Varroa mite: Outbreak origin under the microscope
New Zealand is being investigated as a possible source of the NSW varroa mite outbreak. More details here.
Authorities are moving closer to identifying the origins of the varroa mite outbreak.
A spokeswoman from the NSW Department of Primary Industries said results from the Elizabeth Macarthur Agricultural Institute have confirmed that the varroa mite in NSW belongs to the Korean haplotype group, which is the most common haplotype of varroa mite around the world.
“This does not indicate that Korea was the source for the varroa mite found in NSW, rather it is a way of describing the sub-populations of varroa mite,” the spokeswoman said.
Sequencing of samples from three hives showed the three genomes were quite similar, indicating the varroa mite entered Australia as a single event, the spokeswoman said.
Plant Health Australia chief executive Sarah Corcoran said it was “very hard to find the smoking gun when it comes to finding a plant pest incursion”.
Ms Concoran said one possible pathway for the arrival of varroa mite in Australia was on a swarm of honey bees from New Zealand.
“That seems like the most likely path,” she said. “It is being investigated.”
“There could have been a swarm on a vessel and varroa absconded on the mainland. Or it could have been an illegal import, but it’s really hard to work it out,” she said.
On average an incursion takes “about 10 generations to become apparent to us”, she said. This means varroa mite may have been present in Australia for months before it was first detected on June 22.
“I doubt we’ll ever be conclusive about how they entered,” she said.
Friday August 12
The total number of varroa mite detections in NSW has doubled over the last two weeks, as authorities race to eradicate the pest before spring arrives.
As of July 28, there were 44 varroa mite detections in the state. In the two weeks to August 11, that number had risen to 93.
Newcastle beekeeper and presenter of the Bee Therapy podcast Dani Lloyd-Prichard said the fight against varroa was a “race against time”.
Ms Lloyd-Prichard, who has five hives in an eradication zone, and was working with 25 beekeeper clients across the region until varroa mite struck, said she was already aware of three swarms leaving hives in the area – a red flag for further spread of the pest.
But she said the strategy authorities were employing to identify and eradicate outbreaks was working.
“They’ve been working with teams right on the edge of the red zones to determine the edge of the spread. That’s where they’ve been finding more infected premises. And that’s why you’re seeing more and more red zones are starting to either expand or pop up in other locations around the Hunter,” she said.
“They are finding the edge (of the outbreaks), and that is really, really good.”
The latest detections were inside existing eradication zones, with seven infected properties at Duckenfield, Thornton, Tarro, Nelsons Plains and Anna Bay identified in the last 24 hours.
Ms Lloyd-Prichard said she was waiting for the phone call to let her know authorities would be arriving to euthanise her bees.
Having spoken to friends and clients who had already lost their hives, she said the experience for many people was “crushing”, but she knew eradication had to take place to save the rest of the country from battling outbreaks.
“If we can (eradicate varroa), we have to try. We’ll sacrifice for the better good,” she said.
But the collective impact on beekeepers in the region would be huge.
“I don’t even know what (The Hunter Valley amateur beekeeping club), will do over the next three years other than have therapy sessions,” she said.
When authorities arrived to euthanise bees “it’s like space people are walking around your backyard in the dark, you don’t see their faces, all you see are these white suits. They’re wearing these headlight lamps, and they’re glowing red. They go around to each of the hives and they’ll be looking at the entrances, they slide open the lid carefully and tip the petrol or put the rag in … And then at the end of their exercise, they switch their lights from red to white,” she said.
“Watching from a distance, that tells you your bees are dead.
“It’s crushing. It’s so, so sad.”
NSW Apiarists Association president Steve Fuller said on Friday the increased number of detections over the past two weeks was “expected” and he was confident authorities would be able to eradicate varroa mite in NSW.
Tuesday August 2
Varroa mite has been discovered at a property in NSW’s Tocal, revealing the parasite has spread outside of authorities’ surveillance zones.
The latest detection of the dreaded honey bee pest was discovered on Monday, about 100km north of Maitland in the lower Hunter Valley, along with another four new properties with infected hives inside of red zones.
NSW DPI staff have established three zones as part of their gargantuan effort to eradicate the pest that was first discovered in a sentinel hive at the Port of Newcastle on June 22.
