Although this blog is decidedly not about honey bees, the media has so successfully publicized their plight in recent years that it is now difficult to enter into a discussion about bees without addressing the dreaded “Colony Collapse Disorder” (CCD). Therefore, even though I am a member of the USDA Logan Native Bee lab, which includes several melittologists who delight in rolling their eyes whenever the common honey bee is brought up in conversation, I dedicate this post to the widely recognized, historically revered Apis mellifera, as honey bees are known to the scientific community. As off-topic as it can sometimes feel for me to be asked to talk in circles about CCD with people when they hear I study bees, I love working with an organism to which people feel a connection and have a basic understanding of its global importance (as opposed to when I was the odd, inexplicable “ant researcher girl” on a former project at a Marine Corps Base). I am happy to discuss honey bees, their fascinating hive dynamics, honey flavors, and the pervasive impacts they have on our ecosystem and agricultural functioning. Then I am even happier to shift the conversation to the under-appreciated, under-studied native bees and watch your eyes grow wide with plans to fine tune your wildlife vision the very next time you step outside (see previous post).
But, yes, honey bees…
The issue of CCD is as real as it is mysterious. In 2006 U.S. beekeepers began reporting alarming and sudden declines in their hives, beginning with David Hackenberg of Florida who woke up one morning to find 85% of his 3000 hives nearly empty. But after six years of feverish research in the US and Europe, scientists have yet to pinpoint a singular culprit and outline a solid plan of attack to bring A. mellifera back to its former glory. And with several USDA-ARS labs across the country tasked with resurrecting these commercial pollinators, this is not for a lack of effort or expertise.
That is not to say, of course, that no progress has been made. Cell phones and cell phone towers, for example, have been exonerated of responsibility for this crime, as has the air pollutant ozone. Correlations of bee declines with genetically modified crops or the use of high fructose corn syrup to supplement bee colonies, while objectionable on other grounds, does not hold up to scrutiny. And recent publications compiling current knowledge on causes of CCD have named specific neonicotinoid pesticides as being particularly suspicious in their undocumented dangers towards bees, if sometimes only at sub-lethal levels. Research has shown certain pesticides to cause bees to become disoriented while on foraging flights, forcing them to endure more stress and fatigue in their efforts to return to the hive. Other pesticides seem to not to affect adult bees, but may cause a myriad of developmental problems in larvae, burdening the hive in the next generation. However, since much of the research done on these chemicals is conducted by scientists on the pesticide manufacturers’ payroll who are usually running short-term tests to demonstrate that lethal doses for adult bees are higher than levels found in the environment, such implications are currently inconclusive and a solution to CCD remains stubbornly elusive. Marla Spivak, Director of the Bee Lab at the University of Minnesota, and Gene Robinson, head of the University of Illinois Bee Research Facility, recently explained in an interview on Minnesota Public Radio that the mass destruction of honey bees seems to be the result of a combination of human-induced factors that have been gradually stacking the deck against these nonnative (imported from Europe long ago) pollinators for many years.
In an effort to maximize profits, our agricultural system has increasingly become one of massive monocultures, resulting in a dearth of pollen and nectar diversity for many miles on end. Honey bees are known as generalist pollinators, preferring to visit many types of floral hosts. Being geographically limited to just one type of crop is likely no better for them than a diet of only carrots, though a singular healthful choice, would be for us. Yet this is what we are offering our managed honey bees when we increasingly support a system that sends them, tightly packed on semi trucks, thousands of miles across the country to be liberated for short stints into vast, isolated groves of almond trees, for example, before being herded up again and transported to the next crop of almond blooms. Not only is the stress of highway travel not something to which Apis mellifera has had the chance to adapt, but this practice extends the natural range of honey bees many times over, at great cost to their immune capabilities, just as rapid travels through foreign lands sampling all the local food, water, and microbes might send you straight home to your doctor. Honey bees are typically known to limit foraging to a few mile radius of their hives, only encountering the pathogens, pesticides, and environmental contaminants within a relatively small and familiar area. When hives are brought from Florida to California to Maine in a single flowering season, the load of new pesticides, parasites, and stressors they encounter is more than they are biologically equipped to resist, especially in their malnourished, disoriented state. Up against the insurmountable odds of this new, jetsetter lifestyle, hive defenses weaken and intruders such as the wax moth and the varroa mite move in, which are then transmitted via flowers to nearby native bees and local, wild honey bees in the areas to which these hives are introduced.
So the problem of CCD quickly became a problem of limited local crop pollinator availability, which then rapidly necessitated a trend of trucking bees back and forth across the country, which appears to be resulting in a crash of the entire system…literally. In May, 2010 a truck carrying about 17 million honey bees on a flatbed trailer crashed in Dakota County, MN, releasing thousands of bees onto highway accident victims. In April 2011, highway workers piled hundreds of honey bee hives on the side of the road and burned them after they spilled from a truck on a highway near Casper, WY. A “river of honey” flowed across a road in Island Park, Idaho in July, 2011 when yet another semi driver lost control of his buzzing cargo. And the beehive state joined in on the action in October, 2011 when a highway accident near St. George, Utah released 25 million bees into the air. The problem of honey bee trucking accidents is apparently so prevalent that the University of Tennessee Institute of Agriculture produced a document on “Preparing for Honey Bee Emergencies in Tennessee,” in which they instruct workers on how to contain and kill honey bees that have escaped in truck accidents, including instructions to “call for wrecker gear and forklifts to move hives” and “maintain several protective umbrella sprays on obvious sources of bees.” Perhaps another document is in order, detailing how to restructure our farming practices so that we don’t need to bring honey bees thousands of miles in order to sustain our factory-line crops?
