# Varroa Does Not Feed on Hemolymph. Samuel Ramsey shakes up current knowledge.



## Live Oak (Oct 11, 2008)

Not sure if you all have seen this video. It is and hour and 15 minutes long and MUCH more than worth your time in my opinion. It is a teleconference between Samuel Ramsey PhD. and Flemming Vejsnaes on Samuel Ramsey doctoral research into varroa mites and what exactly they were feeding off of honey bees and their reproductive cycle. It will turn everything you thought you knew about varraoa mites on its head. Enjoy!

https://www.youtube.com/watch?v=DK2Xi0ST4rA

My apologies if this has already been discussed. I did a forum search and could not find anything on this except a link to a 3 minute video.


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## 1102009 (Jul 31, 2015)

Wow thank you!

Well, selection must go to select those bees which interrupt the brood cycle of mites and damage them.
And monitor for those with very low mite numbers to breed from.

There seem to be no "tolerance".

Interesting how in this case you breed mites by feeding pollen patties to the bees. In germany it´s not done mostly. Could be this is why we don´t have such serious problems and be content with organic treatments.


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## little_john (Aug 4, 2014)

There was a brief mention of this on Beemaster back in 2016: https://beemaster.com/forum/index.php?topic=49408.0 (first link on that page is now dead) - but knowledge of Ramsey's work doesn't seem to have spread very far since then, so thanks for that link ! 
LJ

Managed to track-down the original forum source:
https://www.beesource.com/forums/showthread.php?332234-mites-feed-on-vitellogenin


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## little_john (Aug 4, 2014)

Have just watched the video - a most informative talk, which at last offers a credible explanation for the apparent paradox that large, strong and established colonies are at greater risk of winter collapse than those which are newly formed much later in the season, or have experienced a brood-break - but that it's not just a 'numbers game', but rather that it's the underlying mechanism of fat-body depletion which is responsible. A real game-changer.

Ramsey's description that Varroa's feet are "sucker-like" which can readily be dislodged by the presence of fine powder also helps to explain the _modus operandi_ of the Oxalic Acid dust formed by vapourisation, and which is suspected (by others) of then proceeding to destroy the mite's feet and mouth-parts as the result of it's acidity.

A really great talk - thanks for posting the link.
LJ


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## Grins (May 24, 2016)

little_john said:


> Have just watched the video - a most informative talk, which at last offers a credible explanation for the apparent paradox that large, strong and established colonies are at greater risk of winter collapse than those which are newly formed much later in the season, or have experienced a brood-break - but that it's not just a 'numbers game', but rather that it's the underlying mechanism of fat-body depletion which is responsible. A real game-changer.
> 
> Ramsey's description that Varroa's feet are "sucker-like" which can readily be dislodged by the presence of fine powder also helps to explain the _modus operandi_ of the Oxalic Acid dust formed by vapourisation, and which is suspected (by others) of then proceeding to destroy the mite's feet and mouth-parts as the result of it's acidity.
> 
> ...


There was an article in ABJ a few issues back written by an engineer, can't remember his name. He captured mites and applied oxalic acid in tiny amounts to specific body parts. The mites could walk on it and mouth it with no ill effects. When he applied the OA to the carapace, the shell, they were paralyzed and dead over the course of 5 hours or so. His research indicates they absorb the OA through the shell. I have not watched the video posted here yet but it is in a tab for later viewing.


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## Grins (May 24, 2016)

Live Oak said:


> Not sure if you all have seen this video. It is and hour and 15 minutes long and MUCH more than worth your time in my opinion. It is a teleconference between Samuel Ramsey PhD. and Flemming Vejsnaes on Samuel Ramsey doctoral research into varroa mites and what exactly they were feeding off of honey bees and their reproductive cycle. It will turn everything you thought you knew about varraoa mites on its head. Enjoy!
> 
> https://www.youtube.com/watch?v=DK2Xi0ST4rA
> 
> My apologies if this has already been discussed. I did a forum search and could not find anything on this except a link to a 3 minute video.


This was terrific! I learned a great deal and it is so wonderful that Samuel Ramsey is doing this research on mites, he keeps popping up and is performing a great service to all us that keep bees..., alive.
Thanks!
Lee


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## RudyT (Jan 25, 2012)

Samuel Ramsey spoke at EAS in August 2018 and indicated he hopes his article, which is in the process of peer review, will be published this year. This is basic science of great importance and application. I was wowed by the thoroughness of his work.


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## Fivej (Apr 4, 2016)

Wow is right. This explains a lot. For example:
Why large, seemingly healthy colonies collapse suddenly.
Why small "not quite right" colonies seem to linger and just fade away.
Why new beekeepers say "I have only seen a few mites (which have to be on the thorax to see) and my colony just died suddenly.
Why colonies with low mite counts die from mites.
Great research. Watch everybody. Thanks Samuel Ramsey for your excellent work.


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## Fivej (Apr 4, 2016)

As a reminder, Mr Ramsey was a winner of the 3 minute Thesis contest which was posted here some time ago and many of us voted for him to allow him to continue his studies. Best vote I have ever cast in my life (so far). J


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## grozzie2 (Jun 3, 2011)

SiWolKe said:


> Wow thank you!
> 
> Well, selection must go to select those bees which interrupt the brood cycle of mites and damage them.


