The true powder-post or lyctid beetle attacks only hardwoods such as oak, ash, hickory, walnut, and mahogany. Infestations are most likely to occur in hardwood flooring and paneling. Other common infestation sites include bamboo furniture and trim and picture frames made from tropical hardwoods.
Like anobiid beetles, the first sign of an infestation is usually fine talcum powder-like frass coming out of tiny round holes in the wood. Another indicator is the presence of small, elongated black beetles on windowsills and other surfaces. Lyctid beetles are typically introduced into a home as eggs or larvae in firewood or in new molding that has been improperly stored or dried.
They have a relatively short life cycle and an infestation can spread to unpainted wood surfaces within a year or two. The female lays her eggs in the pores of the wood and if these pores are filled with a paint or stain, the wood will not be susceptible to infestation.
Lyctid Beetle Control Measures
• Prevention. Most beetle problems are introduced into homes in lumber or finished wood products (i.e., furniture, paneling, or flooring). Most serious infestations occur when infested wood is installed in the house. Inspect wood to insure that wood is not infested at the time of home construction.
• Wood finishes. Powderpost beetles only lay eggs on bare, unfinished wood. Beetles will not infest wood that is painted, varnished, waxed, or similarly sealed. Beetles emerging from painted or varnished wood were either in the wood before finishing or were a result of reinfestation by eggs that were laid in emergence holes of adult beetles. Sealing holes prevents reinfestation from eggs laid within the hole.
• Wood replacement. Infested wood can be replaced if the infestation appears to be localized. For instance, if emergence holes appear in a member of a door or window frame, the piece can be removed and replaced with a new, uninfested wood.
• Surface treatment. Insecticides are labeled for surface treatment of bare, exposed wood. Spraying or brushing insecticides onto infested wood creates a barrier that kills adult beetles as they chew their way out of wood. The barrier also kills newly-hatched larvae as they attempt to bore into wood. For the surface treatments to work properly, they must penetrate the wood. Therefore, the wood should be unfinished or sanded to remove the finish. In certain situations, the surface treatment can penetrate the wood sufficiently to kill larvae within the wood to prevent the further marring of the surface by additional emergence holes of adults.
• Fumigation. Fumigation is considered the most effective method of controlling wood-boring beetles. However, fumigation can be the most costly method of control and does not provide residual protection of the wood. Only pest control operators certified to apply fumigants can do fumigation work. Fumigation of infested furniture or small articles like picture frames and baskets can be done without fumigating the entire structure.