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Honey bees facing extinction

Posted by lahar9jhadav on April 12, 2007

bees

 

Honey bees in US facing extinction

Albert Einstein once predicted that if bees were to disappear, man would follow only a few years later.

That hypothesis could soon be put to the test, as a mysterious condition that has wiped half of the honey bee population the United States over the last 35 years appears to be repeating itself in Europe.

Experts are at a loss to explain the fall in honey bee populations in America, with fears of that a new disease, the effects of pollution or the increased use of pesticides could be to blame for “colony collapse disorder”. From 1971 to 2006 approximately one half of the US honey bee colonies have vanished.
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Now in Spain, hundreds of thousands of colonies have been lost and beekeepers in northern Croatia estimated that five million bees had died in just 48 hours this week. In Poland, the Swietokrzyskie beekeeper association has estimated that up to 40 per cent of bees were wiped out last year. Greece, Switzerland, Italy and Portugal have also reported heavy losses.

The depopulation of bees could have a huge impact on the environment, which is reliant on the insects for pollination. If taken to the extreme, crops, fodder – and therefore livestock – could die off if there are no pollinating insects left.

In France in 2004, the government banned the pesticide Fipronil after beekeepers in the south-west blamed it for huge losses of hives. The manufacturers denied their products were harmful to bees. Polish beekeeper associations claimed that the losses in their country could be connected to cheap sugar substitutes used in mass honey production.

However, experts at the largest honey bee health company in the world, Vita, based in Basingstoke, said the cause was still unknown, and therefore neither was the cure.

The company’s technical director, Dr Max Watkins, said: “If it turns out to be a disease we will probably find a cure. But if it turns out to be something different, like environmental pollution, then I do not know what can be done.

“At the moment, all we know is colonies are dying and we simply don’t know why. It could be a new disease or a combination of factors. And of course it could turn out what we are seeing here in Europe is different to what has been reported in America, although at the moment they look very, very similar.”

Dennis van Engelsdorp, of the Pennsylvania Department of Agriculture, said: “Preliminary work has identified several likely factors that could be causing or contributing to CCD. Among them are mites and associated diseases, some unknown pathogenic disease and pesticide contamination or poisoning.”

Initial studies of dying colonies in America revealed a large number of disease organisms present, with no one disease being identified as the culprit, van Engelsdorp added.

German bee expert Professor Joergen Tautz from Wurzburg University said: “Bees are vital to bio diversity. There are 130,000 plants for example for which bees are essential to pollination, from melons to pumpkins, raspberries and all kind of fruit trees – as well as animal fodder – like clover.

“Bees are more important than poultry in terms of human nutrition. Bees from one hive can visit a million flowers within a 400 square kilometre area in just one day.

“It is not a sudden problem, I has been happening for a few years now. Five years ago in Germany there were a million hives, now there are less than 800,000. If that continues there will eventually be no bees.”

“Bees are not only working for our welfare, they are also perfect indicators of the state of the environment. We should take note.”

By Michael Leidig in Vienna
Last Updated: 2:20am GMT 14/03/2007
(telegraph)By Michael Leidig in Vienna
Last Updated: 2:20am GMT 14/03/2007
(telegraph)

___________________________________________

Pests and Diseases

Honey Bee Colony Collapsing Disorder (CCD)

During the fall of 2006 to early 2007 a large number of honey bee colony deaths were reported across the continental United States. Investigations suggested that outbreaks of unexplained colony deaths have been ongoing for at least the last two years, i.e. beginning in 2004. Historical reports of similar colony losses are well documented in beekeeping literature, with similar outbreaks possibly occurring as long ago as 1896. The current phenomenon, without a predominant and singular recognizable cause has been cautiously termed “Colony Collapse Disorder” (CCD) and is not meant to suggest that colonies are dying due to a novel agent. Nevertheless colony losses are extreme in some cases such that it represents a significant threat to the pollination industry and the commercial production of honey in the United States.

Initial studies of dying bee colonies has revealed a large number of disease organisms present, with most being “stress related” diseases, but without any one disease as a singular causal agent of colony deaths. The magnitude of detected infectious organism in the adult bees may suggest some type of immunosuppressant or that colonies are overwhelmed by the multitude of pathogenic organisms. Case studies and questionnaires related to management practices and environmental factors have identified a few common factors shared by those beekeepers experiencing CCD. However, no common environmental agents or chemicals were identified by these surveys. The search for underlying causes has been narrowed by the preliminary studies, but key questions remain unanswered.

CCD symptoms and beekeeper actions on suspicion of CCD are outlined below.

1. In collapsed colonies (dead colonies):

1. The complete absence of adult bees in colonies with no or little build-up of dead bees in the colonies or in front of those colonies.
2. The presence of capped (sealed) brood in colonies
3. The presence of food stores both honey and bee bread (pollen)
1. Which is not robbed by other bees
2. When attacked by hive pests such as wax moth and small hive beetle, the attack is noticeably delayed.

2. In cases where the colony appears to be actively collapsing (dying):
1. An insufficient workforce to maintain the brood that is present.
2. The workforce seems to be made up of young adult bees.
3. The queen is present.
4. The cluster is reluctant to consume provided feed, such as sugar syrup and protein supplement


BREAKTHROUGH?

