18 December 2025 Yellow-legged hornet won't be the last: The importance of bioprotection

Dr Mateus Detoni doesn’t think so. He’s a lecturer at Lincoln University and has spent years studying the behaviour of social wasps. He believes investment in biosecurity is key to keeping our ecosystems safe going forward.

Social wasps, like the hornet, have an instinctual mission to spread out and start new colonies, often introducing themselves to new and vulnerable ecosystems.

The yellow-legged hornet did exactly that earlier this year, and its diet poses a problem for our food growers. The yellow-legged hornet is a predator to pollinators, including the honeybee. The situation has many food industries across New Zealand worried.

“In New Zealand, honeybees are used as generalist pollinators for a lot of different crops,” Mateus said. “Food growers rely on honeybees to grow their crops, and that’s part of what we eat or buy in the supermarket.”

“In the worst-case scenario, a large-scale invasion could affect our day-to-day life.

“What we need to do is react quickly. There’s no need to panic, but if you do see something, report it.”

Mateus believes it’s possible for us to eradicate the hornet with our current response methods, or at least contain it.

But securing our biosecurity doesn’t stop with this hornet, nor does it end at New Zealand borders.

Social wasps reproduce using a queen, which is capable of creating an entire new colony all by itself. After mating, a young queen will leave the colony and find somewhere to hibernate. They can hide in very small places, including furniture or export crops, sometimes unknowingly travelling on commercial ships or airplanes.

“It’s not necessarily that our biosecurity system is lacking, more that it’s very, very difficult to find a single insect which can start a whole new population by itself.”

That means we need to invest in predicting which species are potential invasion threats and work on reducing the risk of these species making it here in the first place.

“We need to be able to predict which species are potential invaders, and we need to invest as many resources as possible into controlling existing populations. Not just in New Zealand, but in our neighbouring countries as well.

“They’re a potential source for these invaders and don’t always have the same resources we do to deal with these alien predators.

“This is not the last time we’ll hear about something like this. They’ll keep coming.”

In the meantime, it’s important we keep on top of the yellow-legged hornet. Any sightings should be reported to the Ministry for Primary Industries. You can report sightings here.

Interested in keeping our ecosystems safe? Check out our new Master of Bioprotection.