Controlling Varroa – 89% Of Large-Scale Beekeepers Said They Use Chemical Varroacides, While 61% Of Small-Scale Beekeepers Do

Catch the Buzz May 23, 2019

varroa mite on bee.jpg

With the Varroa destructor mite a pernicious pest of managed honey bee colonies across North America, beekeepers have a variety of control methods to choose from to reduce the mites’ impact on their hives. Which ones do they most prefer?

To answer that question, researchers at the University of Maryland and the Bee Informed Partnership analyzed four years of data from surveys that asked beekeepers about their Varroa-management methods. Their findings, reported in a new study published in April in the Journal of Economic Entomology, highlight a wide variety of combinations of methods used and indicate a lack of any perceived “silver bullet” option for controlling Varroa mites.

Among the range of practices, though, some patterns emerged, says Ariela Haber, Ph.D., lead author of the study and a postdoctoral researcher at the University of Maryland at the time it was conducted. (Haber is now a postdoctoral researcher at the U.S. Department of Agriculture-Agricultural Research Service.) For instance, 89 percent of large-scale beekeepers (managing 50 or more colonies) said they use chemical varroacides, while 61 percent of small-scale beekeepers said they did. And, while about half of large-scale beekeepers said they use nonchemical methods (either exclusively or in combination with varroacides), about three-quarters of small-scale beekeepers said they use them.

Haber says these insights into use of Varroa-management methods “take into account important considerations such as affordability and logistical constraints associated with different practices. Thus, the findings can inform future experiments that directly test the efficacy of different Varroa management practices that beekeepers can realistically use.”

The survey data, which Haber analyzed with University of Maryland colleagues Nathalie Steinhauer and Dennis vanEngelsdorp, Ph.D., covered nearly 19,000 responses over a four-year period, asking beekeepers about their use Varroa-management methods among the bevy of options currently available:

bee informed survey results.jpg

Beekeepers were also asked about colony losses. Across all types of beekeeping operations, use of varroacides was associated with lower colony loss, with amitraz associated with better colony survival than all other varroacides. Meanwhile, among nonchemical methods, splitting colonies was associated with the lowest levels of colony loss, “although our results suggest that nonchemical practices have limited success as stand-alone controls,” the authors note in their report. The survey did not ask about intensity of Varroa infestations or other factors that can influence colony survival, so Haber and colleagues stress that the results are only observational and shouldn’t be interpreted to infer causal links between Varroa-management methods and colony survival rates.

The primacy of chemical management methods, however, indicates the ongoing challenge beekeepers face in managing Varroain their honey bee (Apis mellifera) colonies. Repeated use of varroacides has led to Varroa populations evolving resistance to at least two previously effective products. “Even though evidence from our study and from other studies suggests that chemical treatments tend to be more effective than nonchemical practices for controlling Varroa, we should be cautious in interpreting the results of any varroacide efficacy study and in making recommendations to beekeepers, as it is unlikely that any chemical control will be effective in the long term,” Haber says.

More broadly, Haber says she sees the intensive operations of managed honey bee pollination services in agriculture as an environment with multiple factors contributing to honey bee colony losses, such as low-quality pollen diets in monoculture crops to high-density colonies. “This suggests that honey bee colonies in the U.S. will be vulnerable—to problems we have already seen as well as new, unforeseen problems—as long as we keep our current system in place,” she says.

Read more - Source: Journal of Economic Entomology

See: https://beeinformed.org/

Propolis Power-Up: How Beekeepers Can Encourage Resin Deposits For Better Hive Health

Entomology Today By Andrew Porterfield April 16, 2019

Propolis is a pliable, resinous mixture that honey bees (Apis mellifera) create by mixing a variety of plant resins, saliva, and beeswax and which they apply to interior surfaces of their hives, namely at points of comb attachment and to seal up cracks and crevices on the interior side of hive walls. Greater propolis production is connected with improved hive health, and a new study finds a few simple methods beekeepers can employ to stimulate increased propolis production.

Propolis, a mass of plant resins built by honey bees inside their hives, has drawn attention in recent years partly because of its alleged (but as yet unproven) health benefits to humans. But, perhaps more important, it also shows health benefits to bees themselves. Created from resins and other oils and fats collected from trees, propolis helps preserve the structural integrity of a bee hive and protects against

Propolis has also been connected to benefiting honey bee (Apis mellifera) immune systems, saving energy that would otherwise have been used to protect against nest-invading beetles like Aethina tumida or parasites like the Varroa destructor mite, Nosema fungus, and viruses. In the past, some beekeepers have tried to keep their hives “clean” of propolis, believing it impeded with honey-making activities. Today, though, scientists and beekeepers have begun looking at encouraging propolis production to help sustain healthy hives.

In a new study published recently in the Journal of Economic Entomology, three researches—Cynthia Hodges, master beekeeper and co-owner of Hodges Honey Apiaries in Dunwoody, Georgia; Keith Delaplane, Ph.D., entomology professor at the University of Georgia; and Berry Brosi, Ph.D., associate professor of environmental science at Emory University in Atlanta—looked at four different ways to enhance propolis growth in bee hives. The team found that three surface modifications—plastic trap material on the hive wall interior, parallel saw cuts on hive wall interior, and brush-roughened wall interiors—were all equally capable of resulting in increased propolis production, compared to a fourth method, a control, in which the hive wall interiors we left unmodified.

The researchers divided 20 colonies into five apiary sites and randomly applied one of the three texture treatments or control to each colony. Bees in the colonies foraged for propolis resins from plants common to the Appalachian Piedmont in the southeastern U.S., including conifers, oaks, pecan, red maple, yellow poplar, and urban ornamental plants. The researchers then measured extensiveness and depth of propolis deposits in the hives over time.

Their results showed that any hive interior treatment significantly increased propolis deposition compared to a non-treatment control. Sampling over time showed propolis hoarding and accumulation, as well. None of the texture treatments showed significantly different results from each other.

While all treatments resulted in more propolis deposition, the researchers point to the roughened interior of the hive walls as the best method for encouraging deposition. In fact, leaving lumber naturally rough, with no planning or sanding, would provide a simple and effective surface for boosting propolis, they write.

“We come down in favor of roughened or un-planed wood,” says Delaplane, “because, unlike the plastic trap, it will not subtract from the bee space engineered around the walls and combs. What you see in our pictures is the work of a steel brush. Naturally un-planed wood would be much rougher and, I would expect, even better at stimulating propolis deposition.”

Other researchers have shown that propolis development has a strong effect on the members of the bee hive. These other investigations have shown that interior walls painted with propolis extract resulted in colonies with lower bacterial loads and with worker bees that expressed lower levels of immune gene expression. Sustained activation of immune genes comes at an energy cost, which can result in a reduction in brood numbers and pose a threat to overall colony health. Further studies have shown that reduced immune activation (and therefore less energy spent on fighting infection) comes from reduced pathogen loads in high-propolis colonies and not from immune suppression by propolis.

“I don’t know of any beekeepers deliberately encouraging their bees to collect propolis,” says Delaplane, adding that many keepers in the past have tried to clear propolis from their hives. “But today we know that this bias is misdirected. I believe encouraging propolis deposition is one more thing beekeepers can do to partner with biology instead of ignore it.”

https://www.beeculture.com/catch-the-buzz-propolis-power-up-how-beekeepers-can-encourage-resin-deposits-for-better-hive-health/?utm_source=Catch+The+Buzz&utm_campaign=5b74875a68-Catch_The_Buzz_4_29_2015&utm_medium=email&utm_term=0_0272f190ab-5b74875a68-256252085

https://academic.oup.com/jee/article-abstract/112/2/986/5199372?redirectedFrom=fulltext

Massive Loss Of Thousands Of Hives Afflicts Orchard Growers And Beekeepers

NPR Heard on All Things Considered By Anna King February 18, 2019

Bret Adee, a third-generation beekeeper who owns one of the largest beekeeping companies in the U.S., lost half of his hives — about 50,000 — over the winter. He pops the lid on one of the hives to show off the colony inside.  Greta Mart/KCBX

Bret Adee, a third-generation beekeeper who owns one of the largest beekeeping companies in the U.S., lost half of his hives — about 50,000 — over the winter. He pops the lid on one of the hives to show off the colony inside. Greta Mart/KCBX

Almond bloom comes nearly all at once in California — a flush of delicate pale blooms that unfold around Valentine's Day.

And beekeeper Bret Adee is hustling to get his hives ready, working through them on a Central Valley ranch before placing them in orchards.

He deftly tap-taps open a hive. "We're gonna open this up, and you're going to see a whole lot of bees here," Adee says.

Under the lid, the exposed sleepy occupants hum away. He uses a handheld smoker to keep them calm and huddled around their queen.

This third-generation beekeeper works night and day with a crew of more than 35. Adee has been busy staging more than 100 semi truckloads of his honey bee hives in almond orchards over a 200 mile swath of the Central Valley.

When temperatures rise and the blooms open, his bees wake up and go to work. It's his hives' first yearly stop on a 6,500-mile tour across the nation.

But this almond bloom, Adee's scrambling more than usual.

Deadouts

Adee lost more than half of his hives over the winter — 50,000. And he's not alone.

"You know, in September, I thought we had the most awesome bees ever," Adee says. "The bees looked incredibly good."

Like Adee, many beekeepers across the U.S. have lost half their hives — they call one with no live bees inside a "deadout." Some beekeepers lost as many as 80 percent. That's unusual. And many of the hives that did survive aren't strong in numbers.

