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New weed pests now on AgPest!

Four new weed pests have been added to the AgPest online Pest Directory!

The new profiles on AgPest have information relating to the identification, biology, impact and control for the following weeds:

AgPest contains a number of New Zealand pasture weeds and pests, which have been chosen in consultation with key farming, industry and research personnel. We will continue to identify and add more weeds and pests to the directory.

Click here to view our Pest Directory

Found something new on your farm? Not sure if it’s a pest or not? Click here to use our free online identify tool

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New weeds added to the AgPest directory

Recently we have added 7 new weed pests to the AgPest online Pest Directory.

The new profiles on AgPest have information relating to the identification, biology, impact and control for the following weeds:

AgPest contains a number of New Zealand pasture weeds and pests, which have been chosen in consultation with key farming, industry and research personnel. We will continue to identify and add more weeds and pests to the directory.

Click here to view our Pest Directory

Found something new on your farm? Not sure if it’s a pest or not? Click here to use our free online identify tool

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MPI testing reveals further line of contaminated beet seed

As part of its ongoing response to the incursion of velvetleaf, the Ministry for Primary Industries (MPI) has detected velvetleaf contamination in a further fodder beet seed line.

Read the latest MPI Media Release here

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Velvetleaf search and destroy nears completion

MPI MEDIA RELEASE: 29 APRIL 2016

The management of the pest weed Velvetleaf is entering a new phase as property searches across the country draw to a close.

Search and destroy activities have been conducted on more than 600 properties since March this year when velvetleaf was discovered in several regions.

Velvetleaf has been found in 11 regions on 215 properties associated with fodder beet to date.

Ministry for Primary Industries (MPI) Director of Investigations, Diagnostics and Response, Veronica Herrera, says the operation has involved a large number of people including volunteers.

“It’s been a truly collaborative approach which has enabled us to get through a large number of properties.

“Regional council staff, industry experts, sector leaders and farmers have all contributed a huge amount of time and energy. The search and destroy operation has been hard, physical work.

“People have literally been trudging through vast areas of fodder beet and, in some cases, very rugged terrain in a bid to find and destroy velvetleaf plants.

“MPI would like to thank everyone involved including volunteers who have made a substantial contribution. All efforts have been greatly appreciated.”

Dr Herrera says with the completion of inspections due this afternoon, the focus will turn to the development of a long term management plan for velvetleaf.

“MPI remains fully engaged in this process and we’ll be spearheading a nationally coordinated approach with the objective of containing and potentially reducing geographical spread over time. This may include local elimination in some regions.

“We are now developing a transition plan, in consultation and collaboration with key stakeholders, until a long term management plan is in place.

“Workshops will be held over the next few weeks where we will be seeking input on interim measure as well as long-term management.

“It is important that everyone involved in the management of velvetleaf remains focused on mitigating the associated biological risk until long term management is established.”

Dr Herrera says MPI is continuing to investigate how contaminated fodder beet seed could have entered New Zealand and the beefed up interim border inspections to stop contaminated seed entering the country will remain in place in the interim.

“MPI has already established that some lines of fodder beet seed grown in Italy and pelletised in Denmark were contaminated with velvetleaf. These lines have been banned from entry into New Zealand.

“We continue to inspect seed from other sources to determine if any other lines are contaminated.

“In addition, the import requirements in the Import Health Standards will be reviewed in light of the learnings from this response, the inspections at the border, and the pathway assurance visit to the growing regions that is coming up in June.”

Dr Herrera says in the meantime, the messages around managing velvetleaf remain the same.

“It’s imperative we don’t become complacent. Vigilance is the key to managing this. Landowners need to continue inspecting their properties for late-emerging velvetleaf and farmers should ensure their on-farm biosecurity measures are robust and enduring.

“This includes strict adherence to guidelines on machinery hygiene, feed management and stock movement that are all contained in our farm management plan.

“MPI will continue to manage the velvetleaf 0800 number (0800 80 99 66) and provide advice and material on managing velvetleaf. We are committed to ensuring the transition into long term management is as smooth as possible and look forward to working with the sector on the way forward.”

To view the release and for further information please visit the MPI website

Media contact: MPI media team

Telephone: 029 894 0328

Email: media@mpi.govt.nz

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Farmers urged to remain on lookout for late-emerging velvetleaf

MPI MEDIA RELEASE: 13 APRIL 2016

The Ministry for Primary Industries (MPI) is urging farmers to remain vigilant in their management of the velvetleaf pest plant.

MPI’s Velvetleaf 2016 Response Manager, Carolyn Bleach, says the window of opportunity to control plants that haven’t yet seeded is narrowing and it’s very important farmers remain on the look- out.

