Treatment-Free Beekeeping in Norway scientifically studied - Page 3
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  1. #41
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Both groups showed VSH and grooming!
    Somehow the bees were preventing the mites from reproducing. Female mites smell different maybe??

    If Squarepeg and others ever get there bees tested, might show the same results.

    Still, one more piece of the puzzle!

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  3. #42

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Quote Originally Posted by Scottsbee View Post
    Both groups showed VSH and grooming!
    Yes but in such low and similar levels that that was not behind the differencies.

  4. #43
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Agree. So what is then? Bees sense of smell must be extreme to smell through wax and find the mites in a cell, VSH. Smell the mite on a fellow bee inside a dark cavity and groom it off.

    Makes me wonder if the bees can smell the difference between a male mite and a female mite.

    Maybe smoking the bees is a bad habit? Interfering with the bees sense of smell big time.

    Wondering how many TF keepers don't use smoke or use something else?

    The few TF queen breeders I've read about don't use smoke when working the bees.

  5. #44
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    scotts......

    It has been studied that the mite takes on the bee smell and it is not smell from the mite that triggers grooming. There is a very short window when the mite switches host that might let the bees catch movement and it could be some kind of distress smell from the larva being attacked that causes some kind of smell but most studies say it is not the smell of the mite.
    zone 5b

  6. #45

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Please remember this out of the article. Itīs not about VSH.

    Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies.
    As I understand this itīs pheromones from the worker bees suppressing mite reproductive success, or am I wrong?
    Well, VSH starts a brake in the reproduction of mites too.

    Just remembered that mites are not as productive when having a longer phoretic period. So itīs the brood brake behavior, too. Some hives do brood brakes when mite infestation is high.

    And the small cell beekeepers claim small cell breeding has some impact on mite reproduction too, since the bees hatch earlier. Terje has small cells.

  7. #46
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    SiW....
    As I understand this itīs pheromones from the worker bees suppressing mite reproductive success, or am I wrong?
    I don't think they figured out the why of the lower breeding of the mites. I had see either this study or a differrent one saying the same thing a while ago and I don't think they know what is causeing the lower mite propagation rate. They just know it happends for some reason.
    That is what I got out of the stuff I have read.
    Cheers
    gww
    zone 5b

  8. #47

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    gww,
    yes, we still have no evidential scientific studies about that, you speak the truth.

    The questions I ask myself are:
    - do mites adapt to treatments by having a shorter phoretic state? Hiding faster and earlier in cells probably? Escape from grooming more?
    - do we as beekeepers disturb the hive microclimate and air chemicals so strongly bees are not able to fight the mites as they should?
    - do we as beekeepers disturb the correlations between drone brood,workerbrood and mite reproduction so much we select for "worker-mites"?

  9. #48
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Addressing the fear of selecting for "worker mites," when Nicholas Calderone was researching drone brood for trapping mites his team tried to select for mites that preferred worker brood, but they were unable to do so.

    When mites do not have a phoretic stage they have fewer viable offspring than mites that do have the phoretic stage. Having a shorter phoretic stage may reduce the number of viable offspring also. That could only be determined by controlled studies.

    As for disturbing the hive microclimates, I know of no studies showing that beekeepers that use essential oils have larger mite populations than those that do not. The essential oils would cause the longest lasting disturbance that would be beekeeper induced.
    42 + years - 24 colonies - IPM disciple - Naturally Skeptic

  10. #49

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    The VSH factor counting was done in a strange way:

    - they compared photographs taken at brood age of 10 days versus 20 days
    - the number of cells opened by the bees was counted and divided with total number of cells examined together
    - then they used the infestation rate (of donor colonies?) and formed from these VSH factor for the colony

    Oddie writes:
    "The number of empty cells was taken as a proportion of the total number of cells examined on the frame. This measure together with the mite infestation rates (Harris, 2007) were used to assess the level of VSH in surviving and susceptible colonies."

    This method does not take into account if bees have opened and closed a cell.
    This method is not the one usually used by for instance Arista BeeResearch Project.
    Last edited by Juhani Lunden; 11-01-2017 at 12:57 PM.

  11. #50
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    >Makes me wonder if the bees can smell the difference between a male mite and a female mite.

    If they are phoretic, they are female. YOU can tell the difference without smelling them: http://idtools.org/id/mites/beemites...destructor.jpg

    >Maybe smoking the bees is a bad habit? Interfering with the bees sense of smell big time.

    For about ten minutes... Feed some essential oils and how long to you interfere with their sense of smell?

    >Wondering how many TF keepers don't use smoke or use something else?

    I use smoke.
    Michael Bush bushfarms.com/bees.htm "Everything works if you let it." ThePracticalBeekeeper.com 42y 40h 39yTF

  12. #51

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Quote Originally Posted by AR Beekeeper View Post
    Addressing the fear of selecting for "worker mites," when Nicholas Calderone was researching drone brood for trapping mites his team tried to select for mites that preferred worker brood, but they were unable to do so.

