Bt corn cleared in Honey Bee Colony Collapse Disorder
Bt corn cleared in Colony Collapse Disorder
- Galen P. Dively, American Farm (Maryland), web posted May 1, 2007, Via Agbioview
http://www.americanfarm.com
(See earlier GMO Pundits posts on this issue here)
Colony Collapse Disorder (CCD) has caused much concern among beekeepers nationwide and it is not clear to date what is causing the die-off. Genetically modified crops, specifically Bt corn, have been suggested as a potential cause of CCD. While this possibility has not been ruled out, the weight of evidence based on a multitude of studies argues strongly that the current use of Bt corn is not associated with CCD.
The hazard to bees due to any potential toxicant depends on toxicity and exposure. The endotoxins currently expressed in Bt corn (Cry1 types against caterpillars; Cry3 types against beetles) are not biologically active against hymenopteran insects such as the honey bee, nor do the CCD symptoms resemble those expected in Bt intoxicated organisms. Exposure is also very low because the expression of endotoxins in pollen is barely detectable in most Bt corn hybrids and corn does not produce nectar. For these reasons, bees are not commonly found foraging in corn fields. Some argue that the increase in bee loss has paralleled the increase in Bt corn in the United States; however, severe bee losses have occurred in Europe and in areas of Canada where Bt crops are not grown.
What do the scientific studies say about the issue? Numerous laboratory studies have examined the potential non-target effects of Bt corn on honey bees by feeding high doses of the pollen or purified endotoxin mixed with honey or sugar syrup directly to larvae in brood cells. This approach is a standard protocol for Tier I testing of non-target effects on bees and required by EPA before insect-resistant transgenic crops are approved for registration.
Published studies and other technical reports submitted to EPA have all shown no adverse acute effects. In particular, recent laboratory studies in New Zealand and Switzerland exposed bees by feeding on pollen treated with purified Cry1 endotoxins at doses considered well above the maximum environmental exposure levels encountered in the field. Results showed no negative effects on bee survival.
Laboratory feeding studies at the University of Maryland also showed no effects on the weight and survival of honey bees feeding on Cry1Ab-expressing sweet corn pollen for 35 days.
Potential sublethal effects of Bt corn on honey bees have also been addressed, but not as extensively as the acute effects. For newly-emerged bees, the presence of Bt proteins in ingested pollen may affect hypopharyngeal gland development and thus the ability of nurse bees to make brood food.
However, the same studies in New Zealand and Switzerland reported no effects of Bt pollen or endotoxin on hypopharyngeal gland development of newly-emerged bees.
Results of another recent study conducted in indoor flight cages showed no effects of Cry1Ab protein exposure on mortality, syrup consumption, or learning capacities of free-flying honey bees, but foraging activity was slightly reduced.
A two-year field study (soon to be published in the European bee journal Apidologie) conducted by this author and his graduate student represents the first attempt to expose functional colonies of honey bees to Bt corn pollen under open field conditions. In this Maryland study, colonies placed in Bt sweet corn plots were allowed to forage on corn pollen and also fed Bt pollen cakes for 28 days. The pollen cake consumption alone represented approximately 44 percent of the expected daily pollen requirements of each exposed hive.
Results showed no adverse effects on bee weight, foraging activity, colony bee strength and brood development.
Although there is no evidence thus far of any lethal or sub-lethal effects of the currently used Bt endotoxins on honey bees, insecticidal products expressed by other transgenes in crops may need extended field testing on a case-by-case basis to assess the longer term consequences of sub-lethal changes in colonies and subtle modifications in bee behavior.
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Galen P. Dively is an Extension Pest Management Specialist with the University of Maryland.
Labels: Environmental management, Risk management
posted by GMO Pundit @ 8:09 AM
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13 Comments:
I have just written a few articles about various aspects of the Honeybee crisis which you might find of interest – for example: http://insects.suite101.com/article.cfm/bee_crisis
They used to spray DDT on people and tell them it wasn't hurting them. They used to set of Nuclear Bombs and tell observers that it wouldn't hurt them.
