> Has anyone mapped the geographical spread of the resistance? Eg, Did it
> start in the corn or cotton or rape or soy belts?

This is a good question.  AFAIK, soy and canola in various varieties are grown
in varying amounts throughout the areas in question.  As for GM varieties, that
is harder to say.

It is a good question, but there are other questions that must be asked first
before it becomes meaningful. We've been discussing resistant AFB for some years
on BEE-L, and apparently the most basic and pivotal question in this matter has
never been answered.

The root question is whether one OTC resistant strain developed in one place and
has been spread by international trade in honey and other means, or whether a
number of separate strains have evolved in separate and totally isolated places
with no vector of disease transmission between them.

Answering that one question would save a lot of idle speculation, false rumours
and wasted effort.  It is a simple question, and a simple one to answer with
today's technology.  The answer to that one question decides what other
questions are relevant, including the present one.

For some reason, most people seem to assume that each case is new unique
mutation or selection, yet Occam's Razor tells us given the following facts:

1.) successful mutations are fairly rare.
2.) selection for resistant AFB does not seem to happen
    frequently; we have not seen it over previous decades
3.) diseases often spread from one place to another
    without people immediately figuring out what happened.

...that we must first disprove the most obvious explanation before moving on to
'create new gods'. I personally like this interpretation: "The explanation
requiring the fewest assumptions is most likely to be correct."
Ref: http://staff.vscht.cz/~pokornp/physics/occam.html

Common sense would also dictate that given the above knowledge, the first place
to look is for vectors of disease transmission.  Only after all possibility of
transmission is disproved, should we start to seriously consider extraordinary
causes.

That is not to say that some powerful new factor could not have come into play.
It is just not scientific to jump past the first stage in the investigation and
assume that the usual causes of new disease outbreaks are not responsible for
spreading this new one.

BTW, I'm no geneticist or pathologist and I'm having trouble with the words
here, but hope you understand what I am saying and don't pick me over if I
misuse a word or two that have technical meanings that differ from what we lay
people assume.

I personally always favour the simplest explanation that fits the known facts,
and that is that SAFB started in Argentina, was exported to the US and Canada,
and continues to spread.

That is not to say that the GMO link is not out of the question, but until the
first question is answered all the rest are somewhat premature.

I hope we have an answer soon.

allen