In *A cerana *and *A.m. scutellata*, the VSH trait
remains dominant, due to strong natural selection against colonies that do
not exhibit this trait. I believe that this observable fact refutes the
hypothesis that VSH necessarily slips away.
-- VSH not taking hold is not a hypothesis, it's a fact. You are formulating the hypothesis that it should provide survival benefits. I am saying that observations reveal that it is not retained by stock into which it's introduced. My hypothesis would be that the trait is swamped by wild type genetic combinations, that it provides no clear survival benefit, and that non VSH bees prevail in the general population because they are maintained with acaricides.
But I have bred bees for a few decades, and personally observe
how easy it normally is to breed for traits.
-- Sure, nobody disputes that strains with certain traits can be selected and bred. The question is about what happens to those traits when they are introduced into the general population. The hypothesis is that these traits will provide advantages and will accumulate in populations. Obviously, if the advantage is small, it may be overwhelmed by other more significant factors. Also, as I said (as have so many), no progress can be expected in mite resistance if beekeepers continue to use acaricides.
*Thus, I don't understand your opinion that breeding efforts are futile. On the
contrary, the natural development of mite-resistant stocks would be as expected
-- I have never expressed the opinion that "breeding efforts are futile." However, I have presented Oldroyd's observations that VSH traits have not bee acquired by the bee populations in Australia, that true progress in bee breeding is expensive, and may not pay adequate returns in productivity. Many times I have pointed out that there are at least two ways to increase production: breed better bees, or get more hives.
PLB
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