Re: Flightless bees: Parasitic Mite Syndrome?? Poison?
Deformed wing virus perhaps. Parasitic mite syndrome maybe. Whatever it is, even though I understand theurge to do so, returning the bees that are on the ground and can't get home on their own may not be doing the rest of the bees in your colony a favor. They, the bees on the ground, may be carrying a virus. I'm not sure. But to let bees do what they do and let nature take it's course is perhaps what you should do. As far as the bees on the ground are concerned.
You say that about three weeks ago the bees started this nonflying behavior and they aren't booming and they don't have much honey stored, right? I suspect, being in NC as you are, that your bees are bearding because of the heat and that there is no nectar for them to forage for, ie, a dearth period.
I don't have experience in NC in the summer, but from what I have read on beesource and other places, that is my diagnosis.
Look to see if your colony is healthy. A good brood pattern, w/out disease showing. Honey and pollen stores. Not over run by SHB or wax moth.
Mark Berninghausen "Ships at a distance have every man's wish on board." Zora Neale Hurston