This article by Ann Brouillette first appeared in Wildflora RI, Spring 2022.
Honey bees are everywhere. You sometimes see their hives on conservation land, at nature centers, and even in people’s backyards. They are not native but agriculture in North America is dependent on them for pollinating crops. This is because our native bee populations are simply too small to adequately pollinate crops raised using today’s farming methods. There are an estimated 2.8 million honey bee colonies with about 30,000 bees per colony in the United States, according to entomologist Alison McAfee. What effect do all these honey bees have on our native bees?
I posed this question to Dr. Robert Gegear, professor of Biology at UMass Dartmouth who studies pollinators, especially bumble bees, and runs Beecology, a citizen science project to gather data about pollinators so that we can “effectively develop conservation and restoration strategies for threatened species.” He said, “Honey bees do have negative effects by passing diseases and depleting floral resources (competition).”
Research shows that the effect of honey bees on native bees, though hard to quantify, is generally negative. McAfee, in a Scientific American article, explains, “Honey bees are extreme generalist foragers and monopolize floral resources, thus leading to exploitative competition— that is, where one species uses up a resource, not leaving enough to go around.”
Competition doesn’t just reduce pollen and nectar. In one study, scientists James Cane and Vincent Tepedino found that it also forces native bees to travel farther and forage over a larger area. This weakens them and leads to fewer and smaller offspring. They produce fewer daughters and more sons, further reducing their population. Weakened bees are less likely to live over the winter and are more susceptible to diseases and parasites carried by honey bees and other managed bees.
Another problem is that honey bees sometimes prefer to forage on non- native invasive plants, pollinating them as they feed, encouraging them to proliferate, crowding out the native flora so necessary to native bees. Where invasive plants take over native habitat, we “risk a mass simplification and homogenization of … flora and fauna,” which would lead to the extinction of numerous native species, Dave Goulson points out in Silent Earth. He goes on to say that studies of crop pollination have found that “pollination is more reliable and more resilient over time when more species are present.” In other words, reliance on one pollinator, such as honey bees, is not a good strategy even for big agriculture. Farmers are learning that native bees increase the overall pollination of crops by working in cold wet weather and in other conditions where honey bees don’t function as well.
The Xerces Society acknowledges that honey bees are critical for agriculture, but it has also found that planting strips of native plants along agricultural fields to support native bees can increase crop yields significantly. In addition, having mostly honey bees on the fields can actually reduce the rate of pollination for some crops, which in turn reduces fruit set. This is because the honey bees out-forage the wild bees and expose them to pathogens, reducing their numbers. Dr. Gegear pointed out in a recent email that honey bees “should be restricted to agricultural lands and only present if they are absolutely needed for crop pollination.”
In 2007 honey bees started dying in large numbers, and the term ‘Colony Collapse Disorder’ was coined to identify what was happening. Efforts meant to “Save the Bees” were directed at honey bees. Bee keeping became very popular. But in fact, “honey bees are not in decline; they are probably the most numerous bee on the planet,” says Andrew Whitehouse of Buglife. org. As Scott Black of the Xerces Society puts it, “Keeping honey bees to ‘save the bees’ is like raising chickens to save the birds.”
Another problem? Our lawns. Since honey bees are not native and do harm to native pollinators, and since we have 40 million acres of lawn in the United States, which has eliminated much of the habitat our native bees rely on, keeping bees “might not be the most responsible thing to do,” says Heather Swan, entomologist at the University of Wisconsin. Her advice? “Plant organic native flowers, shrubs, and trees; quit using toxins on your lawn; and become a watcher of native insects.” To attract the greatest number of wild bees it’s best to plant a variety of native plants with bloom times ranging from spring through fall, so sources of nectar and pollen are available from early spring to late fall.
To effectively make a difference beyond our own gardens, we can encourage our neighbors to grow native plants. In addition, we can support green initiatives in our states and towns and encourage the use of native plants as part of these initiatives. School gardens are a great way to start children thinking about preserving the natural world, and plantings for pollinators on community properties can help educate the general public. Most people do not know the difference between native and non-native bees or plants. The key to saving our native bees and the native plants that sustain them will be educating our children, neighbors, and politicians about best practices for stewarding our yards and public spaces.
Angelella, G. M., C. T. McCullough, and M. E. O’Rourke, “Honey bee hives decrease wild bee abundance, species richness, and fruit count on farms regardless of wildflower strips.” www.nature.com/scientificreports
Cane, James H., and Vincent J. Tepedino, “Gauging the Effects of Honey Bee Pollen Collection on Native Bee Communities. Conservation Letters, Vol. 10, Issue 2, 2016. https://conbio.onlinelibrary.wiley.com
Goulson, Dave. Silent Earth–Averting the Insect Apocalypse. HarperCollins, 2021.
Hatfield, R. G., S. Jepsen, M. Vaughan, S. Black, and E. Lee-Mäder. 2018. An Overview of the Potential Impacts of Honey Bees to Native Bees, Plant Communities, and Ecosystems in Wild Landscapes: Recommendations for Land Managers. 12 pp. Portland, OR: The Xerces Society for Invertebrate Conservation.
McAfee, Alison. “The Problem with Honey Bees.” November 4, 2020. Scientificamerican.com
Vance, Erik. “Native Bees often better pollinators than honey bee.” November 14, 2011. Vcresearch.berkeley.edu/news
Whitehouse, Andrew, quoted from an article in The Guardian by Alexander Turner, “Honey bees are voracious: Is it time to put the brakes on the boom in beekeeping?” https://www.theguardian.com/ environment/2021