Posted on 07/19/2007 7:04:28 AM PDT by skimbell
MADRID - A parasite common in Asian bees has spread to Europe and the Americas and is behind the mass disappearance of honeybees in many countries, says a Spanish scientist who has been studying the phenomenon for years.
The culprit is a microscopic parasite called nosema ceranae said Mariano Higes, who leads a team of researchers at a government-funded apiculture centre in Guadalajara, the province east of Madrid that is the heartland of Spain's honey industry. He and his colleagues have analysed thousands of samples from stricken hives in many countries.
"We started in 2000 with the hypothesis that it was pesticides, but soon ruled it out," he told Reuters in an interview on Wednesday.
Pesticide traces were present only in a tiny proportion of samples and bee colonies were also dying in areas many miles from cultivated land, he said.
They then ruled out the varroa mite, which is easy to see and which was not present in most of the affected hives.
For a long time Higes and his colleagues thought a parasite called nosema apis, common in wet weather, was killing the bees.
"We saw the spores, but the symptoms were very different and it was happening in dry weather too."
Then he decided to sequence the parasite's DNA and discovered it was an Asian variant, nosema ceranae. Asian honeybees are less vulnerable to it, but it can kill European bees in a matter of days in laboratory conditions.
"Nosema ceranae is far more dangerous and lives in heat and cold. A hive can become infected in two months and the whole colony can collapse in six to 18 months," said Higes, whose team has published a number of papers on the subject.
"We've no doubt at all it's nosema ceranae and we think 50 percent of Spanish hives are infected," he said.
Spain, with 2.3 million hives, is home to a quarter of the European Union's bees.
His team have also identified this parasite in bees from Austria, Slovenia and other parts of Eastern Europe and assume it has invaded from Asia over a number of years.
Now it seems to have crossed the Atlantic and is present in Canada and Argentina, he said. The Spanish researchers have not tested samples from the United States, where bees have also gone missing.
Treatment for nosema ceranae is effective and cheap -- 1 euro (US$1.4) a hive twice a year -- but beekeepers first have to be convinced the parasite is the problem.
Another theory points a finger at mobile phone aerials, but Higes notes bees use the angle of the sun to navigate and not electromagnetic frequencies.
Other elements, such as drought or misapplied treatments, may play a part in lowering bees' resistance, but Higes is convinced the Asian parasite is the chief assassin.
Story by Julia Hayley
REUTERS NEWS SERVICE
As much as I don’t like some bees, I admit to being concerned for the honeybees. Understanding what is causing the loss of beehives is a huge step, especially since it appears that there is already a remedy for it. Good work!
Gotta find some other animals that cell phones are killing.
Cell phones bad at any cost.
I'd say this is good news. Let's see what happens. Their life is so short so we should be able to "revive a hive" in a short time.
Global Parasite’s Killing West - Scientist
Fixed it.
I hope this is the answer, as it looks like they can kill the culprit. Honeybees are essential for so many crops...it would devastate our food supply if they all died out. I rather like the little critters.
"...Treatment for nosema ceranae is effective and cheap -- 1 euro (US$1.4) a hive twice a year..."
It'll take congress at least a month to get this up to $1 million per hive.
For our congress, No problem can be solved for $1.40 a hit.
But, of course, we know the real reason for the collapse of beehives is global warming, cell phones, pesticices, GM crops and KKKarl Rove.
OK, maybe it's not the catchiest slogan.
Good News Bump!
So much for blaming genetically modified crops.
This guy is wrong and it will be quickly proven that he is.
Surely you know that you are off base on this. Resistance to pests in genetically engineered crops comes from finding genes in other plants that are resistant, not from pesticides.
Why? Because you need so badly to be right? I accept your idea as a possible alternative, but that foam around your mouth makes you seem a bit strident, my friend.
Emma Patten Reuters Health News January 31, 2001
NEW YORK - A soil bacterium that causes lumpy tumors on plants may be able to 'jump kingdoms' and insert its tumor-causing DNA into human cells, new research findings suggest. The bacterium, called Agrobacterium tumefaciens, contains a small piece of DNA that can insert itself into the DNA of a host cell and initiate a tumor. Agrobacterium is already known to cause plant tumors, but researchers wanted to test whether the bacterium could similarly insert its DNA into human cells.
Dr. Vitaly Citovsky from the State University of New York, Stony Brook, and colleagues found that the plant bacterium was able to attach to human cells and insert its DNA into human cells just as it does with plant cells. Whether Agrobacterium is dangerous to humans is unclear, however. "Here (insertion of DNA into) human cells has been observed in laboratory conditions; whether it may be relevant biologically in nature remains unknown," the researchers note in the current early edition of the Proceedings of the National Academy of Sciences.
"Our experiments were done under laboratory conditions," Citovsky told Reuters Health. "In nature, I do not believe Agrobacterium represents a danger. However, for people who work with large concentrations of this bacterium, for example researchers or certain agricultural workers who deal with heavily infected plants, it may be prudent to be careful or at least aware,'' he said.
One implication of this study, said Citovsky, is the potential for genetic flow between bacteria and animals. Another implication is that the basic biochemical and cellular reactions involved in the Agrobacterium-plant cell interaction probably exist in the animal kingdom as well.
"Presently, it appears that Agrobacterium is the only example of trans-kingdom DNA transfer," Citovsky said. "I do not rule out other possibilities but there are no data. Of course, what can be done once, can almost always be done again," he added.
SOURCE: Proceedings of the National Academy of Sciences Early Edition
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Until quite recently, the genetic engineering community has assumed that Agrobacterium does not infect animal cells, and certainly would not transfer genes into them. But this has been proved wrong.
A paper published earlier this year reports that T-DNA can be transferred to the chromosomes of human cancer cells [1]. In fact, Agrobacterium attaches to and genetically transforms several types of human cells. The researchers found that in stably transformed HeLa cells, the integration event occurred at the right border of the Ti plasmid's T-DNA, exactly as would happen when it is being transferred into a plant cell genome. This suggests that Agrobacterium transforms human cells by a mechanism similar to that which it uses for transformation of plants cells.
See http://depts.washington.edu/agro/ http://www.ca.uky.edu/entomology/entfacts/ef130.asp
I’m told that the usual treatment for nosema in America has not had satisfactory results. Perhaps the Nosema ceranae has developed some resistance to the treatment.
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