>>Their own findings say that a single factor certainly does stand out, and it is one or more pathogens.  Anything except a pathogen that can survive on the comb of a deadout should be off the list of prime suspects, if they want to present these findings.

This depends on one's viewpoint.  If one is merely looking at addressing the top level symptoms, than this statement is true.  But if one wants to address the base root causes and prevent reoccurance, this matter has to be looked into deeper.

Honey bees have lived in a sea of pathogens or at least potential pathogens for a very long time.  The bees' immune system has evolved/adapted to successfully deal with just about all these organisms without human interference.  But if the immune system is weakened by chemicals, pesticides, stress .... (feel free to fill in the blanks), the bees can succumb to relatively benign organisms.

Yes, the last nail in the coffin may well turn out to be a pathogen and irradiation my be a shortterm fix until the pathogen re-establishes itself in the hive and wreck havoc again.  But if you fix the real root cause - eliminate the factors whose presence has caused the compromised immune system - and you should fairly assured you have prevented reoccurance of the disease in a sustainable :)) way.

I say fairly above since, from human & livestock studies, we know there are pathogens such as some rotaviruses that are beyond the immune system's detection capabilities where the immune system isn't alerted to develop countermeasures.  Without human intervention, this may be a hopeless situation.

I would resort to irradiation only as the last ditch effort after having done all that can be done in bringing back the immune system to its top level.  Irradiation is an equal opportunity destroyer - there may be organisms in the hive beneficial to the bees that irradiation will eliminate possibly creating another [major/minor] issue.

Waldemar
  

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