>Fairly large scale 2 years testing of the screened bottom board
>tends to show that this equipment can increase significantly the
>varroa population if it is used with an open bottom in the Quebec
>context.  It seems that a cooler brood chamber means better
>conditions for the varroa to proliferate, thus meeting the recent
>data collected by Kraus & Velthuis on the effect of temperature on
>varroa development.  If used with a closed bottom the average
>decrease in fall mite counts is 37% on average but with important
>variations.

This leaves me with some questions regarding screened bottom boards
and IPM for varroa.  Basically, should I use them with a closed
bottom board, or should my only bottom board be the screened one?
Based on the quote above (thanks Lloyd for posting it), a screened
bottom board ONLY will mean more mites because of the cooler
temperatures.  This sounds like a bad thing.

On the other hand, if the screened bottom board was placed on top of
a closed bottom board, (to achieve that 37% decrease in fall mite
counts as claimed above), wouldn't the mites simply climb their way
back up into the hive?  Or do they simply keep still and wait for a
passing bee to grab onto?  (I've heard this claim before, but only
from one source)  I know there are sticky-boards that can be used to
prevent this-- are these sticky-boards necessary?

And if screen bottom boards ONLY are used, would this make it more
difficult for the bees to keep warm in an upstate NY winter?

Unfortunately, most of the books I have were written before Varroa
mites came to the US, so topics such as this are not even mentioned.
I guess that's what Bee-L is for.  (And I need to get some up-to-date
books).

Thanks.

--Nathan Lawrence