Abuzz about Bees
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.
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 lain 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. …