Dave,  How large is the gap between the mesh and the floor?  At a lecture a few years ago Jeff Pettis said that with a half inch gap all the living mites that  fell through found their way back upstairs whereas with a 2 inch gap none did, with a range of success at intermediate gaps.

While having the area beneath the mesh open to the air may have advantages, such as simplicity and reduction in condensation, in some parts it might be too chilly and thus the bees might retreat from it.  In such areas it might be worth having an enclosed drawer under the mesh rather than an open tray.

Chris

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html