I watched the video end to end. It was very specific on mite feeding methods etc etc, but it certainly didn't suggest anything about interruption of brood cycles. I think the only way you can come to that conclusion is by jumping from what was said to pre-disposed confirmation bias of various types.

What I did find interesting was his comments on mite management, powdered sugar doesn't work to control mites in a colony, and he suggested amitraz as the goto method. the concept of 'resistance' was not mentioned at all.


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## gww (Feb 14, 2015)

Grozzie


> What I did find interesting was his comments on mite management, powdered sugar doesn't work to control mites in a colony, and he suggested amitraz as the goto method. the concept of 'resistance' was not mentioned at all.


Me taking the intent of your comment out of context, the only mention of resistance was that mite would eventually be resistant to amitraz.

The concept of resistance was looked at in that (bees) A. M. did not use what A.C. seemed to be using. 

I did find it interesting that sick starving bees were going to hurt mite breeding more then well fed bees. 
Cheers
gww

Ps I also found the fat bodys function and all it effects very interresting also.


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## johno (Dec 4, 2011)

Mr Ramseys work is quite old but does not appear to get much notice from some of the older scientific community as the young upstart seems to have rocked their boat a little. I went to a talk given by him more than a year ago and all his information was outlined there. First he had to confirm the what 25 year old myth that mites existed on the bees heamolymph which he could not, and thereby led him to the studies of mites feeding on the fat of the larvae and also feeding on the bees under belly. There were still naysayers saying well the body fat is much like heamolymph any way. But what really clinches the theory is when he created a larvae like thing from bee belly fat coated with gelatin and set a female mite on this in a cell and the mite thrived and actually laid eggs on the imitation larvae which was the first time an egg had been laid on any matter outside of living larvae. However you will still find published papers referring to bees feeding on haemolymph. The other important thing itook from his lecture was the fact that although a colony may be heavily infested with mites they are not readily visible as when feeding on bees they are between the scales under the abdomen, and generally when observing bees you normally only see the back of the bee,
Johno


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## little_john (Aug 4, 2014)

grozzie2 said:


> I watched the video end to end. It was very specific on mite feeding methods etc etc, but it certainly didn't suggest anything about interruption of brood cycles. I think the only way you can come to that conclusion is by jumping from what was said to pre-disposed confirmation bias of various types.


Ok, so he didn't say that - but it's a logical extension of his discovery. Bias has nothing to do with it. (I don't personally engage in deliberate brood cycle interruption, although it certainly does happen here 'as a by-product') 

What impressed me the most was not just the thoroughness of this guy's work, but rather than simply starting-off his enquiry with such a fundamental assumption, he went back to first principles and questioned how it was that the mite can thrive on a diet of haemolymph, when an energy-rich source of nutrition is required. To challenge established beliefs like that takes some guts as well as brains. 
LJ


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## johno (Dec 4, 2011)

In part of his studies he needed to keep mites alive in laboratory conditions, he could not keep mites alive feeding them heamolymph but could keep them alive and laying eggs with the bees and larval fat. enough said.
Johno


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## 1102009 (Jul 31, 2015)

grozzie2
who cares about treatments here, he said it´s important to treat early and that´s what counts. ( if you treat).
Please don´t imply all my posts to my subsciption.

I agree with LJ


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## johno (Dec 4, 2011)

And I thought it was about what the mites are really feeding on, am I missing something.
Johno


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## MichiganMike (Mar 25, 2014)

Thanks for posting this video. I posted the 3 minute version back in January titled mite study, the post got close to 4000 views but only one response from fivej. This information is important and deserves attention. Also, I am encourged to know that Dr. Ramsey intends to continue his work.


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## little_john (Aug 4, 2014)

johno said:


> And I thought it was about what the mites are really feeding on, am I missing something.
> Johno


As this represents such a fundamental change in our understanding of *how* the Varroa Mite survives with such success - it appears that some of us are now looking at the implications of this. 

Such as the need to ensure that any treatments (chemical *or* physical) are carried out - say, in late summer - but certainly *prior* to the onset of winter, rather than dosing them with VOA (as I've been doing for years) *during *winter - in order that the fat-bodies of winter bees are not excessively depleted beforehand by the so-called 'phoretic' mites. (which are actually not phoretic at all ...)

I know that some people have already been doing this - I guess based on intuition (?) - but the conventional advice up until now has been to treat on a warm day during the height of winter whilst the colony is more-or-less broodless. This advice now needs to be revised, imo, as it has now been shown that the 'phoretic' mite's mode of feeding is not essentially harmless, as previously thought, but actually causes significant damage to the bee by irreversibly depleting it's fat-bodies - even well after feeding on that bee has ceased. Thus the damage caused by 'phoretic' mites is equally as serious as the damage caused within the cell to the developing larva. At least, that's what I've taken from the video at a first viewing.

LJ


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## 1102009 (Jul 31, 2015)

Thanks, LJ.
A good point for my speaking.


