Approval has been given to Horizons Regional Council to bring in the Australian bud-galling wasp (Trichilogaster acaciaelongifoliae).
Approval has been given to Horizons Regional Council to bring in the Australian bud-galling wasp (Trichilogaster acaciaelongifoliae).
The devastating impact of an invasive Australian wattle on the coast from Whanganui to Horowhenua was the driving factor in getting approval for a foreign wasp to be introduced.
The Environmental Protection Authority (EPA) has this week given Horizons Regional Council approval to bring in the Australian bud-galling wasp, which lays its eggs in the flower bud of the invasive Sydney golden wattle.
From there the eggs induce abnormal growths known as galls, which prevents flowers and seeds being produced.
Horizons’ biodiversity and biosecurity manager Craig Davey said they will be able to make use of the wasp shortly.
“This friendly wasp has no bite or sting and has already been through rigorous testing in South Africa and Portugal before the respective countries successfully released the wasp to control Sydney golden wattle.
“The process of utilising the wasp to control golden wattle takes some time, but will dramatically reduce spread and allow for a more natural transition to resilient native plant dominated dunes.”
Davey said the application received strong support from coastal communities.
“We’d like to thank those that took the time to submit in support of the application. These, alongside the scientific research, helped get the release of the wasp over the line.”
Davey said golden wattle (Acacia longifolia) - also referred to as acacia - had serious negative impacts on the local environment.
The Sydney golden wattle was preventing growth of native species and creating what is known as a mono-culture, meaning that only it can thrive. Photo / Supplied
“It suffocates other native species, preventing their growth to create what is known as a mono-culture meaning that only the golden wattle can thrive.”
Coastal communities had been the motivating factor behind securing the wasp, he said.
“They’ve experienced first-hand the devastating impacts on dunes with the golden wattle covering coastlines from Whanganui to Waikawa.
“Others are likely familiar with the plant, especially in places like Himatangi Beach where the infestation covers most of the dunes, although they may not realise it’s a pest.”
Horizons applied for the approval and release of the wasp (Trichilogaster acaciaelongifoliae) on behalf of the National Biocontrol Collective, a group of regional and district councils from across New Zealand and the Department of Conservation (DoC).
The EPA said it would allow the wasp to be introduced after finding it “highly unlikely” it could harm any native species.
“The wasp, which is only a few millimetres long, does not sting or bite and there is no risk to human health,” the EPA said.
Dr Chris Hill, EPA’s general manager of hazardous substances and new organisms, described the wasp as “quite docile, and only active for a few weeks a year”.
An example of the abnormal growths (galls) on wattle flower buds. Photo / Supplied
“They prefer to remain near the host plant, further reducing any possible risk to our native plants and animals.”
The wattle is native to Australia and is a fast growing small tree that was introduced to New Zealand as an ornamental. It became naturalised before 1897.
Hill said risk assessments found that by introducing the wasp, they could reduce reliance on chemical pesticides.
“This will in turn reduce fire hazards, increase water availability and attract native animals.”
The EPA publicly consulted on the wasp application and received 49 submissions, with 31 submissions in support, 16 opposed, and two neutral.
