can’t see the forest

Plight of the Honeybee

Posted in bees, ecology, Environment, GM foods, insects, Nature, News, Science by Curtis on 4/22/07

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About a week ago I spent a warm afternoon at a creek in Bankhead National Forest. I’d sat for some time gazing at the surface of the water and listening to the hawks, and was just about to stand up so as to answer the call of nature, if you will, when a large bee buzzed in from out of nowhere. It hovered inquisitively a few inches from my nose. Hanging between fascination with the moment and my hopes to avoid a sting on the face, I motionlessly marveled at the intricacy of the bee’s anatomy—the delicate yellow banding, creepy-cool eyes, and bee fuzz. Did you know bees are fuzzy? I didn’t. I might have learned more; but the queen must have been calling, for my little interrogator soon darted away as unexpectedly as it had arrived. I wondered what it had been doing so far away from any other bees.

Half of the known bee population of the United States has disappeared over the course of the last thirty-five years. There are numerous documented and suspected causes for this decline, to include parasitic infestation, pesticide use, and habitat destruction. But, as Reclaiming Space wrote earlier this month, the past several years (and, most particularly, the past year) have seen declines unprecedented in size and scope. It appears that the rapid and unexplained disappearance of whole populations of bees—known currently as Colony Collapse Disorder (CCD) and previously as Fall Dwindle Disease—is also being documented throughout much of Europe. The threats to human agriculture are significant, with some US states reporting 2006 population declines as high as 75%. While grain staples are normally pollinated by wind, over 80 cultivated fruit, nut, and vegetable crops rely on feral or commercially farmed bees for pollination. The long-running decline has been a factor in the persistent elevation of some food prices throughout the US and other parts of the world, an impact which is certain to increase in magnitude as more colonies are found “dead-out.” Dr. Diane Cox-Foster of Pennsylvania State University, a member of the CCD Working Group investigating the phenomenon, has said that the consequences of continued decline could spell devastation for a number of food crops.

Colony Collapse Disorder is a process through which a previously healthy colony can die out over a period of time as little as three weeks. In colonies that are found to be in the process of collapse, the workforce is inadequate in size and seems to be made up almost entirely of young bees. The bees are reluctant to consume provided feed, which is unusual. After collapse, there are very few to no adult bees remaining in the colony. The brood remains unhatched, and there are food stores present. Curiously, though, invasive species which would be expected to relish just such a find are not observed to rob the dead colony of its riches, or do so only hesitantly; this suggests to researchers that the colony has been rendered toxic in some way. It’s an apiary Jamestown over and over again. The lights are on, but no one is home.

All indications are that the CCD epidemic is likely the result of a number of causes. Because the recent declines have been so severe, they have garnered a greater than usual measure of attention from academia and the media. Some researchers have suggested that power lines and cell phone signals may be to blame, as studies have shown that the proximity of either to a hive can affect <badpun>beehavior</badpun>. However, the vast majority of dead colonies studied have exhibited signs of multiple diseases, which would suggest that deficient immune response is likely a factor, and no links between the potentially detrimental effects of electromagnetic radiation and such immune weakness has been conclusively established. Furthermore, because less severe but certainly significant and persistent declines have been observed over the past several decades—and some say as far back as 1896—it is not likely that an explanation concerning technology that is unique to the past decade or two is adequate.

Mites such as verroa have proven to be the bee’s most prolific nemeses since such things began to be studied, and international commerce has spread a number of such species beyond the zones to which they are endemic. Likewise, parasitic microorganisms are transferred globally in the same way, into bee populations that are not immune to them.

The chemical treatment of genetically modified and non-GM seeds with insecticides (such as imidacloprid) is also being investigated as a potential cause, since the pollen produced by treated plants has been found in many cases to contain traces of such chemicals. While ongoing, this research has been less than promising; most of the pertinent studies of affected colonies in the United States and in Germany, for instance, have involved specimens from areas where GM crops are not generally present. While it is believed that certain chemicals used in or resulting from the processing of these seeds are potentially detrimental to insect health, the phenomenology of CCD cannot be easily reconciled to just such a cause, at least not based on the research that has been done to date.

NosemaSome researchers have speculated that new and previously undocumented parasites or diseases could be major culprits. Nosema apis (pictured) is a well-known protozoan that can infect the digestive tracts of bees. In 2006 US researchers discovered nosema ceranae, a new species which has been found in many, but not all, CCD-afflicted colonies. They say that adult desertion of the colony is a characteristic of severe ceranae infection, which is consistent with observation.

