Follow-up:
Temps plunged back down to freezing and have struggled to get back up to "spring normal" for this location ever since this swarm decided to camp out on the tree limb. We have been exceedingly puzzled by this particular group, as they have declined a cozy bait hive at a 25' distance from the center of our apiary (the other two hived colonies), and remained on the limb in close proximity to their old home, assuming that these are indeed our bees exiting and not feral bees swarming in-bound, which would be really strange.
I checked inside our long hives, and found the colonies to be healthy from a hands-off vantage point during this sensitive brood-rearing period, but out of care not to do harm, will not begin diving deep into the brood chambers until closer to June. Many other keepers of non-Russian bees would not hesitate to disassemble frames at this point out of concern to re-queen their colony.
Saying a prayer that weather will permit a selected princess to have her mating flight, if needed, without further delay, so that eggs can continue to be layed and the colony brought forward.
