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  1. #21
    Join Date
    Jan 2005
    Location
    FRASER VALLEY, BRITISH COLUMBIA
    Posts
    1,335

    Default Re: Saving a hive from advanced PMS with powdered sugar only!!!

    Alpha , do you have recipes for industrial amounts of syrup. I'm sure you must be mixing more than 5 gallons at a time if you have hundreds/thousands of hives.

    Thanks

    Jean-Marc

  2. #22
    Join Date
    Aug 2009
    Location
    Berkeley,California, USA
    Posts
    483

    Re: Saving a hive from advanced PMS with powdered sugar only!!!

    Another nice sunny day in the Bay Area again today, so I took advantage to peak at the hive and dust.

    I've continued to monitor matural mitefall on a daily basis. On the 7th, 8th and 9th, the 24 hour natural mitefall was 1, 1, 1 (3 mites total in 72 hours).

    When I dusted on the 5th (4 days ago), the 24 dusting drop was 4 mites. Based on the assumption that dusting is about 50% efficient, this should mean that there were about 4 phoretic mites left after dusting on the 5th.

    I read the 24 natural mite drop to be an indication of the new mites emerging in the past 24 hours (since about 50% of the emerging mites drop or die-and-drop soon after emergence), so based on the fact I had one mite dropping every day for the last three days, that ought to mean that I have added about three new phoretic mites over the last three days. Since the earlier natural mitefall counts averaged about 2 mies/day, it would probably be more conservative to assume that there have been between 1-2 new phoretic mites emerging per day (the 50% that did not drop or die), meaning 3-6 new phoretic mites since I last dusted on the 5th.

    Some of the older phoretic mites have probably re-infested open brood cells - if we assume an average phoretic period or 6 days (average of 5 and 7), then about 2 out of the 4 older phoretic mites should have reentered bood cells between the 5th and the 9th. So my simple model would predict 4 - 2 old phoretic mites plus 3 - 6 newly-emerged phoretic mites for a total of between 5 to 8 phoretic mites in the hive when I dusted today.

    The one hour dusting count was 6 mites today (as it was on January 4th, the first day I had dusted following a long period with no dusting), meaning there were about 12 phoretic mites before dusting (if the 50% dusting efficiency is accurate).

    This is a bit higher than my prediction but still a very low mite level. Ether the dusting efficiency could be somewhat less than 50% or the 24h natural mitefall could be a bit less than 50% of the newly-emerging mites, but the bottom line is that this hive has something in the range of 12 phoretic mites even after 4 days of allowing mites to emerge without intervention - more or less confirming my view that the hive infestation has been reduced down to a level roughly 1-3 infested cells emerging per day.

    My thriving 2-deep hive has been reduced to a 5-frame nuc, but I believe it is on the path to recovery and the mite infestation is now at a manageable level. As long as the natural 24h mite drop remains low (1-3 mites in 24h), I am going to hold off on any further dusting. If I see a spike in the 24h natural mite fall, I will dust on the next nice day to get a sense of the overall phoretic mite load.

    Right now, if we assume 10,000-15,000 bees in this nuc, the infestation level based on an assessment of 12 phoretic mites is in the range of 0.1% - I think the colony is in good shape to get into the spring at least from a Varroa infestation level point of view (and if the can nt make it fro this relatively 'clean' starting point, I am going to have to question if this queens genetics are something I want to continue to prop up or if I should replace her with another feral strain from my apiary...).

    -fafrd

  3. #23
    Join Date
    Jan 2010
    Location
    Auckland, New Zealand
    Posts
    35

    Default Re: Saving a hive from advanced PMS with powdered sugar only!!!

    Hey thanks for this info fafrd, based on your findings I intend to trial intensive ps dusting leading into autumn this year, will see how it goes!

  4. #24
    Join Date
    Aug 2009
    Location
    Berkeley,California, USA
    Posts
    483

    Re: Saving a hive from advanced PMS with powdered sugar only!!!

    Matt,

    thanks for the encouragement

    We had an early spring-like day here in the Bay Area today - sunny and 70 degrees!

