good info adam, thanks.

the two operations i know of that are treatment free and sustaining well are my own (four years) and my bee supplier (16 years).

we are both in locations that are heavily wooded (over 2/3rds of the landscape) and we think there are plenty of feral colonies surviving in the area (which are contributing to the dca's).

i have been assuming that in addition to having favorable weather and abundant forage, the genetic contribution from the unmanaged survivors is helping to make being treatment free here possible.