Several wild bee species may be the answer to help augment dwindling feral honeybee colonies that are critical for blueberry pollination in Michigan.
During a three-year study, Julianna Tuell, a post-doctoral entomologist at Michigan State University in East Lansing, found 112 species during blueberry bloom and 116 species overall. At least half of them contribute to blueberry pollination.
In light of the declining wild honeybee populations, Michigan's blueberry growers have had to turn to domesticated honeybees that are brought in during bloom. Even that supply has dwindled because of colony collapse disorder, a mysterious malady of bees.
This makes attracting and maintaining the wild bee species even more important, she says.
“There are some bees, called mason bees, that are managed in other crops such as cherries,” Tuell said in a news release. “We found some of these species present during blueberry bloom, and you can build them up by providing them nesting resources.”
Growers who want to attract mason bees and other natural pollinators can drill holes in blocks of wood and position them around their fields. The bees also will nest in cardboard or paper straws.
In addition to the species survey, the reserach also generated information that growers can use to time spray applications so they will have the least affect on natural pollinators.
Native bees are active in the fields before, during and after blueberry bushes bloom. Growers who avoid pesticide applications during flowering and who don't spray during the day can help the native bees survive, Tuell says.