So I did 10 splits this spring with local mated queens. All are doing great as of August 1st. I went to my bee yard in Bolinas where 2 of the 10 splits are along with 5 other mega hives. I check the first split and it's fine, 3 boxes on plenty of brood, pollen and honey. Queens laying great. I check the second split that only had two boxes on but was doing ok. Top box almost empty, bottom box had 5 out of the 8 frames with bees. No eggs, some honey, just a small amount of capped brood left. Of the brood that was left, some of the cappings had small holes in them. Some of the larvae was dead, still white in various stages of development in their cells. It looked like time stopped and everything died. I didn't have my phone with me otherwise I would have taken pics. Any guesses?