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.