When beekeepers 'unwrapped' (removed winter insulation from) their hives this Spring, they found that, in many, all of the adult worker and virgin queen bees, and most of the young worker bees, had abandoned their principal queen (apparently still healthy), her eggs, larvae and pupae, and a small support team of young worker bees, and vanished. No sign of a battle with invading bees from another colony. No sign of a plague. No piles of corpses inside or outside the hive. There are two particularly unusual characteristics:

• The evacuations, we now know, tend to take place over six to seven days, far more quickly than has been noted in earlier instances of vanishing colonies
• Normally, when a bee colony is weak it is very quickly raided by parasites, wildlife and bees from other colonies. In these cases, raiders delay entering, even up to a week after the hive and queen have been left defenceless. It is as if the raiders are wary of some contamination or negative energy or defensive scent left by the departing bees, which gradually wears off

The phenomenon has been dubbed ‘colony collapse disorder’ (CCD) which, after apparently massively exaggerating the overall proportion of hives affected (see Ed.), the Media has portrayed as a human-caused environmental catastrophe and portent of doom for the human race. After all, they point out, ninety species of fruit and vegetables depend on honey bees for their pollination.

Although bee colony losses at levels seen this year have been reported sporadically since 1880, and although many of the alleged CCD cases may not have had the specific characteristics described above, it is nevertheless true that commercial beekeepers are faced with a problem that no-one can yet explain conclusively. It is also true, however, that, as the level of losses are not significantly higher than previously, the cause will probably turn out to be something within the beekeeping world, either alone or in conjunction with some new factor(s). According to the fundamental principle of Ockham's Razor, the simplest explanation is usually the most likely. Ivor Davis, president of the British Beekeepers Association, for instance, believes that CCD will eventually be traced to the mismanagement of one of two relatively new bee diseases, Varroa destructor mite and Nosema ceranae protozoa, but accepts that it is likely that there is probably some as yet unidentified bee immune system-stressing factor on top.

What's new for bees?
Farmed honey bees are, by the very fact of being hived and harvested, stressed creatures. What new stress or stresses could have been final straws which tipped their immune systems into chaotic behaviour (as in human auto-immune disorders and diseases like M.E.)? At present, the favourite candidates are new parasites, a new family of pesticides called neonicotinoids, GM crops and signals from mobile phone masts. Others have suggested more rarefied phenomena like sun spots and changes in the Earth's magnetic field.

New parasites
In nearly all cases of CCD, beekeepers have found evidence of multi-infection in every one of the few young worker bees remaining in the hive. Some had five or six infections and were also infested with fungus - a sign, experts say, that the insects’ immune systems had been suppressed. We do not yet know, however, whether they contracted the diseases before or after the mass evacuation, so this is not yet proof that parasite infestation caused the evacuations. We also still do not know, therefore, whether the departing bees were healthy or diseased.

A new pesticide
Pesticides have been reported to weaken and sometimes destroy bee colonies, but most cases have been through direct application, where a beekeeper has made a mistake or had an accident when treating a hive for pests. There have been very few reports of serious damage to a colony from indirect exposure of foraging bees exposed to, say, crop-spraying. The Institute for Science in Society points out, however, that a new family of insecticides, called neonicotinoids, was introduced in 1992 and grew steadily in popularity during the next ten years. It is highly toxic to bees and can confuse and disorientate them at very low exposures. France, for instance, blamed the huge fall in its bee population in the 1990s on the neonicotinoid imidacloprid (brand name Gaucho) and progressively (crop by crop) banned it between 1999 and 2005. France has not reported any cases of CCD in 2007.

Since 2000, French and Italian beekeepers have reported that imidacloprid appeared to have caused the decline of hive populations, even to the point of colony death, by affecting the bees’ orientation and ability to return to the hive. It has also been noted that bees inadvertently introduce significant amounts of midacloprid into the hive in the pollen they collect. This might eventually create an intolerable toxic load for the colony, necessitating departure.

To date, however, other than the French experience, no-one has demonstrated a strong correlation between the use of neonicotinoids and vanishing colonies, either in terms of geography or volume.

GM crops
Although the bio-pesticide toxins in GM crops, like Bt toxin Cry1Ab, can harm bees, change their behaviour, and even kill them in certain situations, evidence of a direct link between GM crops and CCD is weak. Firstly, most of the damage noted occurred when bees had been deliberately exposed to concentrations never found in growing plants. Secondly, CCD has occurred in countries, like Switzerland, which have never conducted GM crop trials, let alone commercial GM planting.

There is, however, an indirect link in that most GM seed is ‘dressed’ with neonicotinoid pesticides (see above) and fields used for GM trials and commercial planting are routinely surrounded by a buffer zone drenched in neonicotinoids to protect conventional and organic crops growing nearby. This might explain the report from a former agronomist that one trial of GM crops in the Netherlands quickly led to colony collapse within 100 metres.