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## little_john (Aug 4, 2014)

johno said:


> And I thought it was about what the mites are really feeding on, am I missing something.
> Johno


I'd like to try again to answer that question. I've just re-watched Ramsey's 3-minute video and have now heard far more clearly what he had to say back then. I think the first time I watched that video, there was just too much enthusiasm in his delivery for the core message to fully sink in - also 3 minutes doesn't really do the subject justice.

From the mite's point-of-view, the fat-body (which a lot of people have incorrectly *heard* as 'body-fat') is indeed simply a convenient energy-rich source of food ... *but* ... the fat-body functions more like a discrete organ of the body - although you won't find fat-bodies described within any anatomical diagrams of the honey-bee - the analogy being employed by Ramsey is that it's functions are equivalent to the human liver. 

So - if the mite was simply living on haemolymph, providing that substance was regularly topped-up by the bee's metabolism - there's no _de facto_ reason why this should cause the bees' ultimate demise. A state of equilibrium could easily develop, as with tape-worms living inside a human being provided that an adequate diet is maintained. (btw, these are my words, not Ramsey's)

But - contrast that scenario with having your liver destroyed ! Massive depletion of nine separate functions, each one being essential to the bees' life - including it's immune system, an ability to neutralise toxins, and an ability to extend it's lifetime over the entire winter period. So, with the advantage of hindsight, so many of the ills which befall the bee can now be tentatively laid at the door of this one single parasite and it's feeding behaviour.
Hope that's a better answer 
LJ


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## johno (Dec 4, 2011)

LJ, I heard his lecture on this subject in about June of 2017 at a Virginia State Beekeepers Association meeting. He is specializing in parasites and was searching for subject to do his PHD thesus and decided the Varoa mite would suite his purpose. It had been accepted that the mite lived off bee heamolymph but he could find no study to confirm this and decided that as the mite scat was not consistent with the scat of heamolymph feeding insects there had to be something else that the mite was feeding on, and so began his research. His finding that phoretic mites feeding on the bees under abdomen led to finding the fat storage of bees was in this area. besides acting as a liver function it was also the source of energy storage which was used by nurse bees feeding young and also which provided much extra energy to foragers and also was also involved in the longer life of winter bees so one can see the damage that can be done to a heavily infested colony even without virus infections. So you can see what a great deal of information this young man has revealed and made available to beekeepers. I would even suggest that the research of Mr Ramsey ( I do not know whether he has received a doctorate yet) has been of greater importance to beekeepers since Grandpa fell off the bus and I hope he will get the recognition he deserves.
Johno


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## squarepeg (Jul 9, 2010)

excellent discussion here. many thanks to all for contributing.


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## little_john (Aug 4, 2014)

johno said:


> I would even suggest that the research of Mr Ramsey ( I do not know whether he has received a doctorate yet) has been of greater importance to beekeepers since Grandpa fell off the bus and I hope he will get the recognition he deserves. Johno


Couldn't agree more - the spin-off from this guy's work promises to be a total game-changer. I suspect Ramsey has a great future ahead of him - he certainly deserves it.

Amazing when you consider that we're several decades into the Varroa problem and yet only within the last couple of years has Varroa's actual food source been discovered.

Yes, he was awarded his PhD at Maryland (UMD) after transferring there from Cornell. A very bright guy.

For some reason his PhD hasn't been published yet, but I've requested a copy via ResearchGate. I'll upload it here as and when (or if) it arrives. 
LJ


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## johno (Dec 4, 2011)

I do not know if the paper will reveal all the work he went to to establish his theory and how much time he put in actually bee by bee in infested colonies. One of the things we never considered was that when we saw mites they were always on the bees back so when we saw them there that is where we expected to find mites, however when mites were walking around on the bees back they were in transit, either just out of a cell or waiting to go into a cell or to leave the hive on a forager. This meant that even in a highly infected colony not many mites are visible. However when Dr Ramsey searched these highly infected colonies he did so bee by bee grasping them by the wings and turning them over to find mites feeding on the bee, and here he found that all the mites feeding did so in the same place. They were right in between the scales under the bees abdomen almost totally protected by the scales. Dr Ramsey showed a photo where he dipped the bee in liquid nitrogen then sliced through the abdomen and the mite and actually showed the half a mite under the scale. Now I often think maybe some of those phoretic mites could escape most treatments and could also be the reason for not getting 100% efficacy in treatments.
Johno


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## 1102009 (Jul 31, 2015)

Yes, this research is of high value. I admire the patience of Ramsay to find out about this.


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## dudelt (Mar 18, 2013)

The video and research finally explains how the general belief that mites would not feed at all during the winter broodless period is wrong. It turns out they were feeding all along. It always bothered me to think that mites could go months without eating in really cold environments. Great video and incredible research.


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## clyderoad (Jun 10, 2012)

And some potential practical applications?

From late 2016:


clyderoad said:


> ......................................
> 
> There are potential practical applications of this research by creating a miticide delivery mechanism via vitellogen. Monsanto has shown keen interest in this soon to be published research and has contacted the lab regarding the research.


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## little_john (Aug 4, 2014)

clyderoad said:


> And some potential practical applications?


I can see two potential directions for practical applications: the obvious one being the development of some kind of miticide which becomes concentrated within the adipose tissue of the fat-body itself.