“Farmers and landowners need to maintain a watchful eye until crops have been grazed, particularly as some late emerging plants have been found in crops that have already been inspected.

 “It’s become apparent that velvetleaf shoots up dramatically when it goes to seed.  A plant that may have been hidden by the canopy of the crop one week can appear a week or so later.

 “We are urging farmers not to become complacent and to report any findings of late-emerging plants to the MPI exotic pest/disease hotline:  0800 80 99 66.

“All seeding plants on inspected properties have been mapped and these areas will need to be revisited for several years to eliminate this pest plant.”

 Dr Bleach says farmers are continuing to receive expert advice on how best to manage velvetleaf.

“This week, farmers from affected properties received guidelines that advised them on how to graze fodder beet crops while minimising the risk of spreading velvetleaf across their properties.

“The guidelines are a collaborative effort with input from MPI, Dairy NZ, the Foundation for Arable Research (FAR), AgResearch, Federated Farmers and PGG Wrightsons agronomists. Feedback was provided by industry groups.

“MPI is also developing a ‘ute guide’ of the existing Farm Management Plan to ensure the information is as user-friendly as possible for farmers. We’ll also be releasing a FAQ sheet later this week.”

 Meanwhile, Dr Bleach says MPI is receiving regular updates on the number of cases of velvetleaf across the country.

 “There are 169 confirmed cases in 11 regions throughout New Zealand. Canterbury has recorded the highest number to date (88). We are also focussed on completing property inspections across the various regions.”

 Dr Bleach says MPI is encouraged by the support its received from a wide range of stakeholders including industry representatives, regional councils and farmers ensuring an ‘all hands to the pump’ approach is being taken.

“This is a truly collaborative response and we are heartened by the ongoing hard work that’s being put into containing this pest plant.

“The commitment shown by regional councils to help local farmers through this has been great.

 “Managing this pest locally now will help to reduce its impact in the future.”

Media contact: MPI media team

Telephone: 029 894 0328

Email: media@mpi.govt.nz

http://mpi.govt.nz/news-and-resources/media-releases/farmers-urged-to-remain-on-lookout-for-late-emerging-velvetleaf/

 

 

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Full steam ahead in quest to find aggressive velvetleaf

MPI Media Release

24 March 2016

The Ministry for Primary Industries (MPI), primary sector industry groups and regional councils are stepping up the search for the pest agricultural weed velvetleaf in a bid to contain it to existing locations and halt its spread.

MPI Plants and Environment Surveillance Manager Mark Bullians says while velvetleaf may sound pretty, it’s anything but. In locations where it is established internationally, it has significant impacts on crop production.

“It is a very invasive weed that is very successful at competing with crops for nutrients, space and water,” Mr Bullians says.

“Right now we’re still working to locate outbreaks and remove them from the ground, ideally before seed drops.”

The Ministry’s main message is for farmers who have planted fodder beet seed.

“Check your fodder beet crops and if you believe you have found this weed, photograph any plants, mark the locations so they can be easily found again, and call us on the free hotline 0800 80 99 66.

“We will arrange for technical experts to come and remove velvetleaf plants. Do not attempt to remove them yourself as this risks spreading the seed.” Mr Bullians says there is good advice for farmers on its website.

“There has been a good response to our call for sightings. Currently velvetleaf has been confirmed on 50 properties nationally. There has been some weed found in most regions, but Canterbury has the clear majority of cases.”

The common denominator in all infestations to date is the planting of imported fodder beet seed. Two varieties in particular are implicated – Kyros and Bangor – although MPI is considering the possibility that other varieties could be involved.

“We are also investigating how the contaminated fodder beet seeds could have entered New Zealand. We know that the affected imported fodder beet seed consignments met New Zealand’s importing requirements and were certified by the exporting country. MPI is currently reviewing the import requirements for seed.”

MPI is not just relying on farmers reporting finds. It is working actively with regional councils and the seed industry to trace where potentially contaminated seed was sold and inspect those properties for the presence of the weed.

While the search continues, work is underway developing the best possible options for controlling this pest.

“This is not a situation the Ministry is planning to walk away from,” Mr Bullians says. “Managing this pest will require a sustained combined effort over many years.”
Media contact: MPI media team

Telephone: 029 894 0328

Email: media@mpi.govt.nz

Click here to view the MPI Media Release

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Velvetleaf weed hunt goes national

MPI Media Release:

Date:

The call for sightings of the aggressive weed velvetleaf has shifted to a national one following the detection of the plant in fodder beet crops in the North Island.

