I’m realizing that what I thought was going to be a quick review of CCD has turned into a very long series of detailed articles, and I’m not even near reaching the conclusion. So on this 20th anniversary of my first seeing the parasite that changed beekeeping worldwide, I thought that I’d interrupt the Sick Bees series and attempt to explain, more briefly (hah!), and from an ecological perspective, what’s happening to the bees these days, and how beekeepers are being forced to adapt.
One Wild Ride!
In 1994 I saw my first varroa mite—on a stickyboard that had been placed by the county bee inspector under one of my hives. Little did I know how much that little maroon speck was about to change my life!
Varroa clobbered me (or more precisely my bees). And then did it again; and then again. I finally got pissed off and decided that I should either give up beekeeping altogether, or dust off my scientific training and really learn about bee and mite biology, and how to apply it to practical beekeeping.
What’s interesting is that my very first article (on almond pollination), in the fall of 2006, was published just as Dave Hackenberg’s colonies began to collapse from CCD. The occurrence of CCD put the bee research community into high gear to try to figure out what the heck was happening. And that created a “niche” for a practical beekeeper with a biological background, willing to act as a translator of the scientific findings to an alarmed beekeeping community. I unwittingly stepped into that niche, and it swallowed me up. A mere seven years later, and to my utter surprise, I’ve gone from being an obscure sideline beekeeper to a globetrotting speaker on bee health and management.
I’ve now been fortunate enough to visit both professional and recreational beekeepers in every part of North America and in several other countries. I’ve seen many styles of beekeeping, from the tropics to the Arctic, heard the local problems and concerns, and had the chance to learn from some very smart and successful beekeepers. I’ve attended scores of conferences, read countless scientific papers, and picked the brains of the world’s best apicultural researchers. Then I’ve done my best to share what I’ve learned with others. I’ve met scores of wonderful people and made a lot of new friends, and I’d like to take this opportunity to thank you all for the appreciative and effusive support!
How We’ve Benefitted From CCD
CCD has been a mixed blessing to beekeepers. It brought grown men and women to tears (see the film The Last Beekeeper ), and the elevated rate of colony mortality in recent years has made it difficult to keep our operations in the black. But it also pushed our scientific community to learn more about the biology of the honey bee than they had in a great many years. And many of us are much the better beekeepers for it.
Unlike that of other livestock, the true contribution of pollinators to U.S. agricultural production is not reflected by farm gate sales figures, so bees have traditionally not received their fair share of USDA research funding, nor does the beekeeping industry have the lobbying clout of the cattle, poultry, or pork producers. But we’ve benefitted from the public awareness of the plight of pollinators, which has resulted in the shifting of some funding our way  (although bees still only get about a tenth the amount of money set aside for research on beef production). In addition, universities, grantors, and other governments have recently supported a great deal of research into honey bee and pollinator health (I only wish that the millions who signed the internet petitions to “save the bees” had instead each donated a single dollar toward bee research).
Misunderstanding And Misinformation
Although CCD refers to a specific set of symptoms , the media soon began to use the term for any sort of honey bee mortality (as did many beekeepers). And although the epizootic appears to have largely run its course, speculation ran rampant as to the cause(s) of “CCD,” and continues to do so with every new “documentary” and press release. Although “CCD” remains the poster child of colony losses, a blue-ribbon group of bee researchers cautions:
During the winter of 2008/2009, ∼10% of the 2.3million managed honey bee colonies in the US died with “CCD-like symptoms”, and US beekeepers self-diagnosed CCD as only the 8th most important contributor to colony mortality, behind starvation, queen-related issues, and parasites. The point is, honey bees die from many things. We must be careful to not synonymize CCD with all honey bee losses  (emphasis mine).
I’m typing these words as I fly over the beautiful jigsaw-puzzle-like frozen Manitoba landscape on my return from a speaking engagement in Sweden, where the film More than Honey had been recently shown. To my considerable surprise, the Swedish beekeepers (Fig. 1), after viewing the movie, were under the very strong impression that the bee problems in the U.S. were due to our brutal commercial beekeeping practices, and the moving of hives to the deadly almond orchards in California.