Red zones extend 10km around a known infection site. All hives within these zones are being progressively checked and euthanized to arrest the pest’s spread.
NSW Apiarists Association president Steve Fuller said as of Tuesday morning, the number of infected premises sat at 61.
“We expect that figure to grow, it’s nothing alarming” he said, pointing to the fact that of the roughly 18,000 hives that have been checked, only about 11 per cent were infected with varroa.
“All in all, where it’s at for its 41st day is pretty much on target,” Mr Fuller said.
DNA sequencing that would reveal the origin of the pest is expected to be revealed this week.
So far 4000 hives have been euthanised.
NSW Farmers Coffs Harbour Branch chair Paul Shoker said he was relieved no new detections have been made in the prime horticultural region, following its first detection last week.
He said farmers and beekeepers now needed clarity about when beekeepers could re-enter the region to pollinate millions of dollars worth of berry, avocado and macadamia crops.
“Growers are concerned because they’ve had a tough year in terms of flooding and they’re looking forward to getting those bees out and maximising their yields,” Mr Shoker said. “For most growers here, that pollination period starts in two weeks time.”
Tuesday July 26
A detection of varroa mite in a major NSW horticultural region has prompted concerns this outbreak could be harder to control due to warmer temperatures and large, active bee populations.
Varroa mite was discovered northwest of Coffs Harbour, 400km north of the original outbreak in Newcastle, on Monday.
NSW Farmers Coffs Harbour Branch Chair Paul Shoker said the outbreak could have a “devastating” impact.
“This is the first major horticultural region where we have seen these detections, and it is going to have a real impact on the industry,” he said.
Blueberry crops in the region were now in full flower, meaning bees were active and transmission of the varroa parasite between sites was a real possibility, he said.
“We’re just heading into peak blueberry season, where there are thousands of workers on farm and thousands of beehives.
“It’s going to be very hard to contain,” he said.
“If this had occurred in March it would have been less of a worry because there would be less flowering happening,” Mr Stoker said.
“This is not going to be a couple of weeks and then we’re all good again. It could be months or years. I expect this to be an ongoing issue.”
The new detection brings the total number of infested premises to 43 since varroa mite was first identified during routine surveillance at the Port of Newcastle on 22 June.
NSW DPI has established emergency zones around the infested premises and has put significant measures in place to stop the spread of the Varroa mite
NSW DPI tracing efforts discovered this infested premises near Nana Glen, where hives were moved in earlier this year, prior to our Biosecurity Emergency Order was in place. This property has links to existing infested premises in the Hunter cluster.
Monday July 18
The almond industry says it will be hit with significant losses this season despite a plan by NSW and Victorian authorities to allow controlled movement of beehives ahead of pollination season.
Agriculture Victoria announced on Friday the movement of beehives into Victoria from NSW would remain banned to limit the potential spread of varroa mite – a parasite capable of wiping out honeybees – which has been detected at 40 premises in NSW as of Monday.
Under the plan, beekeepers would be granted permits to move beehives into northwest Victoria from South Australia and Queensland, Victoria’s chief plant health officer Dr Rosa Crnov said.
Meanwhile NSW announced beekeepers outside eradication, surveillance or notification zones would be able to apply for movement permits from this week, the NSW Department of Primary Industries said.
Almond Board of Australia chief executive Tim Jackson said almond growers in northwest Victoria – Australia’s largest almond growing region – who relied on hives from NSW, would be left 80,000 hives short under the plan, with industry losses of at least $400 million.
He called on NSW and Victorian governments to work together to implement “bee bubbles” to allow the movement of bees between states in Murray River towns.
“Right now, there is certainly frustration that despite our industry’s hefty commitment to eradicate varroa, we are facing industry losses of at least $400 million if we can’t develop these bee bubbles right on the Victoria border,” Mr Jackson said.
Australia’s largest almond producer, Select Harvests, said in a statement to investors last week it was “increasingly likely” this year’s almond pollination would be disrupted.
“With 50 per cent of the pollinating industry’s hives in NSW, a potential shortage in Victoria and South Australia is looking like a reality,” the statement said.
However the plan has reduced potential industry losses. One week ago, Mr Jackson estimated if no bees were allowed into Victoria from or via NSW, the industry would be 200,000 hives short and facing potential losses of $750 million.