A healthy hive able to pollinate has at least eight frames mostly covered in bees on both sides. But the fear this year is that there will be many weaker hives put into California almond orchards for pollination because so many hives have died across the country.  Greta Mart/KCBX

A healthy hive able to pollinate has at least eight frames mostly covered in bees on both sides. But the fear this year is that there will be many weaker hives put into California almond orchards for pollination because so many hives have died across the country. Greta Mart/KCBX

For decades Adee says if he lost 5 percent he really got nervous. Now a 40 percent loss every few years is more common, he says. But this many lost hives across the country is concerning.

Every hive

California almond orchards have grown so much over the past 10 years, the bloom requires nearly every commercial hive available in the United States.

Almonds have grown from 765,000 acres to 1.33 million acres in the last decade. Bees travel from as far as Florida and New York to do the job. Without these hives, there is no harvest.

Almond bloom is just as important to the beekeepers. It's a chance to make nearly half their yearly income, and a place for the bees to work and grow early in the spring while healing up from winter.

This year, many beekeepers have had to tell their orchardists that they won't have enough bees this year to cover their entire contracts. And some orchardists are desperately calling beekeepers. Some report pollination prices going up.

Sneaky suckers

Experts say honey bees are dealing with many stressors: chemicals, loss of wildflowers, climate change, nutrition and viruses. But this year, a special problem might have taken down the honey bees more than usual.

A matrix of almond branches show off delicate early blooms near Lost Hills, Calif. Almonds have grown from 765,000 acres to 1.33 million acres in the last decade.  Greta Mart/KCBX

A matrix of almond branches show off delicate early blooms near Lost Hills, Calif. Almonds have grown from 765,000 acres to 1.33 million acres in the last decade. Greta Mart/KCBX

A tiny parasite called the varroa mite sucks at the bee's body, causing big problems.

Ramesh Sagili, a bee expert with Oregon State University, predicted these big bee losses because of mites earlier last year.

"It's a very lethal parasite on honey bees," Sagili says. "It causes significant damage not only to the bee, but to the entire colony. A colony might be decimated in months if this varroa mite isn't taken care of."

He says unusually early and warm spring weather last year made the bees start rearing baby bees early. That gave varroa mites a chance to breed and multiply too.

Varroa mothers crawl into the cells of baby bees and hide there until the bees close the cell up with wax. Then they lay an egg and rear their young on the baby bee.

Emotional sting

When the almond blooms fade, beekeepers will truck their hives across America — from the Northwest and Dakotas to the South and Maine, chasing spring.

Eric Olson, 75, of Selah, Wash., points out the fruiting wood on his cherry tree. Pruning helps to open the canopy so the fruit can ripen well, and cuts back on fast-growing branches called suckers that can sap the tree's energy away from the valuable fruit.  Anna King/Northwest News Network

Eric Olson, 75, of Selah, Wash., points out the fruiting wood on his cherry tree. Pruning helps to open the canopy so the fruit can ripen well, and cuts back on fast-growing branches called suckers that can sap the tree's energy away from the valuable fruit. Anna King/Northwest News Network

In Eric Olson's foggy and frosty Washington state cherry orchard, bloom is still a while off. His crew is busy pruning away the wood that would block light to the fresh fruit.

He's helps manage one of the largest beekeeping businesses in the Northwest.

He says their hives experienced a dramatic loss this year. But it's not as bad a when he lost about 65 percent of them.

"That's when I cried," says Olson, who served 20 years in the Air Force. "I was a pilot and I spent my time in combat situations. Never in my life was I as low as when we lost 65 percent of those bees."

Chasing spring

Still, spokespeople for the almond industry are saying it's all fine.

"Orchard growers who have long-standing relationships with beekeepers are not experiencing problems," says Bob Curtis, a consultant for the Almond Board of California. "Folks that are having trouble are the ones that don't make the contracts in the fall with beekeepers."

If Northwest growers line up beekeepers early, Olson says he expects there will be enough bees for the region's smaller fruit tree bloom. Still, he's worried for his orchardist friends.

"If I can't get bees in my cherries I'm in trouble," Olson says. "I don't have a crop. What do I do? I don't know."

Surveys later this spring will give a better idea of nationwide bee losses, but that might be too late for orchardists at the end of the pollination line.

This story comes to us from the Northwest News Network.

https://www.npr.org/sections/thesalt/2019/02/18/694301239/massive-loss-of-thousands-of-hives-afflicts-orchard-growers-and-beekeepers

Varroa Mites Feed On The Fat Bodies Of Honey Bees, Not The Hemolymph. This Is Important!

Catch The Buzz By Dennis O’Brien January 30, 2019

cross section of honey bee abdomen.jpg

An image showing a cross section of a varroa mite feeding on a honey bee’s abdominal cavity is one of several ARS microscopy images changing what we know about how mites damage honey bees.

Research by scientists at the Agricultural Research Service (ARS) and the University of Maryland released today sheds new light — and reverses decades of scientific dogma — regarding a honey bee pest (Varroa destructor) that is considered the greatest single driver of the global honey bee colony losses. Managed honey bee colonies add at least $15 billion to the value of U.S. agriculture each year through increased yields and superior quality harvests.

The microscopy images are part of a major study showing that the Varroa mite (Varroa destructor) feeds on the honey bee’s fat body tissue (an organ similar to the human liver) rather than on its “blood,” (or hemolymph). This discovery holds broad implications for controlling the pest in honey bee colonies.

The study was published on-line Jan. 15 and in today’s print edition of the Proceedings of the National Academy of Sciences. An image produced by the ARS Electron and Confocal Microscopy Unit in Beltsville, Maryland is on the cover of today’s journal.

Varroa mites have been widely thought to feed on the hemolymph, of honey bees (Apis mellifera) because of studies conducted in the 1970’s which used outdated technology. But today’s collaborative study, by University of Maryland and ARS researchers at the ARS Electron and Confocal Microscopy Unit, offers proof of the mite’s true feeding behavior. Through the use of electron microscopy, the researchers were able to locate feeding wounds on the bee caused by the mites, which were located directly above the bee’s fat body tissue. The images represent the first direct evidence that Varroa mites feed on adult bees, not just the larvae and pupae.

In addition, University of Maryland researchers conducted feeding studies and found that Varroa mites that were fed a diet of fat body tissue survived significantly longer and produced more eggs than mites fed hemolymph. The results show, mites fed a hemolymph-only diet were comparable to those that were starved. Thus, proving conclusively that the Varroa mite feeds primarily on the fat body consumed from bees.

The results are expected to help scientists develop more effective pesticides and other treatments to help bees cope with a mite known to spread at least five viruses. They also help explain why Varroa mites have such detrimental effects on honey bees, weakening their immune systems, and making it harder for them to store protein from pollen and survive through the winter.

The study was part of the Ph.D. thesis of Samuel D. Ramsey from the University of Maryland and was conducted in collaboration with ARS researchers and study co-authors Gary Bauchan, Connor Gulbronson, Joseph Mowery, and Ronald Ochoa.

The study can be found here.

The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.

Catch The Buzz: Varroa mites feed on the fat bodies of honey bees

Also see: https://www.losangelescountybeekeepers.com/blog/2019/1/15/honey-bee-parasites-feed-on-fatty-organs-not-blood

Bee Mite Arrival in Hawaii Causes Pathogen Changes in Honeybee Predators

UC Riverside By Iqbal Pittalwala January 8, 2019

bee mite arrival in Hawaii.jpg

UC Riverside-led research, done on the Big Island, shows effects of mite introduction have cascaded through entire pathogen communities

The reddish-brown varroa mite, a parasite of honeybees and accidentally introduced in the Big Island of Hawaii in 2007-08, is about the size of a pinhead. Yet, its effects there are concerning to entomologists because the mite is found nearly everywhere honeybees are present.

A team led by entomologists at the University of California, Riverside, performed a study on the Big Island and found viruses associated with the mite have spilled over into the western yellowjacket, a honeybee predator and honey raider. The result is a hidden, yet remarkable, change in the genetic diversity of viruses associated with the larger pathogen community of the mite and wasp, with repercussions yet to be understood.

Erin Wilson Rankin examines a western yellowjacket. (I. Pittalwala/UC Riverside)

Erin Wilson Rankin examines a western yellowjacket. (I. Pittalwala/UC Riverside)

“Already, we are seeing that the arrival of the varroa mite in honeybee populations in Hawaii has favored a few virulent strains,” said Erin E. Wilson Rankin, an assistant professor of entomologyand lead investigator of the study published Jan. 9 in the Proceedings of the Royal Society B. “We do not know what the effects of these strains will be. What we know is that the effects of the varroa mite have cascaded through entire communities in Hawaii and probably around the world.”

In particular, the researchers saw a loss in the diversity of deformed wing virus, or DWV, variants, resulting in new strains whose impact is hard to predict. DWV, widespread in honeybee populations globally and made up of several variants, is thought to be partly responsible for global die-off of honeybee colonies. DWV infects bumblebees and has been detected in other insects. The yellowjacket wasps can acquire this virus directly or indirectly from honeybees.

The western honey bee.

The western honey bee.

By a stroke of luck, the researchers had the benefit of studying the honeybee and yellowjacket populations on the Big Island both before and after the varroa mite was introduced there. They saw more association of honeybees with pathogens after the appearance of the mite. Indeed, some pathogens were detected in the honeybee and wasp populations only after the mite was introduced to the island.

“This is one of the first descriptions of pathogens in the western yellowjacket,” Wilson Rankin said. “Evidently, pathogens known to be associated with varroa have spread into non-bee species, despite the mite itself being a bee specialist. We suspect the spread in yellowjackets is partly due to the wasp’s propensity to prey upon bees, which is one way the wasps may be exposed to the pathogens.”

Wilson Rankin noted the pathogens are often incorrectly called “bee pathogens” because they were first found in bees. The pathogens, however, are found in a wide variety of insects.

