Europe versus USA: breeding varroa resistence

Rüdiger Dietrich’s comment is so good I made it into a post of its own as well. Thanks Rüdiger!

As a German I have of course to answer to Eriks contribution “Breeding for Varroa resistance: Germany versus USA”…:-).

When commenting about activities in the varroa resistance breeding area I guess it’s better to compare Europe versus US. Otherwise it would be too bad for Germany…

I think the main drawback for Europe compared to US is that a funded continuous breeding program is missing. The US seems to have at least 3 – Minnesota Hygienic Stock (MNHYG), Russian Honey Bee program (RHB) and VSH program, which all seem to have shown valuable outcomes. Moreover, the organic beekeeping community in the US, e.g. Ed and Dee Lusby, Michael Bush, Dennis Murrel and others have been innovative and could establish treatment free beekeeping since many years. And this could be achieved with local bee races or no complicated bee breeding scheme!!! Their impact with small cells, comb distance, not contaminated bee wax etc. is not only logic and inspiring, it works as stated above.

Europe did of course some funded scientific investigation of Varroa and could contribute to the understanding of infestation mechanism in the 90-ies, e.g. grooming behaviour (Bienefeld, Aumeier, Thakur etc.) or VSH (Rosenkranz, Vandame). However, efforts seem to be sporadic and as already mentioned not continuous, to yield in resistant queens that are distributed via the beekeeping community.

Besides, beekeeping organizations here I can only comment on Germany with the AgT (Arbeitsgemeinsschaft für Toleranzforschung) http://www.toleranzzucht.de/en/breeding-programme/, try to connect and coordinate different breeders in order to achieve bees that combine favourable and varroa resistant traits. However, improvement ratios seem to be small up to now.

But in my eyes Europe could contribute significantly by activities of bee breeders. The idea to use already varroa resistant bees for breeding was first established by Erik Österlund (1989) and John Keyfuss (1993), who cross African bees into A.mellifera mellifera/Buckfast. John uses a Tunisian bee (Apis mellifera intermissa) and Erik Apis mellifera monticola from Kenya. The resulting Elgon bee is since a bee that needs less or even no varroa treatment. The same is true for Kefuss bees and he gain merits by bringing this topic into broad public interest with his “World varroa challenge”.

This approach was copied by Rinderer (RHB), who used Russian bees that lived since 200-250 years with varroa mites and hence, should have developed resistance traits. The same idea was practically followed by P. Jungels (Buckfast – Primorski mixes) and J. Koller (pure Primorski) (Primorski synonyme for Russian bees) in Europe, who contributed significantly by providing varroatolerant queens to the European beekeepers.

A guy that use local (carneolian) bees for his breeding program is Alois Wallner from Austria http://www.voralpenhonig.at/, who has bred since 1990 for bees that groom and kill varroa mites by removing their legs. The result is now a bee that kill nearly every mite (varroa killer factor 100). Additionally his bees express VSH behaviour and hence, bees need only few or no treatment with formic acid.

In my opinion one brave European guy need to be mentioned as well which is Juhani Lunden in Finland http://www.saunalahti.fi/lunden/varroakertomus.htm He managed in a brute force approach to breed varroaresistant bees, which are not treated since 2009. He used a strong selective pressure to achieve his goal and hence, other traits as gentleness or honey crop might be compromised.

So taken together, these efforts need to put on a strong base in Europe as well and both, the spread of “resistant genes” by suitable queens and by suitable programs need to be pushed and furthermore the usage of organic beekeeping principles that result in treatment free bees should be distributed. That includes the courage of not using treatments to outselect non optimal strains. Here the community in Europe is already on the way see http://resistantbees.com/ (Germany and Spain), but Europe should definitely speed up and learn the positives from the US. This is especially true for the scientific sector and funded EC programs.

8 thoughts on “Europe versus USA: breeding varroa resistence

    • Hi Riad,
      I’m living not far from you (Jena, Thüringen). At the moment I’m transferring my hives to 4,9mm followed by guidelines of the resistantbee.com (very good homepage, available in german, english and spain).
      If you are interested we might exchange suitable resistant colonies by the end of this summer (July/August) to increase genetic diversity and hence, gain good elasticity in our stocks. At the moment I have queens with high varroa tolerance from P. Jungels (Buckfast-Primorski) but will definitely ask Erik for suitable Elgons next year as well….:-)

      Rüdiger

      • Hello Rüdiger, it’s very good to know that you are in Jena it’s only 1hour from Chemnitz. Yes sure we can make exchange next Year. I have some very good Queens from Erik and from other breeders and i was allready Transfer the Most of my hive to 4,9 . Did you was doing any Test of the VSH Queen from P.Jungels? I have some Primorski Queens. Riad

        • Hi Riad,
          not up to now. I learned as recently about the test from Eriks contribution. Hence, I’m going to prepare with the right equipment and start with this in spring. However, I do not intend to this on a regular basis, just occasionally. I guess as a rough estimate it is sufficient to measure the VSH behaviour by looking at the amount of opened cells. Although this is not exactly, it might be sufficient. However, for the stocks that we might exchange, I will do so.

