Bee inspection: third treatments and purple problem

We did the last varroa mite treatments today, following up from last week.

This hive (which we might call the yellow hive, after its base) is doing really well:

A bunch of bees on top of the frames in the Flow hive, which has recovered impressively from its earlier swarm:

The purple hive, however, is causing us much concern. It was doing really well, our strongest hive, but seems to have collapsed; there are now hardly any bees, no sign of a queen, lots of brood cells that look dead, and wasps stealing from it:

The top box was pretty much empty, so we decided to remove it, so the surviving bees can consolidate in one box:

It’s quite possible that the purple hive won’t survive the winter. They do have a bunch of honey stored, possibly enough for the reduced number of bees, so if they can make a new queen (if it has in fact lost its queen), they could rebuild. But we didn’t see any queen cells, so aren’t sure what’s going on. We’ll keep a close eye on it.