But Ramsey's very clever method of fooling the mites into feeding from pseudo-larvae is the one I'd favour for future research. If that method could be commercially developed to produce partial or even whole frames of pseudo-lavae, then the mites could be subjected to a constant supply of a miticide, rather than ingest the dyed foodstuff Ramsey gave them. Imagine mites being preferentially attracted to such a special comb - only to then promptly die on it. That scenario really appeals to me. 
LJ


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## AR Beekeeper (Sep 25, 2008)

dudelt;
I have never heard or read that varroa would not feed during the winter, only that they will not reproduce unless there is correct age larvae for them to lay eggs on in the cells. Can you point me to the study about not feeding so I can download a copy?


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## squarepeg (Jul 9, 2010)

vitellogenin samples anyone?

it would interesting to see if there are quantative and/or qualatative differences between surivor-type wild bee stock and managed stock.


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## johno (Dec 4, 2011)

At the end of the day all this leads to the fact that we do not know a great deal about this little blind sucker who Dr Ramsey claims is a very smart little critter. Where once again I feel the more I learn the more I realize how little I know.
Johno


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## Cloverdale (Mar 26, 2012)

little_john said:


> Ok, so he didn't say that - but it's a logical extension of his discovery. Bias has nothing to do with it. (I don't personally engage in deliberate brood cycle interruption, although it certainly does happen here 'as a by-product')
> 
> What impressed me the most was not just the thoroughness of this guy's work, but rather than simply starting-off his enquiry with such a fundamental assumption, he went back to first principles and questioned how it was that the mite can thrive on a diet of haemolymph, when an energy-rich source of nutrition is required. To challenge established beliefs like that takes some guts as well as brains.
> LJ


Agree little john; I didn’t watch the video but saw him at a lecture at SABA here in NY. The slides he showed of a cross section of a mite feeding on a honey bee impressed me the most. You could actually see the fat body being eaten; the mite was filling up on the fat body (another slide). He had a superior presentation. This was in March? not sure. At that time he did not have his Ph.D as of yet. There is a post on here regarding his findings.


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## 1102009 (Jul 31, 2015)

johno said:


> At the end of the day all this leads to the fact that we do not know a great deal about this little blind sucker who Dr Ramsey claims is a very smart little critter. Where once again I feel the more I learn the more I realize how little I know.
> Johno


And about the bees.
Or how can we expalin that colonies with high mite loads survive, no virus to be seen?


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## dudelt (Mar 18, 2013)

AR Beekeeper said:


> dudelt;
> I have never heard or read that varroa would not feed during the winter, only that they will not reproduce unless there is correct age larvae for them to lay eggs on in the cells. Can you point me to the study about not feeding so I can download a copy?


I never said there was a study. The term "phoretic" implies that the mites are there for the ride only, not feeding. The definition of phoretic is an association between two organisms in which one travels on the body of another, without being a parasite. During the winter months when a hive is broodless or almost broodless, there would be no larvae for them to be feeding on. Thus, they may be going months without eating in a really cold climate. It never made sense to me.


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## johno (Dec 4, 2011)

This appears to be correct, another error by the esteemed scientific community as the definition of Phoresis or Phoresy imply that the parasite is using the host for transport and gains nothing else from the host. So what are they at this stage? Non breeding mites?
Johno


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## crofter (May 5, 2011)

I took it to mean free ranging in the colony (ie, not locked under cappings for reproduction) but did not take it to mean that they were not taking the odd suck on their transportation provider. Their caloric intake would be greatly reduced if they were not preparing for the next round of reproduction and of course would be in population decline rather than growth.


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## squarepeg (Jul 9, 2010)

that was my take as well frank.

my first guess is that the nutritional needs for the female mite coasting through the broodless winter would be minimal when compared to when she is making eggs almost the same size as she is.

it was a little disconcerting however that (soon to be) dr. ramsey found under laboratory conditions adult mites die after only a day or two without a fat body meal.


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## gww (Feb 14, 2015)

Squarepeg


> it was a little disconcerting however that (soon to be) dr. ramsey found under laboratory conditions adult mites die after only a day or two without a fat body meal.


Not so disconcerting though. There were studies where bees could pick up mites off of flowers. Dying fast means they would need a fast change out if stranded on a flower.

There were some TF populations studied that were reducing the mite reproduction by 30 percent and the scientist were not sure what the bees were doing to cause that. It may just be that those bees were not as healthy and did not have as much fat body to feed on. 
Cheers
gww
Ps, My bees may be living year to year because they are not as healthy but just healthy enough.


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## JWPalmer (May 1, 2017)

By jove Glenn, you've just solved the TF riddle. Keep your bees just healthy enough to survive, but not healthy enough to thrive, and no treatments are needed.

Before everyone jumps down my throat, I'm kidding, sort of.


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## gww (Feb 14, 2015)

JW
Could be. For last year, I did not have square pegs loss rate (though his is usually low in the other years) but squares bees put lots of honey away and mine just got by. I don't have the riddle solved but still have bees to keep trying. If I move some to dads whose forage looks better, I may know more on whether it is location or bees or a little of both.

