Bijensterfte, oorzaken en gevolgen

Ezine, 26 March 2009

These comments, submitted by the National Honey Bee Advisory Board to EPA concerning the registration of imidacloprid, a systemic pesticide produced by Bayer Chemical Company, have been edited here because of length. But the stories have not been changed or altered. The NHBAB consists of beekeepers from both the AHPA and the ABF, and represents most of the nation’s commercial beekeepers. EPA now must act on these and other comments regarding this compound. At the same time, this group of beekeepers and Bayer are meeting to discuss continued research with this compound. Time will tell if increased regulation, or more precise research improve the situation.

Beekeepers from around the United States, and around the world, have had persistent problems associated with the use of the systemic pesticide imidacloprid. Since the first uses of imidacloprid in France in 1994 on sunflowers beekeepers reported problems. Soon the condition was given a name in France: “mad bee disease.” Problems reported by beekeepers, combined with mounting independent scientific data, caused the French Minister of Agriculture to suspend the use of imidacloprid on sunflowers in January of 1999. In February 2004, France extended the suspension to include uses on corn. At the same time they further broadened the ban on systemic insecticides to include the chemical fipronil.

In Europe the debate goes on, important data from toxicity studies is being produced. Conclusions from this data vary. The chemical manufacturers continue to maintain that the systemic compound imidacloprid is safe for use around honeybees, native pollinators, birds, and does not pose an unreasonable risk to the environment. Reports from the field, however, are telling a different story. The recent dramatic increase in use of imidacloprid on a greatly expanded list of cropland, rangeland, forest, residential, and recreational (golf courses and parks), has greatly increased exposure of pollinators to contaminated nectar and pollen expressed from flowering crops and weeds.

Imidacloprid is only one of six product formulations in the broader class of “systemic neonicotinoids.” Although only imidacloprid is currently ‘up’ for public comment, all six of these products in this class are of great concern to beekeepers. Much attention has been given to the seed treatments such as Gaucho, a trade name for a formulation of imidacloprid.

Recent data from Penn State on crabapple trees, although unpublished, and not yet replicated is extremely concerning. Two controls, and two treated trees were used in the experiment. After three weeks no imidacloprid was detected. However the next spring pollen samples from pollen sacs and anthers tested over 900 ppb combined Imidacloprid and 2 principal degradants: 5- hydroxe and olefin. In nectaries the combined number was 1,450 ppb. Although further research is required for this study to be properly concluded, the initial data raises questions about how imidacloprid is stored and translocated in woody plants, like fruit trees.

Farmers, pesticide applicators, and beekeepers all look to EPA to provide guidance on safe and unsafe ways to apply these economic poisons. We will quote the public comment of Roger Haldenby (Plains Cotton Growers, Inc. tracking number 808bfe56, February 23, 2009) on Imidacloprid: “There are reports of imidacloprid toxicity to bees, birds, earthworms, and some fresh water crustaceans. The impact of imidacloprid on these organisms can be mitigated by proper application of the insecticide in accordance with label instructions.”

Systemic pesticides, like imidacloprid, work on a different principal. The chemical is taken up into the plant tissue, and becomes systemic. Active chemical is moved throughout the plant including the nectar and pollen of the treated crop plant, or inadvertently treated weed. Once the chemical is in the nectar and pollen of the plant, no protective means can be employed to protect the pollinator who gathers the poisoned food. There is no “label warning” currently to protect pollinators from imidacloprid tainted nectar and pollen. EPA does not have “safe label” instructions for imidacloprid.

In an advertisement for Premise 200SC, an imidacloprid product for termite control, Bayer states, “Premise 200SC interferes with (the) instinctive social behavior (of termites), contributing to the termites’ demise. Low doses of Premise 200 SC disorientate the termites and cause them to cease their natural grooming behavior. Grooming is important for termites to protect them against pathogenic soil fungi. When termites stop grooming, the naturally occurring fungi in the soil attack and kill termites. Premise 200SC makes fungi 10,000 times more dangerous to termites. Nature assists Premis in giving unsurpassed control.” (Bayer Premise SC Brochure)

Major incidents have been reported by beekeepers linked to imidacloprid. EPA is aware that their incident reporting database of pesticide effects on honeybees is not working. At the December 2, 2008 meeting between US EPA Office of Pesticide Programs and Beekeepers, the beekeepers explained how the incident reporting system, which utilizes state departments of agriculture and chemical manufacturing companies, is not reporting beekeeper field incidents with pesticides. The beekeepers at the meeting presented a wall chart showing all incidents reported to EPA and then detailed how their own personal incidents, as well as incidents of colleagues not there. Providing a mechanism for reporting bee incidents was one of the eight “action items” listed as coming out of that meeting.

