About the pest
European house borer (EHB) Hylotrupes bajulus Linnaeus is a destructive pest of seasoned coniferous timber including pine, fir and spruce. If allowed to become established it can cause major structural damage to buildings.
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 manufactured articles derived from pine timber.
EHB adult beetles emerge from September to April during flight season. They can live from a few days up to three weeks.
The damage is done by EHB larvae that hatch from the eggs. EHB can live in its larval state for 2-12 years before it matures and emerges from the timber as an adult beetle, to begin the life cycle again. It is only when 2-3 generations have infested the same piece of wood that serious structural damage can result.
In the hot temperate climate of Perth Western Australia, research shows the larvae life cycle to be closer to 2-5 years. The pest is able to live in a wide variety of climatic conditions however it prefers temperate habitats.
Main timbers in use in WA likely to be affected are:
- Pine (Pinus spp)
- Oregon (Douglas fir – Pseudotsuga spp).
Timber manufactured articles (including sawn timbers, structural and non-structural timber, boxes, crates and pallets) are less susceptible to damage when treated with suitable preservative chemicals.
EHB has become a serious pest of seasoned softwood timbers in all countries where it is established.
History
EHB was first discovered in Europe – hence the name European house borer. The pest has since been found in the Middle East (Turkey), South and North Africa, South and North America, USA, China and Asia Minor. EHB probably made its way into WA in a piece of imported timber as larvae.
In South Africa, EHB was first discovered in pine plantations before infesting structural pine in houses and buildings. About 90 per cent of house roofs in suburbs adjacent to these plantations became infested, which resulted in large scale collapse.
EHB has been detected several times in Eastern Australia but those infestations were eradicated by fumigation. Eastern Australia did not have the problem of large scale infestation in pine trees and dead wood material.
The first WA discovery of EHB was made in 2004.
Where in Western Australia has EHB been found?
In WA, a single female EHB was found in 2004, emerging from a structural untreated beam in a Perth house.
Surveillance has found EHB populations mainly in dead pine trees and deadwood parts of live pine trees.
Community awareness to look for signs of EHB activity in household furniture has confirmed a limited number of EHB infestations.
Map of EHB Restricted Movement Zones (RMZs) which act as buffers around sites where infestations have occured may be viewed to check your particular suburb (the majority of these sites have been disinfested but remain as RMZs).
EHB Response Program 2004-11
Following the detection of EHB in 2004, action was taken to determine the extent of the pest and how to tackle the infestation. This included an assessment of 12 000 sites throughout greater metropolitan Perth and the south-west.
The Government of Western Australia initiated an Emergency Plant Pest Response Plan, which focused on surveillance and containment of the pest, while extensive research, cost benefit analyses and regulatory impact assessments were conducted.
To support EHB surveillance, containment and eradication efforts, the Agriculture and Related Resources Protection (European House Borer) Regulations 2006 were gazetted to establish buffer zones around sites of EHB infestation. These are called Restricted Movement Zones (RMZs).
The regulations outlined restrictions on the movement, storage, treatment and disposal of untreated pinewood located in PMZs and RMZs areas.
In 2011, a transition from EHB eradication to containment and management occurred. The EHB eradication efforts and research undertaken since 2004 will continue to ensure effective EHB management and control in the future.
Current containment program
The EHB containment program established at the conclusion of the eradication program focuses on surveillance and regulatory activities to support the identification and localised eradication of EHB infestations in RMZs outside of pine plantations.
The EHB containment program focus on:
- supporting adherence to EHB regulations under ARRPA State-wide communication activities to ensure awareness of EHB
- intensive surveillance of potential host pine trees in Perth affected suburbs
- emphasis on management strategies to support the community in reducing EHB spread and infestation. Negotiation with landowners to disinfest EHB infestations
- education of business and landowners to prevent EHB infestation and minimise further EHB spread by human movement of pinewood articles
- EHB training for pest controllers available through Challenger Institute of Technology, to ensure inspectors will be a valuable source of information and assistance for home owners concerned about EHB infestation
- negotiations with local governments to seek their continued involvement in EHB education and other related issues.
There will also be consultation with other key stakeholders, such as the housing and timber industries, to discuss effective management strategies to deal with EHB in the future.
Information on any new EHB management arrangements will be made available on this website.
Pest potential
EHB has been very destructive in countries where the pest is established.
Following discovery of EHB in 2004, climate modelling showed all of southern WA was at risk, south of a line from Carnarvon to Ceduna. Without action, it was estimated the borer would spread to infest this entire area by 2040.
Subsequent research confirmed that EHB eggs, larvae and beetles could survive in Perth's high summer roof temperatures.
The main threat is homes located close to infested pine trees, as research has shown adult beetles can fly up to 1-2km in search of host material. While an adult beetle will usually only travel after its food source has been exhausted (which could take 10-20 years), some long distance travel has been evident.
DNA testing shows original EHB populations may have migrated from the hills region to Gnangara, which could have resulted from EHB beetles being carried on prevailing easterly and south-easterly winds in Perth summers. The presence of infested pine tree host bridges between two areas may also result in migration.
Additionally, EHB have been known to 'hitch-hike' on vehicles transporting untreated pinewood during the flight season, which poses a threat even to homes not close to infested areas.
The positive news is that EHB has a long lifecycle of 2-5 years (12 at the most), which is believed to be insufficient time for the first generation borer to cause significant structural damage. Significant EHB damage will usually occur when an adult beetle lays eggs in the piece of timber from which it emerged, resulting in 2-3 generations of destructive tunnelling.
In South Africa, it took 20-25 years of EHB infestation for structural collapse to occur. If EHB can be detected in its first generation of infestation, this situation can be avoided in WA.
The EHB Program has developed a number of management strategies to ensure infestation is discovered and eradicated early so spread and damage is minimised.