> The explanation you provide is sideline guessing,  that is actually quite surprising given it also correlates with what several others have noted. 

It is not sideline guessing, because I don't have any idea what went down. I was pointing out that if a product is reliable and someone has a disaster, then logically one would suspect misapplication. In this case, I don't think that was the case at all. I think the bees died for reasons completely unrelated to oxalic acid. Nobody reports 90% loss due to liquid oxalic acid. And like I said, many people reported catastrophic losses and many of them, including me, didn't use oxalic acid. 

> Do you have any of your fall dribble experience to share,  or are you content to question my math and training??  

You don't have to take it personally, it wasn't meant that way. I already said I never used oxalic acid in any form. I don't think its a good idea to be disturbing colonies that late in the season and I don't do it. To me, varroa needs to be knocked down long before then. But speaking of experience, I have in my hand a new report from Luxembourg where they have used liquid oxalic since long before the US, and they are still using it. Nobody is vaporizing it. 

Their results show that mites have to be controlled in summer, and that a follow up with liquid oxalic in December is beneficial. The worst mortality was among those who applied 60% formic in fall followed by oxalic in winter. The most successful beekeepers applied 85% formic in August, and followed up with oxalic in winter. The most crucial factor is summer control. All of them used liquid oxalic in December, so the effect of this is unknown. 

* The data was from a total of 705 apiaries managed by 323 beekeepers, -- 6360 colonies in 2015.

* The average experience in beekeeping of the participating beekeepers was 15 years. 

* The data of the survey were from five survey years (period 2010–2015).

* The higher concentration of 85% formic acid was linked with reduced colony losses when applications were done in August. 

Conclusions

In summary, our results showed that low honey bee colony losses
were associated with a combination of well-timed effective summer and
winter treatments. Effective summer treatments were 85% formic
acid in August or Thymovar in July and in warm Augusts or Apilife in
July and Apivar between July and September. Additionally, oxalic acid
application in December can be recommended. Oxalic acid combined
with an ineffective summer treatment was not sufficient for preventing
high colony losses around 30%.

Beyer, Marco, et al. "Winter honey bee colony losses, Varroa destructor control strategies, and the role of weather conditions: Results from a survey among beekeepers." Research in veterinary science 118 (2018): 52-60.

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