As it happens, the director of that film had stayed with me during his initial scouting visit to the U.S., and I was responsible for introducing him to my friend John Miller, who was unfortunately (and I’m sure unknowingly) to be cast in the role of the evil bee abuser, so I felt some responsibility to dispel those misconceptions to the concerned audience. And this brings me to my next subject…
Bees are currently enjoying a great deal of attention from a fearful public eager to do something, anything to help them. This could be a really good thing for the bees, for beekeepers, and for the environment as a whole if such public concern and activism could be guided into meaningful actions. I can’t really blame the public for being confused, since the entertaining and sensational docu-dramas about the impending extinction of the honey bee resonate more emotionally than do the dry and qualified explanations by scientists as to the “multifactorial” causes of colony mortality.
As a result of all the misinformation and hysteria out there, an unsure and distrustful public puts pressure their representatives to pass this or that new regulation to “save the bees.” This scares me. I feel that we should heed the sage advice of Thomas Jefferson:
People are inherently capable of making proper judgments when they are properly informed.
And therein lies the problem: due to the complexity of what’s happening with bees these days from the biological, environmental, agricultural, and economic standpoints, it’s danged hard to be “properly informed.” My gosh, just look at me trying to do that “informing”—I first thought that the “Sick Bee” series was only going to be two or three articles long! So what to do?
Challenging One’s Beliefs
One should be careful about embracing the popular stories about why “the bees are dying.” Some of the myths resonate so emotionally that they win uncritical acceptance by the mainstream, despite the fact that they cannot be reconciled with obvious facts (e.g., that bees can indeed thrive surrounded by GMO corn and soy, or on neonic-treated canola). As the popular scientific author Stephen Jay Gould pointed out:
The most erroneous stories are those we think we know best – and therefore never scrutinize or question.
Anyone who knows me (or has had the misfortune of trying to promote an unsubstantiated argument in my presence) can tell you that I’m a challenging and provocative person by nature. I’ve found that the best way to get to the truth is to learn how to argue your opponent’s side of a debate as well as you can argue your own. Therefore, I am more than willing to play Devil’s Advocate any time that I see one side of a legitimate argument being ineffectually presented. And I’m ruthlessly skeptical of any claims that do not jibe with what I see with my own eyes.
As you can imagine, this has earned me my share of vitriol from those who “know the truth” (read  for an enlightening discussion). Luckily, my mailbox runs about a hundred to one with thank you letters from beekeepers who appreciate my evaluation of the issues. I take this responsibility seriously; in order to remain objective and unbiased, I go out of my way to constantly question every one of my opinions (I avoid making “conclusions”). I eschew holding any “beliefs,” but rather adhere to the following principles:
- That I should respect Nature and all forms of life (my ethical environmentalist side),
- That I should thoroughly investigate all research and explanations of any subject, and avoid cherry picking data that suits my ideological convictions (my curious open mindedness and willingness to do my homework).
- That I should base my opinions upon information and experimental results which stand up to scrutiny and questioning (my scientific side),
- That I should then truth-check those opinions against on-the-ground evidence and observations (my practical side).
Unfortunately, many crusaders allow their commendable environmental consciousness (and innate fear of technology) to override the last three principles, which is understandable, since doing the homework is really hard, and our understanding of the biology involved is as yet incomplete. But I have some suggestions as to where to start…
A Homework Assignment
Allow me to first assign you some required reading. Put down this article and read Berndt Heinrich’s fascinating book Bumblebee Economics . Heinrich studied the minute details of exactly how bees make a living in their ecological niche, focusing upon the economics of energy utilization. His revelationary insights changed my understanding of bee life completely. Then for something entirely different read Ron Miksha’s Bad Beekeeping  for a perspective on the economic trials and tribulations faced by professional beekeepers (his comments on p. 243 are especially relevant). I’ll wait ‘til you’re done…
OK, I hope those books were as thought-provoking to you as they were to me! Now let’s take a look at the health of bees and beekeeping from ecological and economic perspectives.
It’s All About Economics
Again and again, I find that everything boils down to economics and finding the right niche. This applies to both honey bees and to the business of beekeeping—either thrives in its ideal niche, and either must either adapt or die if the parameters of the niche change. And boy howdy, how we have changed the parameters of both of our niches in recent years!
