I have a friend, that sorta keeps bees, well used to. He does/ did very little with them and when he takes honey is only a frame or two at a time. He went o take a quick peek saturday morning, nothing formal and noticed that there were no bees, no dead bees, no larvae tossed on the ground, but frames with brood in the cells how much I don't precisely know, will have to take a look just to satisify myself. He opened up a few capped cells, and there were pupae most of which were in the final stage of pupation. What would it take to have bees desert brood? I can't readily think of what it would be, copnsidering that no obvious sign of disease, or attack were present or readily apparent.