What to do about Gazanias

By Susanne Govella, Greater Wellington Regional Council

The pest plant biosecurity team in Wellington are quite excited about a control trial of Gazania spp. we will be carrying out on Wellington’s west coast during this coming season.

Gazania linearis and G. rigens are two species of garden plants commonly sold in New Zealand and Australia. The bright colours of their flower heads along with their ability to tolerate dry conditions and poor soils have made them popular among gardeners.

Gazanias are native to South Africa where they can be found from low altitude sandy soils to alpine meadows. Species of Gazania hybridise freely when possible, making identification of any Gazania challenging.

Outside their natural range, Gazanias are known to invade agricultural areas and roadsides and can rapidly out-compete native plants, leading to a decline in biodiversity. Their tolerance of dry conditions and poor soils means that Gazanias pose a significant risk to coastal plant communities in New Zealand. It is for this reason that Gazanias have been classified as a “red alert” species in several coastal management plants both in New Zealand and Australia.

The recommended control option for control of Gazanias has typically involved using the herbicide glyphosate, however the efficiency of this control option has now been questioned following a failed control operation in 2011 on Wellington’s south coast.

GWRC Biosecurity Department has been approached by Wellington City Council and Take Care community groups for advice regarding control of Gazanias in coastal ecosystems, following failed control operations and an increase of Gazania plants found in areas previously occupied by other pest plant species that had been successfully controlled.

Although herbicide trials for control of Gazania are currently being carried out by the Riverland Winegrape Growers Association in Loxton, Australia, the herbicides of choice, Amitrole and Diquat, are not recommended for use in fragile ecosystems such as coastal dunes in New Zealand. Therefore the Biosecurity Department plans to undertake control trials aimed at providing a reliable control method for use in fragile coastal ecosystems in the Wellington region.

The aim of this project is to carry-out a spray trial comparing the performance of four agrichemicals (Glyphosate, Grazon, Tordon XT and Versatill,) as a means of controlling Gazania coastal dune ecosystems. By the end of this trial we hope to be able to recommend either a proven control method for Gazanias in coastal dune ecosystems, or further research into developing reliable control methods for Gazanias.

The trial is an interdepartmental collaboration to assure it meets the scientific standards required by our new work procedures. It has been prepared by Nikki McArthur, Environmental science department, Darryl Kee and Susanne Govella Biosecurity pest plants at Greater Wellington Regional Council.

We are looking forward to report back our results after the completion of the trial in September 2014.





Greg Hoskins Senior Biosecurity Officer Auckland Council

Velvetleaf (Abutilon theophrasti), also known as butter-print, is an invasive species that has been confirmed in the Helensville and Waikato areas.

It is an erect, annual shrub-like herb from the same family as hollyhock, to which it bears some resemblance. The plant can reach a height of 1-3m. The velvety, heart-shaped leaves are alternate, about 3-15 cm long. The seeds are brown/black and hairy, and about 3mm diameter. It has a long taproot.

Velvetleaf originates from China and Tibet, where it was grown as a fibre crop and medicinal plant. Since being introduced as a crop in Europe and North America, velvetleaf has come to be seen as an invasive species. It is one of the most detrimental weeds to corn, causing decreases of up to 34% of crop yield if not controlled.

The first record of velvetleaf in this country was in the late 1940s, when it was imported by the Ministry of Agriculture and Fisheries for testing as a fibre plant. Its presence was later noted in the 1950s as a contaminant of soya bean seed for trials. These were in Wellington and Lincoln respectively, and were isolated records of the plant.

Velvetleaf was recorded in NZ in 1978 at Ararimu, near Papakura, in pasture and cultivated land. It was believed to have come into the country as a seed contaminant.

Velvetleaf has recently been identified in the Waikato area in maize and in feedout lines from silage, and also on two properties in the Helensville area. The owner of one Helensville property believes the velvetleaf may have come onto this property as a seed contaminant in poultry manure that he spread over his farm.

This plant is one of the worst agricultural weeds in corn, sugar beet and soya bean crops in North America. It competes strongly with those crops for light and water, and releases allelochemicals that reduce the growth and emergence of neighbouring plants. Viability of seed in the soil is for 50-60 years, with 500–10,000 seeds/plant produced. The seed also survives in silage and passing through animals.

