In a message dated 05/12/01 05:29:02 GMT Standard Time,
[log in to unmask] writes:

<<  When compared to
 "regular" bottom boards their studies indicated screened/open bottom boards
 showed negligible differences in 3 areas: fall cluster size, honey
 production, and VARROA CONTROL!   >>

Did Dr Calderone explain what aspect of varroa control he was meaning?  From
my own experience a variable proportion of the mites that fall through the
mesh are alive and lively, particularly when warmed.

However, so far, the most valuable use to me of the open floor is that it is
so easy to slide in a tray for an occasional 24 hour natural mite drop count.
 This enabled me this year to omit the annual Bayvarol treatment as mite
numbers were so low.  Reducing treatments will retain efficacy of the
treatment longer by delaying resistance.

So, to my mind, open screened bottom boards do have a value in varroa control.

Chris