Mobile phone masts
Some suspect a link between the growing number of mobile phone masts and CCD. The supposition is that healthy bees went out to forage for pollen, became disoriented by mobile phone signals, got lost and died. Supporters of this hypothesis argue that:

• bees use the magnetic field of the Earth as (at least part of) their navigation system
• both the number and spread of mobile phone masts and mobile phone calls are increasing rapidly and have already been observed to disorient some species of bird by obscuring the Earth's magnetic field
• it has been established that bees (a) can detect and (b) do not like mobile phone signals
• a new, more aggressive form of mobile phone signal called 3G (third generation) was introduced 2001-2003, just before the time reports of vanishing bees in the US began to increase
• there is some suggestion that CCD has tended to occur near heavily-populated areas, where there are more masts and more signals
• some beekeepers have reported that changes in bee behaviour, including CCD, only began when a mast was installed nearby. The critical distance appears to be around 300 metres. According to one beekeeper, his bee colonies also became more prone to various diseases

There are as many strong reasons to challenge this hypothesis:

• Most of the cases of CCD occurred during the winter months, when masses of bees do not leave the hive foraging for honey. It seems more as if a hive became contaminated or infested during this period of low activity, forcing an emergency evacuation
• It supposes that the bees which left the hive intended to return but, disoriented by mobile phone signals, got lost and died. Apparently, however, the mass departures seen in CCD did not occur on one day, but across six to seven days. Bees are intelligent animals which work cooperatively. Would they have not noticed the non-return of (e.g.) a seventh of their colony? Would they have continued in some lemming-like fashion to let a further seventh out to forage, day by day, until the colony collapsed completely?
• It is more likely that the departing bees were diseased and left the hive to die. The very few corpses found just outside the hives have been in a terrible state, suggesting immune system collapse. But that itself raises another question. Why is there not more evidence of mass bee death either near the hive or further afield?
• There are cases of mass evacuations by a healthy colony looking for better accommodation but (i) these are very rare and (ii) if the principal queen bee is healthy, as she appears to be in CCD, the colony takes her, her eggs, larvae and pupae with it
• Contamination of the hive by raised levels of mobile phone signals is, of course, a good reason for evacuation but, again, why leave a healthy principal queen, etc. behind?
• Bees' principal method of navigation is now thought to be a combination of (i) building up a long-term memory of the sun's position vis-à-vis the hive at any time of year, which the bees can use even when the sky is completely obscured by cloud for long periods, and (ii) by recording images of natural features during their travels. Many experts hold that bees only turn to the Earth’s magnetic field, amongst other things, when the bees’ memory of sun positions and journey images no longer suffice
• There have been no reports of CCD from France or Belgium or, for that matter, from dozens of other countries around the world which operate 3G mobile telephone networks. Do these countries' 3G networks operate at lower strengths or different frequencies?
• CCD has occurred in some hives near 3G phone masts, but not in others. Are some colonies more tolerant of mobile phone signals than others? Does it depend on the hive's precise position in relation to the mast? There are certainly places around a mast where signals are stronger or weaker

Beekeeping practices
Could the style of beekeeping - chemical or organic - be the key? Chemically-maintained bee colonies are:

• regularly sprayed with pesticides to protect them against parasites like Wax moths and Varroa destructor mites
• regularly sprayed with antibiotics to prevent disease
• frequently uprooted and taken hundreds of miles to crops needing pollination
• fed high fructose corn syrup (linked to obesity and hormonal changes in humans) or other cheap refined sugars to trick them into believing that Spring and pollen have arrived, triggering early foraging

None of these extremely bee-stressing activities occur in organic beekeeping. According to organic beekeeper Sharon Labchuk, not a single member of a 1,000-strong (mainly American) organic beekeepers’ mailing list has reported CCD. She also reports that no cases of CCD have been found in wild bee colonies.

Bees a l'americaine
Why have most of the reports of CCD come from the US, and from the northern states at that? The most likely explanation is that, in the US, most commercial colonies are not allowed a period of low activity during the Winter months, but shipped down South to help with pollination in States like Florida and California. The bee colonies shipped from the northeastern states travel some of the greatest distances. One example is the pollination of California's almond crop, which takes place in February, and to which literally millions of hives are moved from all over the US and even Canada.

Changes in the Earth's magnetic field and sun spots
The Earth's magnetic field waxes and wanes. There is geological evidence that, when at its weakest, the North and South Poles can even flip over. Some believe that a flip has already begun and that bees may be disoriented by disturbances in the field at this critical time

There is also some evidence that bees are sensitive to quantum-sized electromagnetic effects and even to 'quarks', the predicted but never seen (by humans) quantum-sized particles. Both of these are disturbed before and during sun spot activity. Significant bee disappearances were reported across the southern United States 50 years ago, when geomagnetic events preceded the most active sun spot activity ever recorded. Scientists are predicting that even greater sun spot activity will occur in 2010

The problem with these hypotheses is that:

• disturbances in the Earth's magnetic field due to sun spot activity go in 5½ and 11 year cycles. No such cycles for bee disappearances have been noted
• again, bees are thought to turn to the Earth’s magnetic field, amongst other things, to navigate only when their memory of sun position and journey images no longer suffice

Ed.- (i) American bloggers provide the following information [1] Make of it what you will ...

• Last winter, between 25% and 40% of hived bee colonies in the US perished
• Around a quarter of the colonies which perished seemed to display CCD-like characteristics, meaning that CCD may have taken out 6-10% of hived colonies in the US, not the 30-90% reported in much of the media
• In the US, last winter was unusually warm. Bees were in Spring mode, laying eggs and raising young, at Christmas. Then there was a cold snap for three weeks in February. Could unusual weather have caused unusually high bee colony Winter death rates (10-15% in recent years)?
• Far greater losses of colonies (around a million - 40%) occurred when the first tracheal mites hit North American bee colonies in Winter 1984/1985 and again in Winter 2005/06 after the Varroa destructor mite had developed resistance to the available pesticides

(ii) Back in the 1920s, Rudolf Steiner predicted that the artificial breeding of bees would gradually weaken the species and result in a dramatic die-off in the next 70-100 years!