Practical application: In this real world, each species, and each business, strives to exploit a niche to which it is particularly well adapted. A change in any of the parameters that define a particular niche may affect the profitability and survival of that species or business. If that species or business is efficient and profitable in its particular niche, then it thrives; if not, if must either adapt or go extinct.
For the remainder of this article, I will view the situation of both bees and beekeepers through the lenses of ecology and economics, and the changes that have occurred in the parameters that define our niches.
Let’s Define Some Terms
Pollinators are in decline over much of the world, and have been for some time . We beekeepers are mainly concerned with our favorite pollinator, the European honey bee, Apis mellifera, native to Europe and Africa, but now introduced worldwide. Unless I specify otherwise, henceforth I will be referring to this species.
It occurs to me that if pollinators have long been in decline worldwide, then that would imply that something has changed in their ecological niches (and that it started before the introductions of cell phones, neonics, or GMO’s). It also occurred to me that the niches occupied by beekeepers have changed substantially (mine sure has; indeed several times). I’ll try not to burden you with too many new terms:
Habitat—where the bee species lives (or could live). The bees in the U.S. are mongrel hybrids of various European or African races , each originally adapted to specific microhabitats in their home countries.
Ecological niche—a description of the bees’ “occupation” in its specific microhabitat, including all environmental parameters and interactions with other species.
Fundamental niche— the potential full range of environmental conditions and resources that the honey bee as a species could possibly occupy and use, without the limitations of predation, competition, or other factors.
Realized niche—the less-than-optimal niche that each subspecies of bee actually occupies; constrained by weather, resources, parasites, etc. In its home range, various subspecies of honey bee adapted to narrow realized niches occurring in the warm Mediterranean, the cold Alps, the British heathland, the Egyptian desert, the African savannah, etc. In each of those niches, the bees adapted to the seasonality of local nectar flows, the local plant toxins, temperature, predators, and parasite pressure. Conditions may not have been optimal, but each subspecies was economically successful at “making a living” within those parameters.
So let’s list the most important parameters of the fundamental niche of the European honey bee:
- It is a colonial species, existing as a superorganism with generally a single reproductive queen, supported by multiple patrilines of sterile workers, each exhibiting slightly differing genetics, behaviors, and resistance to parasites, toxins, and diseases (this within-hive diversity is extremely important, but often ignored by beekeepers).
- It is a generalist species, able to gather food resources from a wide variety of plants. As such, it is adapted to metabolizing a wide range of toxic plant alleleochemicals (and by extension, synthetic pesticides).
- It is primarily a pollinator; its diet normally consists solely of nectar and pollen, although those raw foodstuffs are processed into other products (honey, beebread, and jelly) for the actual consumption by the majority of the members of the superorganism.
- The bee cannot forage unless the ambient temperature is above roughly 55°F (12°C). This limiting factor constrains its range to those areas that have adequate bloom available when the temperature exceeds that value; any colony with hungry brood when daytime temperatures do not exceed 55°F will soon become stressed due to an inadequate supply of protein (this is a huge management tip).
- Unlike other insects, the European honey bee stores vast quantities of processed food for later consumption when resources are scarce.
- This allows the colony to do something that no other species of temperate insect can do—maintain an elevated body temperature, and rear brood, throughout the winter.
- In order to maintain that colonial body temperature, the European honey bee requires a protective insulated cavity within which to nest (Fig. 2).
- Somehow, the European honey bee evolved with remarkably few parasites—the only significant ones being Nosema apis, the bacteria causing the two foulbrood diseases, the fly Braula, rare infection by two opportunistic fungi in pollen (chalkbrood or stonebrood), and what were normally “economically unimportant” infections by any of several insect viruses.
In summary, the honey bee requires a dry cavity, in which it maintains a tropical environment throughout the year, allowing it to exploit food sources any time that the temperature is above 55°F, it is adapted to metabolize a wide variety of plant toxins, it only requires a brief honeyflow to provide it with food stores for the remainder of the year, and it evolved under low parasite pressure.
