>killing the mites one needs to create this sort of "soup" on the bottom for
>the varroa to have a higher time exposed to the formic.

Well, that would make sense in the configuration he suggests and that I use, since the tray and solid bottom board under the SBB would create that 'soup.'  I forgot to mention that I also use sliding entrance reducers, which slow the escape of the FA out the entrance.  Maybe having the higher concentration at the bottom helps prevent queen loss?  Just a guess.

Now, just to complicate things a little, it is not static inside the hive - the bees are doing one heck of a ventilation job at this time of year.  With three deep brood boxes there are about 60k bees (theoretically), and the temps can still get very warm during the day.  So, I think everything is pretty well mixed and moving around in there from bottom intake to top exhaust (I use vent boxes over the inner cover).  when I remove the top cover after application, the smell of FA is very noticeable, so they are moving it around.  There is probably a gradient, but I don't think it is the same as you would find in a calm environment.

###################################
Bill 
Claremont, NH
+43  21' 25"  -72 23' 01"
+43.35687     -72.3835
CWOP: D5065
Weather Underground: KNHCLARE3
HonetBeeNet: NH001

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