    When mites do not have a phoretic stage they have fewer viable offspring than mites that do have the phoretic stage. Having a shorter phoretic stage may reduce the number of viable offspring also. That could only be determined by controlled studies.

    As for disturbing the hive microclimates, I know of no studies showing that beekeepers that use essential oils have larger mite populations than those that do not. The essential oils would cause the longest lasting disturbance that would be beekeeper induced.
    How long did they do the selection research?
    I just love science. Are there some results of value? Still nobody knows which are the main factors of tolerance except the bees living in tropical climate are more tolerant.


    http://www.moraybeedinosaurs.co.uk/V...rol-Varroa.pdf
    Under laboratory conditions, Varroa fe- males can successfully be transferred from brood cell to brood cell without a phoretic phase (De Ruijter, 1987); under field conditions, older mites seem to invade brood cells more rapidly than nullipa- rous Varroa females (Fries and Rosenkranz, 1996). It seems that especially under unfavorable conditions, the phoretic phase may have negative effects on the reproductive capacity of Varroa mites: After a long phoretic phase of 5 weeks or more, or after a starvation period of 7–18 h the number of infertile mites was two–three-fold higher than in the control (Rosenkranz and Bartalszky, 1996; Rosenkranz and Stürmer, 1992).
    Fea- tures of the parasite that influence population growth are the reproductive capacity during the mite’s lifetime and the lifespan, features of the host are brood availability, presence of drone brood, swarming, and level of defense behavior, among others (see also in Section 5.2.3). Some of the host features that influ- ence mite population growth are additionally triggered by ambi- ent factors such as climate and nectar flow (Currie and Tahmasbi, 2008). The exact impacts of the individual parameters on the population dynamics are not known.
    Increasing the mites’ phoretic phase during winter times or dry seasons decreases the reproductive success (Rosenk- ranz and Bartalszky, 1996).
    It is likely that environ- mental factors act indirectly via the host on the parasite, for in- stance by modulation of honey bee brood amount, the relation of drone to worker brood or the extent of the hygienic behavior of the bees.
    However, the removal of mites from the brood leads to an interruption of the reproductive cycle of the parasite, a prolonged phoretic phase or even the death of the mites.
    The hygienic behavior is strongly influenced by environmental and in-hive factors (Boecking and Spivak, 1999; Harris, 2008; Spivak 1996a,b).
    Simulations indi- cate that a shortening of the post-capping period by about 10% could reduce the mite population growth by about 30% (Büchler and Drescher, 1990). Africanized honey bees as well as some African subspecies have a significant shorter post-capping per- iod than European honey bee races (Moritz and Mautz, 1990; Rosenkranz, 1999; Rosenkranz and Engels, 1994a). However, Martin (1998) does not expect a considerable effect of a shorten- ing of the developmental time of the bee brood as the number of brood cycles per season may increase; and Bienefeld and Zautke (2007) even expect negative effects due to a reduced vitality of the hatching worker bees.

  13. #52

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Quote Originally Posted by Michael Bush View Post
    >Makes me wonder if the bees can smell the difference between a male mite and a female mite.

    If they are phoretic, they are female. YOU can tell the difference without smelling them: http://idtools.org/id/mites/beemites...destructor.jpg

    >Maybe smoking the bees is a bad habit? Interfering with the bees sense of smell big time.

    For about ten minutes... Feed some essential oils and how long to you interfere with their sense of smell?

    >Wondering how many TF keepers don't use smoke or use something else?

    I use smoke.

    Maybe they smell the male mites hatching in cells? IMO they smell stress pheromones from pupa.

    Michael, I extracted broodnest honey from my deadouts and the smoker smell is still in the wax and honey. I can even distinguish between what I used ( the lavender for example).

  14. #53
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    SiWolke; Calderone was working on trapping with drone brood in 2002, at Cornell University. His paper on drone brood trapping did not state the length of time spent attempting to select varroa that preferred worker brood, just that they tried and were unable to do so.

    I had read that the phoretic phase was not needed by the mite, they could enter the cell to lay immediately after emerging from their birth cell, but with reduced fecundity, but I was unaware that an extended phoretic phase was a cause of infertility. Thanks for that piece of information. There is always something more to learn about the honey bee, isn't beekeeping great!
    42 + years - 24 colonies - IPM disciple - Naturally Skeptic

  15. #54
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Quote Originally Posted by SiWolKe View Post
    Please remember this out of the article. Itīs not about VSH.
    From Le Conte et al. The mechanisms underlying bees suppressing mite reproductive success in two populations resistant to varroa in Avignon and Gotland have been partially discovered. They are: mites infertility; mites with delayed egg-laying; mite offspring mortality.

