Bee decline results from multiple stressors

Bee decline results from multiple stressors

Bee decline is a recognized problem that “demands attention. It’s important that agriculture and apiculture work together,” he said. “They have to identify their needs.

The dilemma: Farmers use approved pesticides at approved rates and in accordance with approved application methods to protect valuable field and tree crops from damaging pests. Beekeepers place their hives as near those fields and orchards as they can to provide adequate nectar to produce as much honey as possible.

But that’s not all. Bees near agriculture operations is only one of a half-dozen or more factors that could contribute to bee colony collapse disorder, and it’s likely not even the most significant.

“We know multiple stress factors affect bee decline,” said Laurie Adams, executive director, Pollinator Partnership, during a panel discussion on agriculture and pollinators at the Ag Issues Forum, annually sponsored by Bayer CropScience prior to the Commodity Classic, held recently in San Antonio.

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Adams, along with Troy Anderson, assistant professor of insect toxicology and pharmacology at Virginia Tech, and Don Parker, integrated pest management manager for the National Cotton Council, explored various reasons for declining bee populations and possible solutions to this complex problem.

Bee research sheds new light on faltering colonies

Adams said neonicotinoid insecticide use is “a very small part of the problem. Climate change is huge,” she said. “Extreme temperatures affect bees’ ability to forage.” Other factors include parasites—such as varroa mites—and bee management.

Anderson is in the early stages of a five-year study to determine “what’s killing the bees?” He agrees that multiple stressors are involved and “interact with other factors.” His study is focusing on pesticide exposure.

“For now, I would like to be able to define what a healthy bee is. I can’t do that now.” 

“Pests destroy crops and we have to destroy those pests,” Parker said. He added that farmers also need the bees to pollinate some crops, creating a dilemma. He said solutions must be “science-based. “I have to compliment the EPA for staying with science and not canceling neonicotinoid insecticides, even with heavy pressure to do so,” he said. “There is no smoking gun to show those insecticides are responsible.”

He wants to know more about bees in cotton. “We want to know what the science says,” Parker added. “We want to see field-relevant science. Cotton self-pollinates. Do bees fly to cotton fields?  We want to determine when bees are active in cotton fields.”

Knowing when bees are most likely in the fields, he said, will allow farmers to adjust spray schedules to apply materials when bees are less active and less likely to be harmed.

He also recommended that any course of action not be a national mandate. “We don’t believe we have a one-size fits all solution to applying insecticides across the country,” he said. “We need local solutions.”

A guideline of best management practices for farmers should help protect bees, he said.

Research is a big need. So is cooperation among interested parties. Adams said the Pollinator Partnership was called in to help determine the effect of corn planting on bee deaths. She explained that planters use lubricants that turn to dust as the machines roll across the fields. The dust drifts and may carry traces of the neonicotinoid insecticides used in seed treatments. “We found that these lubricants add to the problem.”

Partnerships

Bayer and Syngenta worked with the Pollinator Partnership, along with three universities—Ohio State, Iowa State and the University of Guelph—to identify the problem and then consider a solution. The project, The Corn Dust Research Consortium (http://www.pollinator.org/CDRC.htm) also included The American Seed Trade Association, the American Honey Producers Association, the American Beekeeping Federation, the Association of Equipment Manufacturers, Bayer CropScience, the Canadian Honey Council, the Farm Equipment Manufacturers Association, the National Corn Growers Association, the Pollinator Partnership, Syngenta, and the University of Maryland.  

“Everyone was on board,” Adams said. Studies determined that the lubricant, a graphite or talc material, resulted in “fugitive drift” and was a factor in bee exposure. Changing to a new lubricant (recently released by Bayer CropScience) reduces drift and exposure. When the new “lubricant was used, total dust and pesticide load in the dust were reduced when compared to the use of conventional lubricants,” the report states.

A significant finding, according to the report, was “that honey bees collected pollen largely from trees and woody plants (apple, hawthorn, willow, maple, etc.) during the time of corn planting. This was a consistent finding at the Iowa, Ohio and Guelph sites.

“The second honey bee forage discovery had to do with the pesticide levels in the honey bee-collected pollen. Across all three sites, the highest residue levels occurred during the approximately two-week planting period.”

Adams said the study also indicated that beekeepers should pay close attention to where they place their hives.

She said the cooperative nature of the study should serve as a model for others to follow as they try to identify problems and then find acceptable solutions.

“But this was only one year and only in corn.” She added that more work needs to be done to reduce exposure of honey bees to neonicotinoids used to treat seeds. Those efforts should be broad-based to include farmers, beekeepers, pesticide and lubricant manufacturers, equipment manufacturers, land grant universities, even the agricultural media.

A second year of funded research will focus on evaluation of findings, disseminating information and adapting recommended practices.

Adams said access to information about pollinators is important. “But it’s often hard to find information based on science. In our view, farmers are excellent stewards of the landscape. Pollinators have lost habitat, including clean places for bees, butterflies and others to forage and lay eggs.”

Changing bee industry

Parker said the bee industry also has changed “from honey production to pollination providers. One owner now may have 20,000 hives scattered across five states.”

Anderson said bee decline is a recognized problem that “demands attention. It’s important that agriculture and apiculture work together,” he said. “They have to identify their needs.”

Parker said the dilemma is clear. He related an anecdote about a bee keeper’s reaction to a suggestion that he move his hives into a more remote, wooded area, away from agriculture. But the bee keeper said he did not get as much honey in more remote areas as he did close to well fertilized and irrigated crops.

That’s the catch. Beekeepers need well-managed crops for the benefit of their bees and their businesses, and farmers have to protect those crops, but at the same time they need the pollinators.

Panelists expressed hope that reasonable solutions will come from partnerships. Parker said several states have already engaged in projects involving cooperation among affected parties.

“In the next few years we will develop a better understanding of how pollinators interact with a crop and what they carry back to the hive.” He said a recent summit on the effect of the varroa mite is also a positive step.

“We’re looking at pesticide risk exposure,” Anderson said, “but we are also interested in the effect inside the colony. The varroa mite is a significant challenge and is one of the most significant reasons for bee colony collapse.”

“I don’t think research will produce a silver bullet,” Adams said. “It will take multiple approaches, but we are encouraged that this has become an important issue.”

 

 

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