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Discussion Starter · #1 ·
This has probably been discussed, but I was listening to a podcast this morning of Dr. Samuel Ramsey. He described forced brood breaks as risky. He stated that forcing varroa out of their natural reproductive cycles and moving them all, virtually at once, to host on the bees within a colony could cause a rapid spread of viruses within your colony and spike virulence.

I suppose that makes sense, but that is a break from some conventional wisdom -- as well as contrary to my practice of creating artificial brood breaks. Guess I will be thinking hard about this one over the winter. Any thoughts out there?
 

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I cant envision how the "all at once" would occur. New mites will only come into play at the same rate as bees under cappings emerge. The effect of the queen having been caged will only become a factor some 12 days after the fact and that will result in a diminishing rate of mite emergence, not a sudden influx.

Either something is missing from the picture or I am missing something that is there!
 

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This doesn't make sense, and I wonder if he perhaps mis-spoke.

First of all, many of the viruses transferred by varroa infect both adults and larva (e.g. DFV), with some preferentially infecting larva (e.g. sac brood). So it is not like a brood break is moving mites from a unsusceptible larva to a susceptible adult; rather you're moving the mites from one virus-susceptible host to another. For some of these diseases, infection of larva is more serious than infections of adults (e.g. sac brood), so a brood break may actually be beneficial in that case.

Secondly, brood breaks are common in bee lifecycles - be it due to human intervention or swarming. If brood breaks were a reliable inducer of disease transmission, it seems highly unlikely that this phenomena would have been missed given the fairly intense research that has gone into a lot of these diseases and the near-obsessive monitoring that some beekeepers engage in.

But even assuming his statement was correct, its still only half the story - the other half being why a brood break was created. A small outbreak of a disease may be overall a minor cost to pay, compared to the benefits of a reduction in varroa, when a brood break is created as part of a treatment regimen.
 

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Discussion Starter · #5 ·
I cant envision how the "all at once" would occur. New mites will only come into play at the same rate as bees under cappings emerge. The effect of the queen having been caged will only become a factor some 12 days after the fact and that will result in a diminishing rate of mite emergence, not a sudden influx.

Either something is missing from the picture or I am missing something that is there!
A brood nest at its peak will house up to 80% of varroa. So within 12 days you go from 20% phorectic (which Ramsey says "phoretic" is a misnomer BTW) to 100% phoretic.
 

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Discussion Starter · #7 ·
This doesn't make sense, and I wonder if he perhaps mis-spoke.

First of all, many of the viruses transferred by varroa infect both adults and larva (e.g. DFV), with some preferentially infecting larva (e.g. sac brood). So it is not like a brood break is moving mites from a unsusceptible larva to a susceptible adult; rather you're moving the mites from one virus-susceptible host to another. For some of these diseases, infection of larva is more serious than infections of adults (e.g. sac brood), so a brood break may actually be beneficial in that case.

Secondly, brood breaks are common in bee lifecycles - be it due to human intervention or swarming. If brood breaks were a reliable inducer of disease transmission, it seems highly unlikely that this phenomena would have been missed given the fairly intense research that has gone into a lot of these diseases and the near-obsessive monitoring that some beekeepers engage in.

But even assuming his statement was correct, its still only half the story - the other half being why a brood break was created. A small outbreak of a disease may be overall a minor cost to pay, compared to the benefits of a reduction in varroa, when a brood break is created as part of a treatment regimen.
I will let you listen to it because I do not want to misrepresent what he said any more than I may have already. He got Kim Flottum pretty fluxed by the claim as well. I got the impression [this is ME not RAMSEY] that Ramsey believes the primary feeding is done on the fat bodies of the adult bees and not on the larva. That the time spent under the cappings is concentrated on mating and not feeding. Again, MY interpretation.

As to your second point, the obsessive monitoring generally focuses on mite counts, not virulence. There is no doubt that the brood break reduces the amount of mites, which is enhanced by use of pesticides timed in the break. However, I think the majority of this monitoring is focused on mite reduction, not viral load reduction.

In any event, please listen to the podcast. I would like to get your thoughts on it.
 

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I can see where it will change the ratio but gradually; It will change the ratio of a lower numbers total mite load reduced due to the lack of breeding opportunity. Perhaps the question is, which class of victim exposed creates the most net colony damage during the transition period. That would have to be weighed against the lower overall projected mite numbers.

It certainly has been stressed that damage to the fat body cripples the would be "winter bees". Damage to early or mid season bees may not have the same relative impact.

