Page 2 of 2 FirstFirst 12
Results 21 to 29 of 29
  1. #21
    Join Date
    Aug 2003
    Location
    Hotlanta, GA
    Posts
    475

    Post

    I was thinking the same thing...so just cut out a rectangle and staple some #8 hardware cloth over it?
    Ask two beekeepers, get three answers

  2. #22
    Join Date
    Aug 2002
    Location
    Nehawka, Nebraska USA
    Posts
    46,785

    Post

    >If you are trying to make a screened bottom board out of an standard bottom board, you would probably be better off to consider making a screened insert which would also give you the possibility of easier sampling for natural mite drop. What you want to do is maximize the screened area to improve efficiency and accurateness of mite drop count.

    What I want is better ventilation and a way to measure mite drop. The insert will not give me the ventilation I want.
    Michael Bush bushfarms.com/bees.htm "Everything works if you let it." ThePracticalBeekeeper.com 40y 200h 37yTF

  3. #23
    Join Date
    Aug 2002
    Location
    Evansville, IN, USA
    Posts
    2,837

    Post

    Dont waste your time w/ an "insert". Cutting a hole in std BB is best. If you add some "legs/runners/spacers" to bottom of the std BB, you can slide (from back) a "sticky board" underneath, and have excellent ventilation too.

  4. #24
    Join Date
    Oct 2005
    Location
    New Brunswick, Canada
    Posts
    9

    Post

    Michael B

    Your answer has left me confused in understanding your approach to mite control. I understand that you want better ventilation and are therefore opting for an open screen board and that you want a board that can be used for mite counts. The trade off for ventilation would then be an increased mite load?

    Here is a study that showed open screen boards showed higher mite infestations when compared to drawer equipped boards:

    http://www.reineschapleau.wd1.net/research.en.html

    Here is the excerpt from Jean Pierre Chapleau"s study

    "The thermal factor and the anti-varroa bottom board
    The important difference in the global results obtained in 2000 (29.2% more varroa mites) and 2001
    (37% less varroa mites) for sub group AV suggest a confirmation of the negative thermal influence
    assumed in the 2000 trials. In 2000, all of the anti-varroa bottom boards were operated with the
    bottom opened while in 2001, with the exception of the YBO group, the bottom boards were operated
    with the bottom closed. To our knowledge, this is the only operational factor that was systematically
    different between the 2000 and 2001 trials. The results strongly suggest a connection between this
    factor and the negative results obtained with the use of anti-varroa bottom boards during the 2000
    trials. We can legitimately assume that the brood cluster temperature was lowered with the use of the
    opened anti-varroa bottom board. Numerous references can be found in scientific literature
    confirming that lower temperature conditions enhance the development of varroa populations.
    Ingemar Fries (12) states: “(…) mite population seems to grow faster in cooler climates than in
    warmer areas (…) it has been suggested that climatic factors are decisive in determining the mite
    population growth although the mechanism remains unclear.” We can believe that a longer period of
    time in the capped brood stage resulting from a lower temperature favors an increase in the
    reproductive rate of the varroa mite’s population. An increase of time in the capped brood stage
    enables the young female varroa mites to reach maturity before the bee emerges from its cell. Kraus
    and Velthuis (14) found that artificially reducing the brood temperature of colonies had the effect of
    doubling the mite population in comparison with control groups. Their laboratory tests allowed them
    to determine that 33 C was the optimal temperature for varroa mite reproduction. Kraus and Velthuis
    (14) suggest that beekeepers adopt practices that aid colonies in maintaining brood temperature at
    35 C. The results obtained by Kraus and Velthuis were not available when planning for the 2000
    trials as they were published in October of the same year. Reference to the influence of temperature
    on the rhythm of natural varroa drop can also be found in recent scientific literature. Thomas C.
    Webster (4) found that this drop is correlated to the average outdoor daytime temperature. J.T.
    Ambrose (13) also found (2001) that when infested adult bees were exposed to variable temperatures
    in laboratory conditions, the percentage of varroa mites falling from the bees increased with the
    elevation of the ambient temperature. Here again we can deduce that the brood chamber
    temperature should not be lowered.
    Nevertheless, the negative impact of the use of open anti-varroa bottom boards was not universal
    since in 2000, the AV sub groups of two locations (MAI and JOY) demonstrated positive results
    despite opened bottoms. Similarly, in 2001, the only location where the open bottom board was used
    yielded a positive result (YBO 35%). However these exceptions can be logically explained. For
    location MAI in 2000 as well as YBO in 2001, the manner of placing the hives on the ground and the
    terrain conditions limited the air circulation under the open bottom boards and therefore limited the
    cooling effect on the hive. Furthermore the colonies in the MAI group in 2000 were maintained in a
    crowded two super condition for the production of queen cells. No doubt, this condition contributed to
    higher brood chamber temperatures. The third location (JOY) was situated in a well sheltered
    clearing fully exposed to the sun. It is possible that for these locations and in these circumstances,
    the open bottom boards did not cause a lowering of temperature of the brood chamber. In light of
    these facts, the use of the anti-varroa board with an open bottom seems completely inadvisable in
    environmental conditions comparable to those in Quebec. The enclosed table can be consulted in
    regards to the average minimum and maximum temperatures of the area where the tests we..."

