I actually like the idea of stuff falling through the mesh beneath the hive...the ants, pillbugs, spiders, etc., seem to patrol it pretty good. I've got both solid bottom boards, screened bottom boards, and screened bottom boards with oil trays beneath them....they all seem to beard about the same (relative to hive populations, of course). I am a little concerned about later this summer when we start hitting the 100+ degree days...it's hot in the briar patch!!! I'll play it by ear.
People talk about the area beneath the screen being a breeding ground for moth and shb if you have a tray or board underneath...uh, regular inspections take care of that. Matter of fact, as Jim mentioned, it's a good way to monitor things in the hive. Sometimes between inspections I'll simply walk along behind the hives and pull trays looking to see what's going on. If you keep oil in them, well, happy swimming beetles (and moths)!!! :)
The only thing I would say the solid bottom boards might be better at is getting the queen to lay low in the brood chamber...of course if you've got a tray or board beneath the screen bottom board then you've basically got a closed cavity.
Interesting that this thread just came up as I've been tinkering with putting my ISOT mod to three or four more screened bottom boards. I've change the design a bit, maybe tomorrow I can get pictures up in the old thread...
Simple oil tray mod for sbb's...Interesting thing, is that the SHB numbers have been low so far this year. I'm getting ready for them, though. ;)
I think my favorite of the bottom boards are the screened ones with oil tray inserts.
Ed