Bostrichid Beetle

Often named “false” or “large” powderpost beetles, bamboo borers or lead cable borers, bostrichid beetles cause much less damage than lyctid or anobiid beetles. The adults and larvae of bostrichid beetles attack mostly hardwoods. The female bostrichid beetle creates “egg tunnels” to deposit eggs and the larvae then feed on the wood to grow. After they exit, they rarely re-infest the wood that they developed in. They are not a huge concern for most homeowners.


Bostrichid beetles are similar to lyctids in habits and also are able to digest cellulose. Most species feed only on starchy hardwoods or bamboo, however, a few may also attack softwoods. Many species require wood with bark for egg-laying and do not reinfest wood in homes. Some species prefer old wood, such as timbers in barns or sheds, partly because such timber contains fungi, which provide proteins for the developing larvae. Bostrichids have coarser, more tightly packed tunnels filled with wood dust and excrement (frass). The exit holes made by the adults are slightly larger than those of the lyctids. The adult beetle is 6 – 13mm long and is reddish-brown to brown black in colour. Unlike the lyctids, its head is not visible from above.

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.
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