    Here is another abstract that concluded that capping time was influenced by brood temperature:

    http://www.edpsciences.org/articles/...055/M4055.html

    The abstract states:

    Abstract - An assessment was made of tracheal mite susceptibility in honeybees pupated at a low temperature. Using a laboratory bioassay, an experiment was conducted to compare the performance of newly-emerged (callow) bees raised at 30 ºC with those raised at the more normal brood temperature of 34 ºC. The reduced temperature caused a delay of over 5 days in the emergence of the bees from the brood cells. The callow bees raised at 30 ºC had over twice the mite prevalence level. The fecundity of the mites in the tracheae was similar for both temperature conditions. Increased susceptibility to tracheal mites resulting from reduced brood temperature may help to explain the mortality, in the temperature-stressed late winter/early spring period, of colonies with a moderate mite infestation in autumn. Further work is required to identify the mechanism responsible for this increased susceptibility.

    In view of this, and your post on shortened capping times on small cell, would you reconsider the use of open screen boards? I mean no disrespect - just would like your thoughts. A difference of five days in capped brood duration due to temperature is huge. I realize that it gets a lot hotter in your area compared to mine but am quite certain that this is not the case year round.

    In short, these are the reasons for my favoring a drawer equipped board and if trying to make a screen board out of an existing bottom board, then I would opt for an insert.

    Cold,wet and miserable up north,

    Claude

  5. #25
    Join Date
    Aug 2002
    Location
    Nehawka, Nebraska USA
    Posts
    46,785

    Post

    >Your answer has left me confused in understanding your approach to mite control. I understand that you want better ventilation and are therefore opting for an open screen board and that you want a board that can be used for mite counts. The trade off for ventilation would then be an increased mite load?

    I have no discernable mite load.

    I am not having varroa mite problems. Bees bearded on the front of the hive are not making honey. I use SBB to have ventilation so I can keep the nectar eveaporating and the bees working. I let the bees use natural cell size to deal with Varroa.

    >Here is another abstract that concluded that capping time was influenced by brood temperature:

    "bees raised at 30 ºC with those raised at the more normal brood temperature of 34 ºC. The reduced temperature caused a delay of over 5 days in the emergence of the bees from the brood cells."

    I only open them up when the bees start bearding in the late spring I have no expectation of the brood nest of my bees ever being 30 C. What I have observed, with small cell, is two days shorter emergence. 19 days is the norm.

    >The callow bees raised at 30 ºC had over twice the mite prevalence level.

    With five days longer emergence that's what I would expect. How do you keep a brood nest 30 C? Any strong hive will keep it 34 C or so. It would take a weak hive, excess ventilation, and too big a space to get that cool now and then, let alone consitantly, wouldn't it?

    >In view of this, and your post on shortened capping times on small cell, would you reconsider the use of open screen boards?

    I only open them up when the bees are obviously in need of ventilation.

    > I mean no disrespect - just would like your thoughts. A difference of five days in capped brood duration due to temperature is huge.

    And I don't think you can, in a normal hive, cause this to happen.

    > I realize that it gets a lot hotter in your area compared to mine but am quite certain that this is not the case year round.

    Our last day for frost is about the middle of May.

    >In short, these are the reasons for my favoring a drawer equipped board and if trying to make a screen board out of an existing bottom board, then I would opt for an insert.

    I always have inserts. I close them from September or so until May. I also want to be able to open them when it gets hot until it cools off in the fall.
    Michael Bush bushfarms.com/bees.htm "Everything works if you let it." ThePracticalBeekeeper.com 40y 200h 37yTF

  6. #26
    Join Date
    Oct 2005
    Location
    New Brunswick, Canada
    Posts
    9

    Post

    I was under the impression that you were advocating open screen boards for year round use. Makes much more sense to me now. Thanks for the clarification.

    I agree that there would have to be extreme combination of circumstances for brood temperature to be at 30C but if I can help them get it up to 35C then perhaps I am speeding up the brood cycle and providing some degree of mite control. I will have to stop procrastinating and try some small cell...perhaps next week...

  7. #27
    Join Date
    Aug 2002
    Location
    Nehawka, Nebraska USA
    Posts
    46,785

    Post

    I have never advocated open screened bottom boards for year round use.

    >but if I can help them get it up to 35C then perhaps I am speeding up the brood cycle and providing some degree of mite control.

    The core of the brood nest WHEN it has brood in it is like your body temperature. It takes a lot of extreme circumstances to make it fluctuate by very much and then it usually won't last very long. I don't think the bees reqire your help to get it up to 35C. It's really the -20 F nights and the sometimes 60mph winds that make me put in the tray. But I leave it in until the bees tell me it's too hot by bearding. Then I think it's important that I help them get back to work, keep the combs from collapsing, and help them dry the nectar.
    Michael Bush bushfarms.com/bees.htm "Everything works if you let it." ThePracticalBeekeeper.com 40y 200h 37yTF

  8. #28
    Join Date
    Apr 2004
    Location
    Wheatfield, IN
    Posts
    2,068

    Post

    >>I was under the impression that you were advocating open screen boards for year round use.

    Some beekeepers do this very thing. I left one of my SBB open all winter last year. That hive built up as quickly and has performed just as well as those other hives with the SBB closed.

    Our winter was mild this year. I saw only had a few nights around -4 degrees and that was in December.

    I'm not sure I'd do that with all my hives but the results were better than I expected them to be.
    Dan Williamson
    B&C Honey Farm http://www.flickr.com/photos/9848229@N05/

  9. #29
    Join Date
    Jul 2005
    Location
    Perkasie, PA
    Posts
    1,998

    Post

    My SBB are open all year and do not seem to cause any problem. I do use slatted racks though, and this might help protect against some winter drafts. Also, PA has very mild winters compared to the many other regions. When it gets cold, the bees simply migrate up a bit higher into the hives.

Page 2 of 2 FirstFirst 12

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Ads