“We are seeing entirely different predators being affected,” she said. “The mite is not vectoring viruses to the wasps. The viral spread is happening through predation and through flowers. Predators may be passing on pathogens to other species. The yellowjacket, for example, preys on both honeybees and native bees, and may explain why both bee populations are showing the same viruses.”

Wilson Rankin explained wasps have been overlooked by researchers because these arthropods do not have “warm, fuzzy, and furry connotations.”

The western yellowjacket is a honey bee predator and honey-raider.

The western yellowjacket is a honey bee predator and honey-raider.

“They look scary,” she added. “People also get stung by them. People are more afraid of wasps than bees. But our work shows we can examine the health of the arthropod community by using species other than bees. We show for the first time that a predator is being affected by a parasite that does not even infect it.”

The researchers sampled 25-45 bees and wasps for one part of the study, and then about 100 individuals, analyzed in groups, for each of the species during the period before and after the mite was introduced to the Big Island. The researchers did not study native bees, focusing instead on honeybees and yellowjacket wasps, neither of which is native to Hawaii. 

“Our findings suggest that pathogen transmission from domesticated bees, such as honeybees, may be important even for non-bee insects like the wasps we studied,” said Kevin J. Loope, the research paper’s first author, who worked as a postdoctoral scholar in the Wilson Rankin lab during the study. “The impacts may be more subtle than previously observed: we found changes in the genetic variation of viruses found in the wasps, but not changes in the amount of virus. These findings suggest we should look more broadly and in greater detail to figure out how moving domesticated bees for agriculture may influence wild populations of insects.

Loope, now a research assistant professor in the Department of Biology at Georgia Southern University, explained that finding overlap in the pathogens of yellowjacket wasps and domesticated bees also means that using pathogens to control undesirable wasp populations is risky.

“Any biological control efforts using pathogens should be carefully evaluated to prevent inadvertent harm to beneficial bees,” he said.

Kevin Loope excavates a yellowjacket nest in Volcano, Hawaii. (Jessica Purcell/UC Riverside)

Kevin Loope excavates a yellowjacket nest in Volcano, Hawaii. (Jessica Purcell/UC Riverside)

He added that the research team was surprised to find a dramatic difference in the viral genetic diversity between the wasp samples from the two periods — before and after the varroa mite was detected on the Big Island.

“We had predicted we would observe a decline in wasp viral diversity matching the decline described in honeybees in Hawaii, but we were still surprised to see this borne out in the data,” he said. “It’s not so often that you see what you’ve predicted in biology.”

Wilson Rankin and Loope were joined in the research by Philip J. Lester of Victoria University of Wellington, New Zealand; and James W. Baty of Malaghan Institute of Medical Research, New Zealand. Genetic analyses on the bee and wasp samples were performed at UCR and in New Zealand.

Wilson Rankin was supported by grants from the National Science Foundation and the Hellman Fellows Fund. Loope was supported by a postdoctoral fellowship from the National Institute of Food and Agriculture of the U.S. Department of Agriculture.

https://news.ucr.edu/articles/2019/01/08/bee-mite-arrival-hawaii-causes-pathogen-changes-honeybee-predators

The Signs of Mite Damage - How to Identify Progressed Varroosis?

Bee Informed Partnership    September 26, 2018

BIP Tech Transfer Team Member, University of Minnesota, Written by Garett Slater, posted by Anne Marie Fauvel

Varroa infested colonies entered the United States in ~1987, and changed beekeeping forever. Beekeeping has always been time consuming, difficult and experience oriented; however, beekeeping became even more challenging when beekeepers were called to eradicate a bug on another bug. Since its introduction in the US, beekeepers have reported high annual colony losses due to mites. In fact, some beekeepers report 60% losses due to this troublesome pest. While beekeepers have faced devastating challenges before, including American Foulbrood, Varroa mites has presented damages never before seen.

Varroa have become more difficult to manage since their introduction. The mites are seemingly embedded within the honey bee industry reality as nearly, if not all, colonies have Varroa. Like many beekeepers say: ” all my colonies have mites, I just cannot see them”. Even if alcohol washes do not reveal mites, Varroa is present in the brood or will be present soon due to infestation from surrounding colonies. As mites have become more widespread, they became a vector for a variety of viruses. In fact, researchers are finding more and more variants of Deformed Wing Virus (DWV), a virus that affects the honey bee’s essential flight capabilities. Research has shown that DWV-B (Deformed Wing Virus variant B) can be responsible for high over-winter losses.

The point here is that Varroa devastates colonies.  It would also seem that Varroa are transmitting more virulent strains of viruses with each passing year. Because of this, I recommend to keep mite levels below 1 mite/ 100 bees in the spring and below 3 mites/100 bees in the fall. With Varroa loads any higher, beekeepers risk high colony losses.

Monitor, Monitor, Monitor

Beekeepers must consistently monitor mites if they expect to have strong and healthy colonies. Beekeepers can monitor their mites in various ways, but I recommend both of these two methods: perform an alcohol wash (or other monitoring method) and observe the overt signs of mite damage. It is ideal to perform monitoring methods once a month, but we realize this is not always possible. Because of this, combining both monitoring and observation methods are recommended. Ideally, mites should be monitored at least 4 times a year.  As seen in Figure 1: population increase, population peak, population decrease, and fall dormant; it is essential to understand the seasonal changes. For example, brood density varies throughout the year, so certain treatments can be less effective at different times. By understanding seasonal cycles, beekeepers can better manage their mites. I understand Figure 1 does not reflect the reality of every region but it gives a good overall general idea.  Some regions have multiple population peaks due to large honey flows, so you will need to understand the honey bee seasonal phases in your region. But essentially, as the bee and brood population increase, so do the mites.

Figure 1: Honey bee seasonal phases – Beekeepers should monitor mites once a month, but if this is not possible, mites should be monitored at least 4 times a year: during the late winter-early spring dormant, population increase, population peak, population decrease, and fall dormant phases. I recommend alcohol washes (or another monitoring method) during these periods. Photo courtesy of the Honey Bee Health Coalition.

Mite Monitoring Techniques

I attached a chart outlining the 3 major mite monitoring techniques I recommend. Perform one of these techniques 4 times a year: Early spring, late spring, late summer and early fall. Each beekeeper has their preference, so use the method you feel the most comfortable with. I use alcohol washes, but I feel comfortable with sugar rolls or CO2 as well. As long as you monitor, there is not a wrong method!


Advantages 

Disadvantages 

Sugar Rolls

Known research on accuracy

Common method

May not kill bees

Messy

Hard to do on windy, rainy or humid days

More time consuming

Less accurate

Alcohol Wash

Well documented

Quicker than sugar rolls

Can be more accurate than sugar roll

Can be messy

Kills bees

CO2

Quickest method

Easy to do with multiple colonies

Kills the bees (most likely)

When monitoring for mites, beekeepers should review mite thresholds. I outline my recommended thresholds for each monitoring method below. If your colony is above threshold, I recommend taking actions. Mite thresholds are not an exact science, even if you have levels below the threshold, it is no assurance that your colonies will be healthy and successful. For example, I have sampled many commercial beekeepers with mite levels <0.5 mites /100 bees in the spring, and they eventually had huge losses. I typically see mite levels spike in the late summer because: A) summer treatment with honey supers are limited, B) Mites are often lurking in the brood, and C) Mites from other beekeepers nearby can (re)infest colonies. Because of this, always monitor and monitor again. Once mite levels do spike, they may be difficult to bring down. Too often, when you notice, the mite damage is already done. I should note that I recommend alcohol washes, powdered sugar rolls or CO2 over a sticky board. Sticky boards are not nearly as accurate, because they do not quantify the level of infestation. If a sticky board is your only option, you can attest that you have some mites or more mites, but you are not able to assess the level of infestation (1, 2, 3 mites/100 bees). Use other monitoring method options for more accurate results and an infestation level to compare with suggested thresholds. *These thresholds may vary per US regions. These are the threshold I recommend in the Midwest (MN & ND)

Monitoring Method

# of mites in early-spring

# of mites in mid-spring

# of mites in late-spring

# of mites in early-fall

# of mites in late-fall

Alcohol Wash

 

1 mite/100 bees

1 mite/100 bees

1 mite/100 bees

3 mite/100 bees

3 mite/100 bees

Powdered sugar roll

1 mite/100 bees

1 mite/100 bees

1 mite/100 bees

3 mite/100 bees

3 mite/100 bees

CO2

1 mite/100 bees

1 mite/100 bees

1 mite/100 bees

3 mite/100 bees

3 mite/100 bees

Sticky Board

9 mites/24 hours

9 mites/24 hours

9 mites/24 hours

12 mites/24 hours

12 mites/24 hours

Mite related Disease Progression 

I inspect and observe hundreds of colonies annually. When I enter a colony, I often immediately know whether it has (or did) have high mite levels simply by observing progressed signs of mite damage. Just observing progressed mite damage does not suffice, but it is a good start. By noting visual signs of Varroa, you will know just how important your mite levels are and the need for action. Monitoring is best but if you can recognize some of the visual signs, you will better understand the extend of the mite damage to your colony.

I outlined the 5 stages of mite damage, which I relay to my beekeepers. In the spring during population increase, I want to see colonies within the Stage 1- 2. While I hate to see mites in the spring, this is not always a bad sign. Even if I observe mites, the colony may be below the recommended threshold, so just continue to monitor that colony. During the late spring, summer and fall, I like to see colonies within Stage 1-3. Even if Chewed Down brood (CDB) (outlined below) and phoretic mites are seen, it does not mean that beekeepers have high levels. However, a combination of phoretic mites and CDB can signal worse mite issues. If these signs are seen, continue to monitor these colonies. As for Stage 4-5, I never want to see these stages, regardless of temporal period. Deformed Wing Virus (DWV) and Varroa Mite Syndrome (formerly Parasitic Mite Syndrome or PMS) can signify high mite levels.  Specifically for Varroa Mite Syndrome, it signifies very progressed mite damage, which often results in colony deterioration and eventual colony death. If colonies are in stage 4 or stage 5, monitor immediately to determine extent of damage. Action is often required, but may be too late.