I must preface this by intimating that I am not an entomologist. That being duly noted, my own secondary research indicates that neither cell-phone signals nor GM seeds, the most politically charged environmental hazards yet considered as explanations for CCD, is very likely to blame, at least not significantly or exclusively, for this fierce and deep decline in the populations of American and European bees. That does not mean we’ve no room for improvement, not in the least. Human commerce provides free global transport for certain bee parasites, and, based on all observations and analyses to date, it is in this respect that our own lifestyles can most soundly be inferred to be contributory to the decline in question. Some of us are a little loose with the herbicides and pesticides from time to time—our dandelionless lawns stand as testament. Additionally, bee breeding practices in the US are such that only a few hundred breeder queens are used to produce the millions of hive queens commercially available to farmers in search of pollinators, and this could result in genetic “bottlenecking,” which would be expected to have generally detrimental effects upon the immune capacities of bee populations. It is extremely interesting that the imported “Africanized” bees now common to the US southwest do not appear to be nearly so susceptible to CCD as are endemic species—thusfar I haven’t seen any original field research on the possibility that these bees may carry a pathogen to which native bees are not immune. Invasions by imported fire ants are thought to have been responsible for the decimation of ground-nesting bees throughout much of the southern US in recent years.

In short, the plight of the honeybee is an issue to be taken seriously. The complexity of the problem demands research, particularly to the end of remedies. Scientists need to understand what is causing CCD in order to develop strategies with which to cope, but such research should not be used for the purposes of scapegoating, at least not until the picture is much clearer. The long-term effects of pollinator shortage could be potentially severe, even catastrophic in a worst-case scenario, as Einstein famously noted. For now, the consumer can expect, at the very least, continued rises in the prices of affected crops.

Links:

MAAREC – CCD Working Group

NPR – Bee Decline Threatens Farm Economy (Oct 2006)

University of Florida – CCD in Honeybees

Wikipedia – Colony Collapse Disorder

Der Spiegel – Are GM Crops Killing Bees?

Reclaiming Space – To Bee or Not to Bee

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7 Responses

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  1. Livette said, on 4/22/07 at 7:28 am

    Nice blog!

  2. opit said, on 4/23/07 at 2:20 am

    Nicely presented with much better than average research .

  3. Curtis said, on 4/23/07 at 2:17 pm

    Thank you. It’s an interesting (and somewhat frightening) topic, and one which grabbed my interest because of some politically charged and scientifically dubious press coverage. Cell phone signals may disrupt the navigational systems of bees under certain circumstances, granted; I doubt they are responsible for the profuse mite and/or protozoan infestations observed in many CCD cases.

  4. peoplesgeography said, on 4/26/07 at 11:04 am

    ’tis a mystery alright. Its currently 3am here and I’m drooping (that’s my excuse for lack of substantial comment) but wanted to say thanks for the great post on this important issue.

  5. Curtis said, on 4/26/07 at 8:20 pm

    No problem; and thank you for a thoughtful post as well. I was aware that the bee populations in question were in a general state of decline, but had no idea of the staggering acceleration observed in the past few years. It is certainly an important issue which could exert a huge impact in a relatively small timeframe. I must stop typing now before I erupt into a string of apiary puns—I too am drooping.

  6. Sativarg said, on 4/30/07 at 10:31 am

    RE: the possibility of a plant toxin
    (thank you for this article)

    Some of the evidence you have presented here leads me to believe that the problem may be an ornamental plant that attracts bees. This plant may well produce a toxin that is not dangerous at normal levels but when concentrated in a bee colony it reaches a threshold beyond witch it either kills bees or disrupts the their behavior in some way.

    Its what you said about “invasive species which would be expected to relish just such a find are not observed to rob the dead colony of its riches, or do so only hesitantly; this suggests to researchers that the colony has been rendered toxic in some way”. This leads me to believe that an agent of some sort is reaching a threshold in the hive. The bees may even develop a resistance to this agent to some extent.

    Many species of flowering plants do not rely on bees or even insects for pollination. And many new species of ornamental plant are hybridized and even mutated to achieve desirable characteristics. Couldn’t one or more of these or even a newly imported plant harbor a chemistry that might be toxic in some unexpected way to bees. By their very nature bees tent to concentrate environmental factors in their hives.

    The factor could even be binary in nature. Two biochemicals or one man made and one plant born substance combine in the hive to cause problems. I cringe to think of the permutations.

  7. Balkan said, on 5/20/07 at 3:14 pm

    Great post, really. Thank you.


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