The recent boom in third generation mobile phones may be the main culprit for colony collapse disorder in honeybees. Dr. Mae-Wan Ho
Bees worldwide have been involved in a disappearing act called “colony collapse disorder” over the past two years  (Mystery of Disappearing Honeybees, this series), with little sign of the disease or infestations that have resulted in massive loss of colonies in the past. The bees simply leave the hives and fail to return. Beekeepers and scientists alike are stymied as to the cause of this strange phenomenon.
One likely culprit is a new class of systemic pesticides, which are not only sprayed on crops, but also used universally to dress seeds in conventional agriculture, and can confuse and disorientate bees at very low concentrations  (Requiem for the Honeybee, this series). Another candidate is radiation from mobile phone base stations that has become nearly ubiquitous in Europe and North America where the bees are vanishing; this possibility is considerably strengthened by preliminary findings that bees fail to return to the hives if cordless phone base stations are placed in them.
Researchers at Landau University in Germany designed a simple experiment for students on the Environmental Science course . Eight mini-hives, each with approximately 8 000 bees were set up for the experiment. Four of them were equipped with a DECT (Digital Enhanced Cordless Telecommunication)-station at the bottom of the hive, and the other four without the DECT-station served as controls.
At the entrance of each hive, a transparent plastic tube enabled the experimenters to watch the marked bees entering and leaving the hive, so they can be counted and their time of return after release recorded for a period of 45 minutes.
The experimenters also studied building behaviour by measuring the area of the honeycomb and its weight.
In the course of the experiment, three colonies exposed to mobile phone radiation and one non-exposed control colony broke down. The total weights of the honeycombs in all colonies, including those at the time of breakdown were compared. The controls weighed 1 326g, while those exposed to the DECT-stations weighed only 1 045g, a difference of 21 percent. The total area of the honeycomb in the controls was 2 500, compared to just 2050 in the exposed hives.
But it was the number of returning bees and their returning times that were vastly different. For two control hives, 16 out of 25 bees returned in 45 minutes. For the two microwave-exposed hives, however, no bees at all returned to one hive, and only six returned to the other.
These dramatic results are of a preliminary nature, but one should bear in mind that the DECT-station is a simple cordless phone base, widely used in homes and offices.
It emits microwave radiation of about 1 900 MHz continuously, which is frequency modulated at 100 Hz. The average power is 10 mW, with a peak of 250 mW. It represents the exposure levels of perhaps tens of millions worldwide living near mobile phone base stations, or have cordless phones in their homes or offices.
The same scientists had carried out an earlier experiment with the cordless phone base on a standby mode, in which the average power is 2.5 mW, and that appeared to have had no effect on the bees [4, 5].
Clearly the present findings need to be taken much further, but their significance should not be downplayed for a number of reasons. The findings are compatible with evidence accumulating from investigations on many other species including humans, showing that mobile phone radiation is associated with a range of health hazards including cancers  (Drowning in a Sea of Microwaves, SiS 34). Furthermore, bees are known to be extremely sensitive to magnetic and electromagnetic fields, and there have been many suggestions that they could be used as an indicator species for electromagnetic pollution.
Experiments dating well back to the last century have documented the phenomenal sensitivity of honeybees to electromagnetic fields. Bees use the earth’s magnetic field to navigate. Free-flying honeybees are able to detect static intensity fluctuations as weak as 26 nT against the background earth-strength magnetic field (average 500 mT) . This has been demonstrated in experiments where individual honeybees have been trained to discriminate between the presence and the absence of a small static magnetic anomaly in the lab. Honeybees can also learn to distinguish between two 360o panoramic patterns that are identical except for the compass orientation. In this case, the difference was a 90o rotation about the vertical axis . The most powerful cue to direction for the honeybee comes from the sky, but discrimination between patterns is possible in the absence of celestial information, as when the sky is overcast. Under those conditions, bees can use a magnetic direction to discriminate between patterns.
The bees’ waggle dance on the honeycomb, which tells hive mates where to find food, can also be misdirected by anomalies in the earth’s magnetic field or very weak pulsed magnetic fields at about 250 MHz applied in the correct direction . Bees can even learn to detect very low levels of extremely low frequency alternating electromagnetic fields .
But mobile phones have been around for close to 20 years, so why now? There has been a recent change in cell phone technology that coincides with the current crisis. At the beginning of the present century, 3G (third generation) mobile phone systems became publicly available, leading to a surge in popularity of mobile phones, and many more phone towers . Bees are disappearing in North America, Europe and also Australia, wherever mobile phones are greatly in use. Stay tuned.
Article first published 25/04/07
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