Although some may not have good experience with screened bottom boards
reducing mite populations, many claim benefits from using them such as
increased ventilation in the hive leading to increased production in brood
by the queen.  I have heard of many experiencing better hive population and
overwintering using screened bottom boards vs. not using them.  Personally,
I have not tried them yet, but I am going to experiment with it.

Tim Stalnaker
[log in to unmask]