I moved Hive H from my garden to my out-apiary on Friday 30th June. I looked at the removable floor today and found 1 Varroa mite. Just 1 in 8 days. Compare that to Hive H which was dropping 20 per day as a new swarm.
The colony in Hive H has been feral for some time. The colony in Hive F had been a standard bought Buckfast queen 2 or 3 years ago. It's possible that the feral colony is adapting to Varroa and has managed to limit its' numbers. The mite is still present - it's endemic and won't now go away.
I'll see how Hive H fares as it settles in.