Perhaps you have seen my dark wood stained hives here;
http://beemaster.com/beebbs/viewtopic.php?t=2511
The bottom is completely open except for screen. There is no top ventilation. Today it was into the upper 90's F. (97 or 98.) There was no bearding or fanning going on.
Looks like a good working set-up. No trees was definately one of the first things I noticed too. LOL Dang I dislike Texas. :) But heck..... if you move your hives just a bit farther from your house.. and maybe put a couple saw horses out there.... any swarms coming from your hives will have nowhere to land near there except for the saw horses. LOL Easy catches!
Beth