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  1. #261
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    Default Re: Small Cell Studies

    But of course. Then could the offshoot of that be though that it takes a fairly heavy infestation for interbreeding to take place but not too much so that the less virulent mites (and the hive) are able to survive. Eureka! Perhaps survivor hives are then in effect infested with less virulent mites? Hmmmmm
    "People will generally accept facts as truth only if the facts agree with what they already believe."- Andy Rooney

  2. #262
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    Default Re: Small Cell Studies

    In evolutionary theory, a less virulent pathogen that allows it’s host better health, will be likely to do better itself. -Oldtimer
    I'm not convinced of this corollary. It certainly doesn't seem to hold true for parasites. Parasitoids abound among insects, and parasitoids operate by killing their hosts as a result of their parasitism.

    The question, really, is whether the pathogen can reproduce and pass genes into the future. Whether the host survives or dies is less important than the ability of the pathogen to pass genes to future generations.

  3. #263
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    Default Re: Small Cell Studies

    The question, really, is whether the pathogen can reproduce and pass genes into the future. Whether the host survives or dies is less important than the ability of the pathogen to pass genes to future generations.
    This is not direct cause and effect. It gets down to the mechanism involved. If a parasitic wasp lays eggs on a caterpillar and the eggs hatch and the wasp larvae feeds, the caterpillar will surely die. What happens next is that the wasps mature and go out hunting new hosts. The key is that the parasite must be able to go to a new host and begin feeding. This is a balanced parasite/host cycle.

    If that cycle is interrupted because the parasite can't get to a new host, then the parasite dies. The concept under discussion is whether phoretic mites are able to move from a dead colony to another colony where they can continue to feed and multiply. Unfortunately, my experience with varroa is that they have multiple mechanisms for moving from colony to colony, especially when the colonies are very close together. For this reason, I am highly skeptical of claims for less virulent mites.

    From what I have been able to observe, a huge amount of varroa tolerance gets down to enhanced grooming behavior combined with enhanced removal of infested brood.

    DarJones
    DarJones - 44 years, 10 colonies (max 40), sideliner, treatment free since 2005, 11 frame broodnest, small cell

  4. #264
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    Default Re: Small Cell Studies

    I have been reading this thread pretty carefully the last few days... it's rather interesting, but I believe I am still somewhat confused. I keep coming back to something I think I read, that being, "Interbred mites are more virulent than inbred mites". If there is evidence for this.... then does this give a mechanism for LC to be a better breeding place for interbred mites? There would be more room.... (I guess)... so more chance of more mites being capped there in.... (I guess),

  5. #265
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    Default Re: Small Cell Studies

    I don't believe that interbred mites are necessarily more or less virulent than inbred mites. If you inbreed from virulent mites, you'll get virulent mites. If you interbreed virulent mites and avirulent mites, you should get a range of virulence in the mites in that population.

  6. #266
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    Default Re: Small Cell Studies

    Since the discussion's gone this way, here is a link to an interesting video of the Aussie scientist working with varroa in PNG. Shows him id'ing mite types (or strain species sub species, whatever the boffins would call it ), including doing DNA sequencing. It's an hour, but some of it is about other things. So you can skip the preliminaries by going to minute 5, and the really interesting stuff starts at minute 13.30. Some time later it leaves PNG and the more interesting stuff.

    Here it is http://www.youtube.com/watch?v=VF__ezaP3-0
    44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).

  7. #267
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    Default Re: Small Cell Studies

    OT - Thanks... that was an extremely interesting video. It gave me an hour of educational entertainment. I particularly found the part about the dissapearance of the Leatherwood forests from Tasmania to be interesting.. if sad.

  8. #268
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    Default Re: Small Cell Studies

    Yes. I love natural history docos. But the pillage and plunder of our planet is always heartbreaking. In the above case, some people permanently destroying something that's been there since the dinasours, to put a few weeks pay in their pockets.
    44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).

  9. #269
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    Default Re: Small Cell Studies

    Mr. Bush wrote:

    If only one Varroa enters the cell before capping they are inbred. If two or more Varroa enter the cell before capping and those Varroa are not full sisters, then you get interbreeding.

    I agree, and believe that this is a weakness on their part to be exploited. Inbred individuals will not have the vigor of hybrids.

    Fusion power wrote:

    The concept under discussion is whether phoretic mites are able to move from a dead colony to another colony where they can continue to feed and multiply. Unfortunately, my experience with varroa is that they have multiple mechanisms for moving from colony to colony, especially when the colonies are very close together.

    So if you could control your drone population(assuming no colony deaths), you could limit the movement of phoretic mites, and compound the inbreeding issue. The old 1/2 of 1/2 is 1/4 trick. What a crazy thought......