 Stage

Visual Signs

Notes

Stage 1

Zero signs of mites, brood diseases or viruses


Stage 2

Visual signs of phoretic mites on either workers or drones.

 

This does not necessarily mean a mite issue exists, but if mites are seen, monitor to determine extent of varroosis.

 

Stage 3

Chewed Down Brood and/or phoretic mites

 

 

Stage 4

Deformed Wing Virus (DWV) and/or Chewed Down Brood and/or signs of phoretic mites.

Visual signs of Deformed Wing Virus (DWV) can mean larger varroa issues. Obviously, this depends upon the number of bees with DWV and the number of phoretic mites seen, but mite monitoring is recommended to determined extent of varroosis. These signs signal a more progressed form of varroosis.

Stage 5

Varroa Mite Syndrome (VMS) and/or Deformed Wing Virus (DWV) and/or Chewed Down Brood and/or Phoretic mites

Visual signs of Varroa Mite Syndrome usually signal extreme issues with varroasis. If Varroa Mite Syndrome is seen, then mite levels are often a significant issue and has advanced to the most progressed stage of varroosis.

Visual signs

Phoretic Mite

Phoretic mites are Varroa mites seen on the abdomen of worker (or drone bees). Most phoretic mites, however, are found underneath the bee, more precisely tucked between the abdomen’s sclerites where they latch on and feed. Because of this, I typically inspect the ventral abdomen of several worker bees during inspections. This is why beekeepers “never see mites”, even if these beekeepers have higher mite levels. Visually inspect phoretic mites just on the workers, not the drones. If phoretic mites are seen on worker bees, then this represents a more progressed infestation of mites. Signs of phoretic mites indicate the colony is in Stage 2-5. Visually inspect other signs to further pinpoint extent of damage.

Phoretic mite on the thorax of a worker bee. Photo by Rob Snyde Chewed Down Brood (CDB)

Bees can sense mites in the brood. If sensed, bees will uncap and cannibalize the pupae. If CDB is seen, then mites may be at a high level, especially within the brood. CDB can indicate progressed mite damage, so continue to monitor and assess colony health.

Deformed Wing Virus (DWV)

Deformed Wing Virus (DWV) represents the next stage of varroosis progression. Bees with DWV are kicked out of the colony so if bees with DWV are seen than Varroa has become an issue. DWV does not signify un-manageable mite levels for the colony, but it is a more progressed sign of mite damage.

The bottom right corner contains a cell with chewed down brood (CDB). Bees begin chewing brood when they sense mites within the cell, so this can indicate larger mite issues. Photo by Rob Snyder

This bee has deformed wing virus, a debilitating virus than can easily deplete a colony. Oftentimes, bees with the virus are removed from the colony. So if bees with Deformed Wing Virus are seen, than this can indicate larger issues. Photo by Rob Snyder

Symptoms

Spotty brood and Varroa present on adult

Mites may be present on brood

Mites seen on open brood cells

Small population size

No odor present, just sunken brood

Varroa Mite Syndrome (VMS) is the most progressed sign of mite damage. If VMS mite is seen, than the damage is done. These colonies will likely collapse, and there is nothing a beekeeper can really do. At this stage, the colony has already dwindled and deteriorated. Photo by Rob Snyder

Varroa Mite Syndrome (VMS)

A pathogen has not been identified for this diseased, however mites are always present when this disease is seen. This brood symptom looks similar to other brood diseases except the larvae do not rope like foulbrood. Larvae do appear sunken to the side of the cell. If Varroa Mite Syndrome is observed, then colony has likely dwindled and deteriorated. Varroa Mite Syndrome is the most progressed sign of mite damage, and truly at a stage of no return. Even if low phoretic mites are seen, Varroa mite syndrome often means an end to your colony, even if treatment is applied.



Summary

All beekeepers should consistently monitor mites throughout the year. Even if mite levels are low at one point, it does not mean they will stay low. Mite levels can easily spike, so always be aware and monitor and re-monitor. Beekeepers should learn how to monitor and visually inspect for mites. By doing so, varroa mites can effectively be managed. Varroa mites are the most challenging issue beekeepers face, so make sure you know where your colonies stand. If you don’t, then you risk losing your colonies.

https://beeinformed.org/2018/09/26/the-signs-of-mite-damage-how-to-identify-progressed-varroosis/

(Note: Thank you to Jaime E. Garza, Apiary/Agricultural Standards Inspector, Department of Agriculture, Weights & Measures, County of San Diego for the link and his quote, “With the lack of floral resources this year, Varroa mites may put more stress on your colonies. Hopefully the information will help give you a better idea of how to look for signs of Varroa mite infestations and encourage you to monitor and control them if you are currently not doing so.”)

Get Ready For The Mite-A-Thon! September 8 - 15, 2018

CATCH THE BUZZ     August 29, 2018

Spread The Word - Local Beekeeping Clubs And Associations Are Key To Making The Mite-A-Thon A Success!

GET READY FOR THE MITE-A-THON!
September 8 to 15, 2018      

The Mite-A-Thon is a tri-national effort to collect mite infestation data and to visualize Varroa infestations in honey bee colonies across North America within a one-week window.  All beekeepers can participate, creating a rich distribution of sampling sites in Canada, the United States, and Mexico.       

OBJECTIVE: 1) To raise awareness about honey bee colony Varroa infestations in North America through effective monitoring methods. 2) Management strategies will be made available for discussion within bee organizations utilizing Mite-A-Thon partner developed information and outreach materials.     

PARTICIPANTS: All beekeepers in North America are encouraged to participate.

WHAT YOU NEED TO DO: 

Encourage your members to participate in September, through meetings, newsletters, emails, social media etc. 

Teach new beekeepers how to monitor for mites in August.

Help your members prepare their monitoring materials.

Support your members in making sure they are able to monitor mites effectively and report their data.

DATA COLLECTION: Varroa monitoring data will be uploaded to www.mitecheck.com.  

CONTACT: miteathon@pollinator.org or 415 362-1137

Get resources and stay up to date at www.pollinator.org/miteathon!

Thank you,

The Mite-A-Thon Partners

https://www.beeculture.com/catch-the-buzz-local-beekeeping-clubs-and-associations-are-key-to-making-the-mite-a-thon-a-success/

How Do Varroa Mites Feed on Bees?

Western Apicultural Society FB Post  June 17, 2018

Sammy Ramsey, of the vanEngelsdorp Bee Lab, University of Maryland, spoke at the April meeting of the Alameda (CA) Beekeepers Association. This is a summary of his research findings, published in the most recent ABA newsletter.

HOW DO VARROA MITES FEED ON BEES?

Conventional wisdom is that Varroa mites feed on bees' hemolymph, which is like blood. When Sammy reviewed the research, he didn't think it actually supported that.

His PhD thesis was to determine how mites feed and what they feed on. He compared Varroa mites to other arthropods that feed of hemolymph or blood and found differences:
• Their digestive systems and excrement are quite different
• They are not closely related genetically

Next, he did an observational study of where on bees Varroa mites fed. Looking at mite placement, he found 99 percent of mites on the bottoms of the bees, wedging themselves under the plates called the metasomal sternites/tergites.

The mite pierce multiple layers of soft tissue in the membrane between sternites/tergites and then inserts its feeding tube to feed on the "fat body."

Bees typically have a long section of fat, the fat body, running along their undersides. This is an organ, not just a mass of tissue, with nine different functions, including growth and development; metamorphosis; metabolic activity; water and temperature regulation; protein synthesis; immune function; and synthesis of vitellogenin, the substance that allows some bees in the colony to overwinter.

When a mite has been feeding, it gets smaller and more dispersed. This indicates two things: The mite injects something into the bee to predigest tissue; and that fat is the mite's food.

Next, he stained the fat content and hemolymph of bees with specific stains that would fluoresce under a spectrophotometer. Then he put in mites and allowed them to feed. The mites consistently showed they had fed on fat.

Finally, he raised groups of mites off bees, feeding them on various combinations of fat body and/or hemolymph. Mites that were fed on fat body laid the most eggs. Mites fed only on hemolymph laid no eggs. Moreover, mites fed hemolymh died as quickly as those fed nothing. Those fed on fat body lived substantially longer.

His conclusion is that the mites feed on the fat body of the bee, not the hemolymph.

He has also found bacteria inside bees near the feeding wound, and the bee's immune system doesn't seem to attack them. The bacteria haven't been identified yet.

Mites that kill colonies the quickest are also the ones that have a better chance of dispersing into other colonies. He thinks beekeepers should treat or intervene in some way, for example, by removing drone comb right before the drones hatch. He advises using more than one type of treatment, so you reduce mites with different characteristics with the different methods.

Brood breaks are helpful, but there will still be mites on the adult bees.
His data shows that in four consecutive years, beekeepers who treated for Varroa lost fewer colonies than those who didn't treat.

Why does this matter? It shows:
• Need to update recommendations for treatment timing.
• Supplementing protein without controlling Varroa is not helpful.
• This info could lead to the development of systemic pesticides for Varroa.
• Important to make sure bees that will overwinter, which are developing in the cells in August, are not harmed by Varroa—so that's a good time to treat.

