I have three hives on a raised stand to with screen bottom boards one without. I went out this morning and found hundreds of dead and dying bees under the two hives with screen bottom boards. Daytime temperatures have been in the 90s and nighttime lows around 55.

Could the bees cluster underneath the screen board and would a temperature in the 55 range kill them? I don't know how to post pictures so here's the links to photo bucket:
http://s1185.photobucket.com/user/No...?state=replace
http://s1185.photobucket.com/user/No...?state=replace
http://s1185.photobucket.com/user/No...?state=replace
http://s1185.photobucket.com/user/No...?state=replace
http://s1185.photobucket.com/user/No...?state=replace

the bees are directly under the hives and the end hive definitely had the most dead.

We live 2 1/2 miles from the paved road lots of trees and brush. Two small grape vineyards and flight range the closest of which is organic and they tell me they do not use pesticides. Most of the Buckeye is totally dried up and Brown and the only major flow is tar weed that we have right now. We have about an acre of garden with no pesticides. Flowering plants include sunflower, squash, melons, bell pepper, Wolf berry, sunchokes, garlic chives, cat mint and a medium-size mimosa tree.

No medications have been applied to the hives with the exception of powdered sugar dusting three days ago and 1 quart one-to-one syrup. 90% of all hive parts are new except five frames old comb.

End hive is hive number one and a consists of; two 10 frame deep brood boxes, one medium super, inner cover in the garden top. Next hive is hive number two and consist of; two 10 frame deep brood boxes, two medium super's, inner cover and telescoping top. Final hive is hive number three which is a cut out from August 10 and it consist of; one 8 frame deep brood box, one eight frame medium super, inner cover and telescoping top. Hives one and two have 10 frame screen bottom boards 1 quart front feeders and fully opened bottom entrances. Hive Three has a solid bottom board with an entrance reducer and a 1 quart feeder.

August 13 I took two deep frames of open brood from hive number two and one frame of honey from hive number two to boost hive number three the cut out.

Any ideas or questions would be greatly appreciated!!!!