Opened a top bar nuc today for the first time in a couple of weeks. I noticed a few bees struggling outside the hive about a week ago. Today before I opened the hive I noticed a lot more.
They were walking around, not really flying, and their abdomens were pointing "down". They hadn't stung anything. Their wings look good. The ones that are still alive seem relatively "lively", when I pick them up the struggle and stick their stingers out, but they do not move their abdomens. Inside the hive there were a number of dead, maybe half a cup total. The hive looks otherwise OK, strong amount of bees and brood. Was planning on transferring them to a Langstroth tomorrow, but that is on hold until this sorts itself out.
I scooped the dead bees out, noticed that some of the dead ones were still very slowly moving. Almost all the dead ones had their tongues out.
I have two other TBH's about 20 feet from this one and they are showing none of these symptoms.
Here's some pictures.