More about Sammy Ramsey: https://www.vanengelsdorpbeelab.com/samuel-ramsey.html

Refrigerating Honey Bees to Fight Mites, Colony Collapse

Washington State University     By Scott Weybright, College of Agricultural, Human and Natural Resouce Sciences     April 23, 2018

PULLMAN, Wash. – Saving Honey Bees Is Easier When Varroa Mite Infestation Is Reduced. WSU Researchers Are Hoping Mid-Season Hibernation Can Help In The Fight Against The Mighty Mites.

The black bump on this honey bee's back is a varroa mite. Mites weaken bees’ immune systems, transmit viruses, and siphon off nutrients. Photo by Scott Bauer, USDA Agricultural Research Service.

Varroa Mites Are Pests That Weaken Bees’ Immune Systems, Transmit Viruses And Siphon Off Nutrients. They’re A Huge Factor In Colony Collapse Around The Country.

“Most Treatments Only Kill Varroa On Adult Bees, And Are Generally Only Effective For Three Days,” Said Brandon Hopkins, Assistant Professor Of Entomology And Manager Of The WSU Bee Program. “But A Lot Of Mites Live In The Brood, Which Are Under A Wax Cap That Treatments Can’t Touch. Those Bees Hatch Out And Are Already Afflicted.”

Currently, Treating For Mites Requires Three Treatments Over A 21-Day Period To Make Sure You Treat All The New Bees That Come Out Infested With Mites.

These Treatments Are Difficult And Expensive Because Beekeepers Must Treat All Their Colonies On A Specific Schedule. It’s Very Labor Intensive To Treat Thousands Of Colonies By Hand Three Times At Precise Timing Cycles, Hopkins Said.

Cold Storage

Bees Don’t Truly Hibernate, But They Do Change Their Behavior In Winter. Queens Stop Laying Eggs, So No New ‘Brood’ Is Created At That Time.

Last August, WSU Researchers Put 200 Honey Bee Colonies Into Refrigerated Storage. This Is A Time When Bees Are Still Active, But Have Finished Making Honey For The Season, And There Are No Crops That Require Pollination. It’s Also When Beekeepers Normally Do A Round Of Mite Treatments.

By Placing Colonies In Refrigerators, The Queen Stops Laying New Eggs, Which Stops The Production Of Brood. When The Bees Come Out Of Refrigeration, There Is No ‘Capped Brood’.

At That Point, Hopkins And His Team Apply A Varroa Treatment On The Adult Bees.

The Initial Results Were Overwhelmingly Positive. Researchers Found An Average Of Five Mites Per 100 Bees On The Control Colonies (Not Refrigerated) One Month After The Normal Three-Cycle Mite Treatment.

The Refrigerated Colonies Had An Average Of 0.2 Mites Per 100 Bees One Month After The Single Mite Treatment.

“That’s A Significant Decrease,” Hopkins Said. “Refrigeration Is Expensive, So We Need To Do More Work To Prove The Cost Is Worth It For Beekeepers, But We’re Really Excited So Far.”

Additionally, The Infestation Levels Varied Tremendously From Colony To Colony In The Control Samples. That’s Because Of The Difficulty In Treating Colonies Consistently Over Three Cycles. The Colonies That Had The Refrigeration Treatment Had Consistent Mite Numbers With Little Variation.

Doubling Down

Brandon Hopkins in his bee lab.

After Hearing About This Research, A Few Beekeepers Approached The WSU Scientists About Doing A Similar Round Of Refrigeration In The Early Spring. Most Commercial Beekeepers In The U.S. Take Their Colonies To California For Almond Pollination In February And March. But There’s A Time Gap Between The End Of The Almond Pollination Season And The Start Of Pollination Season In The Northwest.

“Beekeepers Generally Have Two Periods Of Time For Mite Treatments, Before The Bees Make Honey And After,” Hopkins Said.

Once Bees Have Mites, The Infestation Increases During The Pollination And Honey Production Months.

“But If They Can Start With Low Mite Numbers, The Bees Are Healthier During The Honey Production Period,” Hopkins Said. “A Lot Of Varroa Damage Comes While The Bees Are Making Honey.”

Calculated Risk With 100 Colonies

This Spring, Belliston Bros., A Commercial Idaho Beekeeper, Donated 100 Honey Bee Colonies To Do A Refrigeration Study Just Like The One Done In August Last Year.

“It’s A Big Risk For Them,” Hopkins Said. “But If It Works, Beekeepers Would Have Significantly Better Varroa Control While Using Fewer Chemicals. And They’ll Have Better Colony Survival During The Following Pollinating Season. It’s A Win All-Around.”

Nobody Really Knows How Bees Will React To Being Put Back Into Their Winter Mode In What Is Normally The Middle Of Their Active Season, He Said. But That’s What Science Is All About. And If This Works, It Could Be A Major And Environmentally Sound Victory In The Great Varroa Mite Battle That Beekeepers Have Been Waging For Decades.

“We’re Hopeful,” Hopkins Said. “We Won’t Have Results Back For Several Months, But We’re Excited We May Have A Way To Help Beekeepers Keep Their Colonies Strong And Stable.”

https://news.wsu.edu/2018/04/23/refrigerating-honey-bees-fight-colony-collapse/

Accidental Discovery Could Save Bees From Their Greatest Threat

Real Clear Science     By Ross Pomeroy     January 15, 2018

Agricultural Research ServiceGerman scientists primarily based out of the University of Hohenheim have stumbled upon a simple solution that could deal a blow to honeybees' greatest threat. They've found that a tiny dose of the compound lithium chloride kills Varroa destructor mites without harming bees.

The scientists detailed their incredible findings in the January 12th publication of Scientific Reports.

V. destructor, more commonly known as the Varroa mite, is a scourge of honeybees across the globe. Upon infiltrating a colony, the mites latch on to bees, sucking their hemolymph (essentially blood) and spreading the diseases they carry. According to the USDA, 42 percent of commercial hives in the U.S. were infested in summer 2017, and 40 percent of beekeepers said the parasite seriously harmed their colonies. By comparison, only 13 percent reported harm from pesticides.

Chemical compounds exist to combat the parasites but they are outdated and growing increasingly ineffective, the researchers write, adding that no new active compounds have been registered in the last 25 years.

The dearth of options prompted scientists at The Hebrew University of Jerusalem to experiment with a technique called RNA interference. In their study, they fed bees double-stranded RNA via a sugar solution to knockout vital genes in Varroamites. The mites ingested the lethal RNA via bees' hemolymph and subsequently died.

Inspired by those results, the German researchers sought to replicate them by repeating the experiment with slightly tweaked methods. Indeed, mites infesting bees that were fed sugar water with the designed RNA rapidly died, but so did mites in a control group given another RNA that should have been ineffective. The astonishing results prompted the researchers to suspect that the lithium chlorideused to produce the RNA – and thus present in the sugar water – was actually killing the parasites. A battery of subsequent examinations confirmed their hypothesis.

The scientists then carried out numerous experiments testing lithium chloride against Varroa mites, including ones that approximated field studies. They found that feeding honeybees minuscule amounts of lithium chloride (at a concentration of no more than 25 millimolar) over 24 to 72 hours wiped out 90 to 100 percent of Varroa mites without significantly increasing bee mortality. (Below: The figure shows the surviving proportion of bees and mites fed lithium chloride compared to those not fed lithium chloride.) Ziegelmann et al. / Scientific Reports

According to the researchers, lithium chloride could be put to use very quickly as it is easily applied via feeding, will not accumulate in beeswax, has a low toxicity for mammals, and is reasonably priced. However, wider studies on free-flying colonies testing long-term side effects are required first, as well as analyses of potential residues in honey.

Francis Ratnieks, a Professor of Apiculture at the University of Sussex, expressed skepticism about the new finding.

"We can kill 97% of the Varroa in a brood less hive with a single application of oxalic acid, which takes five minutes to apply and is already registered and being used by beekeepers," he told RCScience via email. "I think it will be difficult in practice to apply lithium salts to colonies to kill varroa and get the same level of control... There are also the wider issues of registration and potential contamination of the honey with a product that would not normally be there."

It should be noted that studies have shown oxalic acid to be inconsistent at managing mites during the summer months as well as in colonies with capped broods

Regardless, the Hohenheim researchers are pressing forward. They're already speaking with companies to get a lithium chloride treatment refined, approved, and in the hands of beekeepers.

"Lithium chloride has potential as an effective and easy-to-apply treatment for artificial and natural swarms and particularly for the huge number of package bees used for pollination in the United States," they conclude.

Source: Bettina Ziegelmann, Elisabeth Abele, Stefan Hannus, Michaela Beitzinger, Stefan Berg & Peter Rosenkranz. "Lithium chloride effectively kills the honey bee parasite Varroa destructor by a systemic mode of action." Scientific Reports 8, Article number: 683 (2018) doi:10.1038/s41598-017-19137-5

*Article updated 1/15 to include Professor Ratnieks' statement and to include information about oxalic acid.

*An earlier version of this article mistakenly reported that the researchers are based out of the University of Hoffenheim. They are from the University of Hohenheim.

https://www.realclearscience.com/quick_and_clear_science/2018/01/15/accidental_discovery_could_save_bees_from_their_greatest_threat.html

Related articles/info:
http://scientificbeekeeping.com/home/news-and-blogs/

http://www.beesource.com/forums/showthread.php?341995-Lithium-chloride-as-miticide&s=cf01c15735e4ecac52336121d381e000

https://badbeekeepingblog.com/2018/01/17/have-you-lithium-chlorided-your-bees-yet/

Samuel Ramsey - 2017 UMD Three Minute Thesis Winner

(Note from LACBA: Back in October 2017, we posted this note: "Through our volunteer efforts at the Bee Booth at the LA County Fair the Los Angeles County Beekeepers Association supports research through Project Apis m. Take a few minutes and vote for Samuel Ramsey @http://www.u213mt.com/." Note from Project Apis m.: "Thank you for your support! This project alone has pretty big implications for our understanding of Varroa mites- beekeeper enemy #1! - Project Apis m. funded this important project, please vote and help Samuel Ramsey win this contest for his great work!")

