The most significant wood-boring beetle include 3 major families: the deathwatch beetles (family Anobiidae), the true powderpost beetles (family Lyctidae), and the false powderpost beetles (family Bostrichidae). The false powderpost beetles are rarely found in the Northwest. Attack by these pests is characterized by small-to-medium-sized holes in the infested wood where adult beetles have emerged. In severe infestations, the wood looks as if it has been subjected to birdshot-sized shotgun pellets.
The lyctids, or true powderpost beetles, feed predominately on starch in hardwoods such as oak or ash, although they will infest bamboo. Hardwood furniture, tool handles, and crates are commonly infested. Lyctids generally have a 1-year cycle. However, as wood ages, less nutrition becomes available and the life cycle may extend another one or two years.
Adult beetles are small, 1/8-3/8 inch long, and red, brown, or black in color. Adults are active at night and readily fly to lights. Eggs are laid in pores of hardwoods and require 1-3 weeks to develop. Larvae mature over 8-10 months and lyctid damage can be recognized by the powdery frass (much like face powder) produced while feeding. Pupation requires about 3 weeks and adults chew a circular exit hole to emerge.
Male and female beetles live about 2 weeks. Lyctids have become cosmopolitan in distribution due to the movement of commerce throughout the world.
ENTRY AND DAMAGE
Powderpost beetles feed on deciduous trees, including certain hardwoods or softwoods depending on the species. Some hardwoods are naturally immune if they have low starch content or if their pore diameters are too small for the female beetle's ovipositor to lay her eggs in. Wood preservatives can be used to prevent beetle infestation.
Common treatments may use boron. Items that can be infested by powderpost beetles include wooden tools or tool handles, frames, furniture, gun stocks, books, toys, bamboo, flooring, and structural timbers.
Once an infestation of boring beetles, there is little in the way of direct chemical control that is feasible. Plugging the holes and finishing the damaged surface is an obvious remedy. Kiln drying kills all stages of the insect that may be in the wood.