Recognizing that EPA is not aware of beekeeper incidents related to pesticides, we would like to provide you with a partial list of our own. Many beekeepers will be reporting their individual incidents independently. The list below by no means should be considered as complete; it only attempts to showcase a few of the most prominent incidents. Many commercial beekeepers have had problems related to the use of imidacloprid.

The largest incident involved seven beekeepers in North Dakota and Minnesota with Gaucho, a product formulation of Imidacloprid seed treatment on canola. The seven beekeepers initiated legal action against Bayer Crop Science in Federal Court. Private laboratory tests performed on the beekeepers’ wax comb and honey in barrels. “ADPEN analyzed the material for imidacloprid, carbofuran, dichlotvos and coumaphos. They found residues of imidacloprid in all of the samples. The levels of imidacloprid found ranged from 22 to 671 ppb. These levels are much higher than the LD50 and are certainly killing honeybees and causing sub lethal effects” (Mayer sworn and notarized DOC dated 12th January 2007). Chris Charles explained that placing these boxes on top of his hives would cause an immediate die off of the field bees. Concerns about this lethal mix in his wax combs caused him to replace his entire comb with new. He observed that his bees recovered after being given new fresh wax.

Clint Walker relates his experience with imidacloprid and cotton in Texas. “In the summer of 2006 we shipped 500 bee hives to the cotton fields of West Texas. It was a drought year where the only green plants were under irrigation. During the active bloom phase of the cotton it was treated with aerial and ground applications of imidacloprid (Gaucho and Admire) for aphids. All of our 500 hives received sustained exposure to this chemical with no immediate ill effects. Our crop was short due to the drought. As we relocated the bees back to our home territory (Central Texas) in the early fall, the bees were strong and apparently healthy.”

By In January of 2007 we began to see a significant portion of our nearly 2000 hives begin to collapse with Colony Collapse Disorder (CCD) symptoms. As we searched for an explanation to our losses, a disturbing pattern emerged: All of the collapsing hives had been in West Texas four months earlier. We saw no CCD in the Central Texas bee colonies. This was the only difference in the cultural practice of the bees that collapsed and those that were healthy.”

Dave Hackenberg tells his story of CCD on the East coast. In 2004, when our bees were first exposed to imidacloprid, we saw things happen in our bees that we have never seen before. Good colonies of bees run through pollinations and honey crops over the summer that we now know were exposed to Assail in Apple pollination and Admire in pumpkin pollination, by fall when no new food was coming into the hives, began to collapse at a rapid pace, leaving nothing but a queen and a few bees in the boxes. The farmers that I work with are sensitive to using anything that would hurt my bees because they recognize how important good pollination is to the success of their crops. They were told by their chemical suppliers that these ‘new’ pesticides were ‘safer’ for honeybees and they could even apply them during bloom without damage to the bees. We did not see any dead bees in front of our hives while they were in these pollinations. In the fall, it was clear that the bees that had been on honey locations were OK with normal mortality of 10 to 15% loss, while the pollination hives had 75 to 80% loss. The ‘surviving’ pollination hives were not healthy and they failed to build properly in the spring. We saw this same problem with pollination hives in 2005 and 2006. It was in the fall of 2006 that we began to associate these losses with summer pollination exposure. Since then we have communicated to our growers some of our concerns and the losses have gotten better in apple pollination where the grower had ‘options’ to use other products. In pumpkin pollination, the growers have not had such luck since there are few other ‘approved’ products available to them.