The plant blooms in summer (January-February) with flowers approximately 1-2cm wide. The flowers have five petals. The yellow to yellow-orange blooms are quite attractive and are on short flower stalks (pedicels) in the upper portions of the plant, in the axil of the stem and leaf, or where the leaves branch off the stem. The plant has distinctive 2cm-diameter circular seedpods. These have a ring of 'prickles' around the upper edge and have a series of crimps along the sides that resemble those of a piecrust edge. Hence, another common name for this plant is "pie-maker".

Small populations and single plants can be easily pulled or dug up before they go to seed, so early detection and rapid response is a key to controlling the plant. However, because seeds can remain viable in the soil for 50 years or more, velvetleaf can be very difficult to eradicate if infestations are allowed to persist and produce seed. It is important to watch carefully for this plant and remove it as soon as it is found. All plant material should be bagged and disposed of safely, to avoid spreading the seeds.

If any equipment is used where this plant occurs, clean it carefully before working in a new area. Return to the same area each year and look for new plants germinating from the seed bank.

Established populations will take much longer to eradicate because of the long-lived seeds. Plants can be manually dug up or pulled, or they can be mowed close to the ground while the plants are still small. Crop rotation can help prevent favourable growing conditions for velvetleaf.

Chemical controls are generally effective only when velvetleaf is less than 10cm tall. Velvetleaf leaves tend to droop or wilt in the late afternoon, so spraying is more effective in the morning or midday


Have we gone soft on the border?

Speech to NZ Institute of Agricultural and Horticultural Science Biosecurity Forum by Primary Industries Minister Nathan Guy on 12 July.


Before I start I’d like to comment on the title of this conference - Have we gone soft at the border?

I was advised that it would be a ‘courageous’ move to speak at a conference with such a title. But given the importance to me of biosecurity, I saw this event as more of an opportunity than a challenge.

I do want to challenge the title for two reasons. Firstly, I believe it takes too simplistic an approach to addressing how effective our biosecurity system is.

A world class biosecurity system is not about how many people are standing guard at our borders. It takes effect across a number of stages from pre-border to at-border to post-border.

All of these facets of the system need to be strong and need to be regularly reviewed for improvements.

The second reason is that I look out into this room and see some of the best experts in this field, like Dr Stephen Goldson who has been a big contributor on my Biosecurity Ministerial Advisory Committee. It is not too often you get a chance like this. I see great potential for this room to constructively advise me on How we can improve our Biosecurity System.

New Zealand is a trading nation. We live off our exports, but equally we are dependent on a range of imports.

We are also a nation that relies heavily on primary sector exports. These make up 72% of New Zealand’s overall merchandise exports.
Part of the success of our exports is down to New Zealand’s international reputation. And a key part of that reputation is our strong biosecurity system and our relatively pest-free status.

The challenge for me, and for you here today, is how we continue to facilitate and grow trade, yet continue to protect New Zealand from unwanted pests.

It can’t be a choice between these two goals. We have to do both.

The main point I want to make today is that there will always be risk of an unwanted pest being introduced to New Zealand. It is simply impossible to eliminate all risk.

Even if we completely stopped all trade to and from New Zealand, even if we halted all movement of people in and out of New Zealand – something I’m sure no one in this room wants - we would still not completely eliminate all risk.

So the question is how we best manage this risk.

To illustrate our challenge let me provide some context - around 175,000 items come across our border each day, and we receive around 10 million travellers a year.

It is simply not possible, for example, to do an exhaustive search of every item in every container in every consignment that arrives in New Zealand.

So what we need to do, and what MPI do, is to work smartly to manage risk at every level of the biosecurity system and to provide the best level of protection.

I have made it clear to MPI that biosecurity is my number one priority. I expect a high level of attention to be paid at every aspect of the system, and MPI is dedicated to making sure that New Zealand continues to have a world class biosecurity system.

