Biosecurity efforts to eradicate yellow-legged hornets and Queensland fruit flies have intensified. Should either pest establish itself in New Zealand, there could be major economic costs to the horticultural industry and population impacts for bees and other native species.
Eradication efforts of the yellow-legged hornet started in mid-October 2025 after the pest was first detected on Auckland’s North Shore. Queensland fruit fly efforts have been ongoing since 2019, when male flies were detected in surveillance traps.
“There have been 13 incursions of different fruit flies in Auckland and Northland since 1996, and all have been successfully eradicated thanks to the work of Biosecurity New Zealand, our horticulture partners, and local communities who have stepped up to help,” Mike Inglis, Biosecurity New Zealand Commissioner North, says.
He says this experience has formed detailed operational plans to hone work over time. And that work continues in Mt Roskill. Extra traps are in place, fruit testing is underway, and the Commissioner says there has been great community engagement.
“Successfully eradicating this pest depends significantly on support from the local community,” he says. “Our team continues its work on the ground, checking traps, slicing and examining fruit, picking up waste from bins in the area for safe disposal, and talking to the local community.”
Installing signs, sharing information with the community, and collecting and inspecting evidence are also important elements of the biosecurity response.
Biosecurity New Zealand has also imposed legal restrictions on the movement of fruit and vegetables out of the area where the fruit fly was found.
“You may notice increased activity in the neighbourhood as we go about inspections and trapping. Our field officers may ask to look at fruit trees on your property. They will always show you a form of official identification and will only enter your property with your permission.”
As for hornet control, eradication efforts continue to ramp up. “We’re laser focused on our work to eradicate this hornet, guided by international best practice and expert advice,” the Commissioner says.
October marked the first time a queen yellow-legged hornet was found in New Zealand. “We responded quickly to this threat, but we need the public’s help to eliminate any further risk.”
Genetic testing indicates the hornets are closely related, suggesting a small, contained population.
The yellow-legged hornet is a highly adaptable predator with a broad diet, primarily feeding on bees, wasps and flies. It also enjoys ripe fruit and flower nectar, which poses a risk to growers. The hornet, which has a painful sting, might also compete with native insects and birds for food.
“New Zealand is fortunate to be free of hornet populations, and we want it to stay that way.”
New Zealand has among the strictest controls in the world for fruit importation and border checks. The most likely way that fruit flies can enter the country is on fresh fruit and vegetables.
Don’t try to remove or control a suspected hornet nest yourself, and don’t spray hornets or nests with insecticide.
It’s crucial that Biosecurity New Zealand knows exactly where hornets are active. Trying to deal with them on your own can scare them off and make them much harder to locate.
To report suspected finds of fruit flies and hornets, call MPI’s Pest and Diseases Hotline on 0800 809 966.
For further information and general enquiries, call MPI on 0800 008 333 or email info@mpi.govt.nz.
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