UPDATE and CONGRATULATIONS TO SAMUEL RAMSEY.

2017 UMD Three Minute Thesis Winner is Samuel Ramsey

Interesting new research concerning Varroa mites. They seem to feed primarily on the fat body rather than on hemolymph (bee blood). This may influence control strategies in the future.
https://www.youtube.com/watch?time_continue=20&v=Fyfyj-2O47Q

'Varroa Destructor Virus-1: It’s Here…'

By Karen Rennich  October 10, 2017

One of the best things about working in research is that it never fails to surprise – for good or for bad. And occasionally, it is not until much later that the surprise comes. In this case, the “surprise” arrived in the form of another Varroa-vectored, RNA virus, Varroa Destructor Virus-1, or VDV1.

Our University of Maryland lab has been leading the APHIS National Honey Bee Pest and Pathogen survey since 2010. During those years, we have processed thousands of samples from across most states for nosema spore load, Varroa load, pesticides, and viruses with the primary goal to survey whether exotics, not known to be in the US, are here or not. Secondarily, but almost as importantly, we also use the survey results to establish a nationwide honey bee health baseline. It cannot be overstated how important that baseline is, nor how vital archiving all of those samples are. In the case of viral samples, they are archived in a large -80C freezer at the USDA-ARS Beltsville Lab just down the road from us.

Dr. Eugene Ryabov, working at USDA-ARS with Dr. Jay Evans, decided to take a look into our archive freezer with the intent of re-processing those archived samples for VDV1. And we are glad that he did.  After doing a sweep of 2016 samples, he found VDV1 in >64% of all samples, making it just less prevalent and second only to Deformed Wing Virus (currently found in ~90% of all colonies). Reaching further back into that freezer, Dr. Ryabov found that only 2 colonies were positive from our 2010 survey samples – 1 in Indiana and 1 in Pennsylvania, and that temporal snapshot [below] shows the spread of this virus in just 6 years.

 

VDV1 is a species of RNA viruses under the genus iflavirus. Other iflaviruses include Sacbrood virus, Slow Bee Paralysis virus and its closest relative, Deformed Wing virus. Because we have methodically stored all historic samples, it will be possible, looking at the variants of this virus in the US and the world, to possibly help resolve how and when this virus arrived on our shores.  It is important to note that this virus is also present in Hawaii (the Big Island) so it has already migrated beyond the lower 48 states.

In addition to field samples, the APHIS National Survey also asks beekeepers to report colony loss numbers for the 3 months prior to being sampled. Using those losses, it may be possible to correlate those losses now with VDV1 infections and/or the levels of the virus present. This finding, and the further research it demands, provides a unique window into the forensics of this infection.

Additional information about this virus, the details used to screen for it and the possible risks to US honey bee colonies will be published in “Ryabov, E.V., Childers, A.K., Chen, Y., Madella, S., Nessa, A., vanEngelsdorp, D., Evans, J.D. (2017) Recent spread of Varroa destructor virus-1, a honey bee pathogen, in the United States. (Submitted)”.

The notice below was sent to all members of the Apiary Inspectors of America (AIA) and American Association of Professional Apiculturists (AAPA) on October 2nd.

Presence of Varroa destructor virus in the U.S.

Using RNA sequencing methods, the honey bee virus Varroa destructor virus-1 (VDV1, also known as Deformed wing virus strain B) was discovered in US honey bee samples by Dr. Eugene Ryabov, while working in the USDA-ARS Bee Research Laboratory (BRL) under the supervision of Drs. Jay Evans and Judy Chen. With guidance from the Bee Informed Partnership (University of Maryland, Dr. Dennis vanEngelsdorp) and USDA-APHIS (Dr. Robyn Rose), the BRL screened an extensive set of research samples along with U.S. bee samples collected during the USDA-APHIS National Honey Bee Disease survey.  This screening confirmed that VDV was widespread in the US in 2016 and far less common in 2010. Thanks to stored samples from the National Honey Bee Disease survey, it will now be possible to track the spread of this virus in the US and guide work for virus control in order to assure the good health of honey bees and maintain them as the primary pollinator of agricultural crops. There is no indication that VDV1 is significantly more virulent than DWV in US honey bees, and the advice to reduce levels of Varroa mites remains the same for both viruses. We are seeking to inform colleagues of this discovery primarily since VDV1 is not detectable using current genetic markers for DWV, and therefore laboratory methods will need to be tailored to detect this virus. Those involved with the National Honey Bee Disease Survey will notice that VDV1 is now a reported agent in this survey.

https://beeinformed.org/2017/10/10/varroa-destructor-virus-1-its-here/

How To Annotate Your BIP Hive Scale Data

   By John Engelsma   September 22, 2017

Hopefully by now you all have your mites under control and are well on your way in preparing your hives for winter!  If you are operating a hive scale and forwarding your data to the Bee Informed Partnership, as your beekeeping season begins to wind down and you have more time to spare, we’d strongly encourage you to login to the BIP hive scale portal and annotate your scale data.

While many of the “BIP Ready” scales available to beekeepers today collect data well beyond hive weight, the weight of you colony is perhaps the most informative in understanding what is going on in the colony.  Technically, it is not the weight so much but the change in weight over time that provides us with a better understanding of the condition of the colony.  The weight of the colony is often impacted by factors that are external to the activities of the bees themselves.  For example, you the beekeeper, may add or remove equipment, harvest honey, or feed your bees.  These activities of course impact the weight of the colony.  The weather may also effect the weight of the colony.  For example, in a northern climate a major snow storm might result in a significant amount of snow accumulating on the hive’s cover, and subsequently melting over several days.

To help the Bee Informed Partnership better understand / interpret the scale data you send us, it is very important that you login to the portal and annotate these types of events that may impact the weight of your colony.  While its better to annotate your data regularly over time, even if you haven’t done this at all in the past, you should be able to tag the most important events for the entire beekeeping season within a few minutes or less.  Actually, all of the data (past seasons as well!) is available to you on the portal, so if you tweak the date range on your hive scale graph you can also retrieve and annotate previous seasons as well.

To encourage you to complete this important task soon, we’ve put together a short video tutorial (only 4.5 minutes!) which you’ll find embedded below.  Please watch the video and then help improve the quality of the scale data you send us by making sure you annotate our scale data as soon as possible.

https://beeinformed.org/2017/09/22/how-to-annotate-your-bip-hive-scale-data/

Mite-A-Thon has Begun!

 

By The Bee Informed Team   BLOG  September 9, 2017

Mite-A-Thon, the first ever national event to capture and collect Varroa mite infestations in North America has started! Please dust off your sugar shake jars, grab some powdered sugar and join us in the colonies starting today and lasting until September 16th (we hope you continue to monitor your colonies beyond this drive as MiteCheck.com is always open and your data is always welcome).

Add your data to this map and make it light up! Look at the data and see what management practices are being used around the country. If you have questions about what management or treatment strategy you should use, please see this valuable Varroa guide from the Honey Bee Health Coalition.

MiteCheck National Map (found at MiteCheck.com)

If you don’t have a sugar roll jar, please see our previous BIP blog on how to make one and then how to administer a sugar roll test. Read more about sugar roll tests in general and for ways to interpret your data, please read another BIP blog here.

There are still time to purchase ready-made MiteCheck kits (everything you need in 1 bucket!). Please think about buying one from these bee supply houses, Brushy Mountain Bee Farm and Mann Lake.

Please get out, enjoy the wonderful fall weather and contribute to a HUGE citizen science project. You’ll learn how healthy your bees are heading into winter and you’ll make a difference in this valuable research effort. We thank you. Fight the mites.

https://beeinformed.org/2017/09/09/mite-a-thon-has-begun/

Varroa Mites - Bees' Archenemies - Have Genetic Holes in Their Armor

Michigan State University Environment + Science & Technology     August 14, 2017

Contact(s): Layne Cameron, Zachary Huang

National Honeybee Day is celebrated Aug. 19, but MSU scientists work year-round to protect these important pollinators. Varroa mites have decimated honeybee populations and are a primary cause of colony collapse disorder. Researchers have now found genetic holes in the seemingly indestructible pest's armor that could potentially reduce or eliminate the marauding invaders.

Varroa mites attached to honeybees. Photo by Zachary Huang

The team’s results, published in the current issue of the Journal of Insect Science, have identified four genes critical for survival and two that directly affect reproduction.

“The Varroa mite is the worst threat to honeybee health worldwide,” said Zachary Huang, MSU entomologist. “They have developed resistance to many pesticides, so it’s urgent that we explore and target these genes to develop better control methods.”

The mite sucks the blood of honeybees and transmits deadly viruses. Its lifecycle consists of two phases: one where they feed on adult bees, called the phoretic phase, and a reproductive phase that takes place within a sealed honeycomb cell, where the mites lay eggs on a developing bee larva.

Varroa mites' lifecycle consists of two phases: one where they feed on adult bees, called the phoretic phase, and a reproductive phase that takes place within a sealed honeycomb cell, where the mites lay eggs on a developing bee larva. Photo by Zachary HuangHaving the double-whammy of eating bees and spreading disease makes Varroa mites the number-one suspect of honeybee population declines worldwide.

Controlling pests like Varroa mites succeeds by either eliminating them or reducing their ability to reproduce. The team used RNA interference to identify the key genes, which could achieve these outcomes. They injected the mites with double-stranded RNA, or dsRNA.

