The most common Northwest pest is the flatheaded borer commonly known as the golden buprestid, Buprestis aurulenta. The adult is iridescent (shiny), golden green, and about ¾ inch long. When fully grown, the whitish larva is about 1-1/2 inches long. Across the wide, flattened segments of its sharply tapered body, it has a width of about 3/8 inch.
Upon hatching, the larva bores into wood, excavating a mine that grows in size along with the larva. The mines are oval in cross-section, with a width of about 3/8 inch. They vary in length from 3-15 feet from the point where the eggs hatch to the point where the larva reaches its full growth. The tunnels are packed full of borings and excrement produced by the larva.
Under normal conditions, larvae usually complete their development in 2-4 years, but there are documented cases of beetles emerging from wood products used in construction of houses in which eggs must have been deposited at least 15-20 years earlier. When the larvae reach full size, they go into a resting or pupal stage during which they change into adults. This process occurs in oval chambers known as pupal cells usually formed near the surface of the wood.
Adult beetles lay eggs on trees, preferably those that are dead or dying, or recently cut trees with the bark still on them. They are attracted to pitchy wood and may lay eggs on fire scars. The eggs are sometimes laid in cracks of freshly sawed lumber, and less frequently, on older, dry, or partially dried structural material. There is some indication that beetles occasionally lay eggs on older, dry, unpainted, or untreated wood, making it possible for emerging beetles to reinfest a building. Adult beetles live for 3-5 months.
ENTRY AND DAMAGE
After transformation is complete, the adults eat their way out of the wood, leaving a small oval exit. Under natural conditions, adult emergence occurs with greatest frequency during the spring and early summer months. This is often the first sign of infestation. Emerging beetles usually fly away and do no further damage to the wood from which they emerge. In buildings, emergence is more frequently noted from late fall until late spring.
Once an infestation of boring beetles is detected in homes, there is little in the way of direct feasible chemical control. Plugging the holes and finishing the damaged surface is an obvious remedy. Kiln drying lumber before construction kills all stages of the insect that may be in the wood.
Call your local Critter Control of Seattle expert today for golden buprestid beetle prevention tips! 206.317.5048