In recent years, massive and unsustainable losses of Honey Bee hives ("Colony Collapse Disorder" or CCD) have been widely reported by bee keepers in many parts of the world, especially America, but also Britain and Europe. The bees seem to just leave the hive and never return. The complete collapse of the Honey Bee industry within a few years has been widely predicted in the media with major knock-on affects for world agriculture.
Although we tend to think of the bee hives in terms of honey production, this is now an almost insignificant part of the business worldwide. The major part is pollenation services to commercial growers, especially in America. Numerous truckloads of hives of bees are trucked around America to pollenate their vast monoculture orchards; hundreds of hives are required for each farm. This has lead to predictions of massive crop failures in future years.
Causes of CCD: there have been many theories advanced to explain CD - many by special interest groups with an axe to grind. Few of the theories stand up to scrutiny.
| 1. Mobile phone signals. | Hives are doing better in cities than in the countryside - the opposite of what would be expected if mobile phone masts were implicated. The idea that radio signals interfere with bee navigation is a false analogy - bees don’t use radio for navigation - and the fact that they die away from the hive, although suggesting a break-down in navigation ability, could equally well be explained by the known behaviour of sick bees deserting their hive. |
| 2. Intensive management of hives. | Shipping truckloads of hives for thousands of miles is mainly an American phenomenon and has been going on for many years. If this was causing the problem it would be restricted to hives managed in such a way and would have shown up years ago. |
| 3. Loss of wildflowers from the countryside. | This is undoubtedly one of the major causes of falls in pollenator populations generally, especially of wild bees, and has consequently increased the reliance on Honey Bees for crop pollenation. However America has far larger monocultures and flowerless agri-deserts then Britain and CCD has only reached them recently, so this isn’t the cause (although loss of wildflowers is a major factor in the need for America’s pollenation services industry - no doubt they just see it as a "business opportunity"!) |
| 4. Climate change. | Climate change is said to be leading to warmer winters and wetter summers in the UK. Undoubtedly this will affect wildlife, flowers and bees, but in the long term - current changes are much less than the year-to-year variation that we’re so used to. Nevertheless, we now have far fewer frosts in southern England and some species have become more widespread in recent years. This could also happen to bee parasites. However, Climate Change effectively gives each area the climate it would previously have had if it had been a few hundred miles further south. Bees thrive over a wide range of latitudes so it’s hard to see how subjecting them to a more southerly climate would have such catastrophic consequences. |
| 5. Subtle effects of some new pesticide. | This is a plausible hypothesis, given that new products are introduced more or less concurrently worldwide but would need a lot more research to substantiate. |
| 6. Anti-Verroa chemicals. | Both the Verroa mite and CCD have arrived on the scene fairly recently, and Australia is so far free of both, suggesting a causal connection. Various chemicals have been used to control the spread of Verroa, but, like many mites, it is very resistant to attempts to control it and continues to spread. It’s possible that one of these chemicals has a subtle effect on the insects which later leads to colony collapse, but surely it would have been identified by now if it was so simple. |
| 7. Virus load transmitted by Verroa mites. | This is the most likely cause of the problem, but the evidence is mostly circumstantial. Unfortunately the victims die far away from the hive and are never found so can’t be analysed. Virus detection and identification is a highly technical field, and well beyond even the most scientifically-minded amateur beekeeper. | Further work needs serious research money. Fortunately bee decline is finally attracting proper funding so we might see some answers. |
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BioInfo (www.bioinfo.org.uk)