Need for Science Investment Reset
OPINION: New Zealand's prosperity has always been built on farmers and scientists working together to shape our economy.
To understand whether plant disease-causing fungi are being moved this way, scientists from the Bioeconomy Science Institute are identifying the species being carried on beetles found in Kiwi forests and orchards.
Darryl Herron, task lead on the project says that while much is known about the beetles, less is known about the fungi travelling with them.
Since 2024, researchers across the Bioeconomy Science Institute, including teams from Lincoln, Rotorua, Ruakura, Auckland, and Motueka, have collaborated to trap bark and ambrosia beetles across the country and analyse the fungi they carry, through projects funded by Better Border Biosecurity and Zespri.
The work has revealed a broad range of fungi associates linked to native and introduced beetle species.
While most of these fungi are common plant associates, the team has detected species with the potential to disrupt plantation forestry, horticulture and native ecosystems if conditions change or new beetle species arrive.
The work includes assessing potential risks to native bush, urban environments and botanical collections and monitoring beetle activity in and around orchards, where new associations and increased aggressiveness in the beetle-fungal system could pose future threats.
Bark and ambrosia beetles tunnel into trees and interact with fungi in different ways. The latter carry and cultivate specific fungi, while the former pick up a more mixed assortment. Together, they’re associated with a wide range of woody plants across plantation forests, orchards, urban areas and the native estate. Their rapid breeding ability means beetle numbers can rise quickly – so their fungal passengers are never short of taxis.
Herron says it's often these fungi that cause the greatest harm.
"Some fungal species block a tree's ability to move water and nutrients, weaken natural defences or accelerate disease, particularly when trees are already stressed by drought, age or harvesting activity," he says.
"By identifying these fungal 'passengers', we're building a clearer picture of the microscopic communities being moved across New Zealand and which beetles are more important to focus on from a biosecurity perspective. This helps us assess whether these beetles have the potential to facilitate the movement of fungi not currently established in New Zealand."
Overseas, certain beetle–fungus partnerships have caused extensive forest dieback.
Herron says the focus of the research is to understand what risks exist in New Zealand before those impacts occur.
"If we know which beetles can carry damaging fungi and where they’re moving, we can respond faster and reduce the risk to forests and export markets," he says.
The research also contributes valuable information to national surveillance efforts led by the Ministry for Primary Industries (MPI) and industry partners, including the Forest Owners Association, alongside other research programmes. Understanding fungal diversity being carried on these tiny beetle taxis could help refine risk modelling tools, guiding where and how surveillance and monitoring is most effective and strengthening post‑border surveillance.
Together, these investments support New Zealand’s ability to stay ahead of emerging biosecurity risk, helping protect forests, horticulture and ecosystems and the industries and communities that depend on them.
“Maintaining strong biosecurity pathways is critical for protecting plantation forestry and export markets,” Herron concludes.
