Lawrence Harder did some work on nest clumping, published in
Holarctic Ecology. I can't remember whether he addressed habitat
preferences. Nest site preferences are addressed in papers/theses
of KW Richards. Biome preferences of the (imported) New Zealand
species were of long-standing interest to Lou Gurr of Massey
University. While he could assign some (specifically, B.
subterraneus) to particular geographic areas, their demarcations were
always something of a mystery. The distribution maps among
the monographs of HE Milliron indicate a decided dislike on the part
of bumble bees (or their collectors) for the Amazon basin.
Rick Fisher
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