damage wood furniture as well as structural and decorative wood inside of buildings. The beetle larvae feed in and do most of the damage to wood, and when they reach the adult stage, they emerge through round exit holes, which they create by chewing through the wood surface. Adults of some species also bore exit holes through plaster, plastic, and even soft metals that might cover the underlying wood.
Certain species of wood wasps also might emerge from infested wood used in new structures. Invasive wood-boring insects often arrive as hitchhikers from other continents on solid wood packing material such as pallets or in a ship’s dun age, and some of the key beetle pests of wood in structures have likely established worldwide distributions this way.
IDENTIFICATION AND LIFE CYCLES
Powder post Beetles
This fine, powdery frays distinguishes powder post beetles from other wood-boring beetles in homes. It also differs from the larger, granular, and almost pepper like pellets dry wood termites leave behind. Powder post beetles attack hardwoods, apparently because these woods have pores into which they can lay eggs; softwoods don’t have such pores. The large pores in bamboo also make it a favored host material for powder post beetles. In addition to large pore size, powder post beetles also prefer wood with high starch content; the starch content in softwoods is nutritionally low for these beetles.
Adult powder post beetles most often select and lay eggs in wood such as oak, ash, hickory, mahogany, and walnut, and infestations are most likely to occur in wood paneling, molding, flooring, window and door frames, plywood, bamboo articles, and furniture. Infestations can occur if beetles or larvae are brought into a building in furniture, firewood, or wooden decorative articles. They have a life cycle ranging from 3 months to more than 1 year, depending on temperature, humidity, and the nutritional quality of the wood. Adult powder post beetles usually are shades of brown to red.
Wood-boring beetles in the family are known as deathwatch beetles. Adults communicate with each other and probably locate mates by tapping their heads against wood, usually at night. Deathwatch beetles primarily infest softwoods, which is used in girders, beams, foundation timbers, and some types of furniture. Deathwatch beetles prefer wood that is moister.
Deathwatch beetle larvae fill their galleries with very small pellets of frays which gives their frays a slightly grittier consistency than that of powder post beetles. However, the larvae do most of the damage, and their frays are packed in the galleries and are visible only when larvae or adults push it out through emergence holes. Adults are reddish to dark brown and lay eggs in crevices, small openings, or pores of unfinished wood. It can take 2 years to complete each generation.
False Powder post Beetles
Wood-boring beetles in the family are sometimes known as False Powder post beetles. False powder post beetles colonize a variety of hardwoods and sometimes softwoods. Unlike female powder post and deathwatch beetles, which lay their eggs while on the wood surface, false powder post beetle females bore a tunnel, or egg gallery, into wood or other materials then deposit their eggs in pores or cracks within the tunnel.
In buildings, false powder post beetles infest floors, furniture, hardwood paneling, and other wood materials. Adults of some species bore through soft metal such as lead and silver as well as plaster and other non wood materials, searching for sites to deposit eggs or protection from weather extremes.