August 2015 Issue

Protecting Bee Populations
By David Yeager
Today's Dietitian
Vol. 17 No. 8 P. 44

Bees help produce the rich food supply and contribute billions of dollars annually to the North American economy, but their populations are decreasing. Learn why and what's being done to turn the tide.

Imagine a picnic without bees. Before you get too excited, take a minute to consider what that would entail. For starters, there wouldn't be any lemonade. No watermelon, either. That salsa and guacamole you were looking forward to eating? Sorry, that wouldn't be available. You could have your fill of bananas and pineapples, but forget about the blackberry pie.1

Bees and other pollinators, such as butterflies, birds, and bats, are directly or indirectly responsible for the production of at least 90 commercial crops in North America and 35% of global food production.2 It's estimated that pollinators contribute more than $24 billion annually to the US economy, with honey bees alone accounting for more than $15 billion.2 Bees pollinate a wide variety of fruits and vegetables, as well as numerous types of seeds and nuts. Some of the crops they pollinate include almonds, apples, asparagus, blueberries, broccoli, carrots, cantaloupe, cottonseed, grapes, olives, peaches, peanuts, pears, pumpkins, soybeans, squash, strawberries, and sunflowers, to name just a few.3

Undeniably, bees are beneficial for human health. Many of the crops that rely most heavily on pollination are rich in essential micronutrients.4 Honey, which has been eaten for millennia and used as a topical treatment for burns and skin infections, has antibacterial, antioxidant, and anti-inflammatory properties.5,6 Even propolis, the glue that bees use to build their hives, has antioxidant, antimicrobial, anti-inflammatory, and antiulcerative properties.6

Population Decline
Because bees are such an important link in the food chain, significant declines in bee populations could cause serious consequences. For example, if bee populations decrease, vitamin A and iron deficiencies are three times as likely to occur in areas of highest pollination dependence.4 Managed bee colonies generally comprise honey bees, which settlers imported from Europe in the 1700s and 1800s.7

Unfortunately, the number of managed bee colonies in the United States has declined from 6 million in 1947 to 2.5 million today.2 Since 2006, commercial beekeepers have seen winter colony losses of 30%, up from the historical rate of 10% to 15%.2

Dave Baues, a backyard beekeeper and co-owner of Baues' Busy Bees, has been keeping bees for 17 years. He has a total of 10 hives at two sites, one in southeastern Pennsylvania and one in southern Delaware. He says colony losses have become more unpredictable in recent years.

"My strongest hive died last winter," Baues says. "If you get a warm day or two in the winter, you'll see them buzzing around, but one day, everything stopped." Standing next to the hive, he points to a dark patch of ground that's covered with bee carcasses. "If they die from starvation, you'll typically see a lot of dead bees with their heads in the comb. But who sprays pesticides in February? It was weird."

US hive losses from April 2014 to April 2015 reached 42.1%, the second highest annual loss on record.8 Although winter (October to April) losses decreased for the second straight year, summer (April to October) losses outpaced winter losses.8 Small-scale beekeepers tend to lose more colonies in the winter, while large commercial operations typically lose more colonies in the summer.8

Beekeepers make up for colony losses by splitting their hives.9 This helps bee numbers recover, to a degree, but summer losses can have a significant impact on honey production and pollination. Because it can take 40 days or more from the time a new queen is introduced until a hive is recolonized, Baues says summer losses are more problematic than winter ones. "If you're into honey season, [colony losses] really put you behind the eight ball," Baues says.

Causes of Colony Losses
The exact causes of colony loss can be difficult to determine, but there are certain interacting factors that contribute to the problem. A recent literature review found that the three biggest stressors on both domesticated and wild bees are lack of habitat, parasites and viruses, and pesticides.10 Dave Goulson, PhD, a professor of biology and the director of research and knowledge exchange in the School of Life Sciences at the University of Sussex, the study's corresponding author, says, although the reasons for colony loss are complex, the solutions are not.

Bees once had a wide variety of flowers to feed on, Goulson says, but huge swaths of bee habitat in Europe and North America have been claimed by development or converted to agricultural use. Today, with fewer flowers to feed on and the proliferation of monocultures, there's less food for bees and less variation in their diets. Goulson sees this as the single biggest reason for bees' decline.

