Technical Abstract: Like many fruit crops, the American Cranberry (Vaccinium macrocarpon Ait.) requires bees for pollination. Flowering cranberries attract diverse native bees, but on larger commercial cranberry bogs, abundances of native bees are inadequate for pollination. Consequently, growers boost the intensity of cranberry flower visitation by renting hives of honey bees, although until now, their efficacy as cranberry pollinators has been disputable. This is the first study to demonstrate a relationship between pollinator genetics and resultant pollination efficiency, in this case a consequence of a bee's foraging predilection. Cranberry growers that modestly compensate beekeepers for demonstrably stronger hives, particularly if those hives are provided 'Hy-Pollen' queens, are more likely to maximize the numbers of effective pollinators visiting flowering cranberries. The pollen-hoarding trait may prove useful for other crops, too, where it can be shown that pollen-foraging bees are superior to nectar-foragers in their prowess as pollinators.