WA is trying to dodge an invasive bullet

Feral Herald |

In August 2021, a member of the public noticed some troubling symptoms on their maple tree in East Fremantle, WA, reporting signs of tree dieback and dead branches.

Follow-up inspections by state government officials confirmed the symptoms were caused by insects called polyphagus shot-hole borers.

The perfect invader

These tiny beetles are less than 2mm long and native to Southeast Asia. Their proper name is quite a mouthful, so we like to refer to them as “bullet beetles”.

Their distinctive impacts are the tiny tunnels they bore into trees to lay eggs in, leaving the tree looking like it is covered in bullet holes no bigger than the tip of a ballpoint pen.

An adult female polyphagous shot-hole borer or bullet beetle next to a 5 cent coin resting on an infected piece of maple tree. Overlay of an adult female beetle. Photos by: DPIRD.

Acting as a fungus farmer, the beetles carry around fungal spores in a special pouch in their mouthpart that they sow inside their tunnels. These spores then grow to become food for their young. One of the fungal species carried by the beetle causes wilting, die-back and eventually death in host trees.

They probably entered Australia via untreated wooden products or shipping materials, and have since been hitching rides around Perth and Fremantle on untreated garden waste and firewood. The WA Government’s outbreak webpage has now documented 139 confirmed infested premises across the regions as of June this year.

The big question mark now is just how big of an impact these borers could have on Australia’s environment. We already know they can infect hundreds of different tree species globally, including many regulars found in Australian gardens and farms. But there is also evidence they can infect many of our native trees like paperbarks, eucalypts and native figs, and woody plants like acacias.

They are also considered perfect invaders thanks to the ability of female bullet beetles to establish brand new colonies without mating. The fungus she carries guarantees food supply for her offspring.

Billions in damage

A quick check of what bullet beetles have done to similar ecosystems in countries like South Africa should be all we need to hear to take their arrival into Australia seriously.

Polyphagous shot-hole borers were introduced to South Africa in 2012, and have since spread to become the largest outbreak of the pest in any country.

A recent study estimates South Africa is now facing a bill of up to $18.45 billion over the next 10 years to cover the economic impacts caused by bullet beetles. Part of that cost will involve removing and safely disposing of around 65 million urban trees.

One of the symptoms of infection is discolouration in the wood of infected trees caused by the fungus the beetle has a symbiotic relationship with. DPIRD.

Similar stories have come out of Israel and the US after bullet beetles were detected in both countries in 2009 and 2012, respectively.

The most concerning part? While control activities are ongoing, there is no record of a successful eradication anywhere in the world, and there aren’t any established eradication methodologies.

Australia’s response in WA aims to break that record, and we’re optimistic it will be successful. Unlike other countries that have stared down the barrel of invading bullet beetles, this will be the first time a concerted early eradication effort of the pest has ever been attempted.

The current situation in Australia

The good news is that bullet beetles can only disperse a short distance on their own wing, sometimes using a little help from prevailing winds. Larger dispersal distances seen here in Australia and overseas can all be attributed to people moving infected wood. Stopping their spread is therefore a matter of stopping the unsafe movement of untreated wood from infected regions.

That’s why the WA Government has now implemented a quarantine area preventing the removal of wood above a certain size from 21 local government areas in and around Perth. A regularly updated map of the quarantine area and details of quarantine restrictions are currently available here.

The WA Government has sought a national response through the Consultative Committee on Emergency Plant Pests (CCEPP), which is putting in place a phased, three-year plan aiming to eradicate the pest. We commend the national response coordinated by the WA Government and its desire to pursue eradication of a pest that has the potential to be one of Australia’s most problematic emerging invasive species.

Unfortunately, the response was slower than it needed to be given the massive implications for Australia’s unique flora but, finally, there is now sufficient resolve to treat the issue seriously.

We will continue to closely monitor the situation to ensure the state government provides the support and resources necessary to give eradication plans every chance at succeeding.

Polyphagous shot-hole borers have an unknown potential to cause widespread damage to native Australian forest trees. If eradication is possible, we need to achieve it. We can’t let these bullet beetles loose on Australia’s trees.

The current situation in Australia

If you live in or near the current quarantine area, see the WA Government’s reporting advice below:

Residents who suspect they have borer damage to trees should make a report to the WA Department of Primary Industries & Regional Development (DPIRD) through the Pest and Disease Information Service on 9368 3080 or via the department’s MyPestGuide™ Reporter app (available on the Google Play Store and Apple iTunes Store), or email padis@dpird.wa.gov.au.

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Help protect NSW!

Our expert team has written a list of policy asks detailing exactly what the next NSW government needs to do to stamp out some of the worst invasive species impacts across the state. But they will only become a reality if every key political candidate at the 2023 NSW state election hears about it from you!