To study how habitat affects bees, Goulson has been restoring species-rich grasslands in France to mimic the flower-rich hay meadows that were once common in Europe; around 98% of these areas were lost between the 1940s and 1980s. Goulson has observed a dramatic increase in bee populations since he began. He says setting aside land for bees doesn't require huge public or private investments.

"It's pretty simple," Goulson says. "If the farmer is prepared to set aside a strip along the edge of a field or, perhaps, one field on his farm with a flower mix, it works. You boost the wild bee population, you boost the number of honey bee colonies you can support, and there's no doubt, at all, that if you grow more flowers, you get more bees."

Individuals also can help bee populations by planting bee-friendly flowers in their gardens and flowerbeds. Some of the most popular are apple (including crab apple) trees, bee balm, butterfly bush, foxglove, geranium, globe thistle, heather, hollyhock, hyssop, iris, lavender, marjoram, mint, snapdragon, sunflower, thyme, and wisteria.11

A study by the Southern region Sustainable Agriculture Research & Education branch of the USDA also found that manmade hives can increase native bee populations.12 Since most regions in the world have native bee populations, increasing their numbers by planting more flowers and creating bee-friendly conditions may help to offset managed bee colony losses and, potentially, improve pollination efficiency;12 the study found that native bee species in Georgia were able to pollinate approximately 2,450 apples per day, compared with approximately 80 per day by honey bees.12

Other significant threats to bee health are parasites and viruses. Among them, varroa mites are considered the most detrimental.13 The first recorded case of varroa infestation in the United States occurred in 1987, but the mites rapidly spread throughout the country.14 Varroa mites can interfere with the process of establishing a new queen in a hive and have been shown to reduce bees' ability to pollinate efficiently.15,16

Robert Curtis, associate director of agricultural affairs for the Almond Board of California, says new trends in controlling varroa infestations include introducing genetic material from heartier bee stocks that exhibit "bee hygienic behavior." They essentially remove the mites to the greatest degree possible. Because almond growers are the largest users of commercial pollination services in the world, accounting for roughly 60%,2 they work closely with beekeepers. The Almond Board has contributed almost $1.8 million in funding to bee health research and has published Honey Bee Best Management Practices to protect bees in the orchard.17

"One of the things we're funding is technical transfer teams," Curtis says. "These are groups of technical experts who work with the beekeepers and monitor their hives to let them know, for instance, if they have a problem with varroa or another disease or pest, help them determine whether it's time to treat the bees, and, if so, look at what the options are."

Perhaps the most controversial threat to bee health is the use of pesticides. One particular class of pesticides that has drawn much criticism for its effect on bees is neonicotinoids, which are sprayed and also used as seed dressings. Neonicotinoids can accumulate in the environment and remain for months or years in soil, sediment, groundwater, or waterways, or on treated vegetation.18 They also can be absorbed by vegetation that's subsequently planted in areas where neonicotinoids have been used.18 Bees routinely bring pollen and nectar that's contaminated by these pesticides back to their hives.18 Because the food that's stored earliest in the spring is eaten latest in the winter, spring applications of pesticides may not have significant consequences for the hive until late winter, possibly causing a colony loss such as the one Baues experienced, either from toxicity or possibly lowered resistance to viruses, Goulson says.

Neonicotinoids also have been suspected as a contributing factor to colony collapse disorder, a term coined in 2006 to describe a phenomenon in which adult bees leave the hive and don't come back, leaving behind only the queen and immature bees.19 At present, there's no definitive link between neonicotinoids and colony collapse disorder.19 However, recent research suggests that they're a contributing factor.20 Other possible contributors are aluminum residues and cell phone radiation. 21,22 Varroa mites also have been suspected as a contributing factor.19

