Hello Karen and All,
> Overnight drop tests (with no drugs) apparently were much better in
> doing so. And the roll tests don't use those tired old field bees -- you
> need nurse bees for anything like reliable results (just don't scoop up
the queen).
All methods of guessing the number of varroa in the colony are of course
only guesses and can be off by quite a bit with either test *but* they are
all we have came up with so far.
As Karen so accurately pointed out the roll tests should be taken from the
brood nest which involves opening the hive but analysis can be done on the
spot with no return trip. The drop test requires two trips but not opening
the hive.
In my opinion both the roll and natural fall have got their usefulness. I
prefer the drop method for several reasons but still use the rolls at times
and get the information I need from both.
Even checking a couple hundred bees at the entrance can give information
pointing to a very high varroa infestation in late fall.
Sincerely,
Bob