    Have continued to monitor natural mitefall and took advantage of the today's good weather to dust. Here is a quick update:

    4-day natural mitefall of 5 mites (average of 1.25 mites falling naturally per day)

    1-hour dusting mitefall of 6 mites (implying that there were about 12 phoretic mites total before dusting)

    I am heading out of town for a week on business, but I will leave the bottom boards in and check the natural mitefall upon my return. All signs so far point to the mites having been decimated and now down to 1-3 mites emerging per day...

    -fafrd

    p.s. Matt, when you do get around to trying intensive powdered sugar dusting, feel free to send me a PM if you have any questions or just want to chat...

  5. #25
    Join Date
    Aug 2009
    Location
    Berkeley,California, USA
    Posts
    483

    Re: Saving a hive from advanced PMS with powdered sugar only!!!

    A further update on the status of the hive I am attempting to save from advanced PMS, for those who are interested to know the outcome of this experiment.

    I've been out for a week but checked the natural mitefall upon my return:

    After a total of 7 days, the natural mitefall was 5 mites (average of less than 1 mite/day falling).

    Since we had a nice sunny day upon my return, I decided to inspect and to dust as a reality check.

    1-hr post dusting mitecount of 3 and another +1 after another 23 hours (4 mites total in 24 hours post dusting).

    Every sign indicates that this hive has between 1-2 mites emerging per day and a phoretic mite count of about 8 mites.

    The good news is that the mites have been virtually eliminated from the hive with nothing but powdered sugar dusting (from a starting 1-hour dusting mite drop of over 500 in late October to a 1-hour dusting mite drop of only 3 today, the mites have been reduced by more than 99% ).

    The bad news is that the hive continues to dwindle. It is now down to only two frames with brood and the brood pattern is about the size of a softball. Plenty of stores but there seem to be only enough bees to maintain a softball-sized cluster.

    The brood pattern looks good and this is my first winter with this strain of bees, so I have no idea how they typically overwinter. The cluster is now much small than the three medium mating nucs I have attempted to overwinter (those three nucs have been sharing heat within a 3X3 medium queen castle and are now in medium supers stacked on double screen boards, each filling about 7 frames in a 10-frame medium super).

    My plan is to monitor this soft-ball sized cluster to see if the brood successfully emerges. If so, all may be well even if this once mighty double-deep hive has been reduce to a large mating nuc by the severe mite infestation and advanced PMS it suffered last fall.

    Since our weather has been in the 60's during the day and high 40's at night, if the cluster gets any smaller I will think about warming this nuc on top of one of my larger hives or boosting them with a frame or two of brood from one of my stronger hives.

    The queen seems fine and the brood pattern seems fine, it just seems that there were apparwently only a very small population of bees that have been healthy enough to last through the winter...

    -fafrd

  6. #26
    Join Date
    Aug 2009
    Location
    Berkeley,California, USA
    Posts
    483

    Re: Saving a hive from advanced PMS with powdered sugar only!!!

    For those who have been following this sage, there was a break in the rain today, so I had a quick look at my salvaged nuc. I've left it on it's own to see how it would do, and I was pleasantly suprised by what I saw today. In four weeks, the brood cluster has grown from two frames with a soft-ball sized cluster of brood to two full frames of brood. The nuc is not yet full but there are four seams full of bees and the other frames are full of stores. We're supposed to have another couple weeks of 'cold' (40's -50's) and wet weather in front of us, so I will leave them in the nuc to get through this cold snap, but if things keep progressing as well as they have been for the next few weeks, I expect this salvaged hive to be back in a single deep by mid-March.

    I think at this point I am ready to call my intensive-powdered-sugar-dusting-traatment of a hive severely infested by PMS a success !

    Probably more work than it is worth, but this experience has proved to me that it is possible to treat for mites with nothing more than powdered sugar dusting. In the future, I plan to monitor mite levels more closely and intervene before PMS gets this severe in any of my hives. And if I ever treat with powdered sugar dusting again, I think I would keep the hive broodless over a 1-week period and knock out all of the phoretic mites with 5-days of dusting, rather than dusting over many more consecutive days in an attempt to salvage the brood...

    -fafrd
    Last edited by fafrd; 02-20-2011 at 04:57 PM.