This study is just one more to try and put in context with other things read and seen in a connect the dots type fashion. Some day, I may treat and see what difference that makes and early feed and see there and on and on and on. Nothing seems to happen fast in bee keeping cause you have to learn by the year and not by the day.
Cheers
gww


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## jim lyon (Feb 19, 2006)

Phoretic mites are just hitchhikers? Hmmmm, possibly, but I'm not sure what difference it really makes if the mites and the resulting wounds and spread of viruses are damaging bees before or after they are hatched. Isn't the result the same?


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## little_john (Aug 4, 2014)

jim lyon;1669021[b said:


> *Phoretic mites are just hitchhikers? * Hmmmm, possibly, but I'm not sure what difference it really makes if the mites and the resulting wounds and spread of viruses are damaging bees before or after they are hatched. Isn't the result the same?


I think that most (if not all) beekeepers have been using the term 'phoretic' incorrectly to describe mites that are out and about and 'on the loose' and not in the correct sense of 'non-feeding hitchhikers'. Can't speak for biologists - some may have been misled by the incorrect application of the term - difficult to say ... Nice to have this terminology clarified - looks like we need a new term to cover 'ongoing hitchhiker parasitism'.

With regard to differences before and after pupation - Deformed Wing Virus (for example) may well be introduced into the bee at any time during it's life-cycle, but only manifests itself as a deformity during the larval stage.
However, should a bee become infected after pupation (i.e. will not have deformed wings), if the virus should multiply sufficiently, then the bee can die from viral-overload - usually overwinter - without displaying the tell-tale signs of the disease.
LJ


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## aran (May 20, 2015)

This video and the research in it is fascinating.
I wonder how this will change beekeeping going forward. Ominous sounds at the beginning with his saying there is another major threat to bees just around the corner!

For mine i guess this video just cements the need for routine, regular, repeated, varied weapon treatment against varroa throughout the year.
Ive been not testing but instead just treating for varroa. This year has been OAV, formic pro, MAQS ( some left over from last year) and apivar.

Looking forward to what this scientist is able to continue discovering that will help us all.


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## squarepeg (Jul 9, 2010)

JWPalmer said:


> I'm kidding, sort of.


i'm sort of interested in comparing my losses and honey yields with those employing more conventional methods. i'm happy to compare my thrive rate with you jwp. 



gww said:


> For last year, I did not have square pegs loss rate (though his is usually low in the other years) but squares bees put lots of honey away...


yes, last year's loss rate was skewed due to a mite bomb event at my outyard in which i lost 5 of 8 hives for 62.5%.

at the home yard i lost 2 out of 11 for 22% which is just a bit higher than the 8 winter average of about 16%.

average honey yield approached 100 lbs. per hive last year, but i am expecting less this year due to the expansion from 19 to 30 colonies by making more splits.

(sorry for straying off topic, just responding to comments above, we can delve into this further on my thread in the tf section of anyone is interested)


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## johno (Dec 4, 2011)

Following Dr Ramseys research there might be quite a few questions that might require more research. 1) the life span of the mite is given as something like 27 days or so if I remember correctly, now I feel that might differ depending whether the mite is breeding or not. Or what actually controls the mites lifespan. 2) That mites prefer drone brood I feel is an assumption just because the foundress mite can produce more offspring there. I have read that mites are opportunistic and will go to a cell that is ready where ever the nurse bee happens to be. I think that fallacy is derived from the fact that in Apis Cerana the mites breed only in the drone cells which is primarily because mites that try to breed in Cerana worker brood die with the worker pupae which is how they have developed successfully into parasite and host. A question I asked Dr Ramsey is where do phoretic mites defecate, to which he replied only in cells as the scat would effect their disguise of smelling like a bee. He mentioned that while observing live mites in the lab they would often see a mite trying to climb onto the back of another mite and could not understand what they were trying to do. The solution they came up with is that the blind mite thought the other mite was a bee because of its smell. So lots of questions, who will provide answers.
Johno


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## squarepeg (Jul 9, 2010)

good post johno.

i would be interested in knowing how often and how much of a fat body meal is required to sustain a mite during the winter broodless period.

i would also like to know how much or how little vectored viruses impact the health of an adult worker bee as compared to the impact on brood.

i think it would be interesting to perform assays on fat bodies from various cohorts of bees, i.e. treated, untreated, feral survivor, low mite counts, high mite counts, managed survivors, dead outs, ect., and look for differences in quanity and quality.

i'm wondering if it is possible to correlate the 'health' of the fat body with the amount and type of pollen available. if so it could lead the way to better supplements needed due to poor weather or lack of floral diversity.

(you can share these ideas with dr. ramsey if you like)


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## johno (Dec 4, 2011)

I am afraid the only contact I have had with Dr Ramsey was the VSBA meeting in the summer of 2017 and that was where I asked the question about phoretic mites defecating. I must say that his presentation for someone in Academia really impressed as it was covering a subject that has so much rubbish around it and it was great to get actual facts of value to beekeepers. I must admit that I study the speakers and their subjects before going to these meetings as they are normally quite a distance away from my home and I am not driving for 4 hours to listen to someone going on for hours about the ultra violet bees can see on flowers and that kind of stuff that researchers are so full off.
Johno


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## squarepeg (Jul 9, 2010)

understood johno.

if i get a chance i'll see if i can find an email contact for him and send him a link to this thread.

it may interest him to know that his work is being discussed on this popular website.