Interfering reduces transcription of a specific gene, the first step of making a gene, a piece of DNA, into a protein. This process, also known as “gene knockdown,” has been successful in reducing the mating success and the number of eggs produced by cattle ticks, which threaten cows and other livestock around the world.


This bee is suffering from deformed wing virus, which is transmitted by Varroa mites. Photo by Zachary Huang

Using this approach, the team identified two genes that caused high mortality in Varroa mites – Da and Pros26S. In fact, Da killed more than 96 percent of mites. They also identified four genes – RpL8, RpL11, RpP0 and RpS13 – that control reproduction.

Earlier researchhas shown that a combination of dsRNAs can be fed to bees at the colony level. Varroa mites absorb the “genetic cocktail” via bee blood and their population was reduced. Future research will explore whether a single-gene approach can be scaled up and achieve the same effect at a colony-wide setting. Using a single gene with a known mechanism will be more cost effective and safe to the honeybees.

The results may have applications beyond honeybees, too.

“It’s worth noting that Da reduced reproduction in species of mosquitoes and Drosophila,” Huang said. “Future research could help not only protect honeybees, but also reduce disease-carrying mosquitoes or crop-damaging pests.”

Seemingly indestructible Varroa mites. Photo by Zachary Huang

Additional MSU researchers contributing to this study include Guowu Bian and Zhiyong Xi. Xianbing Xie, with Nanchang University (China), also was part of this paper.

This study was supported by the Almond Board of California, the Foundation for the Preservation of Honey Bees, the National Honey Board, MSU’s Project GREEEN, Michigan Beekeepers Association, National Natural Science Foundation of China, General Project of Jiangxi Provincial Department of Education and a fellowship from the China Scholarship Council.

http://msutoday.msu.edu/news/2017/varroa-mites-bees-archenemies-have-genetic-holes-in-their-armor/

Get Ready for the Mite-A-Thon

Varroa mites are one of the greatest threats to honey bee health, honey production, and pollination services. The Honey Bee Health Coalition has been proud to equip beekeepers with the information, tools, and resources they need to detect, monitor, and manage these destructive mites.

We are proud now to share information about the first ever Mite-A-Thon, supported by the Pollinator Partnership and the many partners listed below.

Read on or click HERE for more information about this exciting event

The first annual Mite-A-Thon will take place Saturday, September 9, to Saturday, September 16, and we invite you to participate!

Local beekeeping clubs and associations are key to making Mite-A-Thon a success!

The Mite-A-Thon is a national effort to collect mite infestation data and to visualize Varroa infestations in honey bee colonies across North America within a one week window.  All beekeepers will be asked to participate, creating a rich distribution of sampling sites in Canada, the United States, and Mexico.  Their Varroa monitoring data will be uploaded to www.mitecheck.com.

OBJECTIVE: 1) Raise awareness about honey bee colony Varroa infestations in North America through effective monitoring methods. 2) Management strategies will be made available for discussion within bee organizations utilizing Mite-A-Thon partner developed information and outreach materials.

PARTICIPANTS: All beekeepers are welcome to participate – we need bee associations to help lead this effort!

PARTICIPANTS: All beekeepers are welcome to participate – we need bee associations to help lead this effort!

WHAT YOU NEED TO DO: 

Encourage your members to participate in September, through meetings, newsletters, emails, social media etc. - http://www.pollinator.org/miteathon

Teach new beekeepers how to monitor for mites in August. http://honeybeehealthcoalition.org/varroa/

Help your members prepare their monitoring materials.

Support your members in making sure they are able to monitor mites effectively and report their data.

DATA COLLECTION: Participants will monitor the level of mites (number of mites per 100 bees) using a standardized protocol utilizing two common methods of assessment (powdered sugar roll or alcohol wash) and then enter data, including location, total number of hives, number of hives tested, local habitat, and the number of Varroa mites counted from each hive. The published information will not identify individual participants.

CONTACT: Miteathon@pollinator.org or 415-362-1137

Learn more and stay up to date at www.pollinator.org/miteathon
Thank you,

The Mite-A-Thon Partners

No Offense, American Bees, But Your Sperm Isn't Cutting It

NPR The Sale    By Ryan Bell    July 13, 2017

With an American honeybee queen for a mother and a European honeybee drone for a father, this worker bee has a level of genetic diversity unseen in the U.S. for decades. Researchers at Washington State University hope a deeper gene pool will give a new generation of honeybees much-needed genetic traits, like resistance to varroa mites. The parasite kills a third of American honeybees each year. Megan Asche/Courtesy of Washington State University

Editor's note: This story is for mature bees only.

Seducing a honeybee drone – one of the males in a colony whose only job is to mate with the queen – is not too difficult. They don't have stingers, so you just pick one up. Apply a little pressure to the abdomen and the drone gets randy, blood rushing to his endophallus, bringing him to climax.

"They're really accommodating," says Susan Cobey, a honeybee breeder on Whidbey Island, Wash. "One ejaculate is about 1 microliter, and it takes 10 microliters to artificially inseminate a queen."

Since 2008, Cobey has done her share of bee abdomen rubbing as part of a research team from Washington State University traveling through Europe and Asia. They've collected sperm from native honeybees in Italy, Slovenia, Germany, Kazakhstan and the Republic of Georgia – countries where honeybees have favorable genetic traits, like resistance to the varroa mite. The deadly parasite has been cited as a major factor in bee deaths, along with genetics, poor nutrition and pesticide exposure, according to a major report from the USDA and EPA in 2013.

Varroa mites are an invasive parasite from Asia that sucks hemolymph (bee blood) from adult and larval honeybees, weakening their immune systems and transmitting deadly pathogens, like bent wing virus. If left untreated, a varroa infestation can kill a colony in one year. First detected on U.S. soil in 1987, varroa has spread quickly, infesting upwards of 50 percent of American hives. Last year, 33 percent of U.S. honeybee hives died. That's troubling for the plight of honeybees and U.S. agriculture, which relies on pollinators to produce one-third of the food we eat.

The buzz on American bees: too much inbreeding

According to the WSU research team, the root cause of the U.S. honeybees' vulnerability to varroa is a dwindling gene pool that has left them short on genetic traits that help honeybees resist varroa elsewhere in the world.

"Honeybees aren't native to America," Cobey says. "We brought them here. But the U.S. closed its borders to live honeybee imports in 1922, and our honeybee population has been interbreeding ever since."

WSU has monitored the genetic diversity of honeybee queens in Washington and California since 1994, showing a steady decline. Dr. Brandon Hopkins, the team's expert in freezing and thawing bee sperm, likens honeybee breeding to a poker game played with an incomplete deck of cards. "There's no way to get a four-of-a-kind if there aren't four aces in the deck," Hopkins says.

Brandon Hopkins, a cryopreservation specialist, works in Washington State University's fruit tree orchard in Pullman, Wash. As a doctoral student at WSU, Hopkins perfected a system of freezing and thawing bee semen for use in artificial insemination. Shelly Hanks/Courtesy of Washington State University

The imported semen has restacked the deck. WSU's crossbred honeybees already test positive at a higher level of genetic diversity than the first queens tested in 1994. "This doesn't mean they are superior in performance to the other bees," Hopkins says. "It means we have a better chance of finding rare and unique traits."

It used to be that honeybee breeders selected for bees that produced more honey, grew more populous hives, and were gentler to handle. Now, they want honeybees that can resist varroa. Without it, beekeepers must rely on costly "miticide" treatments to control varroa.

However, studies suggest the mites are developing resistance to pesticides and the chemicals may be harming honeybees, compounding the problem of widespread bee deaths known as Colony Collapse Disorder.

"I lost 40 percent of my colonies to varroa last fall," says Matthew Shakespear, whose company, Olson's Honeybees, raises 16,000 hives in central Washington. "I'm not taking any more chances. We've already done five treatments, compared with the two treatments we applied this time last year."

A problem that blooms in almond orchards

Pollination services like Olson's Honeybees are the cornerstone of a $15 billion segment of U.S. agriculture. A hefty share of that is the almond industry, whose trees are completely reliant on honeybees for pollination. It's also the industry most susceptible to fallout from the varroa epidemic in bees: California's almond groves serve as an incubator for the growth and spread of varroa mites across the United States.

"There are 800,000 acres of almonds in California," says Patrick Heitkam, owner of Heitkam's Honey Bees in Orland, Calif. "It takes two hives to pollinate one acre, so that's a need for 1.6 million hives. There are only 500,000 hives in the state, so the rest are trucked in from around the country."

Almond trees bloom in January, a time of the year when most honeybee varieties are dormant in their hives. But an Italian species of honeybee, Apis mellifera linguistica, which evolved in the warm Mediterranean climate, is active when the first almond blossom pops in late-January, making them the most popular variety in the U.S.

The trouble is, Italian honeybees are extremely susceptible to varroa mites, because their hives grow so big, so fast and so early.

"Italian honeybees rear their babies and varroa mites nearly one-for-one," says Dr. Robert Danka, a research entomologist at the USDA's Honey Bee Breeding, Genetics and Physiology Research Unit in Baton Rouge, La.

Lessons from mighty Russian stingers

Like the WSU team, Danka has also looked to the Old World for an answer to varroa mites. Between 1994 and 2000, he traveled to the Russian far east, where a local honeybee, Apis mellifera, has developed resistance to varroa. They are descended from European honeybees brought by Russian settlers traveling the Trans-Siberian Railway at the turn of the 20th century. The journey inadvertently transplanted the honeybees into the native range of varroa mites in east Asia, where they evolved resistance to the pest.