I am saying it probably does hurt the bees. I would rather eat an apple with a worm or a piece of corn with a worm in it than have nothing to eat at all.
pixie
http://green-mamas.blogspot.com/
Walter Haefeker is a man who is used to painting grim scenarios. He sits on the board of directors of the German Beekeepers Association and is vice president of the European Professional Beekeepers AssociationThe problem, says Haefeker, has a number of causes, one being the varroa mite, introduced from Asia, and another is the widespread practice in agriculture of spraying wildflowers with herbicides and practicing monoculture. Another possible cause, according to Haefeker, is the controversial and growing use of genetic engineering in agriculture As far back as 2005, Haefeker ended an article he contributed to the journal Der Kritischer Agrarbericht (Critical Agricultural Report) with an Albert Einstein quote: "If the bee disappeared off the surface of the globe then man would only have four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man."
Mysterious events in recent months have suddenly made Einstein's apocalyptic vision seem all the more topical. For unknown reasons, bee populations throughout Germany are disappearing -- something that is so far only harming beekeepers. But the situation is different in the United States, where bees are dying in such dramatic numbers that the economic consequences could soon be dire. No one knows what is causing the bees to perish, but some experts believe that the large-scale use of genetically modified plants in the US could be a factor.
I did not write this artical it can be found at ...http://www.spiegel.de/international/world/0,1518,473166,00.html
couldn't even spell article write.
now I get right wrong ..need coffee
Pixie,
Nobody sprays DDT on cropland in the US and Europe, where the collapse disorder is occurring. So your point is pointless.
Laurence,
Albert Einstein was not, repeat, not a noted agronomist. Furthermore, there aren't enough engineered crops in Europe to make any comparison to North America, where 60-90 percent of all maize, soy, cotton and canola are engineered.
In fact, North America would have seen CCD about ten years before anyone else if the uninformed "GM crop" hypothesis were anywhere near the mark.
I live in Hawaii, the big island.
I have purchased a hive, and will obtain more, as my way of helping to sustain a healthy as of yet unaffected Euro Honeybee population. My land is isolated, in a valley. I wrote the Gov to advocate grants or funding to help others do the same, but no response. I will keep trying to increase our "clean" gene pool here in the middle of Pacific. Bunch of mentally challenged folks overlooking this major league crisis threat to life as we know it. We must do what is necessary with out their help. Jay
Sure, this clears DIRECT causation of GM corn with Colony Collapse Disorder...
But what about INDIRECT?
Some think that it may weaken the colonies enough to make them more susceptible to mites and other pathogens...
Also, corn isn't the only crop engineered to produce low levels of pesticide.
Soil Sterility and Pollution In Oregon, scientists found GM bacterium
(klebsiella planticola) meant to break down wood chips, corn stalks and lumber wastes to produce ethanol - with the post-process waste to be used as compost - rendered the soil sterile. It killed essential soil nutrients, robbing the soil of nitrogen and killed nitrogen capturing fungi. A similar result was found in 1997 with the GM bacteria Rhizobium melitoli. Professor Guenther Stotzky of
New York University conducted research showing the toxins that were lethal to Monarch butterfly are also released by the roots to produce soil pollution. The pollution was found to last up to 8 months with depressed microbial activity. An Oregon study showed that GM soil microbes in the lab killed wheat plants when added to the soil...
and that's the TIP of this iceberg- you are being lied to - see the movie about Monsanto (if you can find it because it keeps "disappearing"-
Monsanto has been poisoning the world since it's beginnings with saccharin - they are just duping you into giving them money-
those who control FOOD - control the WORLD- you are crazy if you believe a word they say-
vrfzxbmaI see your point- they are finding GM problems that are killing butterflies and the soil- so why not bees?This is not the Monsanto movie (I don't think) but a great one on GM foods-
http://v.mercola.com/blogs/public_blog/Alarming-Video-About-Contaminated-Food-Supply-33469.aspx
Pollen doesn't matter.
Bees also eat corn dust from cracked corn kernels.
Whoever wrote this article, I hope many your family members get autism. Then maybe you use your time to prevent autism, instead of using your time to defend the people who are responsible for the epidemic!
http://www.hulu.com/watch/67878/the-future-of-food
I don't know much about GMO but I did hear that GMO seeds were given to India farmers back in the 60's. I'm sure certain countries do not want to be guinea pigs but countries that are poor are offered these GMO seeds including the recent help from the United States to Africa.
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