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## squarepeg (Jul 9, 2010)

email sent.


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## dudelt (Mar 18, 2013)

squarepeg said:


> i would be interested in knowing how often and how much of a fat body meal is required to sustain a mite during the winter broodless period.


I believe they would feed fairly frequently. According to what I have seen and heard, once they are away from a bee, they will die within hours. That implies starvation or some other unknown reason I cannot imagine. My best guess would be that the only time they would stop parasitizing a bee would be to breed or find another host because they have already taken everything they can from the first host. I can think of no other reason to stop sucking the life from the original host and attempt to find a new host. If they are going to die from a lack of a host, why leave unless you have to? It would be too big of a risk.


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## squarepeg (Jul 9, 2010)

dudelt said:


> That implies starvation or some other unknown reason I cannot imagine...


yes. perhaps they depend on something in the fat bodies to detoxify metabolic waste products that they are unable to process themselves.


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## justin (Jun 16, 2007)

Does anyone know if this is the same way varroa feed on apis cerana? It seems like there would be some type of adaptation among the bees if it is.


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## crofter (May 5, 2011)

I have read that female mite that has had one successful round of brood rearing can jump right back into a cell one or more breeding cycles but that a newly emerged virgin female will need a feed on a bee before she is ready to produce. I dont know whether that is cut in stone or not. We do know that bees who have gone through the various stages up to foraging are not long lived after. So called winter bees that have not graduated through foraging remain at a stage of suspended development that allows them to survive many months. Perhaps some similar situation exists with female mites that allows them to survive long periods without food intake.

Bees are capable of self thermoregulation; mites not so. This may be the reason for their demise if separated from their hosts, rather than lack of food intake. I am sure we will be hearing more about the mechanics of how they survive the winter and whether their presence is a heavy drain on wintering bees or only becoming important because of the damage occurring once the crucial new brood becomes available.


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## johno (Dec 4, 2011)

From what I gathered from the lecture I attended mites feed on winter bees and also on bees in heavily infested hives before their collapse. Further more they regurgitate into the bee and this is how they ingest the fat from the bee. It was also mentioned that these fat reserves on the winter bees are part of which gives them their longevity. Any of this energy removed would then shorten their lifespan. Dr Ramsey also went on to talk about the wonders of metamorphosis and how the pupae consisting of such a high fat content changes state from larvae to pre pupae to bee and how the DNA and RNA is all in that fat and how these instructions change the fat into parts and organs which can surely be effected by the feeding of all those mites in the cell besides the virus aspect of the whole exercise. So in my opinion mites will feed on whatever they can feed on no matter what time of the year, if there is no brood available they will feed on bees.
Johno


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## HillBilly2 (Jul 26, 2015)

I just saw his presentation "Varroa feed on Hemolyph and 2 other alternate facts". Fascinating presentation.

"Phoretic mites are just hitchhikers?" He explained that the term Phoretic was incorrect because it meant they did not feed outside the cell. His new term is "Questing Mites"

"the life span of the mite is given as something like 27 days or so if I remember correctly" The fat bodies also produce vitellogens. These allow the winter bees to live all winter. Mites feeding on winter bees ingest vitellogens, which enable them to live all winter long.

Other things I noted from his talk were, Think of fat bodies as organs, not fat. Similar to liver tissue. They control 9 different functions in a bee. Everyone has seen fat bodies, look at larva, the white goo inside the transparent skin is fat bodies. Varroa chew a hole into the abdomen and inject their saliva. This saliva then digests the organs, and the mites feed on the digested organs. The mites inject much more saliva than needed for their meal; after they move to another bee the saliva continues to digest the fat bodies. Foundress mites can go through as many as 4 breeding cycles but the average is 2. If we do not treat and let the hive die, bees and mites will transfer to nearby hives. Bees only reproduce once a year. Mites reproduce every 26 days. If we allow a hive to die in hopes of raising a mite resistant bee, we are instead creating more and more virulent mites.

And not from his presentation was Varroa and Apis Cerana have acheived balanced parasitism. They rarely threaten the hive, and rarely go into worker brood. I suspect that is because the life cycle of worker brood is 19 days instead of 21 in Apis Mellifera. It might be harder for a mature mite to develop in their worker brood.

Fascinating stuff.


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## 1102009 (Jul 31, 2015)

i


> t was a little disconcerting however that (soon to be) dr. ramsey found under laboratory conditions adult mites die after only a day or two without a fat body meal.


I have put living bees with mites on them in plastic boxes. The mites leave the bees 2 hours after the bees death. They live for 5 days then.



> For mine i guess this video just cements the need for routine, regular, repeated, varied weapon treatment against varroa throughout the year.


Ramsay works with Dennis VanEngelsdorp. This guy is regarded by some as a promoter of chemical treatments but I don´t know if it´s true.
I googled and found him promoting IPM and monitoring, which is a good thing.

I really hope studies like that won´t lead beekeepers back to do more prophylactic treatments since this strategy is the cause of all our today`s problems IME.


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## HillBilly2 (Jul 26, 2015)

Dr Ramsey has taken a new position very recently. He will be working with the Bee Lab in Beltsville Md. 

