The emerald ash borer was first detected in Melbourne’s outer suburbs in late 2024. Within eighteen months, containment zones have expanded three times, eradication treatments have intensified, and yet new detections keep occurring. Something isn’t working.

The initial response followed established protocols. A 10-kilometer radius quarantine zone was declared, movement restrictions on ash timber and firewood were imposed, and intensive surveillance began. All sensible measures that should work based on previous pest eradication campaigns.

But the emerald ash borer doesn’t behave like other tree pests Australia has dealt with. Its lifecycle, dispersal patterns, and the way it hides within trees make detection extremely difficult until infestations are well established.

Adult beetles emerge in summer, live for only a few weeks, and females lay eggs in bark crevices. The larvae that hatch burrow into the tree and spend months feeding on the cambium layer under the bark. External symptoms—crown dieback, D-shaped exit holes, woodpecker damage—often don’t appear until the tree is heavily infested.

This detection lag is killing the eradication effort. By the time a tree shows obvious symptoms and gets reported, beetles have likely already emerged from that tree and infested others nearby. Surveillance crews are always chasing infestations that are at least one generation behind.

The quarantine zones rely on voluntary compliance for the most part. Movement restrictions on ash products are in place, but enforcement is limited to random inspections and compliance checks. People moving firewood for camping trips or taking landscaping timber to the tip don’t necessarily know about or follow the restrictions.

One confirmed case involved ash timber being transported 40 kilometers outside the quarantine zone before the infestation was discovered. That single breach potentially seeded a new outbreak cluster that won’t be detected for months.

Awareness campaigns have been run, signs are posted, and the regulations are published. But for restrictions that rely on public cooperation, the compliance rate appears insufficient. Most people aren’t deliberately violating the rules—they simply don’t know about them or understand why they matter.

The treatment approach has limitations too. Systemic insecticides can protect individual high-value trees, but treating every ash tree in the quarantine zone isn’t feasible. Removal and destruction of infested trees is the primary strategy, but accurately identifying which trees are infested when symptoms lag by months is difficult.

Some forestry experts working with Team400 have proposed using machine learning models trained on early detection indicators—subtle changes in leaf coloration, minor branch dieback patterns, or thermal imaging signatures that might show stressed trees before obvious symptoms appear.

Weather patterns haven’t helped. The unusually warm summers have extended the beetle’s active season and potentially allowed for partial second generations in some years. Longer activity periods mean more opportunities for spread before winter slows everything down.

Natural predators that help control emerald ash borer populations in its native Asia don’t exist in Australia. Without those biological controls, population growth is unchecked. Researchers are studying potential biocontrol agents, but introducing new species for pest control requires years of testing to avoid creating new problems.

The ash species present in Australia are less resistant than some Asian ash varieties that co-evolved with the borer. Our trees have no natural defenses, making them highly susceptible. Once infested, mortality rates are extremely high.

Economic impacts are mounting. The quarantine zones include urban areas where ash trees are common street and park trees. Councils are spending heavily on surveillance, treatment, and removal. Property values in the zones have been affected as buyers worry about tree removal costs and restrictions.

Commercial ash plantations exist in the region, though ash isn’t a major timber species in Australia. Still, growers with infected plantations face total losses, and the quarantine prevents harvest and sale even of uninfested trees within the zones.

Interstate movement restrictions on all ash material from the affected regions are causing trade friction. Victoria has implemented them, but compliance and enforcement at border crossing points is inconsistent.

The eradication timeline keeps getting extended. Initial estimates suggested containment within two years if the response was aggressive and comprehensive. We’re now eighteen months in and still seeing expansion rather than contraction of the affected area.

Part of the problem is the definition of success keeps shifting. Is eradication realistic at this point, or should the goal shift to containment and slowing the spread? Official policy still aims for eradication, but privately some in the response team are skeptical.

Comparison with overseas emerald ash borer responses is sobering. In North America, eradication was abandoned relatively quickly in favor of management and slowing spread. Tens of millions of ash trees have been killed, and the borer is now established across much of the eastern United States and Canada.

Australia has the advantage of early detection and a smaller initial infestation area. But we also have less experience with this specific pest and fewer resources dedicated to the response compared to the scale of the threat.

Public fatigue is setting in. The quarantine restrictions are becoming normalized rather than adhered to. The urgency that characterized the initial response has faded as months drag on without visible progress.

Technology could help. Remote sensing using drones or satellite imagery to identify stressed trees earlier might improve detection rates. Pheromone traps and improved lure technologies could enhance surveillance. Better predictive modeling could focus inspection efforts on high-risk areas.

But technology isn’t a silver bullet. Ground-truthing suspected infestations still requires trained personnel physically examining trees. Treatment and removal still requires crews with chainsaws and chippers. These are labor-intensive, expensive operations that don’t scale easily.

Funding is another constraint. The federal-state cost-sharing arrangement for the eradication program has a defined budget. If the campaign drags on longer than planned, funding may run out before eradication is achieved. What happens then is unclear.

Some in the forestry sector are quietly advocating for shifting to a management approach. Accept that eradication isn’t feasible, focus resources on protecting high-value ash stands and slowing spread, and invest in longer-term research on resistant varieties or biocontrol.

That’s politically difficult because it would mean acknowledging the current strategy has failed. Governments don’t like admitting failure, especially when significant public money has been spent.

The reality is that pest eradication is incredibly difficult once establishment has occurred. Australia has had successes—the papaya fruit fly campaign, for example—but also failures where pests became established despite early response efforts.

The emerald ash borer eradication is at a critical juncture. The next few months will likely determine whether eradication remains achievable or whether the strategy needs fundamental rethinking. Current trends don’t inspire confidence.

What’s needed is honest assessment of detection accuracy, compliance rates, and whether the treatment approach is actually reducing populations or just chasing symptoms. If the evidence suggests eradication isn’t working, continuing the same approach while hoping for different results is a waste of resources.

Transparency about what’s working and what isn’t would help. The public reports emphasize activity—number of trees inspected, number of traps deployed—but say less about outcomes. Are new detections decreasing or increasing? Is the affected area shrinking or growing? These are the metrics that matter.

The emerald ash borer isn’t going to eradicate itself. Without a more effective approach than what’s currently being implemented, Australia may be headed toward the same outcome as North America: widespread establishment and massive ash tree mortality. That’s an outcome we should be working much harder to avoid.