Seven years after a sharp decrease in honeybee populations sparked global concern about the fate of the essential pollinators, government officials in the United States and European Union have come to differing conclusions about what is causing “colony collapse disorder.” While European regulators have moved to temporarily ban a class of pesticides called neonicotinoids that some scientists say is a principal cause of the die-offs, officials in the US say the pesticides are just one of many factors contributing to the declining bee numbers.
photo Karunakar Rayker
EU member states in March failed to agree to ban three widely used pesticides linked to bee deaths. Thirteen EU governments were in favor of the ban, nine voted against, and five others – including Britain and Germany – abstained. Campaigners with the online advocacy group Avaaz, which had collected 2.5 million signatures on a petition calling for a neonicotinoid ban, accused European governments of ignoring public opinion. “Germany and Britain have caved in to the industry lobby,” Avaaz campaigner Iain Keith said.
Pesticide makers Bayer and Syngenta fought hard against the proposed ban. While few people deny that neonicotinoids (or “neonics,” as they are often referred to) can be harmful to bees, biologists have mixed opinions about the degree to which they are reducing bee populations. “Of course they can kill bees; they are insecticides, but whether they actually do this, or whether sub-lethal effects occur and damage the colonies on any important scale, has not been proven,” says Lin Field, head of biological chemistry at Britain’s Rothamsted Research center.
A recent study published in the journal Nature Communications offers a counterargument. The study says neonics and another type of pesticide, coumaphos, which is used to kill varroa mites, directly impact bees’ brain physiology. As many as one-third of bees exposed to the pesticides failed to learn or performed poorly on memory tests. “Disruption in this important function has profound implications for honeybee colony survival, because bees that cannot learn will not be able to find food,” says Dr. Geraldine Wright, a study co-author.
European officials eventually decided that precaution is the best course of action. In late April, the European Commission announced a two-year moratorium on the use of neonics.
In the United States, meanwhile, environmentalists are also pushing to get neonics off the market. But government officials here aren’t as sympathetic to a ban, saying that neonics are just one of several threats to honeybees.
In May the Department of Agriculture and the Environmental Protection Agency released a report that concluded a host of other factors including the parasitic varroa mite, bacteria, poor nutrition, and genetics were to blame for the rapid decline in honeybees. The USDA-EPA report said more research was needed to determine the extent to which neonics are responsible for bee deaths.
Environmentalists were unimpressed. “We’ve got so much research on neonicotinoids now that all point to major impacts on honeybees and other beneficial insects,” says Scott Hoffman Black, director of the Xerces Society, which works for the conservation of invertebrates.
This spring, the National Resources Defense Council issued a scathing report showing that the EPA has used a loophole to allow more than 10,000 “untested or undertested” pesticides to be sold. About 65 percent of the pesticides on the market only have a “conditional registration.” Neonicotinoids are among them.
The Center for Food Safety has filed a lawsuit in federal court to try to force the EPA to ban or better regulate two neonicotinoids implicated in bee deaths: clothianidin and thiamethoxam. But the EPA appears in no hurry to address the chemicals’ impact. When asked by CBS News how long it will take to conduct a new review of neonics, an agency spokesperson responded that it “should be completed in five years.”
Environmentalists argue that, in the meantime, US officials should operate under the precautionary principle and keep neonics off the market. “The bees are in a crisis situation and therefore so is agriculture and so you take the action that can be taken now,” says Jennifer Sass, a senior scientist with NRDC. “If you already know that neonics are part of the problem, then you need to get rid of them.”
—Reuters, 3/18 & 3/28; AFP, 3/27; Chemical & Engineering News 4,1; The Guardian, 4/2; BBC 4/2
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