The Environmental Protection Authority has given the green-light to the use of a predator to fight any invasion by the brown marmorated stink bug.
Stink bug (Eocanthecona furcellata) on green leaves. Photo: 123RF
The bug poses one of the highest biosecurity threats to New Zealand and it's estimated that if it took hold in this country it would devastate the fruit, vegetable and wine industries, destroying more than $4 billion of exports and costing thousands of jobs.
The stink bugs, which originate in Asia, have been detected entering this country from time to time, with the most recent incursion found on three car carriers that arrived at the Port of Auckland earlier this year.
The EPA has approved the use of the Samurai wasp, but only if an incursion by the brown stink bug has been detected.
New Zealand winegrowers biosecurity manager and emergency response manager, Dr Edwin Massey, who is also a member of the Brown Marmorated Stink Bug Council said the samurai wasp is both a surveillance and control tool.
He said it hunts out the egg-masses of brown marmorated stink bugs (BMSB) and lays its eggs inside them and as the wasps larvae hatches it eats the egg from the inside.
Dr Massey supports the decision by the EPA to only introduce the wasp after a stink bug invasion has been detected.
"The wasp favours brown marmorated stink bug eggs over any other stink bug egg, so releasing it only when there is a stink bug incursion is exactly the right thing to do."
The Samurai wasp is the size of a sesame seed.
"It doesn't sting or harm humans or other wildlife."
Dr Massey said host-testing showed the wasp tends to parasitise BMSB eggs over the eggs of any other species given the choice.
Once the wasp is released it will be here to stay, he said.
"If it was to establish permanently in New Zealand there would be no feasible way to eradicate it."
Dr Massey said all is being done to prepare the ability to respond to an incursion.
"MPI are certainly doing a great job in strengthening up controls pre-border and post-border."
Dr Massey said the risk of an incursion is getting higher by the day.
"The populations are expanding overseas and because of its hitch-hiking nature we get more and more interactions with it at the border each year.
"It's important that we are ready as we can be for an incursion," he said.
Dr Massey says scientists still need to do a lot more work before the wasp is ready to be used."
"It's not a silver bullet."
The wasps first have to be sourced from overseas, reared and then a readiness plan for how it would be used needs to be developed.