Einstein once said “if bees disappear from the surface of the Earth, man would have no more than 4 years to live.”
Colony Collapse Disorder (CCD) or honey bee depopulation syndrome (HBDS) is a phenomenon in which worker bees from a beehive or honey bee colony abruptly disappear. The term colony collapse disorder was first applied to a drastic rise in the number of disappearances of Western honey bee colonies in North America in late 2006. European beekeepers observed similar phenomena in Belgium, France, the Netherlands, Greece, Italy, Portugal, and Spain, and initial reports have also come in from Switzerland and Germany, albeit to a lesser degree while the Northern Ireland Assembly received reports of a decline greater than 50% Possible cases of CCD have also been reported in Taiwan since April 2007. The cause or causes of the syndrome are not yet fully understood, although many authorities attribute the problem to biotic factors, environmental change or modern use of equipments. Their descriptions are given below:-
Malnutrition
Some researchers state that colony collapse disorder is mainly a problem of feeding the bees a monoculture diet when they should receive food from a variety of sources/plants. In winter the bees are given single foods source such as corn syrup (high-fructose or other), sugar and pollen substitute. In summer they may only pollinate a single crop (e.g., almonds, cherries, or apples).
A study published in 2010 found that bees that were fed pollen from a variety of different plant species showed signs of having a healthier immune system than those eating pollen from a single species. Bees fed pollen from five species had higher levels of glucose oxidase than bees fed pollen from one species, even if the pollen had a higher protein content. The authors hypothesized that CCD may be linked to a loss of plant diversity.
Insect diseases (Pathogens & Immunodeficiency)
Researchers initially suggested a connection between Varroa destructor mite infestation and CCD, suggesting that a combination of these bee mites, deformed wing virus (which the mites transmit) and bacteria work together to suppress immunity and may be one cause of CCD. This research group is reported to be focusing on a search for possible viral, bacterial, or fungal pathogens which may be involved. According to a 2007 article, the mites Varroa destructor remain the world's most destructive honey bee killer due in part to the viruses they carry. Dr. Enesto Guzman, an entomological researcher at the University of Guelph in Canada, studied 413 Ontario bee colonies in 2007-08. About 27% of hives did not survive the winter, and the Varroa mite was identified as the cause in 85% of the cases.
When a colony is dying, for whatever cause, and there are other healthy colonies nearby (as is typical in a bee yard), those healthy colonies often enter the dying colony and rob its provisions for their own use. If the dying colony's provisions were contaminated (by natural or man-made toxins), the resulting pattern (of healthy colonies becoming sick when in proximity to a dying colony) might suggest to an observer that a contagious disease is involved.
Climate Change
A few scientists have suggested that climate change can make bee hives more vulnerable to CCD, although it is not implicated as a direct cause of the disorder. "We see plants blooming at different times of the year", says amateur beekeeper Wayne Esaias, a researcher at the NASA Goddard Space Flight Center, "and that's why the nectar flows are so much earlier now. I need to underscore that I have no evidence that global warming is a key player in colony collapse disorder. But it might be a contributor, and changes like this might be upping the stress level of our bee populations".
Electromagnetic Radiation
One of the few peer-reviewed studies was published in 1981by Gary and Westerdahl. This study was conducted as part of a research program to assess possible environmental impacts of solar power satellite systems, which would beam immense amounts of microwave energy from satellites to receiving stations on the ground to be converted into electrical power. The investigators measured flight, orientation, and memory functions in honey bees after thirty minutes' exposure to 2.45-GHz continuous-wave microwaves at power densities from 30 to 500 watts per square meter - similar in frequency to that used by mobile phone networks but at far higher power densities than produced at nearly all locations from base station antennas except very close to the antennas. The investigators found "no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with solar power satellite ground-based microwave receiving stations". This issue (of effect of microwave energy on honey bees) has reappeared in context of the present controversy about possible health risks of wireless communications systems. However, no studies have appeared that have an adequate experimental design and exposure assessment to allow reliable conclusions to be drawn.
In April 2007, news of a study conducted by investigators at University of Landau appeared in various media outlets, beginning with an article in The Independent, which stated that the subject of the study included mobile phones and had related them to CCD. Though Cellular phones were implicated by other media reports at the time, they were not covered in the 2007 study. Researchers involved with the 2007 study have since stated that their research did not include findings on cell phones, or their relationship to CCD, and indicated that the Independent article had misinterpreted their results and created "a horror story".
(Source-Wikipedia)
-Sailesh Bataju
B.Sc 1st year
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