Gene Brandi tells his story of watermelon pollination in California. “Another route of imidacloprid exposure to which my bees have been subjected is by chemigation with Admire on watermelons. Growers who chemigate with pesticides highly toxic to bees are not required to notify registered beekeepers in California, so I was not aware until after the fact that this practice was occurring. In the summer of 2007 I pollinated watermelons with nearly one thousand colonies of my bees. After approximately 50% of these colonies died during the following winter (compared to an 18% winter loss in my colonies that did not pollinate watermelons), I contacted the grower and discovered that the watermelons had been chemigated with Admire. My colonies that were not in watermelon pollination were exposed to other products, and yet did not sustain the same magnitude of winter loss. Although I do not have conclusive proof that exposure to imidacloprid was the cause of this bee loss, the correlation of this loss to watermelon pollination was enough for me to stop pollinating watermelons.

Dave Mendes tells his story of orange orchards in Florida. “I am a commercial beekeeper operating 7500 hives for honey production and crop pollination in the states of Florida, California, Maine, and Massachusetts. I participated in a research project organized through Penn State from March 2007 until January 2008 to follow a group of beehives through a complete season to monitor several different conditions in these hives to determine what factors may contribute to hive mortality. I was one of three beekeepers in this study who each selected 18 to 24 hives that would be sampled each time they were moved to a new location. My hives were sampled 7 times during the test period. I started the study with 18 hives and ended with 4 hives total and only one of these was in good enough shape to produce honey or pollinate an agricultural crop. The first samples taken while the bees were in Florida citrus showed levels of 14 to 17 ppb of imidacloprid in the pollen inside the hives. I spoke to the grove manager and found out that Admire Pro had been applied to the younger trees in his grove (40,000 trees in a grove of 600,000 trees) in February as a ground application as the trees began to bloom. The research on imidacloprid that I could find showed levels of 3 to 5 ppb as the highest recorded levels in citrus nectar or pollen. I inquired to Bayer Crop Science and the Florida pesticide regulatory people to find out more about what effect these levels of imidacloprid could cause in my beehives. I found very little information that addressed my concerns.

Imidacloprid, a systemic insecticide, moves through the treated plant to the nectar and pollen. The chemical remains persistent in soils for several years, can be taken up by subsequent plantings and weeds, and expressed in their pollen and nectar. No mechanism exists to protect honeybees from this exposure. Due to the vitally important nature of pollinators we recommend that imidacloprid be removed from use in the United States. Simply stated there is just no way to protect bees from this danger.

The reader may ask how did we find ourselves at the point where an extremely dangerous chemical compound has come into such widespread use, threatening the very existence and viability of the pollination framework of the country. The answer is simple. Deregulation, the same concept which precipitated our financial collapse, has precipitated an environmental collapse no less serious. At the same time that financial institutions were being given a free reign to regulate themselves on the naive assumption that industry knew best, pesticide regulation was being turned over from EPA to industry on the same assumption.

US EPA used to do pesticide screening in honeybees, do pesticide toxicity study themselves, but today industry directs and funds the critical toxicity studies to determine product safety themselves. The studies are shown to EPA for registration purposes, then filed away as “proprietary information” far from the scrutiny of the public eye. Enforcement actions are not taken by EPA; instead these critically important functions are delegated to individual state departments of agriculture, under an arrangement ironically called a “primacy agreement.”

The problems faced by the beekeeping industry are not limited to one single chemical compound. They are in fact linked to a pervasive regulatory failure. When the EPA was first set up, it was in response to environmental challenges of an unprecedented nature. At that time the country was using 200,000,000 pounds of active ingredient chemical pesticides. Today that number is over 5,000,000,000 pounds of active ingredient. Simply put, the country is drowning in chemicals. These very “economic poisons” are doing their job too well, and because of the deregulation process we are faced with a perfect storm today capable of destroying our countries pollinator base which will carry with it agricultural and environmental catastrophe.

The fundamental change which is necessary is to return to a system at EPA which independently tests chemical compounds before they are released for widespread use. Precaution and prevention are words which need to return to environmental protection. Massive field experiments, such as what has occurred with the neonicotinoid class of systemic insecticides is just too high risk of a behavior. Environmental catastrophe such as global warming, and our current pollinator crisis are big flashing warning lights. These warning lights are there to tell us something, they are telling us to take action before it is too late.

Bron: ezene 26 maart 2009