By KEVIN WALKER
Michigan Correspondent

OTTAWA COUNTY, Mich. — Growers are concerned about the lack of free pollinators for their crops, but now have more information and a few ideas about what they can do to make the situation better.
Several years ago some blueberry growers in southwestern Michigan cooperated with a Michigan State University researcher, Julianna Tuell, to get more information about the number of bee species in their fields. The results were published in the March issue of the Annals of the Entomological Society of America.

According to the study, “(S)ince the late 1980s, there have been concerns about the state of the honey bee industry in the United States. After recent reports of Colony Collapse Disorder, in which beekeepers find hives full of honey but few bees, it is clear that a more diverse pollination strategy would be beneficial to the long-term sustainability of crops that require insect-mediated pollination.
“A first step toward that goal is to determine the community of bees present in agro-ecosystems.”

The main findings were somewhat surprising. Tuell and her fellow researchers, John Ascher and Rufus Isaacs, discovered 166 different species of bees in and around blueberry fields at 15 different farm sites. There were six sites in Ottawa County, five in Allegan County and four in Van Buren County. There were 167 species found altogether, including the honeybee.

Tuell said she suspects most, if not all, the honeybees were probably from rented colonies. They discovered 112 of the species were active during the Highbush Blueberry bloom period, which lasts only a few weeks. Twenty-six of these species are known to visit blueberry flowers and are likely to be pollinating a portion of the crop where they are abundant.

Unlike honeybees, most bee species are solitary and many make their nests in the ground. Tuell said growers who want to use the wild bees to pollinate their crops in greater numbers can build nests for these bees by drilling holes into pieces of wood or cutting pieces of bamboo and setting them in their fields.

“If we can do things to improve the quality of life for these other bees, then we may be able to better rebound from catastrophic events that affect other species,” she said.

The study explains that the bees would benefit from having more plants they can get nectar and pollen from after the blueberries are done blooming. The study puts it this way: “Activity periods that extend beyond crop bloom suggest a need for non-crop floral resources to help support populations of bees nesting in or near blueberry fields.”

To some extent, growers are already using other bee species to pollinate their crops. Joshua Wunsch, for example, has been using mason bees for the past six years to help pollinate his 400 acres of apple trees, sweet cherry trees and tart cherry trees. He’s located in Old Michigan Peninsula, which juts out into Grand Traverse Bay in the northwestern corner of the Lower Peninsula.

He started using the mason bees, also called horn-faced bees, to help pollinate some of his cherry trees that always bloom early in the spring. He said that’s one of the big advantages of mason bees – they stay active in cool weather.

“We’ve got them quite domesticated,” he said. “We give them lots and lots of flowers to visit.”

Once he got started using the mason bees, he expanded their use over time. “You can get them replicating. You actually can get more and more of them that way,” Wunsch said.

These bees are managed completely differently than honeybees. They are solitary bees and lay eggs inside tubes that are placed in five-gallon buckets. He also said mason bees are useful for pollinating apple trees.

“Incompletely pollinated apples can be misshapen,” Wunsch said. He explained that honeybees tend to “bump and run,” whereas mason bees are “very thorough.”

Mason bees, however, have a range of only about 600 feet from the nester, Wunsch said, whereas honeybees can pollinate up to three miles from their hive.

He has honeybees for pollination purposes, also, but he has found mason bees to be quite useful.