In a message dated 31/10/01 05:04:13 GMT Standard Time,
[log in to unmask] writes:

<< If you have
 bees in several stories, what is the likelihood that a mite could
 simply fall all the way to the bottom? Think about it, a mite loses
 it's grip and begins to fall. It's two feet or more to the bottom. >>

Peter, and yet a proportion of the mites that fall are not just alive, but
very lively, particularly when warmed up under a lamp.  When I say "a
proportion" I do not mean a precise or a large proportion as I have not
counted.  I should do so. A guesstimate would be somewhere between 10% and
20%.  This is in the UK where most hives have a single brood chamber about 9"
deep.

I like open mesh floors and am gradually moving over to them as they appear
to benefit the colony in other ways than that mentioned.  First, it is easy
to slide a tray in for a 24 hour count. This means I can monitor mite drop
and therefore not treat unless numbers indicate that it is necessary.  This
will delay the onset of resistant mites and also save me the money and effort
of treating, besides the mental reassurance that the comb honey from that
hive should be uncontaminated by the chemical.  This year I have elected not
to treat those hives with a low single figure mite drop.  They were last
treated a year previously.

Secondly, there appears to be a great reduction in chalk brood.  Thirdly, and
this may be connected, the hive is much drier.

My most productive hive in this, rather poor, year was on a mesh floor, but
it was also partly on 4.9 foundation so there was more than one variable.

Chris