The Ministry for Primary Industries is encouraging farmers and growers who have planted fodder beet seed to check their crops and if they believe they have found the pest, to contact the Ministry on its free hotline 0800 80 99 66.

Velvet leaf is a serious weed pest overseas, damaging crops by competing with them for nutrients and water. In New Zealand, it is an Unwanted Organism under the Biosecurity Act.

MPI had been investigating the appearance of velvetleaf on a number of South Island properties and spread the net wider on the understanding that potentially contaminated fodder beet seed had also been sold in the North Island.

Plants and Environment Surveillance Manager Mark Bullians says MPI has now positively identified the weed on a property in the Waikato.

The latest information is that velvetleaf has been confirmed on properties in Canterbury, Central Otago, Marlborough and Waikato.

“The common denominator in all cases is fodder beet crops grown from imported seed,” Mr Bullians says.

“While we are not certain this is the full picture, we now know that some lines of two particular seed varieties – Kyros and Bangor – are very likely to have been contaminated with velvetleaf seed. We believe there may be some other seed varieties implicated.

“For this reason, we urge all farmers and growers who have planted fodder beet this season to check their fields immediately. If you believe you have found this distinctive weed, call MPI immediately on 0800 80 99 66.”

Velvetleaf is a tall-growing weed reaching heights of up to 2m. It has buttery yellow flowers and large velvety heart shaped leaves.

Mr Bullians says farmers are advised to photograph any plants, contact MPI and mark the location of plants so they can be found again easily.

He cautions against pulling up plants and says a technical expert will visit and carefully remove any plants to make sure velvetleaf seed, if present, is not spread.

MPI is investigating how the contaminated weed seeds could have entered New Zealand. The affected imported fodder beet seed consignments met New Zealand’s importing requirements and were certified by the exporting country. The Ministry has contacted the exporting authority and is currently reviewing the import requirements for seed.

Mr Bullians says MPI is working closely with primary industry bodies from both the animal and grain/seed sectors as well as regional councils on managing this situation.

“At this time we are focused on finding outbreaks of the weed and containing it. The earlier we find velvetleaf, the better our chances of controlling it.”

To request a velvetleaf image, email media@mpi.govt.nz.

Media contact: MPI media team

Telephone: 029 894 0328

Email: media@mpi.govt.nz

http://mpi.govt.nz/news-and-resources/media-releases/velvetleaf-weed-hunt-goes-national/

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Velvetleaf focus firmly on fodder beet seed

The Ministry for Primary Industries (MPI) is encouraging farmers and growers who have planted certain varieties of imported fodder beet seed to check their crops for the presence of an aggressive agricultural weed, velvetleaf.

MPI has been investigating the appearance of this pest weed on a small number of South Island properties and has been steadily building a picture of where the weed is present and if there are any common factors between affected properties.

Plants and Environment Surveillance Manager Mark Bullians says MPI has now positively identified velvetleaf on 10 properties across the South Island and has seven further suspected cases yet to be verified.

“The common denominator is fodder beet crops and, in particular, crops grown from two varieties of imported fodder beet seed.

“Velvetleaf plants are appearing in rows where this fodder beet seed has been drilled and farms concerned have planted either Kyros and/or Bangor seed.

“While we are not certain this is the full picture, we now know that some lines of these two seed varieties are very likely to have been contaminated with velvetleaf seed. For this reason we urge anyone who has planted Kyros and Bangor fodder beet seed to check their fields immediately for the presence of velvetleaf. The seed has been distributed mostly in the South Island but some has been sold in the North Island.

“If you believe you have found this distinctive weed, call MPI immediately on 0800 80 99 66.”

Velvetleaf is a tall-growing weed reaching heights of up to 2m. It has buttery yellow flowers and large velvety heart shaped leaves.

Mr Bullians says farmers are advised to photograph any plants, contact MPI and mark the location of plants so they can be found again easily. He cautions against pulling up plants, or allowing cattle to graze infested crops, and says an MPI or local council representative will visit and carefully remove any plants to make sure velvetleaf seed, if present, is not spread.

Velvet leaf is a serious weed pest overseas, damaging crops by competing with them for nutrients and water. It is an Unwanted Organism under the Biosecurity Act, and as such, entry to New Zealand is prohibited.

MPI is investigating how the weed seeds could have entered New Zealand. The affected consignments met New Zealand’s importing requirements and were certified as weed-free by the exporting country. The Ministry is currently reviewing the import requirements for seed.

Mr Bullians says the Ministry is working closely with primary industry bodies from both the animal and grain/seed sectors as well as regional councils on managing this situation. As a precautionary measure, MPI has directed seed and grain retailers not to sell or distribute any remaining stock of the affected seed lines and these retailers have also been directed to instruct buyers to return any unsown seed.