Dr Crnov said the Victorian permit system and on the ground monitoring of hives would “help protect bees during this busy time and assist efficient tracing if varroa mite is detected”.
To report suspected varroa mite, call the exotic plant pest hotline on 1800 084 881.
Friday July 15: New outbreak at Wards River
A new varroa mite detection in NSW on Thursday is the first new detection of the pest since Sunday.
Varroa mite was detected in hives at a property at Wards River, northwest of Bulahdelah, on Thursday.
The detection is the first since Sunday July 10, and brings the total number of infested premises in NSW to 39.
As of Friday, hives remain locked down in NSW to contain the varroa mite outbreak and are unable to move to orchards to pollinate crops until the standstill order is lifted.
Industry groups say it is increasingly likely the varroa mite outbreak could be contained, but pollination is likely to be disrupted for early flowering crops like almonds.
Monday July 11: New outbreaks west of Newcastle
New varroa mite emergency zones have been declared in NSW over the weekend after the parasite was detected at sites west of Newcastle.
Varroa mite was found on properties in Jerrys Plains, Denman and Heatherbrae on Saturday, bringing the total number of infested premises to 38 since June 22.
Australian Honey Bee Industry Council acting chief executive Danny Le Feuvre said authorities were still confident they would be able to eliminate the pest from the country.
“We’re still thinking we’ve got it contained. Every new site that we find is an effort of tracing. So it’s a direct line of sight to the original infected premise,” Mr Le Feuvre said.
“We’re still very confident, we’re still very much on track and pushing towards eradication.”
Rain and flooding across the state had been “causing a lot of headaches” for inspection teams, but cold weather was helping to minimise the movement of bees.
“It’s really slowed down field operations, but at the same time, it’s also meant because it’s been so wet and cold that the bees haven’t been flying either,” he said.
Mr Le Feuvre said authorities were working to develop a permit system that would allow beekeepers to transport their hives to almond crops in August.
“All our decisions are around risk, and making sure that we don’t take unnecessary risks in terms of varroa spread. And if that means that we can’t do pollination because the risk is too great, then that’s what will have to happen,” he said.
“But at this stage, we believe that we are working very hard towards having a permit system in place towards the end of July.”
Friday 8 July: Almond industry facing $750m losses
The almond industry could lose crops worth $750 million if orders preventing the movement of NSW beehives aren’t lifted by July 24, the industry peak body says.
Almond Board of Australia chief executive Tim Jackson said growers in the Sunraysia region of northwest Victoria and south east NSW were reliant on honey bees to pollinate their crops when almond trees bloomed in August.
Industry modelling as of Friday showed about 200,000 out of the 300,000 beehives needed in the Sunraysia region were stuck in NSW and unable to move.
“We are a pretty anxious industry at the moment,” Mr Jackson said.
“Sunraysia is the engine room of the Australian almond industry,” he said.
The region hosts more than 28,000ha of almonds – almost half of all almonds planted in Australia.
Standstill orders put in place by NSW authorities to prevent the spread of varroa mite mean hives cannot be moved either within NSW or from NSW to Victoria.
“We’ve got a $1 billion crop coming (in Sunraysia) if we can get it pollinated,” Mr Jackson said.
“We’ve got a scenario right now we’ve got 145,000 hives in NSW on lockdown, and we’ve got between 50,000 and 60,000 Victorian hives on holidays in warmer climates in NSW that need to get back across the border for pollination.
“We’re talking about $750m of product that if it is unable to be pollinated, there is no other way around it. It will be lost.”
To beekeepers, the pollination of Australian almond orchards is worth $45-$50 million annually, according to almond industry estimates.
Mr Jackson said any delays to lifting standstill orders later than July 24 would be very costly to the industry.
So far heavy rain and flooding in NSW meant surveillance efforts were proceeding slower than hoped, he said.
“There are a number of surveillance teams out and about, but unfortunately that activity has been frustrated by the record rains and floods.”
Mr Jackson said the industry already used almost all the commercial beehives it was able to access in Australia so it had little room to move.
“I think there needs to be a commonsense approach. If we get to the point where varroa is out and it can’t be contained … we have to work with it and manage it. We have to be pragmatic about it,” Mr Jackson said.
Varroa mite was first detected in Newcastle on June 22 and the NSW Department of Primary Industries had euthanised 1693 hives at 34 infested premises as of Thursday.