Government and Corporate Involvement
Since bees face numerous threats, many people and organizations, from individuals to corporations to the highest office in the land, have taken notice. In 2013, the European Union imposed a two-year moratorium on neonicotinoids.23 In 2014, a judge in Mexico's Yucatán region revoked Monsanto's permit to plant soybeans that are genetically engineered (GE) to resist the pesticide Round Up because he was convinced that the soybeans posed a threat to honey production in several Yucatán states,24 in light of research showing that pollen from GE soybeans was being introduced to Yucatán honey, which resulted in a price reduction in honey produced for the export market.25

A challenge for conventional farmers in the United States is that most corn seed and some soybean seed are precoated with neonicotinoid insecticides. A recent study found that 79% to 100% of corn acres and 34% to 44% of soybean acres were coated with neonicotinoid insecticides in 2011. When these seed coatings were taken into account, this research found that application of neonicotinoids to corn and soybean seeds has driven an increase in the US cropland treated with insecticides since the mid-2000s.26 The ability to patent engineered traits such as Bacillus thuringiensis has facilitated domination of the seed industry by only a few companies, which, in turn, promotes the ubiquity of pesticide-coated seed.27

"This is a silent issue that nobody's addressing," says Christine McCullum-Gomez, PhD, RD, LD, a consultant, writer, and speaker, whose areas of expertise include community food security, public health nutrition, sustainable food systems, and school and worksite wellness (

On July 1, 2015, Ontario, Canada, became the first jurisdiction in North America to reduce the number of acres planted with neonicotinoid-coated corn and soybean seeds. The total acreage of such seeds is expected to be reduced by 80% by 2017.28 In addition, many cities, municipalities, and individuals in North, Central, and South America have signed on to become Honey Bee Havens, "pledging to provide a safe, pesticide-free haven, with access to food, water, and shelter" for honey bees.29

Large corporations are getting involved, too. Lowe's recently announced that it will stop selling neonicotinoid pesticides, and large retailers BJ's Wholesale Club and Home Depot have asked their suppliers to label plants that have been treated with neonicotinoids.30 In 2011, Bayer AG asked the state of California to restrict the use of imadacloprid, one of its neonicotinoid pesticides and one of its most profitable products, on almond crops.31 However, data for 2010 show that imadacloprid was used only in 58 applications on 5,425 of California's estimated 810,000 almond orchard acres that year,32 before being discontinued for use on almonds in 2011. And Curtis notes that applications were done in late spring and summer, after the bees had left the orchards.

Beginning in 2016 in the United States, the Fish and Wildlife Service will phase out the use of neonicotinoids in the National Wildlife Refuge System, and the Environmental Protection Agency (EPA) has proposed a rule that would create temporary, pesticide-free zones when certain plants are in bloom and commercial honey bees are in the area.33,34 Congress also has gotten involved. On May 13, the House of Representatives' Agriculture Committee held a hearing on pollinator health, and HR 1284, the Saving America's Pollinators Act of 2015, was introduced to the Agriculture Committee by Representatives John Conyers and Earl Blumenauer on March 4.35,36 The act proposes to suspend the sale and distribution of neonicotinoids until the EPA can determine whether they cause unnecessary harm to pollinators.36

Perhaps the most anticipated piece of governmental action, though, has been the report of the White House's Pollinator Health Task Force. The three main goals outlined in the report are reducing honey bee colony winter losses to no more than 15% within 10 years; increasing the Eastern population of monarch butterflies to 225 million, covering an area of 15 acres at their winter habitat in Mexico by 2020; and restoring or enhancing 7 million acres of land for pollinators over the next five years.37 To help meet these goals, $82 million has been included in the President's fiscal year 2016 budget request, an increase of $34 million from fiscal year 2015.37

Curtis is hopeful that the increased attention on bee health will translate to public policy. Specifically, he would like to see more California land made available for bee forage. He notes, however, that bees in other areas of the country need help, such as the Upper Midwest. Forty percent of bees that are brought to California make their last stop in the Upper Midwest, he says.

"I'm hoping that we've turned the corner and that bee health will improve," Curtis says. "The bottom line for us is that beekeepers have worked extremely hard to provide almond pollination and have done it successfully, even though they're combatting these colony losses during their season. It takes quite a bit of management. Maintaining honey bee hives is a bit more fluid than typical livestock operations."