    "Investigations of the individual parameters involved in the mite's overall reproductive success also revealed differences between surviving and control colonies at each location, as well as differences between the two mite-surviving populations (Table 1). Although all the parameters rendered statistically significant differences between groups in each location, a few are highly significant and biologically interesting. In Avignon, the significantly high rates of infertility and secondly the high proportion of mites with delayed egg-laying seemed to be the most influential parameters in reducing the mite's reproductive success (Table 1). In Gotland however, the proportion of mites with delayed egg-laying was the parameter most significantly different from control colonies with a high proportion of mite offspring mortality a secondary significant factor." source: http://onlinelibrary.wiley.com/doi/1.../ece3.248/full

  16. #55
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Likely mechanisms underlying mites infertility and mites with delayed egg-laying

    "V. destructor has only a very narrow time window for starting reproduction after enclosure in the brood cell (Rosenkranz et al., 2010). Within 5 h after the capping of the brood cell, the mite consumes the first haemolymph meal and only a few hours later oogenesis begins. If the female mite fails to initiate ovary activation in this narrow time window, it will remain infertile. The ovary activation has been suggested to depend on cuticular hydrocarbon stimuli (Aumeier et al., 2000; Frey et al., 2013). Hence, a lack of such stimuli might be one way to prevent mite reproduction. However, it is also possible that specific compounds in the first haemolymph meal can inhibit the activation of the mite’s reproductive cycle. Clearly, understanding the underlying physiological processes that interfere with the crosstalk between the mite and the host larva will be fundamental to comprehend this important step in host–parasite coevolution. This is the most critical phase in the reproductive cycle of the mite, where the host has the opportunity to evolve true resistance." source: http://www.sciencedirect.com/science...44200616300198

  17. #56
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Eduardo
    Thanks for posting.
    Cheers
    gww
    zone 5b

  18. #57

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Quote Originally Posted by Eduardo Gomes View Post
    Likely mechanisms underlying mites infertility and mites with delayed egg-laying

    "V. destructor has only a very narrow time window for starting reproduction after enclosure in the brood cell (Rosenkranz et al., 2010). Within 5 h after the capping of the brood cell, the mite consumes the first haemolymph meal and only a few hours later oogenesis begins. If the female mite fails to initiate ovary activation in this narrow time window, it will remain infertile. The ovary activation has been suggested to depend on cuticular hydrocarbon stimuli (Aumeier et al., 2000; Frey et al., 2013). Hence, a lack of such stimuli might be one way to prevent mite reproduction. However, it is also possible that specific compounds in the first haemolymph meal can inhibit the activation of the mite’s reproductive cycle. Clearly, understanding the underlying physiological processes that interfere with the crosstalk between the mite and the host larva will be fundamental to comprehend this important step in host–parasite coevolution. This is the most critical phase in the reproductive cycle of the mite, where the host has the opportunity to evolve true resistance." source: http://www.sciencedirect.com/science...44200616300198
    Great info Eduardo, thanks!

    In this Norwegian study they conclude: "changes in brood volatiles (Nazzi & Le Conte, 2016) are not a factor in the results obtained."

    If VSH bees get their clues through the cappings of cells, could it be thinkable that mites get some volatiles through cell walls? If yes, then Terjes bees and larvae volatiles may have effected mites in cells in a different way than in control colonies.

  19. #58

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Quote Originally Posted by AR Beekeeper View Post
    , but I was unaware that an extended phoretic phase was a cause of infertility.
    The long winter of Finland makes record long phoretic phase, but still mite problems are serious and use of oxalic acid has been doubled in professional apiaries in the last 5 years.

    There is usually at least 2 months broodless period in Finland, but beekeepers end up in troubles in a year if they donīt do treatments properly.

    This reminds me: did you notice that in the Norwegian study they mentioned that some of the control populations was treated biannually, that is every second year.
    Quote: "Susceptible local control colonies were located ∼60*km away from the surviving apiaries in a local A.*m.*carnica conservation area and treated against V.*destructor on a biannual basis."

    Terjes bees are said to be "mixed origin (Buckfast)", control is carnica.

  20. #59

    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    Many thanks, Eduardo.

    Many thanks, Juhani, for updating about Terje and the norwegian study. Very interesting, I hope they reveal more.

    This topic of volatiles in the bee hive is the most interesting thing and I hope this is studied more.

    I do not understand that there is no interest of research in an information pool coming from the smaller hobbyist or sideliner tf beekeepers. There are many of those but they work in secret because of laws which are a barrier to every development in that direction.
    Sure, one can take part in some research programs, but rules must be followed.
    Only the observation of a variety of beekeeping methods can reveal what happens in a beehive with all the correlations between bee behaviours, environement, genetics and the handling of bees.
    Lab science is not what happens in a natural setting.

    So scientifically research must have itīs own reasons for this, aka money funds and and importance.

    Thank god tf beekeepers share their hard work and experience in forums and blogs. Sometimes in studies also.
    Last edited by 1102009; 11-02-2017 at 12:48 AM.

  21. #60
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    Default Re: Treatment-Free Beekeeping in Norway scientifically studied

    I light the smoker. I put one puff in the door and after taking off the top, a puff across the top. That is usually the extent of my smoking bees and certainly when I'm harvesting it's the extent.
    Michael Bush bushfarms.com/bees.htm "Everything works if you let it." ThePracticalBeekeeper.com 42y 40h 39yTF

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