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Thread: EFB & cell cleaning questions

  1. #1

    Default EFB & cell cleaning questions

    Confused as usual !
    My understanding:
    The cells become coated with millions of M.plutonius when the mid gut of the prepupae joins with the rectum & the bee poops into the cell for the first time
    The prepupa then spins a silk coccoon against the walls of the cell but as the bee has been weakened by the infection the coccoon might be a bit substandard (therefore some of the infected poop is exposed) A young cleaner bee comes along to polish the cell after the new bee has emerged & gets infected with the EFB bacterium

    Is this correct?

    I know they use propalis in the polishing process but exactly what is involved?

    In ordinary circumstances (ie no EFB ) is the larval poop sealed under the coccoon for all time or is it removed? (sorry if this is basic stuff but I thought I
    understood it until I realised I don't )

    I think the coccoon is not removed but therefore what stops the internal dimensions of the cell from getting progressively smaller with use?

    Where does the infection reside in the newly infected cleaner bees? Does it live in the hypopharyngeal glands like Sacbrood? & why doesn't the 9 HDA in the mouth kill it (as they say it stops the adult bees from being infected with AFB?

    Mellissococcus or Melisococcus ? I see it spelled both ways ( even in the same BBKA info pdf)

    Can anyone enlighten me please. If I can get to grips with this I will be a happier bunny

  2. #2

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    Not going to go into the fine details about the EFB side of this....mainly because much of it I don't actually know...suspect Gavin is your man for that.


    However......do know that the bees undoubtedly re-engineer the cell from time to time.

    We had some brood combs in service a long time back that were ancient. I have mentioned these before as they were very unusual frames with a very strange grid pattern wired foundation in them. They were black and like cardboard but the cells were no different in size from any other older brood comb. Astonishingly Dave Cushman had information about the origin of the frames AND the foundation. The frame pattern was in use from the late 19th century up to the 1950s and the foundation pattern was a short lived bright idea from the 1920s. Until these were destroyed by a new and failed extractor we foolishly bought some years ago they were still good brood combs.

    The concept of comb cleaning in spring was finally proven to me when we went in for white Pierco plastic frames. After a full season of brood rearing in these the combs were just as black as any conventional comb. Completely opaque. In spring, during the initial brood nest expansion, the bees removed brown dust, which can be a little fibrous and drop it outside the door, usually at the outer edges of where the cluster is active. When examined you found that the plastic combs once again had translucent cell bases, so the bees had been removing the old cocoons. The cell walls remained dark, but I think that is due to coccoon material having partly replaced the wax.

    Its less easy to see the dust if you have OMF's as they seem partly to just let it down through the mesh, but in spring on solid floor you can frequently see this housecleaning material dumped outside. Its a great sign of a colony growing well and expanding onto combs that were not in full use during winter.

  3. #3
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    (Honeybunch). Sacbrood is a virus but EFB is a bacterium. The bacteria of EFB get moved from the infected cell to the brood food via trophylaxis.
    We should change brood comb regularly to rid the colony of diseases and to give the larvae clean full size cells to grow in. The size of the emerging bee is determined by the depth of the cell it developed in.
    Last edited by GRIZZLY; 25-02-2016 at 10:12 AM.

  4. #4
    Senior Member Jon's Avatar
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    Surely it is just another of the many beekeeping myths that cells get smaller over time.

  5. #5

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    Quote Originally Posted by Jon View Post
    Surely it is just another of the many beekeeping myths that cells get smaller over time.
    100% agree with you.

  6. #6
    Administrator gavin's Avatar
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    Not sure there is a lot I can add but here goes ....

    Yes, as C4U says, walls get stripped down from time to time. Maybe not all the time, maybe from time to time, like you see when removing wallpaper from some old house walls. No need to suggest imperfect cocoons as they'll dig down and expose old stuff anyway. Dave Cushman posted a picture on his site of old comb cut through with a razor and sitting in honey. You could see the laminated base of the cell with several generations of cocoon, but the side walls had been stripped back to its original thickness. You could also see wisps of dark stuff coming out of the cut wall of the comb into the honey.

    So walls can be a source of old bacteria, bacteria that survive quite well for years.

    There will be other sources of infection too, infection that could persist long enough on mouthparts to get into brood food then reinfect larvae. The scale from dried, dead EFB-infected larvae is supposed to be loose and so you may expect workers to be able to lift them out in one piece without exposing gut contents. Hopefully they then fly off and deposit them outside. However in some cells you can see larvae that died when just a day or two old and look like they have been glued to the floor in the dried brood food. These would have to be cut out piece by piece, risking the contamination of mouthparts. Another source of infection could be the larvae that staggered on and were capped over before they died. These end up a slimy mess and can't be removed in one piece in that state. The EFB bacterium does get (largely?) replaced by other bacteria but it seems likely there will still be some of the pathogenic type in there.

    PS Little of this comes from reading the books, so isn't necessarily what people get taught.
    Last edited by gavin; 25-02-2016 at 01:48 PM.

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    Quote Originally Posted by gavin View Post

    PS Little of this comes from reading the books, so isn't necessarily what people get taught.
    I agree.
    One of the first and most enduring lessons i was taught with regards to foulbrood, either type but especially with afb when it gets gooey and tacky, is that the bees would deal with them fine by themselves if only they could use a little shovel and spade. It may sound a bit silly, but this image of the physical problem the bees have with cleaning up infective material explained an enormous amount about how the diseases persist and spread within a colony

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    Senior Member fatshark's Avatar
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    The other re-engineering you sometimes see is when a swarm moves into a box which only has drone comb in it ... they re-engineer the cells to raise workers.

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    Senior Member busybeephilip's Avatar
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    Quote Originally Posted by Jon View Post
    Surely it is just another of the many beekeeping myths that cells get smaller over time.
    Afraid I don't agree with you on that one. There are plenty of images of cross sections of old comb that shows the larvae/pupal molts which are not removed by the bees on cleaning the cells, therefore, logically, cells do get smaller cross1.jpgcross2.jpg

    see the difference between virgin comb and brood comb
    Last edited by gavin; 25-02-2016 at 05:59 PM. Reason: An image with a 'Getty Images' flag on it has been removed. Well, I tried to! Phew, managed it.

  10. #10
    Senior Member Jon's Avatar
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    Quote Originally Posted by busybeephilip View Post
    logically, cells do get smaller
    But as others have noted above, the old cocoons get cleaned out every now and again.
    If you look at new comb which bees have been allowed to draw naturally the cells vary quite a lot in size and not just between worker size/drone size.

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