A UCSF researcher who found the SARS virus in 2003 and later won a MacArthur Foundation “genius grant” for his work thinks he has discovered a culprit in the alarming deaths of honeybees across the United States.

Tests of genetic material taken from a “collapsed colony” in Merced County point to a once-rare microbe that previously affected only Asian bees but might have evolved into a strain lethal to those in Europe and the United States, biochemist Joe DeRisi said Wednesday.

DeRisi said tests conducted on material from dead bees at his Mission Bay lab found genes of the single-celled, spore-producing parasite Nosema ceranae, which researchers in Spain have recently shown is capable of wiping out a beehive.

“It is wise to strike a conservative note, because this is early data, but it is interesting,” he said.

Government scientists who have been tracking the phenomenon they call Colony Collapse Disorder were skeptical, however, saying the parasite had been an early suspect in the bee die-off but that they had concluded it probably was not responsible.

With a mounting sense of urgency, agricultural scientists are trying to find out just what has caused the disappearance of as much as a quarter of the nation’s 2.4 million honeybee colonies since November, when the die-off was first observed by a Pennsylvania beekeeper.

It’s not just bad news for beekeepers and honey lovers. Growers of fruits, nuts and many vegetables rely on honeybees to pollinate their crops, which contribute $15 billion to the nation’s agricultural output, according to a Cornell University study.

DeRisi is a specialist in the rapid identification of killer germs. In March 2003, he played a key role in helping the federal Centers for Disease Control and Prevention identify the cause of SARS, or severe acute respiratory syndrome, the viral illness that claimed 774 lives and wreaked havoc for a time on the Asian economy.

Using a laboratory tool called a microarray — which can instantly match a sample to gene sequences from more than a thousand viruses — he found that SARS was caused by a previously unknown variant of coronavirus, a microbial family responsible for a variety of ailments including the common cold.

The following year, he was awarded a $500,000 MacArthur Fellowship, the prize given by the foundation to individuals who have no idea they were nominated until they win. The awards are popularly known as genius grants.

In researching the bee die-offs, DeRisi’s team evaluated samples of potential bee pathogens supplied by the Army’s biodefense laboratory, the Edgewood Chemical Biological Center at the Aberdeen Proving Ground in Maryland.

Scientists there had developed a technique to concentrate possible pathogens into a sample that could be run through a rapid genetic screen test such as DeRisi’s. Samples taken from dead bees in a collapsed colony from Le Grand (Merced County) were shipped via overnight mail to DeRisi’s San Francisco lab last week.

DeRisi used a technique that allows rapid reading of the genetic code of the suspect bug. It is the same approach, known as “shotgun sequencing,” that has been used to read the genomes, or the genetic code, of creatures ranging from bacteria to human beings.

The strips of genetic code are then matched to computerized libraries of known genes from thousands of germs. It was this test that pinpointed Nosema ceranae.

“The bees must have been loaded with this stuff,” said DeRisi, who collaborated in the experiment with Dr. Donald Ganem of the UCSF Department of Microbiology and Immunology.

Fueling the UCSF scientists’ interest in the parasite is a recent paper, published by the Journal of Invertebrate Pathology in January, in which a team of Spanish researchers infected hives of European honeybees with Nosema ceranae. Within eight days, the colonies were wiped out.

The federal government’s leading honeybee scientists, however, are not ready to conclude that DeRisi has found anything significant. Jeffery Pettis, research leader for the U.S. Agriculture Department’s Bee Research Laboratory in Beltsville, Md., said reports suggesting that this parasite has recently appeared in the United States are simply wrong. “There are historical samples from the mid-1990s,” he said.

Before then, the parasite was seldom seen outside Asia, where it favored a species of honeybee found only there. It did not cause colony collapse in Asia.

Now, Pettis said, tests have shown that Nosema ceranae has displaced a related strain that had been the dominant form of the parasite in the United States, Pettis said. However, large quantities of the microbe have been found in bee colonies that are healthy, as well as in those that have collapsed, he said.

Pettis said the parasite could simply be taking advantage of a newly developed weakness in the insects’ immune systems. “Mostly we think of Nosema as a stress disorder of honeybees,” he said.

It is possible that a more virulent strain of Nosema ceranae has evolved in the United States, but Pettis doubts it. “We can’t rule it out completely,” he said.

Evan Skowronski, senior team leader for biosciences at the Army lab and a friend of DeRisi’s, said that because the stake are high, every important lead in the search for the cause of the honeybee deaths needs to be pursued.

“We’re not ready to say this is it, but it is a pathogen of interest,” he said.

Skowronski said there is no reason to think that the cause of Colony Collapse Disorder is “anything other than Mother Nature.” However, he said that any natural threat to honeybees has major implications for the United States. “This needs a high level of attention,” he said.

DeRisi agreed that more tests will be needed to prove or disprove the parasite’s role in the disappearance of the bees.

“In our results, the control bees did not have it, and the sick ones were loaded with the stuff,” he said. “It is going to take a lot of time to figure out.”

E-mail Sabin Russell at srussell@sfchronicle.com.

This article appeared on page A – 1 of the San Francisco Chronicle

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