>As to South Africa, I'm not terribly familiar, but doesn't Africa already have a large population of resistant bees to draw from that have spent many many years in contact with varroa already?

South African, when Varroa arrived, had a mixture of breeds of bees including European and African stock of various kinds (Scutella, Adonsii etc.). The beekeepers decided do approach the problem as a group, and as a group, decided to not treat. They have heavy losses for a couple of years and they dropped off every since.

"As to South Africa, I'm not terribly familiar, but doesn't Africa already have a large population of resistant bees to draw from that have spent many many years in contact with varroa already?" -- http://upetd.up.ac.za/thesis/availab...ssertation.pdf