Aside from government and corporate actions, individuals also have a responsibility to protect pollinators. McCullum-Gomez, who's also a column editor for the Journal of Hunger & Environmental Nutrition, says people need to understand the role that pollinators play in our food system, and dietitians can use their expertise to educate them.

"If we really want to see change in our food system, we have to be a part of that change," McCullum-Gomez says. "So that could mean developing partnerships with nonprofit organizations that are promoting school and community gardens, working with farmers at farmers' markets, or even working with bee keepers."

There are many ways for people to get involved, McCullum-Gomez says. Kitchen gardens are a simple option. Farm-to-school programs offer opportunities to contribute to pollinator health through building youth beekeeping programs, while engaging kids' natural curiosity. Supermarket dietitians also can help spread the word. In April 2015, Whole Foods and the Xerces Society for Invertebrate Conservation launched a two-week "Share the Buzz!" campaign, aimed at educating and mobilizing consumers to help protect pollinators and their habitats.38 McCullum-Gomez says there's even a Bee Smart app that provides information about more than 1,000 native pollinator-friendly plants.39

Many people and organizations also offer opportunities to get involved with pollinator health. The Center for Food Safety and Beyond Pesticides are cosponsors of the Bee Protective Campaign, which provides information and resources for people to help pollinators in their communities.40 And Goulson runs a citizen science project that aims to monitor populations of wild bees and other pollinators. Although that project is under way only in the United Kingdom, he recommends the Great Sunflower Project in North America, which is serving a similar purpose.41

Making Progress
With all of the talk about threats to pollinators, it can be easy to overlook the progress that's being made. There's still much more to be done, but it's doable, Goulson says. The key is to convince people to take pollinator health seriously.

"Bees aren't going to go extinct," Goulson says. "But if they keep declining in number, then we will, possibly very soon, see yields starting to decline for the crops that require pollination, which make up about a third of the food that we eat. So, given that there are 7 billion people on the planet who need to be fed, we really can't afford for crop yields to start to fall."

— David Yeager is a freelance writer and editor in southeastern Pennsylvania.

1. A picnic without bees. Earthjustice website. Accessed June 1, 2015.

2. Fact sheet: the economic challenge posed by declining pollinator populations. The White House website. Updated June 20, 2014. Accessed June 1, 2015.

3. Vanishing bees. Natural Resources Defense Council website. Updated July 25, 2008. Accessed June 1, 2015.

4. Chaplin-Kramer R, Dombeck E, Gerber J, et al. Global malnutrition overlaps with pollinator-dependent micronutrient production. Proc Biol Sci. 2014;281(1794):20141799.

5. Kwakman PHS, te Velde AA, de Boer L, Speijer D, Vandenbroucke-Grauls CM, Zaat SA. How honey kills bacteria. FASEB J. 2010;24(7):2576-2582.

6. Viuda-Martos M, Ruiz-Navajas Y, Fernández-López J, Pérez-Alvarez JA. Functional properties of honey, propolis, and royal jelly. J Food Sci. 2008;73(9):R117-R124.

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8. Colony loss 2014–2105: preliminary results. Bee Informed website. Updated May 13, 2015. Accessed June 2, 2015.

9. More than 40 percent of bee hives died in the past year: study. NBC News website. Updated May 13, 2015. Accessed June 2, 2015.

10. Gouslon D, Nicholls E, Botías C, Rotheray EL. Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Science. 2015;347(6229):1255957.

11. The best garden flowers for bees. University of Sussex: Goulson Lab website. Accessed June 3, 2015.

12. Southern region Sustainable Agriculture Research & Education. Enhancement of native bee pollination services in apple orchards in Georgia: 2015 final report. Published June 3, 2015. Accessed June 8, 2015.

13. United States Department of Agriculture. Report on the National Stakeholders Conference on Honey Bee Health: National Honey Bee Health Stakeholder Conference Steering Committee. Published May 2, 2013. Accessed June 4, 2015.

14. Wenner AM, Bushing WW. Varroa mite spread in the United States. Bee Culture. 1996;124:341-343.

15. Cargel RA, Rinderer TE. USDA Honey Bee Breeding, Genetics and Physiology Laboratory. Effects of Varroa destructor infestation honey bee queen introduction. Published February 2009. Accessed June 4, 2015.