Dear National Deer Management Coordinator,

Please accept this as a submission to the National Feral Deer Action Plan.

[Your personalised message will appear here] 

I am very concerned about the spread of deer and am pleased that a national plan has finally been developed. Without urgent action, funding and commitment from all levels of government it is clear that feral deer will continue to spread and damage our environment.

The feral deer population in Australia is growing rapidly and spreading across the country, damaging our natural environment, causing havoc for farmers and foresters and threatening public safety. Unlike much of the world where deer are native, our plants and wildlife haven’t evolved to deal with these heavy hard hooved animals with a voracious appetite.
With no natural predators and an ability to adapt to almost all environments, they could occupy almost all of Australia unless stopped. Despite this, state and territory governments have been slow to respond and in Victoria and Tasmania they are still protected by law for the enjoyment of hunters.

This plan should be adopted by all governments but must also be underpinned by dedicated funding and clear responsibilities. A plan without funding or accountability is a plan that will fail and Australia cannot afford for this to fail.

In order to prevent the spread of feral deer and reduce their impact on our native wildlife, ecosystems and agriculture, I ask that the following recommendations be adopted for the final National Feral Deer Action Plan:

1. All federal, state and territory governments should adopt the National Feral Deer Action Plan and declare feral deer to be a priority pest animal species.

2. All federal, state and territory governments should commit to:

  • Contain deer to the existing large population areas.
  • Reduce and eradicate smaller and isolated populations.
  • Protect important environmental assets such as world and national heritage areas.
  • Develop and fund regional plans and strategies to manage deer populations which involve land managers across all tenures.

3. In order to drive action and the success of this plan, there should be dedicated Commonwealth funding and support for:

  • A permanent national feral deer coordinator position.
  • A permanent federal feral deer action committee with representatives from the commonwealth and state and territory governments and the environmental and agricultural sectors.
  • An ongoing public education campaign on feral deer.
  • A network of regional feral deer coordinators to drive local action across tenures.

4. The expected outcomes for the plan need to be more ambitious, with clear interim targets including:

  • Within one year, all States and Territories should have in place arrangements to implement the National Feral Deer Action Plan, including allocating dedicated funding for implementation.
  • Within one year, feral deer management plans should be developed for key environmental assets of national significance, including the Tasmanian Wilderness World Heritage Area, the Greater Blue Mountains, the Australian Alps, the Gondwana Rainforests and the Wet Tropics of Queensland.
  • Within five years coordinated landscape scale management should be in place where land owners, land managers, government and community are demonstrably working together.

5. A national feral deer containment map with three zones should be adopted. It should be more ambitious than the zone map in the current draft plan and there should be greater clarity in the naming of the zones. Improvements that should be adopted include:

  • Renaming the zones to better reflect the management intention to ‘Containment Zone 1’ (the current large population zone), ‘Containment Buffer Zone 2’ (the current buffer zone) and ‘Eradication and prevention Zone 3’ (the current small isolated population zone).
  • The NSW northern rivers area should be in the eradication and prevention zone as there are few feral deer currently in this region and eradicating isolated populations and preventing spread into this area is still possible.
  • The whole of South Australia should be in the eradication and prevention zone as eradication is the goal of the SA Government.
  • The Tasmanian region in the containment zone should be smaller to reflect greater ambition and potential for eradication of deer populations.
  • In eastern Victoria areas such as Wilson’s Promontory, Westernport islands and the Mornington Peninsula should be in the eradication and prevention zone.

6. There should be consistent laws and regulations across all states and territories that:

  • Recognise feral deer as a pest animal and treat them as such.
  • Establish a clear responsibility for all landholders and managers to be involved in feral deer control programs.
  • Set clear penalties to stop the wilful or negligent release of feral deer.
  • Prevent new deer farms in areas where no feral deer are present and phase out all deer farms in the eradication and prevention zone.
  • Enable enforcement of compliance, including on government land.

I support the follow principles being adopted in the final National Feral Deer Action Plan:

  • Feral deer are a pest and should be treated as such on all tenures, except on approved deer farms.
  • Federal, state and territory governments have a responsibility to fund the outcomes under this plan.
  • All land managers in areas where feral deer are present have a responsibility to be involved in feral deer control programs.
  • The focus of management efforts should be on eradication of isolated, satellite populations, protection of key environmental assets currently impacted and stopping the spread to new regions.
  • Feral deer control should be undertaken humanely, safely and professionally according to agreed protocols and all tools which meet this criteria should be adopted, including aerial control.
  • Funding for coordination, regional planning and community engagement is necessary for effective feral deer management.
  • Ongoing management and follow up control efforts are required to achieve long lasting results.
  • Rules and regulations should be consistent across jurisdictions and land tenures.
  • Recreational hunting is not an effective strategy for feral deer control and should not be relied upon.
[Your name]
[Your email address]
[Your suburb], [Your state]