>>> I have also observed healthy colonies of bees
>>> on old dark combs, some with considerable
>>> residues (by analysis).

>> "Apparently healthy" would be a more accurate description.
>> The residues will, at some point, start to foster robust
>> miticide-resistant mites, implying bees that would not
>> be so healthy over the long term.

> Only if one uses synthetic miticides, and depends only upon
> them for varroa management. Not all of us use synthetic miticides.

Hold on there, the example you offered was a hive on old dark combs that
TESTED as having considerable residues.  I was speaking of THOSE hives,
where synthetic miticides clearly were used. The example was offered in the
context of a thread entitled "Amitraz in wax?", further narrowing the scope
of the issues.

But if one was not using synthetic miticides, then one would have the
build-up of the long list of agricultural pesticides similar to the build-up
detected by MaryAnn Frasier, et al in the paper I cited.  They would also
become an issue at some point, given the impact on larvae of even low levels
of common agricultural pesticides, and the known higher levels found in
comb, for example the mean 8 ppb level found in MaryAnn's paper and the
impact on larvae reported at 2 ppb over only 2 weeks exposure:

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0068191
or
http://tinyurl.com/k4ktced

Metal thumbtacks in queen colors... the antique solution to modern problems.
(The Chevy Chase 1980s comedy "Modern Problems" was about implications for
humans exposed to toxic substances, and was a good laugh.)

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