Scientists remain baffled as to why bee populations are vanishing in North America. Should European beekeepers be worried about Colony Collapse Disorder?
By Nathan Johnson
Bee populations in some parts of the world are dying off in astonishing numbers. The phenomenon, known as Colony Collapse Disorder (CCD), is triggering widespread concern in both the scientific and agricultural communities; and while several theories have been put forward to explain a cause (or causes), it appears that no one is really certain why so many bees are flying away from the hive and never coming back. While there have been reports of some bee die-offs in parts of Europe, the problem appears to be most pronounced in North America, and the US in particular.
According to an article published in the UK's Independent on April 15, CCD has struck half of all US states, with the east and west coasts reporting bee population losses of 70 percent and 60 percent respectively. The article alleged that CCD has spread to continental Europe, and possibly to the UK. A CNN article appearing two weeks later claimed that CCD has spread to 27 US states, and reported "similar collapses" in Brazil and Canada.
With alarming frequency, hive inhabitants are suddenly disappearing, leaving behind them only queens, eggs and undeveloped workers. It is normally the case when a colony dies that a hive will be taken over by parasites, wildlife or other bees making a raid on the honey and pollen left behind. Not so with many of the CCD hives, it appears: Nothing is going anywhere near them.
And while most of the vanished bees seem to be dying singly in undetermined locations, consider the following episode described by an anonymous poster from California on a bee-related forum: "I recently witnessed a hive self-destructing. I saw 200 to 2,000 bees circling next to the intake of a new industrial-sized air conditioner in Burbank. The sun had become hidden by late-afternoon clouds. To me it looked as if the bees were lost: They thought they were near their hive, but they [weren't].
"The next day, janitors were sweeping up thousands of dead bees. I got down on my hands and knees with a paper cup afterward, and still managed to pick up about 50 to 200 bees that were left. Fewer than five showed any signs of life. They appeared to have starved from flying around in circles until they dropped."
Multiple suspects
In a quest to discover the cause of CCD — a one-time "phenomenon" that is now a serious concern — scientists and agricultural experts have built up a portfolio that includes a wide range of suspects: global warming, GM crops, parasitic mites (e.g. varroa), stress, pesticides, genome weakness, genetic mutation, unknown viruses or bacteria, or a lethal combination of any of the above. Another possible culprit, and the one identified in the Independent article, is radiation from increased mobile phone usage.
While there is yet far too little upon which to build an overwhelming case to identify the cause of CCD, it is worth noting that a paper on the electrical properties of insect hairs was published as early as 1929, and that it has been known for some time that the effects of electric charges on honeybees is especially pronounced. The most important research in this area has been carried out in Germany.
In a remarkable study published in 1976, Ulrich Warnke from the University of Saarbrucken wrote: "It is possible to record the arrival or departure of an individual bee, within a suitable distance of the hive entrance, by recording the change in the potential of the colony with a sufficiently sensitive instrument."
Warnke went on to demonstrate how bees and colonies are charged in relation to the weather (i.e. positively charged in fine weather, and mainly negatively charged during rainfall). He then demonstrated: "Before a thunderstorm breaks, the high relative humidity causes a discharge of bees on the ground, and a high bipolar concentration of atmospheric ions discharges bees in the air. During the discharge of lightning, very high variations in electric potential occur in the colony."
Warnke then turned to earlier studies to justify documented hyperactivity of bee colonies near high-tension electrical wires, and also to substantiate claims that a bee's ability to return to its home or hive varies according to the level of atmospheric disturbances (i.e. electromagnetic oscillations in the long-wavelength range). While admitting at the time that more experimentation was needed, Warnke posited: "If an electric charge is basically important for the orientation of insects, discharge would be followed by disorientation, and possibly aggressiveness."
The Independent article lacks enough hard evidence to support the claim that cell phones are to blame for CCD, and critics of theory point to the fact that cell phone penetration is much higher in Europe than in the US. However, the German findings of recent decades suggest that such claims should not be dismissed out of hand as ridiculous.
But what about other possible causes?
Cited in the aforementioned CNN piece, University of Illinois entomologist May Berenbaum said that scientists, having recently mapped the honeybee genome, discovered that the insect lacks the normal complement of genes to remove poisons from its system.
"Honeybees may be peculiarly vulnerable to disease and toxins," Berenbaum said, noting that "the fruit-fly or mosquito has twice the number of genes to fight toxins."
No place like home
Hoping to gain some Hungarian perspective, I paid a visit to Szentendre-based beekeeper Gusztav Adamis, who keeps around 40 families of honeybees in his spacious backyard.
Having kept bees for a little over a decade, Adamis makes and sells his own honey, but is not overly fearful that his livelihood is under imminent threat. "I think what is happening to bees in the US has more to do with monoculture farming [which is physically weakening the bees], harsh winter temperatures, and overwork," he said. "That's not so much the case with bees in Europe, or at least with bees in Hungary."
Adamis explained that most US bees are used for crop pollination, and are trucked across the country from one farm to the next. This, he claims, leaves the bees exhausted, disoriented and lacking the nutritional foundation of a cultivated, stable home environment. Not only does the honey produced in the hive deliver valuable nutrients that contribute to a bee's health and immune system, but good drinking water is another health benefit that Adamis' bees enjoy. The beekeeper showed me several 'watering holes' for his bees, into which he places special volcanic blocks that filter and add nutrients to the water.
Asked about the navigational abilities of the insect, Adamis told me that his bees can find their way back to the hive from distances of up to five kilometres, an enormous distance compared to a bee's body size. "But if they somehow go beyond that range, they die," he says, which goes someway toward explaining how it is possible that bees shipped for commercial pollination could eventually become disoriented.
Adamis said that the biggest threat to his hives, and to most commercial bee farmers, is the varroa mite. The varroa arrived a few decades ago from the Asian subcontinent and nearly wiped out European bee populations before an effective pesticide was introduced, which beekeepers are now able to use to keep damage to a minimum.
Alarm and optimism
Sharon Labchuck, a native of Canada's Prince Edward Island, is a part-time organic beekeeper and leader of the provincial wing of the Canadian Green Party. She wrote recently in a widely circulated email: "I'm on an organic beekeeping list of about 1,000 people, mostly Americans, and no one in the organic beekeeping world, including commercial beekeepers, is reporting colony collapse on this list. The problem with the big commercial guys is that they put pesticides in their hives to fumigate for varroa mites, and they feed antibiotics to the bees. They also haul the hives by truck all over the place to make more money with pollination services, which stresses the colonies."
If Labchuck and Adamis (who seem generally in agreement) are correct in their assessment of what is causing, or not causing, Colony Collapse Disorder, then maybe we can breathe easier for the world's bee population. Maybe the US die-offs can then be addressed effectively so that bees can grow back in robust numbers in the near future.
On the other hand, maybe there is something sinister afoot that science and agriculture can't yet properly identify, and maybe we should worry. The bee and nature have coexisted for some 50 million years, but the threat of bee colony extinction is a not-so-subtle reminder of our fragile connection to life on Earth.