Practical application: this last point is of huge import when we attempt to understand the biological changes that have occurred in European honey bee populations worldwide in the last decades. To wit, virus infections have become serious “emerging diseases” .
Add The Beekeeper
OK, now let’s add one more term:
Facilitation—Optimal conditions in the fundamental niche occur infrequently, if ever. The job of the beekeeper is to optimize the conditions for his bees as best he can, such as by supplemental feeding, medicating for parasites, protecting from predators, providing a larger nest cavity, or providing water or winter insulation. Such “facilitation” may allow bees to survive outside of their fundamental niche.
Practical application: I recently enjoyed a lunchtime conversation with a couple of professional beekeepers who moved their hives from almonds, to the tallow bloom in Texas, to the Dakotas for summer, and then to a mild area in California for wintering (their problem is having too many bees each spring). What they are doing is facilitating the optimal fundamental niche for their bees for the entire year (there are many other ways of doing so).
Practical application flip side: If a beekeeper is keeping colonies alive outside of their fundamental niche, such as in densely-packed apiaries, in areas of crop monoculture or high exposure to toxic chemicals, in flowerless forest or dry grassland, or by the chemical suppression of parasites, should that beekeeper falter in his constant facilitation, his bees may not be able to continue to survive without such help.
The realized niche of the honey bee is constrained by limiting factors, which may change from season to season. Common limiting factors for populations of honey bees are:
Climate—bees have very wide “tolerance limits” for cold, heat, rain, and length of seasons. But at the edges of their tolerance limits, colonies will be stressed, and may not be able to deal with other limiting factors.
Competition for food—in some areas there is such an abundance of nectar during the main flow that there is little competition (an important point when speaking with native pollinator advocates). The main competition for food resources occurs at other times of the year; assume that there is serious competition happening if robbing behavior is evident.
Suitability of available food—not all plants produce honey-bee-friendly nectar or pollen, especially outside of the honey bees’ native range. This is clearly evident in America and Australia, where some pollen sources are notably nutritionally inadequate for honey bees (think corn, blueberry, watermelon, pumpkin, some eucalypts). And in some areas or under dearth conditions, bees will unwittingly collect naturally toxic pollen or nectar. And of course, some human-applied pesticides make the available food unsuitable.
Competition for nest sites—without hollow trees or other natural cavities, honey bees cannot survive the winter in temperate climates (Fig. 3).
Predation—Such as birds, bears, wasps, and ants. The main predator of bees, of course, are humans, who often rob too much honey from the hive, resulting in winter starvation.
Parasitism—Again, natural populations of European honey bees appear to historically have been minimally affected by parasites under normal conditions. We will return to how this has changed.
Transmission of parasites—This is very density dependent—the more colonies within flight range, and the more competition for resources, the greater the transmission of parasites. The swapping of combs by beekeepers also changes this dynamic.
Toxins—Natural plant allelochemicals, soil metals, industrial pollution, agrochemicals, and recently, a huge influx of beekeeper-applied miticides.
Bees have a wide range of tolerance for some limiting factors, and more narrow ranges for others. Usually, several factors interact (sometimes synergistically) to limit bee populations.
Practical application: there is often a single limiting factor that is the determinant for colony survival. A concept used in ecology is “Liebig’s law of the Minimum” (Fig. 4). A beekeeper can work hard all season long to do everything he can for his bees, but should he overlook any single critical limiting factor, Liebig’s Law may come into play, and he may lose his colonies.
Practical application: Each race of honey bee in Europe specialized by adapting to certain combinations of limiting factors, and thus gained a fitness advantage in its particular habitat. Since the arrival of varroa, which wiped out much of the feral population, the overall genetics of the U.S. bee population have likely shifted toward those propagated by commercial queen producers .
These “all-purpose” bee stocks are typically bred for color, temperament, and honey production, and maintained with a high degree of facilitation by the queen producer (feeding, treatments). There is no reason to expect those stocks to be well adapted for survival without constant facilitation. This is why I strongly support regional queen breeding for locally-adapted stock.
What Are The Limiting Factors For Honey Bees Today?