He also hinted there might be better treatments in the pipeline. No relevations as to what though.


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## squarepeg (Jul 9, 2010)

squarepeg said:


> email sent.


i received a nice reply from dr. ramsey who appears to have successfully defended his dissertation and received his ph.d.

he took a look at our thread here and found it encouraging that his work has been well received and his presentations engaging.

as hb2 mentioned he is now listing himself at the beltsville bee lab.

his current area of interest is how differences in fat body content might influence varroa mite development.


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## Cloverdale (Mar 26, 2012)

squarepeg said:


> i received a nice reply from dr. ramsey who appears to have successfully defended his dissertation and received his ph.d.
> 
> he took a look at our thread here and found it encouraging that his work has been well received and his presentations engaging.
> 
> ...


Wonderful!


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## GregB (Dec 26, 2017)

gww said:


> Squarepeg
> 
> 
> Not so disconcerting though. There were studies where bees could pick up mites off of flowers. Dying fast means they would need a fast change out if stranded on a flower.
> ...


Here is another thought along this line - it is possible that some colonies are "tastier" than others (propose a better term than "tastier"; i just don't know).
So the mites prefer some colonies over the others.

A case in point:
- I have about 20-30 apple trees under my care of various varieties (some I don't even know that they are)
- I do not treat the apple trees in any way (but do the spring pruning)
- observational fact - the pests (mostly apple maggots) *clearly prefer* some apple trees and mostly ignore the others
- I already gave up on some of the trees since ~100% of the crops is consistently wasted; McIntosh apple, for example, is only good for apple sauce - while the sauce is excellent, it takes lots of apple cutting/cleaning; 
- I also realized the benefit of having those "wasted" trees around - those are *pest sinks *and attract and retain the bulk of the pests onto them while several other varieties are less affected (the range of pest damage also varies tree by a tree; some trees are nearly entirely avoided by apple maggots and produce excellent, chemical-free apples).
- Also, it maybe that lateness of the apples going ripe has something to do with this (those apples that match the cycle of apple maggot the best - "taste" better).

This is all a true situation as of the moment.
Bee situation could similar in many ways.


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## Alex Madsen (Aug 26, 2018)

dr. ramsey did some superb research for that pice. Very insightful.


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## Marcin (Jun 15, 2011)

crofter said:


> Bees are capable of self thermoregulation; mites not so. This may be the reason for their demise if separated from their hosts, rather than lack of food intake.


Some years back I cut out capped drone brood and put it in a plastic tub to check it for mites when I got home. I forgot about it and it was in the trunk of my car for 3 days before I remembered. It was mid May and the temps were in mid to upper 80's during those day ( and probably warmer inside the locked car ). When I finally looked at the comb, the pupa had turned brown and was dead, but mites were still crawling around on some of the brood. I was amazed that they survived the heat.


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## crofter (May 5, 2011)

i guess in that case the temperature was within their survivable range. Had they died we would not know conclusively whether it was temperature or feeding related. We just have to be careful that we do not arrive at a correct answer for the wrong reason. 

I certainly have not absorbed all the implications of mites feeding on vitelligellin rather than haemolymph. One theory was that the disturbance of feeding mites caused a higher metabolic rate leading to greater stores consumption and colony mortality. It is looking possible that direct depletion of bees fat body reduces their brood rearing ability come spring. Regardless of the mechanics of that process I try to get the mite levels at fall closeout as close as possible to zero. 

It could be useful to know what level of mites your bees can tolerate and feed that info into breeding selection but I will be leaving that to someone else to play with.


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## little_john (Aug 4, 2014)

crofter said:


> I certainly have not absorbed all the implications of mites feeding on vitelligellin rather than haemolymph.


As I see it, one major implication of fat-body depletion is that an extra link has now been inserted into the chain of events which ultimately lead to the honey-bee's death, and that it is the multi-variable *consequences* of the mite's newly discovered feeding behaviour which actually causes death, the lack of awareness of which appears to have been responsible for many riddles and much confusion (... maybe).

From this new perspective, reasonable explanations can now be postulated for how it is that a Treatment-Free regime can indeed work (sometimes, but not always), and why laboratory results for pesticide poisoning are often quite different from real-world field studies.

A whole Pandora's Box has now been opened up and it's going to take quite a while for re-adjusted thinking to take place.
LJ


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## pastorjimk (Jul 2, 2017)

I don't post often, but read regularly... I watched presentation and lights and bells were going off the whole time. Here are some of my thoughts and questions...

1. Is our alcohol/sugar roll as effective as we thought it was? Will it wash off mites that are actively feeding between the plates? do we need a procedure change to do a more effective test? For example leaving the bees in the alcohol longer, putting them in a jar and not adding alcohol right away giving the mites time to realize their demise and "let go" so we can wash them off and count them more accurately? I have a dozen hives and tested with alcohol recently on 2 week interval. 8 hive had no mites, 1 had 1 mite, and 1 had 6 mites. Two weeks later I found no mites on any hive and I had not had time to treat the hive that had 6...