For full information visit: mpi.govt.nz/alerts or contact MPI Mediaphone 029 8940328 or media@mpi.govt.nz

 

velvetleaf-mid-shotwebres

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MPI enlists support in hunt for pest weed

The Ministry for Primary Industries (MPI) is asking farmers and growers of arable crops to look out for a highly invasive pest weed that has appeared on a handful of South Island properties.

Velvetleaf, a serious cropping pest, has been found in fodder beet crops in North Canterbury and Central Otago. It affects many arable crops by competing for nutrients, water and space.

The Ministry is investigating how it got there and building a picture of how widespread the situation is. At this time it appears the finds are associated with fodder beet crops and MPI is looking at all possible ways the plants could have arrived at the properties concerned.

Manager of Plants and Environment Surveillance, Mark Bullians, says it’s important those who sowed fodder beet this season check their crop for the presence of this very distinctive weed.

Velvetleaf is a broad-leafed weed that grows to between 1m and 2.5m. It has buttery-yellow flowers which appear over summer and autumn. Leaves are heart shaped and velvety to touch.

“We are hoping that in most cases we will be able to locate any velvetleaf plants and remove them before they can spread their seed. Once seed falls, it can persist for decades, making control a very long term process,” Mr Bullians says.

“If farmers and growers find this pest we urge them to photograph it, mark its location so it can be found again easily and immediately call MPI on its free hotline – 0800 80 99 66.

“Calls will be referred to an incursion investigator who will make arrangements to safely remove and collect any plants. We advise people not to remove any plants themselves as this could risk seed being spread.”

Velvetleaf is known to be present in the Waikato where it is well managed by the regional council. The South Island discovery looks to be recent and MPI is working with partners in the seed and farming industries and regional councils to manage it.

“Immediate reporting to MPI will give us the best possible chance of dealing with this weed,” Mr Bullians says.

velvet-leaf-scale-shotwebres  velvetleaf-mid-shotwebres

Full information is at: www.mpi.govt.nz/alerts

Media contact: 029 8940328 or media@mpi.govt.nz

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Online tool tackles worst of NZ pasture pests and weeds

The AgPest website is a feature of the AgResearch display in the Mystery Creek Pavilion at this year’s National Agricultural Fieldays.

The AgPest (formerly known as Pestweb) display highlights some of New Zealand’s worst pasture pests, and demonstrates the online tool as a practical way for farmers to identify and then tackle the problem.

Scientist Colin Ferguson says the aim of the AgPest display is to ensure continued and productive pasture growth, and it fits with the theme of the AgResearch stand, which is featuring science which farmers can use to increase their knowledge on farm.

“We’re highlighting pests such as porina and black beetle; both are causing damage to New Zealand pastures currently as the mild winters and warm springs over the past few years have produced the perfect conditions for adult black beetle and porina survival.”

Porina are grazers that will eat all herbage that is on surface of the ground. The amount of damage depends on the number of insects; at low densities they are direct competitors with stock for food and reduce the amount of foliage available. At higher densities plants are destroyed allowing inferior plant species to establish reducing long term pasture quality and production.

“Paddocks that are two to three years out of cultivation are particularly prone to porina infestation,” says Mr Ferguson.

Black beetle numbers are also high where populations are found in the upper North Island.

“Black beetle adults usually go into a rest period over winter, becoming more active again when it warms up in spring,” says Mr Ferguson.

“Awareness will help farmers plan for combat strategies to make up for the feed consumed by this pest. These may include putting in a maize silage block or buying in additional feed if appropriate.

“You can find out more about the control of both porina and black beetle at the AgPest website.”

Built for farmers and agricultural professionals, the recently renamed website (www.agpest.co.nz) is a free online tool to assist with pest and weed management decision making.

“Visitors can find over 80 pests and weeds that affect New Zealand pasture in the pest directory. Each pest profile includes the biology of the pest, its impact on pastures and the latest information on control measures,” says AgResearch weed scientist Dr Katherine Tozer.

“One of the site’s key features is the ability to help farmers identify a particular weed or insect pest they find on the farm through a simple query and response system.

“While we were rebranding the site we also took the opportunity to include a new site-wide search function.

“AgPest Alerts is a free subscription email service providing timely alerts to farmers about pest outbreaks in their region. They are delivered via email, text, Twitter or Facebook and link to the AgPest site for further information. You can sign-up for the service on the AgPest site,” says Dr Tozer.