    Crazy Roland

  10. #270
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    Default Re: Small Cell Studies

    I don't think drifting is confined to drones.

    Sometimes people drop around to the house to ask something about bees. Some people were there wanting to find out how to mark a queen. There were 1/2 dozen or so hives on the front lawn so I scooped maybe 30 bees off a landing board and took them into the shed for people to practise marking on.

    The ones that didn't get beaten to death during the marking process , were marked, and released. I was quite surprised over the next few weeks, I found marked bees in every one of those hives. I had to conclude there is actually a heckuva lot of worker drifting going on, the hives were at least 2 - 3 yards apart each.

    The other surprising thing, was just how long a bee can live. Quite a few months later I was still finding marked bees.
    44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).

  11. #271
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    Default Re: Small Cell Studies

    The Hive and Honey Bee Revisited, pg.202 note 42 "When bees are moved for pollination the figures approach 25% of the foragers were reared in other colonies."

    The Hive and the Honey Bee, pg.298 "Raushmeyer (1928) studied drifting of bees in German bee houses and found that, when there are no orientation landmarks, bees drift in extraordinarily large numbers (up to 50%)."

    So depending how the yards are set up, hives in rows and painted the same color, drifting could be quite high.

  12. #272
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    Default Re: Small Cell Studies

    Oldtimer and JD, I agree that workers drift. Now do the test with Drones. I bet you wi9ll find that the drift is higher. As anexample, we had a yard with a few Cordovan and NWC hives. It was easy to see which drones came from which hives. They seem to wander at will, whereas the workers seem to TRY to return to the proper hive, if they are adequately marked.

    I still bet that the mites can inbreed towards less virulence faster than the bees can breed resistance, purely on the life cycle time. Change can only occur with a new generation, and the mites are alot faster at that.

    Crazy Roland


    The

  13. #273
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    Default Re: Small Cell Studies

    Perhaps a more revealing study than that of small cell would be one in which inbred and crossbred mites could be compared and analyzed for virulence.
    A: By keeping mite levels at low levels over an extended period of time and maximizing inbreeding mite virulence would eventually be reduced or:
    B: When varroa populations explode and there is massive crossbreeding that the mites in the surviving hives become dominated by a less virulent strain. Thus giving rise to the theory that those non-treated hives that eventually recover and seem to be able to better deal with mites is perhaps more a result of a slightly different strain of mite than what many consider "survivor genetics"?

    Or are there way too many variables for this hypothesis to even be testable?
    "People will generally accept facts as truth only if the facts agree with what they already believe."- Andy Rooney

  14. #274
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    Default Re: Small Cell Studies

    You might be on to something, Jim. Controlling the variables to actually test the hypotheses would be the difficult part, but could likely be done if someone put the time and effort into it.

    Supporting these hypotheses, of course, could take some of the credit/blame away from cell size with regards to hive survival and mite populations.

    I'd like to get back to discussing and critiquing the papers at the outset of this thread. I'm still curious why mite populations in small cell hives during Berry et al's study were higher than in the other hives. Seems like an odd effect given the hypothesis and the independent variable (the "cause" in the experiment).

  15. #275
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    Default Re: Small Cell Studies

    How many hives were tested? Wasn't it only one? It seems the hive in question was suffering in general, as he notes it probably wouldn't have survived the winter. Does that explain the high mite count?

  16. #276
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    Default Re: Small Cell Studies

    Let's read the studies before commenting on them.
    Solomon Parker, Parker Farms, ParkerFarms.biz
    11 Years Treatment-Free, ~25 Colony Baseline

  17. #277
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    Default Re: Small Cell Studies

    No there was more than one, and there's been several studies, all finding small cell didn't work. Re your comment on the hive "suffering", they've tried mixing all the bees together before the experiment and then putting them in the different hives, to ensure bees and mites are spread randomly. Still didn't work. They've tried using plastic comb to ensure cell size, and they've tried small cells built out of natural wax, still didn't work. They've tried regressing bees during the experiment, and they've tried using bees that were already small cell bees at the beginning of the experiment. Still didn't work.
    44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).

  18. #278
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    Default Re: Small Cell Studies

    Thanks - as Solomon mentioned I need to reread the studies mentioned.

  19. #279
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    Default Re: Small Cell Studies

    Quote Originally Posted by Oldtimer View Post
    they've tried...
    They've tried ...
    and they've tried ...
    They've tried ...
    and they've tried
    They've just never tried doing it the way "we've" done it.
    Regards, Barry

  20. #280
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    Default Re: Small Cell Studies

    I think they're trying to figure out what that is. I know I'd like to know. The definitive "whatever it is you do", to make small cell work.
    44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).

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