thanks to j.edwards for his post on updated webpage with link
to his & j.schmidt's study of feral bees in arizona including
references to native pollinators, european and africanized honey
bees:
http://198.22.133.109/home/schmidt/jsjeopnm.txt
"...In conclusion, feral European honey bees
maintained a permanent population within all areas of
Organ Pipe Cactus National Monument and adopted
an ecological strategy that can be described as cryptic
survivors. During poor years, these cryptic survivors
were mostly inactive; during good years, they
explosively reproduced, and their activity was seen
throughout the areas of the monument. We cannot
characterize the Africanized population in any detail at
this point and do not know if they are simply migrants
coming into the monument, where they will likely have
poor survival, or whether they can establish viable
reproductive populations there.
The questions relating to the impact of honey bees
and their effects on pollinator and plant communities in
the monument cannot be answered directly from the
results of this investigation. It appeared that feral
European honey bees might not have had a severe
impact on native pollinators because their populations,
especially their foraging populations, were low during
the harsh dry-to-normal years. In the xeric areas, we
often could not detect even a single forager at flowers,
or even at water sources (unpublished observations).
Thus, they likely were not serious competitors for
native pollinators during these times. During wet
years, there likely were enough floral resources that
all pollinators -honey bees and native pollinators
alike- had excess floral resources available. The story
with Africanized bees might be different. We do not
know if Africanized bees will be able to establish much
larger populations than the feral European bees, and if
these populations will be able to be active during the
dry years and seasons during the year. If they are
populous and active, they might well outcompete
native pollinators during critical resource times and
drive the latter to low populations or extinction...."