I am with you on that. Good luck finding good local stock.
From Seeley/Loftus/Smith:
“It is likely that the spike in the mean Varroa infestation rate in the small-hive colonies in mid-September was due to importation of mites by small-hive colonies that had robbed honey from the collapsing large-hive colony. If so, then this spike in the Varroa infestation rate in the small-hive colonies, which were living only 60 m from the large-hive colonies, is an artifact of the experimental setup.”
“This spike in Varroa infestation rate may explain why there was considerable colony mortality (4 out of 12 colonies) in the small-hive group. One small-hive colony died because its queen ran out of sperm, so eventually only drones were produced in this colony. Interestingly, the other 3 small-hive colonies that died were the 3 colonies that experienced strong spikes in their Varroa infestation rates during September. Thus the possible importation of Varroa (and associated viruses) from the collapsing large-hive colony in September may have led to the deaths of these three small-hive colonies over the winter. Because robber bees probably transfer diseases mainly between hives in close proximity [25], it is regrettable that we did not space the two apiaries for the two treatment groups farther apart. A recent study [29] of the effects of colony crowding has shown that crowding renders colonies more likely to acquire high infestations of Varroa in late summer, when robbing behavior is most common.”
Interesting that this is opposite of what many treatment-free beeks are accused of, which is that their untreated robbers infest treated hives. I hope that Seely does follow-up research to explore his further questions.