Minister Guy used the rest of this speech to provide an over view of what his Ministry is doing to improve New Zealand biosecurity:

He mentioned funding has not been cut for biosecurity. He noted the decrease of staff over the last five years has averaged in the order of 1.9% per annum. He said the largest factor in this reduction was the global financial crisis, which reduced trade, meaning less products and people come across the border so less people are needed to check them. He said MPI is in the process, of bolstering its staff as trade increases. He said MPI’s biosecurity detector dog programme has expanded. He said every international passenger who comes through New Zealand airports undergoes a form of biosecurity screening allowing MPI staff to focus resources on high-risk rather than the low-risk passengers. He said managing outbreaks of significant animal disease, in particular foot and mouth, remains a high priority.


Passenger Biosecurity Survey

MPI has released the results of a survey carried out earlier this year, to check its effectiveness at preventing international air passengers from bringing in goods with a high chance of damaging New Zealand’s biosecurity.

It reports that its overall result across all risk goods has improved.

The survey, conducted at Auckland, Christchurch and Wellington airports between 6 May and 21 June, involved checking some 6800 passengers to see if they were carrying goods that pose a biosecurity risk after passing through airport checks.

The survey showed 98.8 percent of passengers who had been through checks were not carrying medium or high-risk goods, including materials that may host fruit fly or serious animal diseases.

The overall compliance result for all risk goods was 96.9 percent. MPI’s target is 98.5 percent.

MPI’s Border Clearance Services Director, Steve Gilbert said the shortfall was mostly due to low-risk items like used equipment, such as footwear contaminated with blades of grass getting past border checks. Last year’s result was 95.3 percent.

The survey report is available at


Red-vented bulbul

The recent “Angry Bird” campaign, to increase awareness of a pest bird in Auckland, has sparked an increase in confirmed public sightings of the red-vented-bulbul, an aggressive Asian species that threatens our crops.

Red-vented bulbuls are known to cause significant damage to fruit and vegetable crops. They are likely to feed on native fruits, berries, insects, flower nectar, seeds and buds, displacing native species such as kereru (native woodpigeon) with their aggressive competitive nature. They may also spread seeds of invasive plants.

The Ministry for Primary Industries (MPI) has confirmed that red-vented bulbuls are located in three clusters: south Auckland (Manurewa/Alfriston), west Auckland (Henderson/Te Atatu/Massey), and on Auckland’s North Shore (Devonport/Belmont/Takapuna).

There have also been possible sightings on the Whangaparaoa Peninsula about 12 kilometres north of the confirmed North Shore sightings.

The red-vented bulbul is one of the most invasive bird species in the world and in New Zealand is listed as an unwanted organism under the Biosecurity Act 1993. MPI is working in partnership with the Department of Conservation (DOC) and Auckland Council to track down the red-vented bulbuls in Auckland and eradicate them.

“We think there are at least five red-vented bulbuls in Auckland,” says MPI Response Manager Jaap Knegtmans. “It’s difficult to know exactly how many there are because they are quite mobile, moving large distances around the city.”

Red-vented bulbuls are a medium-sized bird about the size of a starling (20 cm in length - body and tail). They have a black head with a slight crest, a dark back, grey-white belly and a distinctive crimson-red patch beneath their tail.

“This red patch is a key identification feature,” said Mr Knegtmans.

“If people have seen a bird with bright red feathers beneath the tail, we urge them to contact MPI on our free Exotic Pest and Disease Hotline - 0800 80 99 66. Taking a photo, if possible, would also be a huge help.”

Red-vented bulbuls also have a very distinctive call, unlike other birds you normally hear around Auckland. Their call can be heard on the MPI website at:

Red-vented bulbuls are found in Asia from Pakistan to southwest China. They have invaded parts of the Pacific, including Hawaii, Fiji and Samoa.

Red-vented bulbuls have been found in Auckland before, in the 1950s and in 2006, and were successfully eradicated on both occasions. It’s believed the red-vented bulbuls now in Auckland arrived on a ship or yacht.

“These birds are aggressive and prolific breeders and we need to remove them before they become established. Continued help from the public is crucial to tracking the birds down and eradicating them.” said Mr Knegtmans.

“It’s vital we get sightings from the public as soon as possible. They’ll become harder to spot as Spring advances and leaves start returning to trees,” said Mr Knegtmans.


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