My hive with the superseded Saskatraz queen required a save this fall. (I have named the hive my Saskacruz hive Saskatraz x Santa Cruz as this queen mated here locally) It was dwindling down and upon inspection I found, yup, EFB. Good thing I had the terramycin on hand. I did three rounds of treatment and boosted it up with brood from other hives. I'm glad to say that it bounced back and is now filling their 8 frame box. I haven't noticed EFB in any of my other hives but fed a probiotic to all my hives to help compete with any EFB. I also fed this to the treated hive to rebuild their flora as I hate using antibiotics. All is looking well from here.
Am I simply having bad luck with the Saskatraz queens?
Why are only my Saskatraz lines getting EFB?
Should I try again?