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.