Bee Collapse and Pesticides

In 2006/2007 bee hives were being compromised and bees were vanishing all across the country. Numerous theories from cellphone radiation, poor diet, mites, stress, climate change or low-level pesticide exposure were being considered as the reason for colony collapse.

Some beekeepers have now singled out two pesticides to be the culprit . The chemicals produced by Bayer CropScience, imidacloprid and its chemical cousin clothianidin, are thought to be the cause of bee die-offs around the world for over a decade. [...]

Imidacloprid and clothianidin are chloronicotinoids, a synthetic compound that combines nicotine, a powerful toxin, with chlorine to attack an insect's nervous system. The chemical is applied to the seed of a plant, added to soil, or sprayed on a crop and spreads to every corner of the plant's tissue, killing the pests that feed on it.

Pennsylvania beekeeper John Macdonald has been keeping bees for over 30 years and recently became convinced that imidacloprid is linked to colony collapse disorder. It's the only explanation he can find for why his bees, whose hives border farmland that uses the pesticide, started dropping dead a few years ago.

Bayer CropScience spokesman Jack Boyne says his company's pesticides are not to blame. "We do a lot of research on our products and we feel like we have a very good body of evidence to suggest that pesticides, including insecticides, are not the cause of colony collapse disorder," he says. "Pesticides have been around for a lot of years now and honeybee collapse has only been a factor for the last few years." (Imidacloprid has been approved for use in the U.S. since 1994 and clothianidin has been used since 2003.)

Scientists continue to investigate the causes of colony collapse disorder. Leading theories suggest a combination of factors that include parasitic mites, disease, malnutrition and environmental contaminants like pesticides, insecticides and fungicides. The current EPA review will provide further insight into the role of pesticides, as it will uncover whether honeybees sickened by exposure to imidacloprid spread it around by bringing contaminated nectar and pollen back to the hive. [...]

In a statement, the EPA says that before banning a pesticide, it "must find that an 'imminent hazard' exists. The federal courts have ruled that to make this finding, EPA must conclude, among other things, that there is a substantial likelihood that imminent, serious harm will be experienced from use of the pesticide." The EPA did not clarify what is meant by "imminent hazard" and why the death of honeybees does not qualify.

There seems to be too many theories and not enough testing or regulation.