The "genetics of AHB" was the crux of Bill Wilson's point made in a
series 
of articles he wrote for ABJ in the mid-1960s.  The problem was called 
"disappearing disease" back then, but the symptoms were essentially 
identical to those listed for what we now call "CCD".  (The significant 
unusual feature was the largish brood area, without enough bees to tend 
the brood, the frequent presence of the queen, and a lack of any other 
obvious symptoms.)

The source of the "AHB Genetics" was not hard to find, it was the
deliberate 
use of semen from AHB drones at the Baton Rouge Bee Lab. Bill was
treated 
very poorly by his masters at the USDA-ARS, not for presuming to trace
down 
the source of this problem on his own, but for following the fairly
obvious 
clues from his lab in Laramie, Wyoming to the doorstep of another USDA 
research facility.  You see, the folks at Baton Rouge had distributed
their 
most recent hybrids for "field testing" all over the place, so the
"clues" 
were many and compelling.

Due to the hostile reception Bill got, the matter was never settled with
any 
authoritative testing at Baton Rouge. 

To my knowledge, no one has witnessed "CCD bees" leaving.

The question "Are they going out to forage and not coming back 
or are they leaving emasse?" Ignores that more than forgaers 
are absent from affected hives.

Both "house bees" and "foragers" are gone in large numbers, so this is
not 
merely a matter of foragers not returning.  Affected hives do not have
enough 
"house bees" to support the amount of brood present in the hive, so
something 
is causing "house bees" to leave and not return.

This is much less the stuff of horror movies than it may sound at first.

Any bee that is ill or dying seems to be somehow driven to leave the
hive. 
I've asked dozens of researchers about this specific point, and the
consensus 
is that there are multiple scenarios where a bee will be "sick", but
able 
to fly/crawl, and will leave the hive to die.

And yes, photos DO show abandoned brood.
They look exactly like someone shook all of the adult bees out

As for "How does this happen?", as soon as someone figures 
anything out, I'm sure they will tell us. :) 

So far, all anyone has is vague suspicions. 
Data will be forthcoming soon, not to worry.
Perhaps some of it will be conclusive.

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