EHB can cause major structural damage to seasoned (dry) coniferous softwood timber, including pine, fir and spruce.
The adult beetle lays its eggs into cracks, holes and joints in dead pine trees, dead branches, or other dead parts of living trees and untreated pine timber.
The damage is done by EHB larvae that hatch from the eggs. EHB can live in its larval state for 2-12 years (2-5 years in WA) until it matures and emerges from the timber as an adult beetle, to begin the life cycle again.
By re-infesting the same piece of wood, larvae will keep feeding until the point of structural collapse. Infestation to structural collapse may take 15-25 years. The scale of damage can be seen from infestations in Europe and the eastern States. In WA, this level of damage has not been possible due to untreated pinewood being used only since 2000.
EHB has been found only in one home in WA, and the level of damage was minimal due to the short period of infestation. This home has since been fumigated to prevent further infestation.
Wood infested with EHB larvae is hard to identify, as larvae can tunnel without ever breaking the surface of the wood. It is only when the adult beetle emerges from exit holes that infestation is usually evident.
The damage done is usually not evident until the timber has been split or planed. Although, damage can sometimes be seen when larvae tunnel near the surface of the wood. Additionally, blistering may occur when frass (excrement and wood dust) has been packed into the tunnels.
EHB has been found mainly in living trees with dried out branch stubs and damaged branches and trunks, dead trees and logs. In structural timbers, EHB most often infests roofs, but is also known to infest architraves, door frames and timber articles such as pine furniture.
If allowed to go unrestricted, the consequences of EHB infestation can be devastating. The previous EHB Response Program occuring 2004-11 achieved significant progress in decreasing EHB populations. A number of management strategies is available.