In the world of pollinators, honey bees clearly have the best public relations team, since they tend to be the best known. The fact that honey is the byproduct of their work does not hurt their image either.
Thanks to their reputation as pollinators of agricultural crops, every year hundreds of hives each containing up to 50,000 honey bees are shipped to Maine and placed in blueberry barrens and other commercial farming fields.
It’s big business for both the bees and the farmers. Honey bees pollinate $15 billion worth of crops in the United States each year, according to the U.S. Department of Agriculture. These include more than 130 types of fruits, nuts and vegetables.
More than 90 percent of the commercially grown crops in the country owe their existence to honey bees and their pollination work. The bees do this as they fly from flower to flower gathering both nectar and pollen to bring back to their hives.
Along the way, some of that gathered pollen falls off into other flowers where it plays a crucial role in plant reproduction.
While there is no discounting the environmental importance of honey bees, a host of other industrious insects, mammals and birds are also important pollinators. In Maine, there are 90 native pollinators that visit wild and cultivated flowering plants. All of them are far more efficient at pollination than domestic honey bees.
Think of them as the unsung heroes of pollination.
All flowering and cone-bearing plants produce pollen. It’s a fine powder that is essential for the plants’ reproduction. Each grain of pollen contains the genetic material needed for plant fertilization. But first they need to travel to another plant of the same species.
“Our best pollinators are bumble bees,” said Phillip Fanning, assistant professor of agriculture entomology at the University of Maine. “They are very efficient.”
Efficient and not afraid to get their feet wet, unlike the more fair weather honey bees, according to Jim Dill, pest management specialist at the University of Maine Cooperative Extension.
“Bumble bees will go out and work in much worse weather than the honey bees,” Dill said. “So if you have a cool, wet spring and the honeybees don’t want to go out and get their tootsies wet, you have the bumble bee saying, ‘I’m tough and I will go out.’”
Growers are starting to realize the efficient work ethic of bumble bees, Dill said. It’s now possible to purchase packages of bumble bees for crop pollination. They are especially good at pollinating tomatoes, sweet peppers, eggplants, melons, strawberries, apples, pears and cherries.
People put bumble bees in their greenhouses because they tend not to be aggressive and workers don’t have to worry about getting attacked and stung, Dill said.
Without this transportation of pollen on the bodies of insects, most food-producing crops would quickly die out.
“These bugs will go looking for the [flower] nectar which is their coffee or can of coke,” Fanning said. “While they are feeding, pollen will fall on their bodies [and] some of it will fall off on the next flower they go to.”
The more plants an insect visits, the more pollen gets spread around, Fanning said.
Just about any pollinating insect will visit more flowers and carry more pollen around in a day than honey bees.
When honey bees visit plants to collect nectar and pollen, static electricity from hairs all over their bodies attracts pollen. The bees then use their legs to push the pollen grains into specialized “pockets” to carry it back to their hives. Along the way, some of that pollen will fall off into, and fertilize other flowers the bees visit.
It works but it is not the most efficient system, Fanning said.
Honey bees are general feeders that collect pollen from a wide variety of flowering plant species. So it’s not guaranteed that the pollen a honey bee carries from one plant to another will do any reproductive good. It’s pretty random that they manage to get the right pollen to the right plant.
Insects like wild bees, bumble bees, wasps, moths, butterflies and beetles, on the other hand, have evolved to feed on single species. That means they transport pollen only between plants that need it.
Few insects work harder during the day than domestic honey bees. But they don’t work nights.
Flowering plants like moonflowers, angel’s trumpets and night phlox are closed up during the day and only open their flowers after dark.
Covering the pollinating night shift are several species of nocturnal moths in Maine. While most people think of insects when it comes to pollination, hummingbirds in Maine also play an important part.
“They are primarily wildflower and wild ecosystem pollinators,” said Adrienne Leppold, a landbird specialist with the Maine Department of Inland Fisheries and Wildlife. “They don’t pollinate agricultural crops. Maybe that’s why they get less credit.”
Hummingbirds are far more mobile and cover a lot more ground than insect pollinators, Leppold said.
“Hummingbirds have been credited with making dramatic contributions to genetic diversity on the landscape,” she said. “Any flower or plant that attracts a hummingbird is likely to have its genetic material spread more far and wide than a honey bee would carry.”
Just like insects, hummingbirds get coated with pollen that then falls off as they feed on the nectar from multiple flowers, often of the same species.
So, while honey bees will likely continue to benefit from the popular concept that they are the superstars of pollinating, it’s the lesser known unsung heroes we should really be thanking.