Jim,

I'm trying to follow this debate from the perspective of one who doesn't have to deal with varroa mites ('cos we don't have 'em yet in Western Australia), but I sure want to stay in business when the evil day arrives! 

Randy and Eric, it seems to me, have given a pretty straightforward, warts and all, description of the way in which mite fall counts can be used to trigger a particular management strategy, which is appropriate for them and their bees, in their locations at that point in their seasonal cycle. As I understand it, the aim is to reduce total mite burdens to non critical levels that will ensure colony survival and productivity for the following parts of their seasonal cycle. The management strategies, or in Randy's military terms, weapons selected from the armoury, are again based on their relevant experiences. So what's wrong with that? Isn't that what we all do, all the time, in making management decisions for our livestocks' welfare and productivity? I hope I haven't missed anything here.

In reading your post, it appears to me that you are railing against the concept of a "one size fits all" mite drop threshold, because anybody relying on such a figure which materialises out of the "research" ether with no regard to their bees location and their own management practices and objectives, is doomed to a future of catastrophic hive losses. Very true from what I have read, and I am sure both Eric and Randy would agree with you on that. The problem I have is that neither have advocated that approach.  
From experience Eric has arrived at "a rule"; for him a mite drop count of >55 per 24 hours in early September requires action, and this is also based on an eyeballing of relative population strength.
 He also states;
"Are there special factors (variables) that could interfere with the rule?  
Sure.  Will I have hives that are big enough to withstand >55 mites?  I'm 
sure I will.  Could the 55 number be unnecessarily conservative?  Perhaps, 
but more than enough hives (on average a majority) come under that 
threshold for it to still be very useful.  Is every winter going to be the 
same?  Of course not.  Is every strain of bee and every strain of mite 
going to follow the same rules?  Of course not.  Are there going to be 
regional differences?  Sure.  In short, there are lots of variables, but 
they don't render the information we do have meaningless.".......
"So from my perspective, experience, good sense, and scientific research 
all strongly indicate that thresholds are a meaningful and useful 
management tool."
Randy followed with;
 "The concept of thresholds only fails if they 
are used as a magic number that you wait for until you treat your colonies.
They are very useful as predictors if you're on a dangerous trajectory, and 
I believe I covered them well as such in my article in ABJ.
It's not at all hard to adjust them for colony strength by eyeballing.
The most important thing is to use a sampling technique that is accurate and 
appropriate for the season."

Your response was; 
"So, I'll insist again - thresholds are bunk.
An unscientific approach with no more value than 
a guess, at odds with the basic precepts of IPM as
practiced in every other aspect of agriculture."

So please Jim, for the varroa-illiterate, including me, what would we actually do instead?
You said;
"And what of migratory beekeepers?  What might
they do?
Well, they could take advantage of the experience
of EVERY OTHER segment of agriculture, and their
IPM programs, which are based on doing more than
one measurement of one variable."

OK, which variables? How many measurements?

Regards

PeterDetchon

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