Bees and food plants
A recently-published study identified 166 bee species on 15 Michigan blueberry farms. (Michigan is one of the largest producers of blueberries.)
Full text of the article is available at http://www.entsoc.org/wildbees.htm
The summary distributed by the journal included the following
Unlike honey bees, which live together in hives, most of the bees found by the authors were solitary bees that nest in the soil or in wood cavities. While soil-nesting bees may be difficult to manage, the authors see potential for cavity-nesting bees, such as several species of mason bees, to be managed by growers who can support their populations by providing nesting materials.
"Untreated bamboo or reeds are good materials because they provide natural variation in hole diameter to attract the broadest range of species," said Dr. Julianna Tuell. "There are also a number of commercially manufactured options that growers can use, such as foam blocks with pre-drilled holes and cardboard tubes made to a particular diameter to suit a particular species of interest. Drilling different sized holes in wood is another option. If a grower is interested in trying to build up populations of a particular species, there are also details about how to do so available online."
Besides blueberries, many of the species in this study also visit cherries, apples, and cranberries, and managed mason bees are already being used to pollinate cherry orchards.