Hello Ron & All,
Sorry to hear about your problems. I have had serious losses three times in
the last 15 years. Each documented in the archives in detail. Each time the
main cause was the lack of a registered effective method of control or a
product which didn't work as advertised.  I still take part of the blame but
not all.
In the late 80's I found tracheal mites and had high losses.  I had the
tracheal mites confirmed through lab samples.  I used menthol crystals in
the fall but our weather was to cold for the menthol to work so losses kept
mounting.
When varroa arrived all we had at first was the mitacur strip(Amatraz).  I
suffered heavy losses till Apistan(fluvalinate) was registered.   When i
started getting fluvalinate resistant mites I had a year of losses till
Coumaphos was given the section 18.
If you read my posts from last fall you will see I warned beekeepers *formic
acid gel* might not be the answer.  I based my opinion on the test results
various researchers had ran.  All my friends which used the gel are sorry
they did.  I expect a year of heavy losses when coumaphos resistant varroa
arrive(like Italy) until we come up with another solution.   I believe (as I
posted last fall) that the *apicure* would have worked better if two gel
packs had been used like Nick Carldarone used in his tests .  Nick however
used a higher dose of formic acid gell in his packets. Nick reported 97%
varroa control.  I hate to say how low the varroa control was when
researchers only used one pack.
Two things you need to research from the archives Ron is *mite load* and
*economic threshold*.  Both are talked about in great detail in the new
Dadant book *Mites of the Honeybee* by Webster & Delaplane. I believe now
varroa can be detected in every hive in the U.S..  The amount of varroa in
the have at any given time is *mite load*.  The point at which the hive has
a mite load so high that you need to treat is called the *economic
threshold*. There is a point (above economic threshold) when if the mite
load is at that level that the hive can not be saved even with a 98%
chemical treatment. I have only given a brief discription of the two
subjects but every beekeeper needs to be aware of the terms as we continue
to battle varroa.
Sincerely,
Bob Harrison
ps. Thanks for joining me Ron  talking about our problems. If all the Bee-L
beekeepers would send in their stories many Bee-L beekeepers would be
shocked at the problems the mites and problems with treatments have caused.