I suspect that other responses will address the culture
of bumble bees, but let me suggest a couple of papers dealing
with the pollination of kiwifruit:
Corbet, S.A. et al. 1988. Functional Ecology 2:147-155
Goodwin, R.M. 1986. New Zealand Journal of Experimental
Agriculture 14:449-452
Goodwin, R.M. et al. 1991. New Zealand Journal of Crop
and Horticultural Science 19:259-262