Hi Tom & all

I use full bottom screens and do 24 hr natural mite drop counts every two
weeks throughout the season.  My experience is that mite counts are low most
of the time then take off exponentially.  I use a treatment threshold of 40
mites,and believe that the use of 30 40 or 50 for your threshold doesnt
matter because they will be passed before the next 2 weeks are up.  If I
find a hive with 32 mites, I treat even though my threshold is 40.  I make
my judgement based the level two weeks ago and interpolate the likely count
2 weeks from now.  I find that I must treat some hives while their neighbour
is clean.  Genetics I guess.

Bob Darrell
Caledon Ontario
Canada
80W44N