For further information please contact: 

Alex Fear
Senior Communications Advisor
AgResearch Limited
T   07 834 6636
M 021 773 674
E alex.fear@agresearch.co.nz

Black beetle numbers on the rise

AgResearch scientists warn that one more mild winter could result in a population explosion of black beetle.

Black beetle male and female

Black beetle male and female

“Recent AgResearch trial work shows that black beetle populations are on the increase and development is more advanced in autumn 2014 than in the previous five years,” says AgResearch Science Team Leader Biocontrol and Biosecurity Dr Alison Popay.

“This means that the adult black beetles will have plenty of time to feed and build up fat reserves to help them through the winter.  If warm conditions continue through autumn and spring conditions are right, some farmers could be facing another serious black beetle outbreak next summer.”

A black beetle field day was recently held on the Taupiri farm of Martin Henton. Martin is part of the Waikato Black Beetle Action Group who obtained Sustainable Farming Fund investment for the project “Beating black beetle: developing pest-resistant dairy pastures in the Waikato.” His property was hit very hard in the last black beetle outbreak in 2007-2010 and since then the pest has persisted at higher levels than on many other farms. Because of this AgResearch, the research partner in the Sustainable Farming Fund project, has used Martin’s farm for a number of project trials.

AgResearch scientist Dr Kumar Vetharanium has used the trial data and that available from the severe outbreak in the 1980s to build a model that should give farmers more advance warning of outbreaks.

“The model predicts that if it’s warm and dry again in the next spring-summer period, we will be heading for trouble and there would be huge problems if this continued into 2016,” says Dr Popay.

“NIWA is predicting about 50% chance of an El Niño event July – Sept. While Waikato farmers may not like the cold wet conditions it may bring, it should help reduce overwintering black beetle adult populations.”

Dr Popay says that farmers can make decisions now that will prepare their farm for the likely black beetle outbreak if winter is warmer and drier than average.

“When renovating this autumn, use a black beetle-active endophyte and manage pastures to ensure no gaps develop where beetle-friendly paspalum and summer grasses can establish. Establish endophyte pasture now to ensure it will be robust enough next summer when pressure from the black beetle increases.

“Legumes are not attacked by black beetle. Also consider crops like chicory, which are not a good host for black beetle and can help break the pests’ lifecycle.”

Dr Popay warns that endophytes in grasses will be of little use in breaking the life cycle of black beetle if an alternative feed source such as C4 grasses (especially paspalum), Poa annua, other grass weeds or endophyte-free ryegrass, including annuals and Italian ryegrass, are available.

“These alternative feed sources will only add fuel to the fire as it provides the perfect environment for the pest,” she says.

One trial on Martin Henton’s and fellow action group member Stu King’s properties is investigating the possible benefits of liming in reducing black beetle populations.

“It is too early to give definitive recommendations from the lime trial other than to say low soil pH appears to favour black beetle and getting soil pH into the optimum range for your soil type will help pasture production and quality,” says Dr Popay.

She advises farmers looking for more information to contact their local DairyNZ Consulting Officer.

“They will be able to discuss the range of options available to you.”

DairyNZ also has a black beetle Farmfact available on www.dairynz.co.nz. Further information about the black beetle can be found here on AgPest.

For further information please contact:

Alex Fear
Senior Communications Advisor
AgResearch Limited
T  07 834 6636
M 021 773 674
E alex.fear@agresearch.co.nz

Bumper summer for native moth

Farmers in the North Island are reporting to AgResearch plantain crop damage from a normally benign New Zealand native.

Plantain moth on Tonic plantain

Plantain moth on Tonic plantain

The Epyaxa rosearia is a widespread native New Zealand moth, occasionally reaching pest levels, that feeds on a range of plants including plantain. Its recent appearance in large numbers in plantain crops has given rise to the name plantain moth.          ​Reports started to come in around early December from farmers concerned about the number of plantain moth caterpillars they were seeing in their fields and the resulting damage occurring in plantain crops, says AgResearch scientist Mr Colin Ferguson.

“Some farmers have reported up to 90% of their crop being decimated by the insect.”

Until recently the plantain moth has caused little concern to farmers.

“It is a native of which we know virtually nothing, but its activities this summer has put it firmly on our radar,” says Mr Ferguson.

“In the past plantain used to be planted within a mixture of ryegrass, chicory and clover. Due to its drought resistant properties we are seeing more and more farmers using plantain as a monoculture: single source pasture. These plantain crops should last a number of years but it looks as though populations of the moth build up in the first year and, assuming conditions are right, it is those second year crops that are getting hit by moth populations which increase exponentially.”

