Andy,
It is interesting that the limit of AHB in South America is where they
hit cold winters. If cold is a factor, then it may not be viruses alone
-everything I have read says viruses are a major factor- but that they
cannot keep up with the losses caused by varroa. Cold does interrupt the
brood cycle, while in the tropics they can keep propagating, swarming
and absconding and keep up with varroa's effects, no matter what bee.
Good post, Andy.
Bill Truesdell
Bath, ME
 
Andy Nachbaur wrote:
>
> *1st seen in the sci.beekeeping news group.
>                     ----------------------------------------
> In the October 1997 issue of the AMERICAN BEE JOURNAL's section on
> APICULTURAL RESEARCH page 742-747 are published two interesting papers
> one AN ISOLATED POPULATION OF ITALIAN BEES THAT HAS SURVIVED VARROA
> JACOBSONI INFESTATION WITHOUT TREATMENT FOR OVER 12 YEARS, and the
> DEFENSE OF AFRICANIZED BEE WORKERS AGAINST THE MITE VARROA JACOBSONI IN
> SOUTHERN BRAZIL. Please do read them.
>
> These papers confirm some of my own thoughts with one exception and
> that is the role of other pathogens and what the total load means to the
> health of the apiary..........