Bostrichid (family Bostrichidae) beetles are primarily pests in hardwoods, but some species attack softwoods. Infestations often are in rough-cut lumber used for pallets, or in hardwood used before it is seasoned.
Bostrichids do not reinfest wood after it is seasoned and the moisture content reduced. Adult beetles are 1/4 inch long and cylindrical. There is a patch of short spines on the region above the head, and there may be spines or hooks at the end of the body. Entry and emergence holes are about 1/8 inch in diameter. The larval galleries are filled with powdery frass.
Development. Females bore into the wood surface and prepare tunnels for egg laying. Adult beetles feed on wood as they tunnel. Eggs are laid inside the tunnels, and the larvae create their own tunnels and frass as they feed. Larvae complete development in about 12 months.
Frass. The frass is fine powder, but it does not fall from the entry or emergence holes.
Habits. These beetles infest unseasoned hardwoods, and are not common in household materials. The bamboo borer infests ornamental pieces. Bamboo is a grass but has high starch content and can provide adequate food and moisture for Bostrichid larvae.