Mr Ferguson says the effects of the move to plantain as a single source forage crop was compounded by the very mild conditions last winter.

“The mild conditions allowed a greater number of moth eggs to hatch and more of the caterpillars and moths survived right through the winter. Warm, dry summers, like the one we are having now, are perfect insect breeding conditions and as result the plantain moth population has just exploded in some areas.”

Normally the growth of plantain is so great that feeding by these caterpillars has very little impact on plant production. Occasionally however, severe damage is reported as a consequence of very high caterpillar numbers and may be concentrated in some paddocks while others close by are unaffected.

Why, and how, this situation arises is currently unknown but is under investigation. Crop health, plant stress and growing conditions may have a significant role to play in the severity of damage observed.

Although current information suggests the moth is widespread throughout New Zealand, Mr Ferguson has had no reports of damage to plantain south of the Manawatu.

“This may be because weather conditions do not allow the moth to breed as many times as it does in northern areas.

There are no registered insecticides for control of plantain moth caterpillars but broad spectrum insecticides with good activity against other caterpillars may also provide control of plantain moth. AgResearch scientists strongly recommend consultation with agrichemical professionals before using these insecticides for off-label use.

“We believe that treatment in early summer, if moths are present then, would knock back the season’s first generation leading to less pressure for autumn pastures,” says Mr Ferguson.

“Further investigation into this and grazing management practices is underway. As a general guide a healthy crop will tolerate more insect damage than an unhealthy one.”

About the Plantain Moth

Moths are small, less than 20mm wide, light brown with darker spots and a distinct darker brown band towards the end on the wings. It belongs to a group of moths commonly called carpet moths. When present the moths will often fly up from the crop in front of people, stock or vehicles, sometimes in very large numbers, particularly in autumn.

Caterpillars are brown and small, less than 20mm long. They are known as loopers as they raise part of their body off the ground or plant when moving.

Very little is known about the biology of this insect.

It appears to have a short generation time and several generations per year are likely leading to the massive numbers sometimes seen but this needs further study. It is most abundant in late summer and largely disappears from crops in late autumn. It probably feeds on a wide range of plants and appears to find plantain and Caucasian clover to its liking having been observed causing noticeable damage to both. The caterpillars feed on the plant leaves causing small holes which can join up and in severe cases leave only leaf veins.

Generally little plant damage is attributed to this insect but it has been recorded as causing damage to Caucasian clover and is very commonly found in plantain stands.

Too little is currently known about this insect for management options that may affect build-up of caterpillars to be suggested. When its biology is better known some options may present themselves.

More information about the Plantain Moth found here on AgPest. Farmers can also sign up to receive management and control advice specific to their region through the Pest Alerts.

For further information or images please contact:
Alex Fear
Senior Communications Advisor AgResearch Limited
T  07 834 6636
M 021 773 674
E alex.fear@agresearch.co.nz

Industry-wide effort required to combat damaging weevil

One million tiny insects are going to make a huge economic difference to the Southland region this autumn, thanks to the joint efforts of AgResearch, Beef + Lamb New Zealand, DairyNZ and Environment Southland.546--Scott-Hardwick-collecting-clover-root-weevil-using-a-blower-vac

The project, which has been releasing parasitised clover root weevils on Southland farms for some time, is being considerably accelerated.

“If we can make releases of clover root weevil infected with the Irish wasp parasite on up to 1,000 Southland farms before winter, then we will have done as much as we can possibly hope to this year,” says AgResearch pest specialist and scientist Colin Ferguson.

“To do this we aim to collect up to one million parasitised clover root weevil over the next few months.”         Last year’s mild winter has meant that clover root weevil has taken its small foothold on the farms of Southland to a widespread infestation that has had a huge impact on the production ability of the region’s pastures.

“Unfortunately there is little that farmers can do by changing their management practices to minimise the impact of clover root weevil and there are no current effective pesticides,” says Mr Ferguson.

“If the farm budget allows, farmers can use N fertiliser to boost pasture production and cover for the lack of clover, however there are no quick fixes and they shouldn’t adopt any unproven miracle cures.”

Based at AgResearch’s Invermay campus, Mr Ferguson has seen the damage wrought by the weevil on Southland farms first-hand.

“The clover root weevil has been present in Southland since 2010, but large numbers were present in only a few locations.” he says.

“That was until last year – what we didn’t need was the very mild winter.

“The mild conditions allowed a greater number of clover root weevil eggs to hatch and more of the larvae survived right through the winter. As a result the population of the weevil just exploded.