It would have been so simple had CCD actually been caused by cell phones! We could have banned the danged things, and wouldn’t have to listen to people walking around loudly and obliviously talking to themselves. But alas, it appears to be more complex than that.
So as a biologist, it occurs to me to go back before CCD, in fact, to go back even further in time, and ask the question, “Which factor(s) limited honey bee populations in Europe prior to modern management by humans”? And then we can work forward in time to see what’s changed since then. To be continued…
Footnotes and Citations
1 Directed by Jeremy Simmons (2009), and recommended for those who didn’t experience the horror of CCD personally. Unfortunately, I can’t suggest anywhere to purchase a copy of this well-done and heart wrenching film.
2 Pollinator Research.–The Committee is aware that pollinators are responsible for the production of one-third of the Nation’s food supply, but the number of managed honeybee colonies in the United States has dropped in half since 1940. Because of the importance of pollinators in the production of the Nation’s food supply and their impact on the stability of our agricultural economy, the Committee encourages [the Agricultural Research Service] to continue to dedicate resources to protecting the health of both honeybees and other native bees, including continued research into colony collapse disorder. http://www.gpo.gov/fdsys/pkg/CRPT-112srpt73/html/CRPT-112srpt73.htm
3 Symptoms of CCD:
1) In collapsed colonies
a) The complete absence of adult bees in colonies, with no or little build up of dead bees in the colonies or in front of those colonies.
b) The presence of capped brood in colonies.
c) The presence of food stores, both honey and bee bread
i) which is not immediately robbed by other bees
ii) when attacked by hive pests such as wax moth and small hive beetle, the attack is noticeably delayed.
2) In cases where the colony appear to be actively collapsing
a) An insufficient workforce to maintain the brood that is present
b) The workforce seems to be made up of young adult bees
c) The queen is present
d) The cluster is reluctant to consume provided feed, such as sugar syrup and protein supplement
From vanEngelsdorp, D, et al (2006, revised Jan 5, 2007) Investigations into the causes of sudden and alarming colony losses experienced by beekeepers in the fall of 2006. Preliminary Report: First Revision.
4 Williams, GR, et al (2010) Colony Collapse Disorder in context. Bioessays 32(10): 845–846. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3034041/
5 Janabi, F (2013) From anti-GMO to pro-science: ‘A Layman’s Guide to GMOs’. http://www.geneticliteracyproject.org/2013/12/03/from-anti-gmo-to-pro-science-a-laymans-guide-to-gmos/#.UqkDXdJ_dyI
6 Heinrich, B (2004) Bumblebee Economics. Harvard University Press. I highly recommend all of Heinrich’s books—he’s a brilliant scientist and an engaging writer whose passion it is to understand the details of how organisms survive in their niches.
7 Miksha, R (2004) Bad Beekeeping. Trafford. For a more data-based analysis, see:
Laate, EA (2013) Economics of Beekeeping in Alberta 2011. http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/agdex14472/$FILE/821-62.pdf
8 CSPNA &NRC (2007) Status of Pollinators in North America. https://download.nap.edu/login.php?record_id=11761&page=%2Fdownload.php%3Frecord_id%3D11761
9 The evolutionary origin of the European honey bee is currently under debate by scientists. See the following:
Han, F, et al (2012) From where did the Western honeybee (Apis mellifera) originate? Ecol. Evol. 2(8): 1949–1957. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3433997/
Kotthoff, U, et al (2013), Greater past disparity and diversity hints at ancient migrations of European honey bee lineages into Africa and Asia. Journal of Biogeography 40: 1832–1838. http://onlinelibrary.wiley.com/doi/10.1111/jbi.12151/pdf
10 Genersch, E & M Aubert (2010) Emerging and re-emerging viruses of the honey bee (Apis mellifera L.). Vet Res. 41(6): 54. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883145/
11 Barrel illustration after Dobenecks, taken from Wikipedia http://en.wikipedia.org/wiki/Liebig%27s_law_of_the_minimum
12 Delaney, DA, et al (2009) Genetic characterization of commercial honey bee (Hymenoptera: Apidae) populations in the United States by using mitochondrial and microsatellite markers. Ann. Entomol. Soc. Am. 102(4): 666-673.