CCD – Colony Collapse Disorder
While it still seems more prolific in the USA, colony collapse disorder or CCD is a problem in many countries worldwide. There does not appear to be a single factor which causes CCD making it impossible for beekeepers to manage, reduce or eradicate. The colony will just disappear from a hive with no warning and without leaving a dead colony behind in the hive as you would usually find if the bees has died of a known cause, they also often leave capped brood with stores of honey and pollen behind.
Feral honeybee colonies would have died naturally from time to time, however they would have swarmed and naturally reproduced too, maintaining a healthy wild population, however in recent years CCD in the USA is said to have virtually wiped out feral colonies. In particular, from 2006 onwards, beekeepers have been noticing a dramatic rise in absconding colonies. As yet nobody has come up with an answer to exactly why this happens or even where the bees go.
Possible Causes of CCD
Whilst the specific cause is not yet known, there are a number of factors, of which a combination are likely, these are in no particular order:
- PARASITES – It’s quite possible that parasites, most likely Varroa Destructor which are already known to weaken hives and spread other diseases, could be transporting an, as yet unknown virus. Or as this report indicates, a combination of 2 knows viruses contracted simultaneously could be a cause.
- BEEKEEPING METHODS – Although necessary for apiary management and honeybee health, the inspection of hives, treatment of already known diseases and manipulation of colonies all stress the bees to varying extents. Whilst undoubtedly not the sole cause this could be a contributing factor.
- INBREEDING – In many countries, particularly the USA where the higher levels of CCD have been experienced, the gene pool is quite limited due to intensive queen rearing by a number of major queen suppliers, this limited gene pool could weaken honeybees.
- MIGRATORY BEEKEEPING – In many countries hives are transported huge distances, in some cases thousands of miles to pollinate huge mono-crop areas, two factors here could contribute. Firstly the process of transportation causing stress, but also the limited diet the bees have whilst on a single crop.
- CLIMATE CHANGE – This impacts the seasonal flowering and species of forage in a given geographical area, many beekeepers believe this is disrupting the natural seasons for our honeybee populations and although not the single contributing factor, could have an impact.
- MOBILE PHONES – A story in the Telegraph last year claims that mobile phone signals are a culprit. Personally I doubt this as instances of CCD have been found in locations so remote that they are unlikely to have mobile masts in the area.
- GM CROPS – German researchers have noted a possible reduced resistance to Nosema in bees which forage on BT pollen (a toxin generated by GM corn). While there is no direct evidence of GM crops having a detrimental effect on the number of colonies affected by CCD, the two have only been around in significant numbers for a similar amount of time, therefore needs further investigation.
- ENVIRONMENTAL TOXINS – These are present in varying degrees where Colony Collapse Disorder has been experienced. Such a wide range of pollutants are found in the air and water sources, that bees undoubtedly absorb them to some degree.
- PESTICIDES – Whilst legislation is constantly tightening and products being banned from use, pesticides are widely used both domestically and commercially. There is particular attention on Neonictinoids (nicotine based pesticides) as their effect on other insects is similar to the Simpsons of colonies affected by CCD.
For a detailed analysis and figures on colony losses in recent years, the IBRA, International Bee Research Association, have a number of studies available on their website.
Hopefully the cause of Colony Collapse Disorder will be identified in the near future and I will be able to update this page accordingly.