Does anyone know what the grey substance is that is on the comb? It appears that it is consuming the comb. This is an area that is just inside the entrance to the deep which is empty except for a few rows of honey near the top bars. The hive has a full super of honey over the deep. This occured over the past two weeks which was mostly cold weather with a few days of 60+degree weather. There were two hives approx 20 feet apart and both appeared strong. Now only one and I have no idea what happened. Both hives were being treated for hive beetles with the traps with small pcs of check-mite inside.