[We have solved it now with formic acid, thymol and oxalic acid. ]
What you are telling me is that your varroa problem is solved with various chemicals, not mite resistance.
The point that I am trying to get you to bring out is that these chemicals are not necessary.
The bees do have a genetic resistance and that can be tested for and bred into our own lines.
This would avoid the costly purchasing of bees and potentially damaging shipping of queens.
You seem to be side-tracked as if you are being attacked, but that is not the case.
I am trying to respect your knowledge and let you tell everyone what you know.
This is becoming more combative than productive, so I will quit trying to get you tell us.
There are two types of resistance.
There is SMR (or smart bees as finsky referenced) and hygienic bees.
The difference between the two is genetics.
Hygienics is a recessive trait, it means that both mother and father must carry the trait.
Because both must have the trait, it is easy to loose the trait.
But since 1 in 10 bees generally carry the trait, its easy to find it again too.
There are 7 traits tied to hygienics, some to uncapping, some to grooming instincts.
So we as beekeepers can test for hygienics and saturate out yards with them.
This increases the likelihood of Hy-Queen and Hy-Drone matings.
Hygienics can be field tested in two ways.
There is the pin prick method, where you take capped brood and sewing needle and poke through the capping into the larvae killing it. You do this on 10 or 20 adjacent cells, place back in the colony and in 48 hours remove and count the cells cleaned out. A dot of paint over the set of cells help identify which set you used.
The second method required taking a chunk of brood out (like a cut-comb cutter) and freezing it for 24 hours to kill, but not moosh the brood. More than 24 hours will over freezing will cause false hygienic removal, so be careful. The chunk is reinserted and 48 hours is allowed to pass again. Then the cells removed are counted.
In either method, ideally you want more than 80% removal in 48 hours.
Queens not demonstrating this should be culled, and requeened with stocks that do demonstrate it.
SMR is an additive trait, which means that if mother and father carry the trait, the stronger the SMR characteristic.
Also, the more grandparents that had the trait, the more likely it is passed on (up to 5 trait locations).
I like the anology of a parking lot with 5 spaces. Once 5 are used, theres no more additive advantage.
Lets say a queen with 5 points is mated with a non-smr drone, then the offspring drop to 4 points.
As you can see, it may take several non-smr mating to loose SMR.
But its not as naturally occuring in our italian stocks as hygienics, and so it may not ever be regained in open matings.
This means that you will likely need to re-purchase SMR stocks after a few years, or saturate the drone mating areas with your SMR drones.
Sue Colby of (soon UC Davis) Ohio State University, Marla Spivak or Unv. Minn and Glenn Apiaries in California, have great information about the topic. Glenn Apiaries even uses Medel genetic diagrams to explain the matings and cross matings. I would strongly suggest reading all of these if you want a good understanding of where genetics are today, and what to expect in the future.
Some folks point you to books and articles and tell you to go read.
I'm giving you the facts and the tools to do it.
This is what I was talking about Finski