“Tremendous pressure is now being placed on pasture from the increased numbers of larvae that fed on the clover roots and their nodules last winter. That damage was followed by the large population of adult clover root weevil emerging in early summer and feeding on the clover leaf. Normal spring and summer grazing of clover has added to the stress on already struggling plants.”

“Affected farmers are either seeing clover that disappears very quickly once grazed or a complete absence of clover plants in their pasture. Without clover farmers can’t fatten lambs and those that are looking to overwinter dairy grazers can’t do that. It is having a huge impact on farm returns right now.”

There is a solution to this difficult situation and it comes in the form of a tiny parasitic wasp from Ireland.

The Irish wasp is a highly effective bio-control of clover root weevil. AgResearch scientists have seen reductions of greater than 90% of the clover root weevil population in monitored North Island farms where the wasp has been released.

AgResearch scientist Dr Scott Hardwick leads the Lincoln-based clover root weevil collection team.

“We are literally vacuuming up weevils from Canterbury farmland where the bio-control wasp is already hard at work,” he says.

“While most of these collected weevils are already parasitised, we boost the parasitism levels by adding a few Irish wasps to the packs of 100 we make up for farm release. These packs are then delivered to Southland for release. The result will significantly accelerate spread of the bio-control and the process of clover recovery will begin.

“Southland farmers can expect clover content to return to normal levels two to four years after the wasps’ arrival on their farms.”

Dr Hardwick advises farmers not to worry if their farm is not one of the selected release sites.

“In Canterbury and North Otago we have seen the Irish wasp spreading up to 30 km per year from release sites, so even if your farm is not one of selected release sites, the Irish wasp released on your neighbour’s farm will quickly arrive on your farm.” Beef + Lamb New Zealand, DairyNZ, Environment Southland and AgResearch are working together to ensure that farms selected as release sites will have the maximum impact for the region.

Mr Ferguson advises farmers not to panic.

“While this is causing a lot of pain at the moment it will pass over time.  Although things are going to be tough for the next few years farmers will get through this with the help of the bio-control.  North Island farmers have already gone through this process and clover root weevil is not much of an issue now for any of them.

“If we had let things run their natural course the Irish wasp would have continued to spread down the South Island, following the clover root weevil, and eventually arrived everywhere in Southland. These actions by the industry this autumn will considerably speed up this process and make a huge economic difference to Southland.”

Southland farmers who suspect they may have clover root weevil – it can be identified by the distinctive U-shaped notches on clover leaves made by the adults – should attend one of the Beef + Lamb New Zealand clover root weevil field days being held over the next month. Four are scheduled.  On March 17 one will be held in Waikoikoi starting at 10 am and in the afternoon another will run at Glenham starting at 3 pm.  The following day, March 18, a workshop will be held in Winton starting at 10 and another will follow in Mossburn starting at 3 pm. Contact Beef + Lamb New Zealand Extension Manager, Paul McCauley for more information paul.mccauley@beeflambnz.com

Farmers can also contact their local Beef + Lamb New Zealand and DairyNZ consulting officers for more advice. DairyNZ also has a Farmfact on managing dairy pastures with clover root weevil which includes advice on how to support clover depleted pasture.

More information about the weevil and how to recognise it can be found here, in the directory of New Zealand’s most damaging pests and weeds. Farmers can also sign up to receive management and control advice specific to their region through the Pest Alerts.

Image caption: AgResearch scientist Dr Scott Hardwick collecting clover root weevil from South Canterbury pasture using a blower-vac.

For further information or a high resolution of the above image please contact:

Alex Fear Senior Communications Advisor – AgResearch
Phone: 07 834 6636 / 021 773 674
Email: alex.fear@agresearch.co.nz

Irish wasp may need help moving west

Increasing clover root weevil populations are being seen on the West Coast, but the AgResearch-introduced biocontrol is hot on its tail.

Clover root weevil being stalked by its biocontrol agent

Clover root weevil being stalked by its biocontrol agent

AgResearch entomologists Dr Scott Hardwick and Mark McNeill, based at the Lincoln Campus in Canterbury, have been tracking the spread of clover root weevil (CRW) in the South Island, so that they know if and where to release the Irish wasp, a very effective biocontrol agent for this serious pest of white clover.

Sampling last winter and early spring for the DairyNZ-funded biocontrol project has revealed that the weevil is now present through much of the northern parts of the West Coast. AgResearch is now asking southern West Coast farmers who suspect they may have the weevil to get in touch, so they can be sure the wasp keeps apace of the problem.

In 2006, AgResearch scientists, supported by DairyNZ, Beef + Lamb NZ and AGMARDT, made a breakthrough in CRW control by releasing a potential biocontrol agent, a tiny parasitic wasp from Ireland.

