Feral swarms die out a couple times per year, and the comb gets recolonized quickly. In my region, anyone talking about a single colony surviving year after year is just telling you a fairy tale.
I have a great story along this line. Years ago when we first started with bees, found out that an acquaintance had a house with a hive in the soffets. We didn't think much of it, till talking to our neighbor across the street. Apparently they owned that house for many years and said the bees were in that soffet for at least 15 years and they had a local beekeeper get swarms there almost every year. Then at a club meeting, the local long time commercial beekeeper confirmed the story, he had picked up a swarm at that house at least once a year over a 10 year span before the house was sold. We were excited, we had found long term surviving feral bees, the holy grail. We had a plan, following spring we would set up swarm traps around Dave's house and surely get us a feral survivor queen. As a side note, at the time we were also the hosts for the club extractor, so we met a bunch of club member that never came to meetings, but they did come to get the extractor.
Over the winter we had a couple colonies beside our house, and one day in February it was a beautiful sunny day, with lots of bees orienting at the hives, and LOTS of dead bees on the ground in front of the hives as they cleaned up inside. We popped by Dave's place to see how much activity was there. Nothing, nada, not even a dead bee on the ground by the entrance. Walk all around the house, no sign of a bee coming and going anywhere.
Wind the clock forward, it's mid April, and our phone rings, it's Dave, the bees have 'woke up', and are now coming and going constantly from the soffet. Off to check, sure enough, they are. We set out the swarm traip.
Wind the clock forward, it's September. One club member has borrowed the extractor, but he doesn't have a vehicle to return it with. Another member is on the list to get it that day, and it just so happens I'll be driving past both later with a trailer behind my van. I picked up the extractor from the first place, and was unloading at the second place, chatting with the guy, one of the folks that never comes to club meetings. He is 2 blocks up the street from Dave's place, has 4 colonies in the back yard. Apparently he feeds pollen in mid February and syrup in March so the bees get big and strong colonies, they make anywhere from 60 to 100 lb of honey over the spring bloom cycle. It's normal to lose one or two swarms in April or May happens almost every year he says.
So, now we know where the bees in Dave's soffits came from year over year....
, this would be it...Finding the percentage of mites on colonies that thrive yearly regardless of “high” counts. Are you sure it is the same continuous colony for eight years? Personally, I would not treat them, but isolate them in a yard, & keep counting them mites to see if they can truly thrive with this percentage