NSW DPI told The Weekly Times this week the agency had a team of more than 200 on the ground monitoring hives across the state.
The agency is working together with the apiary industry, Local Land Services, NSW Police, NSW Rural Fire Service and volunteers to detect and euthanise infested hives.
July 4: Infected hives found 400km from Newcastle
On Monday the NSW Department of Primary Industries announced new varroa mite infections had been confirmed in Narrabri, Ferodale and Lambton, more than 400km from the first detected outbreak in Newcastle.
To date DPI has euthanised more than 1000 bee colonies, with 19 infested premises detected.
All infections detected so far are epidemiologically linked to previously known cases in the Newcastle area.
A NSW DPI spokesman said the agency was confident the staff and resources available to it were adequate to contain the spread of the pest.
July 1: Horticulture and honey industries ‘preparing for the worst’
Speaking to The Weekly Times on Friday, Victorian Farmers Federation beekeeping branch president Peter McDonald said beekeepers were “preparing for the worst”.
“ (Varroa mite) is an insidious pest. It can kill hives quite effectively,” Mr McDonald said.
If varroa mite became established in Australia, beekeepers would be able to continue producing honey and providing services to agriculture, but the effort and labour cost of managing hives would increase substantially, he said.
“The input costs to our business would go up markedly, and that is going to have a flow-on effect.”
Victorian Farmers Federation horticulture president Nathan Free said horticulturalists were “very, very nervous” about the potential spread of varroa mite, as many were reliant on the pollination services beekeepers provided.
“Bees are a must-have for most of horticulture in Victoria, all the way from almonds in the north down to apples in the south and vegetables across the state,” Mr Free said.
Blueberries, cherries, stone fruit, pears and avocados could also be affected by the incursion, industry groups say.
Almond producer Select Harvests hit hard
Almond producers are already feeling the impact of the pest’s incursion into the country, with the planned migration of thousands of beehives from NSW to crops in NSW and Victoria on hold.
Australian Securities Exchange-listed almond producer Select Harvests announced last week the lockdown of beehives in NSW threatened to disrupt the pollination of more than 40 per cent of its orchards.
The company’s orchards rely entirely on pollination by honey bees to produce commercial crops.
Select Harvests managing director Paul Thompson said the varroa mite outbreak was an “extremely serious issue” for the company, which needed hives in place by August when almond orchards bloom.
“In the event the incursion does not get contained, it will impact Select’s 2023 crop pollination,” he said.
Mr Thompson said the inability to move hives in or out of NSW meant 29 per cent of the company’s orchards located in NSW would be affected, in addition to 11 per cent of interstate orchards dependent on NSW hives, and four per cent of orchards dependent on hives from Queensland, which could now not travel through NSW.
The Federal and State Governments, in consultation with key industry bodies, are reviewing the establishment of a certification system that would allow bees to freely move between Queensland, Victoria and South Australia in order to allow apiarists to provide pollination service to agricultural crops.
Why is this outbreak worse than previous outbreaks?
Australia’s national varroa mite eradication program, which has been in place since June 2016, has so far managed to contain incursions of the pest.
The species varroa jacobsoni was detected at the Port of Townsville in May 2019 and April 2020. Hives in the area were destroyed and the incursion was successfully contained.
The Port of Newcastle detection has been confirmed to be the species varroa destructor, which is considered to be more damaging than varroa jacobsoni.
Mr McDonald said varroa destructor was adapted to breed on the European honeybee, while varroa jacobsoni was adapted to breed on Asian honeybees.
Varroa destructor is capable of “outbreed(ing), outcompet (ing) and transmit(ting) disease among a hive”, he said.
On the positive side, Mr Le Feuvre said current cold temperatures should slow the NSW outbreak.
“We’re lucky because we are in winter at the moment. So there is minimal honey production and minimal movements,” he said.
How varroa mite management would work
Australian Honey Bee Industry Council acting chief executive Danny Le Feuvre said if varroa mite pest unable to be eliminated from Australia, apiarists will be able to adopt management practices similar to those employed overseas to continue to be able to provide pollination services to agriculture.
“One of the key things will be determining (the varroa mite’s) country of origin. That will give us a good picture of how to manage them,” he said.
“We know in different countries there is different resistance to chemicals.”
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