I have been keeping bees for 7 years now and I have never seen this before. I hope someone can shed some light on the problem.
This is a second year hive, in two ten frame deeps on small cell foundation. The hive started out in the spring with plenty of stores of food. 4 full frames of honey on the outside frames. The brood chamber had healthy laying pattern with honey and pollen stored on the outside corners. So around late June the bees were busting out of the hive so I put two medium boxes of drown out foundation for honey surplus. I left the hive for about a month, only checking the bees by observing how many are flying in and out. I saw pollen baskets full and plenty of bees traveling out to the fields. I would say I didn't see any signs of concern. Now the honey in this area hasn't been that good this year, but when I did my most recent inspection I had my fingers crossed.
When I did my inspection this is what I saw. Mold on the top frames, of the top medium, and on the inner cover. Then as I moved down the boxes the frames were empty! Every frame in the hive has nothing in it, no eggs, no pollen, no nectar. But this is where it gets weird, there are plenty of bees, I would say at least one deep box full, and a queen that is not laying eggs. Why did this happen? I don't see any signs of noemsa, varroa mite, DWV. The hive is located on an organic farm backing up to a nature reserve. Also, none of my other hives are showing any signs of this.
Of course my first instinct is to save the hive, so I grabbed a top feeder and filled it with sugar water, shrunk the hive down to two deeps. Then I have pollen patties coming on Monday. Is there anything I can do?
I hope I gave enough background information and appreciate any insight this community can give me.