16. Proceedings of the American Bee Research Council 2010. Effects of varroa mites and bee diseases on pollination efficacy of honey bees. Published August 13, 2013. Accessed June 4, 2015.

17. Bee BMPs. Almond Board of California website. Accessed June 18, 2015.

18. The Task Force on Systemic Pesticides. Worldwide integrated assessment of the impacts of systemic pesticides on biodiversity and ecosystems. Published January 9, 2015. Accessed June 5, 2015.

19. Honey bee health and colony collapse disorder. United States Department of Agriculture — Agricultural Research Service website. Updated May 13, 2015. Accessed June 5, 2015.

20. Lu C, Warchol KM, Callahan RA. Sub-lethal exposure to neonicotinoids impaired honey bees winterization before proceeding to colony collapse disorder. Bull Insectology. 2014;67(1):125-130.

21. Exley C, Rotheray E, Goulson D. Bumblebee pupae contain high levels of aluminum. PLoS One. 2015;10(6):e0127665.

22. Herriman S. Study links bee decline to cell phones. CNN website. Updated June 30, 2010. Accessed June 8, 2015.

23. Bee deaths: EU to ban neonicotinoid pesticides. BBC website. Updated April 29, 2013. Accessed June 9, 2015.

24. Walia A. Monsanto loses GMO permit in Mexico — judge sides with the bees. Collective Evolution website. Updated August 27, 2014. Accessed June 9, 2015.

25. Villanueva-Gutiérrez R, Echazarreta-González C, Roubik DW, Moguel-Ordóñez YB. Transgenic soybean pollen (Glycine max L.) in honey from the Yucatán peninsula, Mexico. Sci Rep. 2014;4:4022.

26. Douglas MR, Tooker JF. Large-scale deployment of seed treatments has driven rapid increase in use of neonicotinoid insecticides and preemptive pest management in US field crops. Environ Sci Technol. 2015;49(8):5088-5097.

27. Gurian-Sherman D. How seed and pesticide companies push farmers to use bee-killing insecticides. Civil Eats website. Updated April 29, 2015. Accessed June 17, 2015.

28. Benzie R. Ontario first in North America to curb bee-killing neonicotinoid pesticides. Toronto Star. Published June 9, 2015. Accessed June 11, 2015.

29. Put your Honey Bee Haven on the map. Honey Haven website. Updated June 15, 2015. Accessed June 15, 2015.

30. Lowe's to stop selling neonicotinoid pesticides that may be harmful to bees. The Huffington Post website. Updated April 9, 2015. Accessed June 10, 2015.

31. Almond joy! — victory for bees. Pesticide Action Network website. Updated December 22, 2011. Accessed June 10, 2015.

32. California Department of Pesticide Regulation. Summary of pesticide use report data 2010: indexed by commodity. Published December 2011. Accessed June 18, 2015.

33. Fish and Wildlife Service, US Dept of the Interior. Use of agricultural practices in wildlife management in the national wildlife refuge system. Published July 17, 2014.

34. Proposal to protect bees from acutely toxic pesticides. United States Environmental Protection Agency website. Updated June 12, 2015. Accessed June 13, 2015.

35. Subcommittee reviews the federal coordination and response regarding pollinator health. House Committee on Agriculture website. Updated May 13, 2015. Accessed June 10, 2015.

36. Saving America's Pollinators Act of 2015, HR 1284, 114th Cong, 1st Sess (2015).

37. Pollinator Health Task Force. National strategy to promote the health of honey bees and other pollinators.
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38. Saulsbery G. Whole Foods and Xerces Society work to help pollinators at risk. Modern Farmer website. Updated April 22, 2015. Accessed June 17, 2015.

39. Bee Smart Pollinator Gardener. Pollinator Partnership website. Accessed June 15, 2015.

40. Join the BEE Protective Campaign. Center for Food Safety website. Accessed June 13, 2015.

41. The Great Sunflower Project. The Great Sunflower Project website. Accessed June 13, 2015.