Interesting.
 

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This piece of info has no value without mentioning the pre-forced-brood-break infestation level. Well may be that by forcing a brood break in a heavily infested colony one is just serving that last nail. The mite/virus dynamics may be quite different for low mite count hives.
 

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Discussion Starter · #10 ·
Frank:

I hope you will listen to the podcast. It really has a lot of stuff I have never heard before. And I am a straight-up bee nerd that consumes it all. Not saying I digest it or understand it all. I just put a lot of hours into the literature.
 

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by that theory a two step break should be magnificent; Drop a drone frame in there from a donor, and freeze
 

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Yes, some interesting stuff for sure. A good idea of starting to study the new (to us) pest that may be just around the corner. Tropilaelaps Much quicker reproduction cycle and more viable offspring per cycle.

I wish him well with his go fund me for research. A lot more worthwhile that many!
 

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Listened to the podcast on my way home. It was an interesting discussion, but a lot of what was said was hypotheses/supposition, not scientifically supported conclusions, which I think is where the OPs "confusion" comes from.

To clarify this (or explain to those who don't have the time for the podcast), Dr. Ramsey has previoisly done some beautiful work which very convincingly shows that varroa feeds off the fat bodies (essentially the liver) of bees. For this work he's recieved his PhD, and recently moved to a new research based job.

One hypothesis he developed during his PhD research, but ***did not test***, was that "forcing" more mites onto adult bees via a brood break may promote the spread of some mite-transmitted diseases, as the increased feeding of varroa on adults (rather than larval) bees would potentially lead to more infections of the adults. This hypothesis is the foundation of the new research he is conducting at his new job. Given his previous work, this is a perfectly reasonable hypothesis - but it is just that, a hypothesis, and to-date remains untested.

Mid-way through the podcast he brings up what I think the crux of this discussion is - brood breaks have very well established positive effects when used as part of a mite treatment. He does not question that, nor their utility. However, no one has looked at the possible negative effects, including the possible increase in disease. As such, we don't understand the true cost:benifit of using broodbreaks as part of varroa control.

A better understanding of the costs would allow us to improve and optimize our use of broodbreaks as a treatment tool, as this knowedge can help decided when/if to treat, determine the optimal timing of treatment application relative to a brood break, and can help to inform better treatment design.

From a practical standpoint, our best way forward is to continue with treatments as before. There is no evidence at this point to suggest that a change is needed, or that existing treatment practices are unsound. But we should keep an eye on this work, as once it is complete, it may inform us as to better practices to use in the future. Likewise, a little more vigilance for adult disease during a broodbreak would not be untoward.
 

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I've read researchers who report observing the foundress mite feeding on the developing bee in the cell. The reports state that the foundress mite bites into the larva, taking 30-60 minutes to conclude feeding. The first portion of that time seemed to be waiting for the larval tissue to dissolve, or ooze, enough to slurp it up. I think young mites feed there as well before leaving the cell.

I know of no other studies to refute Dr. Ramesy's conclusions. Until more is done in this area, he is the expert. In my view, his discovery was a big step forward and explains Randy Oliver's pre-discovery focus on adequate fat reserves needed for successful hive growth and health. JMO :)
 

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Discussion Starter · #16 ·
Don’t really understand what you believe I got “confused.” I used Dr. Ramsey’s word — “risky.”

He laments that researchers have been so focused on the rewards of artificial brood breaks (and he acknowledges what those rewards are) that very little if any consideration has been given to the risks of artificial brood breaks to the health of the bees. Admittedly, it had never occurred to me.

He also counters the conventional “knowledge” that mites primarily feed on larva. He points out that the mite’s flat, elliptical shape is perfectly formed to slide between the spiracles of the adult bee and its mouth parts can easily pierce the thin membrane which coats the fat body. He also states that these areas under the spiracles are where he often finds the mites.

So why would a parasite that feeds on defenseless pupae in a capped cell spend all of this evolutionary energy to hone its body into a living wedge that can access these fat bodies of the adult bee?

Ramsey’s hypothesis is that the fat bodies of the larva are not the primary feed of the mite. Instead, he thinks there is a strong possibility that it is the fat bodies of the adult bee. He provides further argument to this point that mites, when separated from bees and left with brood, will die. But mites that are separated from brood, but left with bees, will continue to live.

But, he does state the determining which is the primary food source of the mite is a very difficult thing to discern.

