Here's another reference about interactions between native bees and
introduced honeybees:
Sugden, E. A., and G. H. Pyke. 1991. Effects of honey bees on colonies of
Exoneura asimillima, an Australian native bee. Australian Journal of
Ecology 16:171-181.
It cites some other appropriate references, including:
Roubik, D. W. 1978. Competitive interactions between Neotropical
pollinators and Africanized honey bees. Science 201:1030-1032.
Roubik, D. W. 1983. Experimental community studies: time-series tests of
competition between African and Neotropical bees. Ecology 64:971-978.
David Inouye
Dept. of Zoology
University of Maryland