> Did Dr Calderone explain what aspect of varroa control he was meaning?
As far as I know, the experiments simply compared autumn mite counts in the
screened vs. solid bottom board hives.  No other varroa controls were
deployed.  Peter mentioned that some of the hives were treated with
coumaphos, but my recollection of the presentation was that some of the
studied hives were started from packages and some of the studied hives were
established/over wintered hives that were treated with coumaphos PRIOR to
being used for the study.  My recollection (and I hope Peter will correct me
if I'm wrong) is that once the hives were entered into the study, all other
variables (such as mechanical or chemical controls for varroa) were kept to
a minimum (zero).  I believe the study attempted to examine solely the
premise that screened bottom boards and ONLY screened bottom boards can be
an effective means of varroa control.

The discussions that screened bottom boards can be an effect tool in varroa
control when used in combination with other tools (such as powdered sugar,
tobacco smoke, chemicals, hitting the mites with the kitchen sink) was not
addressed by the study to the best of my knowledge.  And again, I hope Peter
will correct me if I've made false statements.

Aaron Morris - thinking there's more than one way to destruct Varroa