But if the hypothesis is correct, and it is the adult bee — not the larvae — that is the primary food source of the mite, then we may very well be putting our bees at risk by artificially forcing the mites onto the bees.
 

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I will let you listen to it because I do not want to misrepresent what he said any more than I may have already. He got Kim Flottum pretty fluxed by the claim as well. I got the impression [this is ME not RAMSEY] that Ramsey believes the primary feeding is done on the fat bodies of the adult bees and not on the larva. That the time spent under the cappings is concentrated on mating and not feeding. Again, MY interpretation.

As to your second point, the obsessive monitoring generally focuses on mite counts, not virulence. There is no doubt that the brood break reduces the amount of mites, which is enhanced by use of pesticides timed in the break. However, I think the majority of this monitoring is focused on mite reduction, not viral load reduction.

In any event, please listen to the podcast. I would like to get your thoughts on it.

I will listen to it, and probably should before I reply: but for those that have...…..The idea that the verroa cause the problems from the bite according to what Bill Ellis in Fla and I think Randy Oliver have been saying? By reducing the mites, reducing the stressors, reducing bee loss?
 

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I will listen to it, and probably should before I reply: but for those that have...…..
If you haven't already done so, I'd recommend watching https://www.youtube.com/watch?v=DK2Xi0ST4rA before the linked 'podcast' (I really HATE these new words ... 'webinar' is another ...) in order to put what Ramsey is talking about into context.
There's a BeeSource thread about his discovery: https://www.beesource.com/forums/sh...mph-Samuel-Ramsey-shakes-up-current-knowledge which has turned our assumptions (masquerading as knowledge) upside-down.

In the linked 'podcast', Ramsey was asked to speculate on possible applications of his discovery, and that's just what he did - he speculated, he conjectured - but always tempering his words appropriately. He was outlining a line of enquiry he considers worth pursuing, that's all - a procedure that he considers has risks attached to it. Perhaps Ramsey has indeed over-stepped the mark prematurely by such speculation - but that's the sort of thing which happens when scientists are asked to chat informally about their work. It was a casual chat, not a conference lecture.
LJ
 

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Don’t really understand what you believe I got “confused.”
Confused was in quotes because I couldn't think of a correct adjective. No insult was made nor implied.

He also counters the conventional “knowledge” that mites primarily feed on larva. He points out that the mite’s flat, elliptical shape is perfectly formed to slide between the spiracles of the adult bee and its mouth parts can easily pierce the thin membrane which coats the fat body. He also states that these areas under the spiracles are where he often finds the mites.

So why would a parasite that feeds on defenseless pupae in a capped cell spend all of this evolutionary energy to hone its body into a living wedge that can access these fat bodies of the adult bee?
This isn't what he said. It is well established - and he described the process in some detail in the podcast - that mites feed on larva. In the podcast, Dr. Ramsey describes in some detail this process - the adult mite chews a hole in the bee larva, through which the adult and larval mites feed. This is requried for the growth and survival of the larval mites - in Dr. Ramsey's words, their mouth pieces are too "squishy" to allow them to feed on their own - and its required for the adult mite as it has no other food source once sealed in the cell. This feeding behaviour has been well described, for example:
https://www.ncbi.nlm.nih.gov/pubmed/19381843

So to answer your question more directly, varroa adults feed off of larva, even though the have the capacity to feed off of adult bees, because 1) that feeding behaviour is required for the mites larva to survive, and 2) because the mite is stuck in the cell with the bee/mite larva and has no other food source during that time.

But if the hypothesis is correct, and it is the adult bee — not the larvae — that is the primary food source of the mite, then we may very well be putting our bees at risk by artificially forcing the mites onto the bees.
I don't disagree, however if it was a significant risk it is extremely unlikely that it would not have been detected already, given the frequency that brood breaks are used in both research and in bee husbandry.
 

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"So why would a parasite that feeds on defenseless pupae in a capped cell spend all of this evolutionary energy to hone its body into a living wedge that can access these fat bodies of the adult bee?"

Feeding on adult bees would be essential survival mechanism, otherwise swarm conditions and areas with winter broodless conditions would be deadly for them. Survival of both phoretic and non phoretic conditions is essential.

I think the author makes it clear that there is still a lot of conjecture as to the "why" of much of his thinking. One of his main thrusts is to not get locked into a fixed way of looking at things.

I noticed a lot of clips and breaks in the podcast so perhaps some of the context has been omitted. My impression is that he is quite objective.
 
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