March 24, 2010
Pesticides Eliminating Bees Quickly
A federal survey has discovered more honeybees died off this winter, and another study revealed honeybees' pollen and hives are burdened with pesticides, according to a recent Associated Press (AP) report.
Two federal agencies and regulators in California and Canada, which are all trying to find what is behind this relatively recent threat, have ordered new research on pesticides used in fields and orchards.
On Thursday, chemists at a scientific conference in San Francisco plan to respond to the new study by taking on the issue of chemicals and dwindling bees.
Scientists are concerned about the important role bees play in our food supply. Close to one-third of the human diet is from plants that require pollination from honeybees.
The bee population has been on the decline over decades for various reasons. However, in 2006 a new concern, "colony collapse disorder," was the cause for large, inexplicable die-offs. The disorder causes adult bees to abandon their hives and fly off to die. Experts say it is most likely a combination of parasites, viruses, bacteria, poor nutrition and pesticides.
"It's just gotten so much worse in the past four years," Jeff Pettis, research leader of the Department of Agriculture's Bee Research Laboratory in Beltsville, Md., told AP. "We're just not keeping bees alive that long."
According to an informal survey of commercial bee brokers cited in an internal USDA document, bees seem to be in bigger trouble this year than normally after a bad winter. One-third of those surveyed had trouble finding enough hives to pollinate California's nut trees, which grows the majority of the world's almonds. There will be a more formal survey performed in April.
"There were a lot of beekeepers scrambling to fill their orders and that implies that mortality was high," said Penn State University bee researcher Dennis vanEngelsdorp, who worked on the USDA snapshot survey.
Zac Browning, a beekeeper, told AP that he has shipped hives from Idaho to California to pollinate the blossoming almond groves. When he checked on the item he was shocked to find hundreds of hives empty, abandoned by the worker bees.
The losses were three times higher than the previous year.
"It wasn't one load or two loads, but every load we were pulling out that was dead. It got extremely depressing to see a third of my livestock gone," Browning said, standing next to stacks of dead bee colonies in a clearing near Merced, at the center of California's fertile San Joaquin Valley.
Pesticides are attracting scrutiny now amongst all the stresses to bee health. A study published Friday in the scientific journal Public Library of Science (PLOS) One said about three out of five pollen and wax samples from 23 states had at least one systemic pesticide, which is a chemical designed to spread throughout all parts of a plant.
EPA officials said they know of the problems involving pesticides and bees and the agency is "very seriously concerned."
Federal officials say that pesticides are not a risk to honey sold to consumers. And Pettis said that the pollen people eat is probably safe because it is usually from remote areas where pesticides are not used. However, the PLOS reported 121 different types of pesticides within 887 wax, pollen, bee and hive samples.
"The pollen is not in good shape," said Chris Mullin of Penn State University, lead author.
He said that none of the chemicals were at high enough levels to kill bees, but it was the combination and variety of them that is the problem.
University of Illinois entomologist May Berenbaum told AP that the results are "kind of alarming."
Environmental groups do not think the EPA is doing enough on pesticides, despite their assurances they are.
In 2006, Bayer Crop Science started petitioning the agency to approve a new pesticide for sale. Once the company's studies on its effects on bees was reviewed, the EPA gave Bayer conditional approval to sell the product two years later, but it had to carry a label warning that it was "potentially toxic to honey bee larvae through residues in pollen and nectar."
The Natural Resources Defense Council then sued the agency saying they filed to give the public timely notice for the new pesticide application. A federal judge in New York agreed last December to ban the pesticide's sale. And, earlier this month two more judges upheld the ruling.
"This court decision is obviously very painful for us right now, and for growers who don't have access to that product," said Jack Boyne, an entomologist and spokesman for Bayer Crop Science. "This product quite frankly is not harmful to honeybees."
Boyne said the pesticide was sold for close to a year and that most sales were in California, Arizona and Florida. He said the product is intended to disrupt the mating patterns of insects that threaten citrus, lettuce and grapes.
Berenbaum's research found that pesticides are not the only problem, but multiple viruses are also attacking the bees, making it tough to propose a single solution.
"Things are still heading downhill," she told AP.
Browning, the largest commercial beekeeper, have reported a $1 million loss this year.
"It's just hard to get past this," he said, watching as workers cleaned honey from empty wooden hives Monday. "I'm going to rebuild, but I have plenty of friends who aren't going to make it."
On the Net:
- Environmental Protection Agency
- Bee Research Laboratory
- PLoS ONE
- Penn State University
- Bayer Crop Science
- Natural Resources Defense Council