On the brood comb longevity issue: I think somewhere in the BBKA's leaflets on the foulbroods and hive disinfection they mention that pathogen counts gradually rise with comb age, suggesting that comb renewal is good practice, particularly in areas where the foulbroods are a problem.

It would also be a good idea if you have high local levels of agrisprays on forage, or are using persistent miticides.

Like Steve's beekeeper friend, I have found that remediating EFB affected colonies is a long and low-reward process. The affected colonies are set back by the EFB itself thanks to larval loss. If you just use OTC, you are inviting recurrences of the EFB. If you do the shook swarm, which is your best route to clearing the apiary, the colonies are set back so hard they are not productive and may not have enough time to rebuild for winter. Colonies raising queens during EFB infection seem to struggle with raising the queen cells....I expect the queen larvae are also vulnerable to EFB.

If the strain of EFB you have is OTC resistant, then shook swarm is your only option. Happily it is also, long term, your best option.

Either way, you have equipment purchases to make and some form of disinfection process to tackle. At the very least, you lose the foundation the brood and stores are on: they cannot be disinfected.

This is why, if you have one or two cases in the apiary, it is better to euthanize than remediate. Particularly as your colonies under remediation pose some risk of EFB spread.

This May, 18 out of 20 colonies were suddenly symptomatic and EFB positive. I began euthanizing, expecting only one or two cases, but when I realized most of them were infected, I decided to do the medication-shook swarm-medication protocol again. Those colonies are due to go off meds now. I have to say, I am afraid for them.

When I had my first big hit last spring, the advice I got was to medicate and it would go away. IMHE, and as detailed in the UK research, that is not what happens. You may suppress symptoms successfully but you set yourself up for a high chance of rebloom in the next season. **And if the source of the infection persists, you will be reinfected over and over. Tolerating reservoirs of EFB in bee stocks, particularly mobile bee stocks, is not sustainable. 

I am nettled that EFB is seen as "not a big deal". It is a HUGE (and expensive) deal. 

 

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