2. Since the mites feed between the plates, how does that affect our treatment methods and timing?

3. One of my hives went through last winter with a virgin queen and ended up drone laying this spring. I used the screen method to stop the drone laying, then introduced a queen cell from a hive about to swarm. This went through summer as my strongest hive and produced the most honey. Then after harvest they started to tail off in numbers. the alcohol wash resulted in 0 mites both times, no DWV, no EFB/AFB and the queen appeared to be laying good the whole time and never saw a sign of swarming or queen cells. Could their have been mites feeding on bees but not washed off during my tests?

seems to me that we are on track to learn what procedures need modified to better test/treat and therefore better manage the mite load.


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## SuiGeneris (Feb 13, 2018)

I'm a scientist (but not bee scientist) by profession, so the first two of these questions are right up my alley...


pastorjimk said:


> 1. Is our alcohol/sugar roll as effective as we thought it was? Will it wash off mites that are actively feeding between the plates?


I've inspected by bees post alcohol wash (not just the backs) and not found residual mites, and I know others have as well with similar results. So it appears that an alcohol wash does work. However, from a scientific perspective it doesn't really matter. What matters is that the portion of mites dislodged is consistent between tests and that the threshold of apparent infestation (e.g. the level of infestation measured by the wash) where we treat is sufficient for control.

Keep in mind, the goal for anyone not doing research is to monitor and control infestation; its not to get the most accurate count possible. So whether the count is total versus statistically representative doesn't matter for our needs - so long as in the later case the test is actually statistically representative (e.g. consistent in the relationship between counts and actual infestation rates). Of course, if you're doing mite washes for research purposes, the issues are different.



pastorjimk said:


> 2. Since the mites feed between the plates, how does that affect our treatment methods and timing?


Not at all. Treatment schedules and doses are determined empirically - e.g. infested hives are treated with the various treatments to identify the appropriate treatment course. As such, the incorrect assumption of feeding site has already been "accounted for", during the testing & certification of the treatments.

One thing that may change is the approach used by companies/labs developing next-gen treatments, as fat body-targeting compounds (e.g. lipophillic/fat-loving mitacides) may be more effective than hydrophillic/water-loving ones.



pastorjimk said:


> 3. One of my hives went through last winter...the alcohol wash resulted in 0 mites both times, no DWV, no EFB/AFB


I'll leave this one to the more experienced keeps.

B


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## johno (Dec 4, 2011)

It is my opinion that those mites feeding under the bees abdomen in large numbers only takes place on highly infested colonies and I would think that these colonies are not likely to survive and would be soon be exporting mites to other colonies. Of coarse this would change during the winter broodless period, but in cared for colonies the number would not be so great and those are the mites you are going to cull with your winter broodless treatments. The problem I see with alcohol or sugar rolls is we never know the percentage of the total that is in the capped brood and sometimes a low count might not necessarily mean a low infestation. I think in dealing with mites we still have a way to go.
Johno


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## AR Beekeeper (Sep 25, 2008)

Every mite that has a phoretic period feeds on it's adult host, this causes the mite to be able to lay more viable eggs than a mite that goes directly to another cell after emerging.

When I washed broodless shaken swarms this summer their counts were 15 to 20 mites per 300 bee samples, 2 weeks later when they had frames of brood the count dropped to 1 or 2 mites per sample.


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## johno (Dec 4, 2011)

Interesting on the swarm wash, perhaps on the next one after two weeks you could end up with zero and so would believe you were mite free. Now the story that every phoretic mite will feed on the bee it is on could be like the story that mites feed on the bees Haemolymph. Do we really know or just assume. Where the mite feeds on the bee is difficult to see unless you look under the bee, I spend a fair amount of time examining the bees in my observation hive searching for mites with a magnifying glass which is quite easy as many bees are resting on the glass and the underbelly is in plain sight and the only time I have seen mites feeding there has been in early winter with declining brood. Also to be born in mind is that a mature mite and an immature mite will leave the cell when the bee emerges, I would imagine that the immature mite will require a certain amount of time to mature which could amount to a number of days however does the same hold true for the mature mite who has just emerged. Maybe some of that data is out there but I am not to sure any of it is written in stone and this is the reason I believe there is still much to be learned.
Johno


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## sesk (Aug 18, 2015)

Marcin said:


> ... It was mid May and the temps were in mid to upper 80's during those day ( and probably warmer inside the locked car ). When I finally looked at the comb, the pupa had turned brown and was dead, but mites were still crawling around on some of the brood. I was amazed that they survived the heat.


In Russia, some beekeepers use the thermal method of release from the mites. The temperature of this treatment is about 117F. Only at this temperature, the mites fall from the bees and yours (80F) is not so high for their death.
It is believed that mites die since they can not withstand low humidity during thermal processing. In my opinion it may be due to bee water vapor excretion: the mites fall off from the bee due to bee sweat. Bees also suffer from high temperature but due to higher weight they more tolerant to the water loss.


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## sesk (Aug 18, 2015)

AR Beekeeper said:


> ...
> When I washed broodless shaken swarms this summer their counts were 15 to 20 mites per 300 bee samples, 2 weeks later when they had frames of brood the count dropped to 1 or 2 mites per sample.


Probably, the mites have moved from the bees to brood, because larvae are more delicious for them than old bees.


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