> The differences in the number of mites "found" by each approach is only a concern to beekeepers who still believe in the fallacy of a "threshold". 

All of the points you mention were addressed in the 2015 article. The point of the article was to assess the accuracy of previous studies. They cite the BEEBOOK results in the third paragraph:

> These methods have been revised and extended upon in the BEEBOOK (Dietemann et al., 2013).

I think it's significant that they did a sugar shake followed by alcohol wash and found that after the shake there were twice as many mites still on the bees as the number that was dislodged. In other words, the test itself is highly inaccurate. 

The aim of our study was to assess the reliability of Varroa
diagnostic methods used by veterinary inspectors and
beekeepers under field conditions, especially in au-
tumn season, when the research was carried out and
when the colonies need healthy bees for overwinter.

it is important to
know mite populations in the fall when treatments are
applied to the hives or to determine infestation levels
prior to overwintering.

The methods we have evaluated could
be useful for indicative purposes, but are not reliable
for determining the total Varroa mite population in
beehives.

If no mites are recorded, the colony
would have a low infestation rate; however, if a larger
number of mites is recorded, it would not be a reliable
indicator of the actual Varroa population in beehives.

In conclusion, our results showed that only the
number of Varroa that fell over a 4-day period was significantly
correlated with the actual mite population in beehives.

* * *

Obviously, this study contradicts previous ones. That's why I posted it. You can say that the older studies are correct, but this one seems to cast a significant doubt on them. Science is about testing and retesting, as opposed to accepting such and such as an established fact that cannot be subject to revision. 

PLB

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