EHB Surveillance Activities
EHB Response surveillance crews are undertaking extensive surveys in the Perth Metropolitan area to determine the spread of EHB.
Originally, dead pine trees in approximately 1200 sites throughout the greater Perth metropolitan area and the South-West were surveyed.
As of August 2009, staff commenced their 5th annual delimiting survey, driving every street from Geraldton to Esperance in the search for EHB, as well as continuing doorknock surveys of residences within two kilometres of every confirmed infestation (Restricted Movement Zones -RMZ).
All businesses within RMZs that are involved in the movement of pinewood are also being visited. Where appropriate, business risk assessments are being undertaken to develop Risk Management Plans, to assist businesses prevent the spread of EHB through the movement of untreated pinewood. Further information on pine movement restrictions can be obtained from the Pine Movement Regulations brochure.
The current phase of surveillance includes targetted roof inspections in Ellenbrook. This suburb was chosen due to its proximity to the heavily EHB infested Gnangara pine plantation, and the large percentage of Ellenbrook homes built with untreated structural pine. As a result, Ellenbrook is a high risk suburb, and EHB is more likely to be found in Ellenbrook housing than in most other Perth suburbs.
Other surveillance has included the placement of trap poles to measure the existing population density and identify areas of concentrated pest activity.
As of August 2009, horizontal trap poles which have been in the field for two or more seasons are being removed for assessment of EHB infestation. This is the first large scale removal of trap poles to be undertaken as part of the EHB Response. Data from evaluation of the poles will be available in 12 months.
In the meantime, a new trap pole grid is being developed to replace the trap poles currently being extracted and assessed. New trap poles in the Priority Management Zones that have been cleared of all EHB host material will help to establish if EHB has been officially eradicated from these areas. As of August 2009, some 50% of the 94 PMZs had been cleared. Cleared areas must remain ‘EHB free’ for a period of six years before eradication can be verified.
In the first phase of the EHB program, EHB detections were limited to just 27 properties in 10 outer Perth suburbs. Surveys as of August 2009 have now confirmed 152 findings in 52 suburbs.
EHB infestations have been confined to the greater Perth Metropolitan area, except for one confirmed find in Albany. There have not been any discoveries in the main softwood plantations and private plantations in the South West.
Parts of the Gnangara and Mundaring pine plantations have been infested, predominantly in dead standing pine trees. Infestation in the Peel pine plantation has also been confirmed.
As of August 2009, there has been one confirmed structural find of EHB in a home that is the result of EHB migrating from nearby infested pine trees. This occurred in a house in Brigadoon. EHB has also been detected in house beams in Parkerville and Beechina, where infestation of the structural timber occurred prior to the timber being installed.
Additionally, EHB has been discovered in timber stored in an Albany shed, which before detection was used in the construction of a house on the same property. This untreated pine originates from a Perth timber yard located in an EHB infested area. This situation highlights how easily EHB can be spread from one area to another, and how EHB can make its way into a residential home. It is for this reason that restrictions now apply to the movement of untreated pine in and out of EHB infested areas.
New Surveillance Methods
The Department of Agriculture and Food embarked on a world first when it enlisted the help of two detector dogs to target EHB. The dogs underwent specialised training to detect EHB larvae or adults within pinewood, such as dead parts of pine trees, seasoned pine and untreated pine timber located in pine plantations, at businesses and on private property. The dogs will make detection of the pest quicker by being able to detect EHB in the pine trap poles placed in affected areas.
As part of the EHB research and development program, five prototypes of an EHB acoustic sensing device have been completed by engineers from Edith Cowan University and supplied to the EHB research team for testing. The devices have been developed to monitor trap poles in the field for EHB chewing sounds, which can then be transmitted back to computers at South Perth. Laboratory tests are being undertaken to determine effectiveness in various situations, such as detecting different EHB larvae sizes, distance from the microphone, distinguishing between other borer sounds and successful transmission.
Research is also continuing to refine a DNA test for EHB using the frass produced by wood boring larvae. Where wood borer galleries have been found but beetles and larvae are not present, the test will enable researchers to extract DNA from frass to determine if the holes have been made by EHB. Given that other wood boring beetles, such as the jewel beetle, create similar galleries filled with frass, the test will play an important role in EHB confirmation, particularly when assessing trap poles removed from the field for evaluation.