The first trial releases were made in Waikato, Hawke’s Bay and Manawatu, and within just 18 months the wasps’ performance had exceeded the expectations of even the most optimistic scientists.

Dr Hardwick says they found potentially damaging populations of the weevil from Greymouth north through to Karamea but in spite of extensive sampling south of Greymouth, they only discovered a single infested site in Waitahi.

“The good news is that clover root weevil has brought its own destruction with it. The Irish wasp has been confirmed at many localities including Little Wanganui, the outskirts of Westport, Cronadun, and Greymouth,” he says.

“However, we’re concerned that the weevil may be getting a jump start on the wasp further south on the West Coast. In wetter areas, clover root weevil may not fly as readily as it does in summer dry areas such as Canterbury.

“This both limits the dispersal power of the Irish wasp, as it needs to be carried into new areas as eggs inside parasitised weevils, and leads to isolated ‘hot spots’ of CRW, which are often started by CRW hitching a ride on vehicles,” says Dr Hardwick.

“We’re now considering carrying out releases of the Irish wasp south of Greymouth when new populations of the weevil are found, rather than relying on it making its own way.”

West Coast farmers who suspect they may have CRW – it can be identified by the distinctive U-shaped notches on clover leaves made by the adults – should contact AgResearch.

This will help them confirm the need and locations for Irish wasp releases this year.

More information about the weevil and how to recognise it can be found here on Pestweb (now AgPest).

Contact:
Dr Scott Hardwick at info@agresearch.co.nz

Media contact:
Stephen Doran, Senior Communications Advisor, AgResearch.
Tel: 07 834 6629 / 021 938 548
Email: stephen.doran@agresearch.co.nz

Summer pasture pest numbers on the rise

AgResearch scientists are predicting larger than normal numbers of the pasture pests porina and black beetle this summer.

Adult porina moth

Adult porina moth

“The mild winter and warmer than normal spring are perfect conditions for adult black beetle and porina survival,” says Dr Alison Popay, AgResearch Science Team Leader – Biocontrol & Biosecurity.

“We are giving farmers the heads-up – they need to be aware of the potential for increased pasture damage from these pests.”

Porina are grazers that will eat all herbage that is on surface of the ground. The amount of damage depends on the number of insects; at low densities they are direct competitors with stock for food and reduce the amount of foliage available. At higher densities plants are destroyed allowing inferior plant species to establish reducing long term pasture quality and production.

“This time of year, particularly in porina prone areas, the adult insects start to fly; they will be banging into farmers’ windows as they are attracted to light,” says Dr Popay.

“Paddocks that are two to three years out of cultivation are particularly prone to porina infestation.

“Farmers that are constantly battling against this pest can continue paddock monitoring and plan to spray four months after the sighting flying moths with the insect growth regulator Diflubenzuron.”

Black beetle numbers are also on the rise.

“Black beetle adults usually go into a rest period over winter, becoming more active again when it warms up in spring,” says Dr Popay.

“Their ability to feed dictates their egg-laying cycle, so this year we are likely to have an earlier and more successful hatching.

“If these warm conditions continue and high soil moistures don’t reduce survival of the very young larvae, black beetle will be on the increase. Awareness will help farmers plan for combat strategies to make up for the feed consumed by this pest. These may include putting in a maize silage block or buying in additional feed if appropriate.

“Farmers can find out more about the control of both porina and black beetle at the Pestweb website.”

Built for farmers and agricultural professionals, the recently updated Pestweb (now AgPest) is a free online tool to assist with pest and weed management decision making.

“Visitors can find 50 pests and weeds that affect New Zealand pasture in the pest directory. Each pest profile includes the biology of the pest, its impact on pastures and the latest information on control measures,” says AgResearch weed scientist Dr Katherine Tozer.

“One of the site’s key features is the ability to help farmers identify a particular weed or insect pest they find on the farm through a simple query and response system.

“We also took the opportunity to update the pest search function, improve the viewability of the images on the site and expanded our PestAlerts service.

“PestAlerts is a free subscription email service providing timely alerts to farmers about pest outbreaks in their region. They are delivered via email, text, Twitter or Facebook and link to the Pestweb site for further information. Farmers can sign-up for the service on the Pestweb site.”

The website is managed by AgResearch with support by numerous industry partners such as MPI, DairyNZ, Beef + Lamb New Zealand, AbacusBio Ltd and The New Zealand Plant Protection Society.

For further information please contact:

Alex Fear
Senior Communications Advisor
AgResearch Limited
T   07 834 6636
M  021 773 674
alex.fear@agresearch.co.nz