          Rüdiger

          • Hi Rüdiger
            Observing that the bees are cleaning out brood cells is of course good, in a way. But maybe you don’t know the mite population in the hive. Maybe it’s high and that has triggered the bees to clean out. If so that doesn’t mean the bees show good resistance, it may mean that they started cleaning out too late. And you don’t know if the bees have distinguished between mites with offspring and without, which is VSH. So to really know if the colony is good at VSH you have to know the ratio between the two, mites with offspring and mites without (here you could include offspring that are not viable, for example just one male and no female).
            But I agree that you don’t have to check all colonies. Depending on what other types of measurement you have and selection (for example good honeycrop) you can make a first selection and check those that you suspect and those you hope are good at VSH.

  1. Dear Eric,
    from a breeding perspective I would definitely agree with you, as doing the test is the most accurate you can do at the moment.

    Anyway, allow me to comment a bit on this test:
    1. Harris commented in the nice link you have cited http://www.extension.org/pages/30984/selecting-for-varroa-sensitive-hygiene#.UsHLe_vqKSo , that there are several ways to select for VSH. The one which you discussed in your June blog and in the above post is the mite infertility ratio, which means the total number of infested pupae divided by the number of mites that don’t reproduce. Hence, only when no mite offspring is present, the OVR (ovipositioning ratio) is 0 or the VSH is 100%. Hope I understand this correctly….
    I definitely see the advantage of doing only one test (day 7-10 after capping), however, the risk is that you have a stock which brilliantly removes infested pupae but has no effect on mite fertility. Hence, you would measure a OVR of 6 (standard because no effect on mite infertility – translates into a VSH of 15-20%) but might have a hygienic factor of 50% (hygienic behaviour is measured by quantifying the infestation rate on day 0-3 after capping and in a second test after day 7-10). Harbo called this “brood removal”.

    In the link you have identified (cited above), Harris indicated that mite infertility is linked to brood removal and hence, can be used as selection criteria. However, there might be stocks where mite infertility and brood removing are not linked, ecpecially because Harbo and Harris have selected with this cirteria….

    2. There might be factors that influence the %VSH number, like infestation number. You and Harris indicated that there might exist a stimulus threshold for VSH. When too less pupae are infested, VSH might not work. With other words you might get a lower VSH value, when doing the test at low mite infestion compared to higher mite infestation. This can be of course counter checked by doing several test per hive at different times and compare whether the number is always the same or similar.

    3. VSH ratio can be influenced by epigenetic regulation and hence, different e.g. when worker bees are heavily busy with honey crop. Again a counter check would answer.

    Perhaps one should crosslinks the values to the overall mite infestion ratio. Either by the VSH test or by counting the number of mites below the hive. That should help….

    But please do not missunderstand me, I find this test useful.

    Rüdiger

    • Hello Rüdiger
      I like exchanging thoughts and I think your logic is correct. But let me do some additional comments.
      1. You use the word “might” a few times indicating there can be uncertainties concerning the effectiveness of using the “ratio method” for selecting VSH. The one Harbo uses today and suggests as an simplified method for ordinary and everybody beekeeper. The important note to make here is that Harbo IS using this simplified method with success today, after his retirement, as he doesn’t have to produce scientifically valid figures. It’s enough for him now. Which means it’s seems good enough for us to try. Bob Danka on the Bee lab in Baton Rouge says something similar actually, which he says is going from the science of beekeeping to the art of beekeeping. http://vshbreeders.org/forum/showthread.php?tid=192&page=2
      2. The same comment holds for this discussion. And most probably there is a threshold level for removal of all infested cells as well.
      3. Might be so, but as the VSH is a result of earlier activities concerning identifying and removal of fertile mites in brood, the effects resulting in the “ratio” will most probably have a prolonged effect as those mites being infertile probably are “old” mites, no longer being fertile after having been laying their number of eggs they are capable of.
      But to conclude. We have to try and get experience to be able to draw our own conclusions. Let’s do it the way we find best and then share experiences.

      • Hello Eric,
        thanks for hinting at that discussion in the VSH breeder blog. It seems that I was a bit behind with my arguments. This answers a lot.
        I especially like your comments on p.2 discussing on the relationsship of approaches of scientists versus beekeepers.
        I think to find the own way in practical beekeeping business by using the amount of useful information and necessary practical effort is a nice creative process, which involves several skills. And the result will tell… The good thing is that several strategies work, which does not mean that this is always an easy process.

        Finally, for a breeder using the OVR ratio as selection criteria is certainly the better idea, as you integrate other VSH mechanims in your selection scheme that focus on mite fertility. Plus you have a lower practical effort. Completely agreed.
        If you are a beekeeper that focus on honey production it simply might be enough if colonies survive and can control the mites, whether by affecting the fertility of mites as well or not.

        Hence, I have to acknowledge you useful thoughts!

        Best regards,

        Rüdiger

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