Enter Claire Kremen (UC-Berkeley), Neal Williams (UC-Davis), Rae Winfree (Rutgers) and others working to solve this very problem with brilliant ideas on transforming our monocultures. They suggest installing pollinator-specific hedgerows and other sources of native bee habitat near larger crops, and establishing small, organic crops to boost native bee abundance and help offset our alarming dependence on managed, transported honey bees. The three researchers mentioned above, along with Jonathan Dushoff of McMaster University, completed a study in 2007 on the ability of native bees to provide ‘biological insurance’ against ongoing honey bee losses. Using field measurements of watermelon pollination, along with a simulation model to differentiate between the pollen provided by honey bees and that provided by native bees, they determined that wild, native bees could provide 90% of the necessary pollination in the absence of the honey bees now rented for the job at the farms studied….IF their habitat requirements are factored in to the neighborhood plan.
In dramatic conclusion, native bees emerge the heroes of this sad tale of unresolved honey bee decline. (Didn’t see that coming? Didn’t I promise I would bring the conversation back to native bees?) There is evidence that native bees could be poised to swoop in and save pollination, and thus the diversity of our food and landscapes, if only we can sufficiently restructure our agricultural system to support them. This is a daunting enough challenge in itself, but it is also necessary to address the very scary concept that, though we may find ways around our heavy dependence on honey bee pollination and we could learn to live without honey (though we really wouldn’t want to), the truth about what Colony Collapse Disorder means for us is even worse than the total loss of honey and the vital ecosystem services provided by its producers. Spivak and Robinson reminded listeners on MPR that, through CCD, the honey bee has revealed itself as a “poster child” for the current state of our ecosystems. They are what is known in ecology as an “indicator species,” indicating, like a canary in a coal mine, the quality of the habitat in which we are all living. So the fact that the cause of CCD remains unclear and is thought to be a combination of a multitude of deplorable conditions for bees is damning news for the chemical and biological state of our world. There are thousands of beekeepers managing billions of bees, keeping a very close eye on them and poised to raise the alarm when they show signs of trouble. What might be the condition of the millions of other species (including native bees) on whom we don’t have such thorough surveillance? Are we standing in the middle of a rapidly disintegrating system, unaware of the vanishing pieces of our ‘biological insurance?’
I found the quote below in a book about honey variety around the world (Honey and Dust by Piers Moore Ede). With all the recent buzz about how bees support our agricultural system, which often turns into calculations of their economic value as pollinators, I think Tolstoy makes an important point about the outrageous arrogance of trying to define the purpose of any living being from the standpoint of any other. The more we can learn about our cohabitants on this planet, the better we can respect the complex web of species interactions within which we are cradled during our short time on Earth. Let us hope we don’t have to discover the vital ecosystem contributions of many species more obscure than Apis mellifera by experiencing the harsh sting of the consequences of their absence.
A bee settling on a flower has stung a child. And the child is afraid of bees and declares that bees exist to sting people. A poet admires the bee sucking from the chalice of a flower and says it exists to suck the fragrances of flowers. A beekeeper, seeing the bee collect pollen from flowers and carry it to the hive, says that it exists to gather honey. Another beekeeper who has studied the life of the hive more closely says that the bee gathers pollen dust to feed the young bees and rear a queen, and that it exists to perpetuate its race. A botanist notices that the bee flying with the pollen of a male flower to a pistil fertilizes the latter, and sees in this the purpose of the bee’s existence. Another, observing the migration of plants, notices that the bee helps in this work, and may say that in this lies the purpose of the bee. But the ultimate purpose of the bee is not exhausted by the first, the second, or any of the processes the human mind can discern. The higher the human intellect rises in the discovery of these purposes, the more obvious it becomes, that the ultimate purpose is beyond our comprehension.
-Leo Tolstoy, War and Peace
Ede, Piers Moore. (2005) Honey and Dust: Travels in Search of Sweetness. Bloomsbury Publishing, London.
Ghazoul, Jaboury. (2005) Buzziness as usual? Questioning the global pollination crisis. Trends in Ecology and Evolution, Vol. 20 No. 7.
Kaplan, J. Kim. (2012) Colony Collapse Disorder: An Incomplete Puzzle. Agricultural Research, Vol. 60, No. 6.
Krebs J.R. et al. (1999) The Second Silent Spring? Nature, Vol. 400.
Pilatic, H. et al. (2012) Pesticides and Honey Bees: State of the Silence. Pesticide Action Network North America <www.panna.org>
Potts, S.G. et al. (2010) Global pollinator declines: trends, impacts and drivers. Trends in Ecology and Evolution, Vol. 25 No. 6
Stokstad, Erik. (2007) The Case of the Empty Hives. Science, Vol. 316.
Winfree, R. (2008) Pollinator-Dependent Crops: An Increasingly Risky Business. Current Biology, Vol. 18 No 20.
Winfree, R. et al. (2007) Native bees provide insurance against ongoing honey bee losses. Ecology Letters, 10:1105-1113.