  7. #27
    Join Date
    Jan 2008
    Location
    Faulkner Manitoba, Canada
    Posts
    1,699

    Default Re: Saving a hive from advanced PMS with powdered sugar only!!!

    I am interested in the cost of the icing sugar to save this hive by dusting. care to share. And the number of hours put into dusting each week or what have you.
    Please and thanks

  8. #28
    Join Date
    Aug 2009
    Location
    Berkeley,California, USA
    Posts
    483

    Default Re: Saving a hive from advanced PMS with powdered sugar only!!!

    Honeyshack,

    good questions and happy to share.

    This is the first time I have tried powdered sugar dusting, so the effort needs to be amortized over the learning I gained...

    That being said, here are the numbers:

    POWDERED SUGAR: I probably dusted this hive about 30 times and get about 8 dustings out of a single 1-lb bag of powdered sugar costing $0.69. So let's call it $3 for the cost of the powdered sugar - not a big deal.

    TIME: Using my canning-jar & screen shaker, I got my techniques down to below 10 minutes for a full dusting, including prep time, so 5 hours invested over 30 days. Would have been less expenesive to have allowed the hive to perish and purchased a new package, but I was learning (and I also now have a proven queen and a nuc that will be far more productive by early May than any April package I could have bought...).

    The other thing I learned is that t is not worth making the effort to save the brood. If I ever try to save another hive using intensive powdered sugar dusting, here is how I would do it:

    1/ remove all open and capped brood

    2/ cage queen for duration of treatment period (4-7 days)

    3/ dust 4-7 times until phoretic mites are reduced close to 0 (ideally 4-7 consecutive days)

    4/ release queen and allow the colony to reestablish brood

    The new powdered sugar blowers available on the market now can probably reduce the dusting time even further, but my guess is that it is not the cost of the sugar or the time needed for dusting that is problematic for a commercial operation, but the fact that this technique is not a 'one-shot' treatment - it needs to be applied 4-7 times consecutively to be effective (usually on 4-7 consecutive days).

    One of the other things I have learned and which has astounded me is how quickly the colony recovers from being dusted. White bees everywhere, wings beating up a cloud of white dust, white bees jammed up around the entrance and powder sugar flying everywhere, it seems like the entire hive is drowning in a blizzard of white powder...

    Close them up and 30 minutes, and from the observed activity coming and going at the entrance you would think that all is back to normal... Open the hive up an hour after dusting, and except for some build up of sugar on the outermost frames that they have not cleaned off yet, you are hard-pressed to find signs that the hive had been dusted just an hour earlier.

    Next time I have an infested hive I am going to treat, I may try dustng them two times or even three times in a single day (without brood). If it is true that half the phoretic mites are knocked off with each dusting, this may allow a full treatment to be achieved in a matter of 2-3 days.

    Happy to answer any additional questions you may have. For a relatively low-tech (and low-impact) mechanical treatment for severe mite infestation, I have been very impressed with how effective this technique can be. From my point of view, the greatest problem with the popular literature on this subject is that the frequency is wrong - dusting once a week for three weeks with brood present does nothing to combat a Varroa infestation and at most delays the continued worsening of the infestation by three weeks. To be effective, powdered sugar dusting with brood present needs to be applied daily (or at least every other day) over a 3-week period (impractical), or over a shorter period of 4-7 days without any brood present (or 2-3 days if dusting 2 or 3 times per day proves to be equally effective).

    -fafrd

  9. #29
    Join Date
    Oct 2010
    Location
    Lewistown,Pa,USA
    Posts
    178

    Default Re: Saving a hive from advanced PMS with powdered sugar only!!!

    Thank you for all the info please keep on posting the progres of this experiment. I am interested in how you continue PS treatment in future. I use Formic acid at his point with great results. Formic will evapoate in 2 weeks but the stuff can be wicked to handle and it will set brood back a week or so but I think that is part of the reason it works so well. I think you are right in thinking on not saving the brood in your method. But I like being able to apply formic then come back 3 weeks later and remove and at that time I could tell the treated hives werebouncing back in a big way. This was last fall Oct 10 to Nov 7. Last week we got up to 60 so check the girls to find all strong with lots of honey and didn't see any mites on any bees but I didn't pull any frames.

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