These Russian bees groom themselves, biting and crushing the mites. They also have a prevalent genetic trait called varroa sensitive hygiene (VSH), aborting larval honeybees infested with mites and removing them from the hive before the parasite can spread.

Danka brought back 360 queens, the basis for what is now a robust Russian honeybee population in the United States. While their prowess as mite biters continues, Russian honeybees haven't proven up to task as commercial pollinators. The queens are used to long Russian winters, so they are slow at building up their hives, meaning only a small number are ready to fly in the almond groves come January.

Survival of the fittest bees

Still, Danka says the Russian honeybee offers proof that a European subspecies can develop varroa mite resistance through natural selection. That evolutionary process is interrupted in commercial beehives, because of the "prophylactic use of miticides," Danka says. "We're maintaining varroa-susceptible bees through chemistry. If we took away all those pesticide treatments – and to be clear, I'm not advocating for this – the results would be horrific. But in a rather short period of time, only varroa-resistant bees would be left." And those bees could be the basis of a new population.

Matthew Shakespear, the commercial honeybee keeper in Yakima, Wash., would rather not spend money treating his hives for varroa mites. Starting last year, he diversified his business to include hives of Carniolan honeybees, Apis mellifera carnica, a subspecies native to Eastern Europe.

The queens he bought were the great-great-great granddaughters of a honeybee drone that Susan Cobey found in the mountains of Slovenia.

"Maybe these new genetics can deal with the varroa mites naturally, rather than having to rely on chemicals," Shakespear says. "It's time to start widening our gene pool.

http://www.npr.org/sections/thesalt/2017/07/13/536884827/no-offense-american-bees-but-your-sperm-isnt-cutting-it

Bee Hive Thermal Industries, Breaking News, Saving Honey Bees Organically

Bee Hive Thermal Industries   Press Release     June 21, 2017

PAGELAND, S.C., June 21, 2017 /PRNewswire/ -- An organic and noninvasive solution in targeting and killing Varroa Mite infestations, that are killing honey bees, was developed by the joined forces of, Bee Hive Thermal Industries (www.beehivethermalindustries.com) and OVEN Industries (www.ovenind.com), experts in temperature control.

Even if you're not in the bee keeping business, commercially or as a Hobbyist, you may have heard that, "honey bees are in trouble". There are a few main reasons that we could list in this dilemma and most experts will most likely agree that the Varroa Mite is near or at the top of that list. Bee Hive Thermal Industries designed this Thermal System utilizing an industrial grade heater blanket and electronic controls which are easily installed and removed from the hive. The end goal of the product is to raise the temperature of the hive to a programmed temperature, killing the mites without harming the bees based on studies done in Europe. To see the game changing product in action, click the link and view the video. https://youtu.be/D3I4G2Ws91o

In the fight against today's Varroa Mites, beekeepers are often, if not always, resorting to pesticides as the solution. Bees have many other predators and hardships to endure, including weather related issues such as cold temperatures, moisture and diseases. The effect of the Mite on the overall colony is paralyzing to both general activity and honey production within the hive.  This revolutionary product is showing positive results in killing and controlling mites and hive beetles, with only a few applications annually.

Bee Hive Thermal Industries, located in beautiful Pageland South Carolina, is to be recognized as a global leader in the design, development and distribution of organically suitable products for the bee industry globally. The company strives daily to provide unique and safe solutions for bee keepers everywhere, providing them with high quality, value and reliability. Caring for our bees is very important to the mission of Bee Hive Thermal Industries.

To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/bee-hive-thermal-industries-breaking-news-saving-honey-bees-organically-300477782.html

How the Varroa Mite Co-Opts Honey Bee Behaviors to Its Own Advantage

Entomology Today    By Entomology Today   May 10, 2017

While the Varroa destructor mite is not a highly mobile insect on its own, it takes advantage of the behaviors of honey bees in managed beekeeping settings to spread. In particular, bee colonies in close proximity to each other and less swarming allow mite populations to grow, according to new research. (Photo credit: Scott Bauer, USDA Agricultural Research Service, Bugwood.org)

As the managed honey bee industry continues to grapple with significant annual colony losses, the Varroa destructor mite is emerging as the leading culprit. And, it turns out, the very nature of modern beekeeping may be giving the parasite the exact conditions it needs to spread nearly beyond control.

In an article published yesterday in Environmental Entomology, researchers argue that the Varroa mite has “co-opted” several honey bee behaviors to its own benefit, allowing it to disperse widely even though the mite itself is not a highly mobile insect. The mite’s ability to hitchhike on wandering bees, the infections it transmits to bees, and the density of colonies in managed beekeeping settings make for a deadly combination.

“Beekeepers need to rethink Varroa control and treat Varroa as a migratory pest,” says Gloria DeGrandi-Hoffman, Ph.D., research leader and location coordinator at the U.S. Department of Agriculture-Agricultural Research Service’s Carl Hayden Bee Research Center in Tucson, Arizona, and lead author of the research.

In the wild, bee colonies tend to survive despite Varroa infestations, and colonies are usually located far enough apart to prevent mites from hitching rides to other colonies on foraging bees. Wild bee colonies’ natural habit of periodically swarming—when the colony grows large enough that a portion of its bees splinter off to create a new colony elsewhere—also serves as a mechanism for thinning out the density of mite infestations and their associated pathogens. In managed honey bee settings, though, these dynamics are disrupted, DeGrandi-Hoffman says. Colonies are kept in close proximity, and swarming is prevented.

DeGrandi-Hoffman, USDA-ARS colleague Henry Graham, and Fabiana Ahumada of AgScience Consulting, conducted an 11-month study of 120 honey bee colonies in one commercial bee operation, comparing those treated with mite-targeting insecticide (miticide) in the spring and fall with those treated only in the fall, and they found no significant difference in the results: more than half of the colonies were lost across the board. This aligns with what has been seen by beekeepers and researchers alike in recent years: Varroa populations continue to grow even after being treated with effective miticides. But why? The answer may be in its dispersal mechanisms.

The researchers also conducted mathematical simulations of Varroa mite population dynamics to examine the effects of both migration of foragers between colonies and swarming. When bees can wander into other colonies—either to “rob” them of their honey or because they’ve simply lost their way—Varroa populations across colonies climb. Likewise, prohibiting colonies from splintering periodically via swarming also leads mite populations to rise.

In the wild, DeGrandi-Hoffman and her colleagues note, driving a colony to collapse is against Varroa mites’ own interest; if the colony dies, the mites die with it. But in commercial beekeeping settings, increasing infestation of a colony activates the dispersal mechanisms the mites need to spread. Weakened foragers are more likely to wander to other colonies, and weakened colonies are more likely to see foragers from healthy colonies visit to rob them of honey. In both cases, mites can hitch a ride from one colony to another.

It all adds up to a critical point for managed honey bee industry. The researchers cite the need for new integrated pest management strategies to treat Varroa destructor as a migratory pest, as well as for further research into the specifics of Varroa dispersal.

“Colony losses in the U.S. are at unsustainable levels for commercial beekeepers. These beekeepers supply colonies for the pollination of crops that represent one-third of U.S. agriculture and are essential components of heart healthy and cancer-prevention diets,” says DeGrandi-Hoffman. “This research provides evidence that the tried and true ways of controlling Varroa are no longer feasible, and that new methods that are designed for control of a migratory pest are required.”

https://entomologytoday.org/2017/05/10/how-the-varroa-mite-co-opts-honey-bee-behaviors-to-its-own-advantage/

Read More:
Are Dispersal Mechanisms Changing the Host–Parasite Relationship and Increasing the Virulence of Varroa destructor (Mesostigmata: Varroidae) in Managed Honey Bee (Hymenoptera: Apidae) Colonies? “Are Dispersal Mechanisms Changing the Host–Parasite Relationship and Increasing the Virulence of Varroa destructor (Mesostigmata: Varroidae) in Managed Honey Bee (Hymenoptera: Apidae) Colonies?”  Environmental Entomology

Beyond Taktic

Scientific Beekeeping    By Randy Oliver    First published in: American Bee Journal, January 2017

The miticide Taktic has been the savior of the commercial bee industry since the early 2000s. But it may be time to move on. I’ve been experimenting with a promising potential replacement.

Our Situation

As I recently pointed out, there are signs that mites in areas of the U.S. are exhibiting some degree of resistance to Taktic’s active ingredient–amitraz. And since Taktic has been pulled from the U.S. market, some beekeepers are justifiably concerned that the EPA may stop looking the other way about them illegally using the product (Canada’s already hit one beekeeper with a hefty fine; no telling when some State enforcement branch will make an example of a U.S. beekeeper).

I’m freshly returned from the California State Beekeepers Assoc. conference, where Dr. Juliana Rangel presented the findings of her student Liz Walsh (who previously found negative effects on queens from residues of miticides in the comb). Liz recently found that field-realistic residues of amitraz in queen cell wax appeared to reduce the egg laying rate of queens reared in those cells. I’ve suspected something like this, since queen problems appear to have increased since the widespread adoption of amitraz as a miticide. Of further concern is that amitraz residues are increasingly being detected in U.S. honey. In any case, commercial beekeepers are (or I suspect will soon be) looking for alternatives to Taktic.

The Ideal Treatment

In this same issue of ABJ, I’m pushing our industry to get serious about shifting to mite-resistant stocks so that we can give up treatments altogether. But I know that my own operation would collapse if I were to attempt an abrupt transition, and have no doubt that most others would too. So although I don’t use amitraz in my own operation, I have a common interest with my professional brethren to find mite treatments that are cheap, don’t harm the bees, queen, or brood, and don’t get into the honey.

Continue reading the full article at: http://scientificbeekeeping.com/beyond-taktic/