Just before the big snow, I checked the hives. The center one is dead already. The other two [on either end of the row] are doing fine. I seized the moment during the warm weather we had before the big snow to make some more bee candy and put it on the tops of the frames in each hive. I figured it would be extra insulation when the temps dropped way down after the storm. [The shortest darker blue box is just an empty super. No bees in there.]
I'm thinking that the cause of the deadout was bees weakened by varroa. I noticed some bees with deformed wings in the summer and fall. The deformed wings are caused by Deformed Wing Virus [DWV], one of the many ills that varroa mites bring to a hive. I didn't treat for mites in an effort to be chemical free and the hive was too weak to last very long at all. Gone by the beginning of December.
I hate losing a hive this way but I have very mixed feelings about treating with chemicals. Maybe I should have done more sugar shakes.
At any rate, the other two hives seemed good and active [and defensive] and now they have plenty of candy for the next two months. On warm days I'll see if there's any action up there.
We left the snow on the hives as extra insulation for the deep freeze that followed the storm. The lower entrances are covered with snow but the bees have a top entrance under the lip of the telescoping lids so they can get out if they really want to. I doubt they do.