Bees are pulling a disappearing act. Honeybees are vanishing from their hives. Bumblebee numbers have crashed so radically that some species are believed extinct. Even native solitary bees are in decline. Food supplies dependent upon pollinators are threatened.
But gardeners can help. There is no single explanation for what is causing the pollinator losses, said Matt O'Neal, an associate professor of entomology at Iowa State University.
"There are multiple sources of stress," he said. "There are your basic pests, also pathogens like viruses, pesticide exposure and land use practices reducing the kinds of forages bees can feed on. It looks like a combination of all those."
As insect pollinators, bees broaden our diets beyond meats and wind-pollinated grains. An estimated one-third of all foods and beverages are made possible by pollination, mainly by honeybees, the U.S. Department of Agriculture says. Pollinators also are essential for flowering plants and entire plant communities.
"Common species are disappearing at a dramatic rate. I'm terrified in the extreme," said Mace Vaughan, pollinator program director with The Xerces Society for Invertebrate Conservation in Portland, Ore. "I worry in particular about pollinator species with limited ranges and that have unique habitat requirements that are being threatened. A lot of species are dropping out of the landscape." You don't have to become a beekeeper to restore or boost bee populations. Gardeners can:
l Plant flowers and create green spaces, especially in urban areas.
Leave patches of bare soil, rocks and brush piles for use by ground-dwelling native bees. Add caterpillar host plants. "I can't recommend particular plants for all areas of the country but I can recommend the concept," O'Neal said. "Provide pollen and nectar throughout the (growing) season. Plant the right habitat. Every state has land grant agencies and agents. Look to them for help."