They aren't magical, but their level of genetic diversity is very high compared to the average commercial queen in the U.S. Genetic diversity gives them a better chance of having genetics to resist diseases.
A commly held belief that seems not so much in at least the post varroa age, moving bee means moving genetics
“the feral bees in our study region are of recent origin, we found higher genetic diversity in managed than feral honey bee colonies”
“Feral bees had a stronger immune response, even though they were less diverse. However, our findings indicate that the increased genetic diversity of managed A. mellifera may not bear fitness benefits thatcorrelate with immunocompetence. Our results support that management increases genetic diversity in honey bees probably as a result of admixture among progenitor populations as honey bee queens are shipped among regions (Harpur et al. 2012). Domesticated species are generally thought to be less genetically diverse than are their wild relatives (Wang et al. 2014). However, honey bees are unique in that feral bees are derived from domesticated lines in their nonnative range. In addition, honey bees, even when managed, undergo a mix of local breeding, regional dispersal, and natural reproduction among hives from different sources. Yet, what is interesting is that despite this diversity of managed bees, they are less rather than more immunocompetent than the feral populations, suggesting that while diversity matters to immune function, so may the ability of natural selection to increase the frequency of resistant varieties.”
López-Uribe1 Et Al 2017
http://elsakristen.com/docs/LopezUribe_2017_Apis_diversity_immunity.pdf
Diversity is a double edge sword, ferals have had diversity removed as they have been subject to MORE selective pressures… think about it, the whole point of a bond program is a whole bunch of the diversity dies off.
I agree that previous testing seemed to indicate that hygienic bees were EFB susceptible, but it is not proven that there is a linkage between the traits. In other words, it is very likely that bees can be selected for both hygienic behavior and EFB resistance.
Problem is you can’t select for what you don’t have. Hygienic behavior stocks were sussfully selected do to the ability to easily empirically test the trait.
But it has been done.. The early Weaver program was left with EFB/chalk plagued stocks after bonding out a few thousand hives, they had to work very hard to combine efb/mite restiance
it has also failed, Kefuss was able to turn around the EFB issues in his Chile stock, but never got the mite restiance up top TF like he had in France
I think feral bees would quickly develop resistance should a new efb type come through but for a while it would be miserable. I am interested to see how studied feral bees do should an disease outbreak like this hit them.
Well I am not sure they developed genetic resistance to the old EFB to begin with, centuries of “bond” and bees are still sustibult to it
in his book (1853) Quimby notes “Mr. Weeks, in a communication to the N.E. Farmer, says, "Since the potato rot commenced, I have lost one-fourth of my stocks annually, by this disease;"
“Mr. Quimby said foulbrood was not as bad in 1870 as it had been ten years earlier. (This was probably because Italian queens were just being introduced and they are more resistant to European foulbrood)”
https://static1.squarespace.com/sta...story+of+the+empire+state+honey+producers.pdf
About 100 years of “bond” between Quimby recognizing foulbrood and the “invention” of antibiotics… and it still plagues us as it plaged them pre treatment era