Pesticide News Story: EPA Acts to Protect Bees
For Release: July 1, 2008
EPA has received a number of inquiries about recent bee deaths in Germany associated with the use of the pesticide clothianidin and whether this incident might be related to Colony Collapse Disorder (CCD). Based on discussions with German authorities, EPA believes this incident is not related to CCD. Although pesticide exposure is one of four theoretical factors associated with CCD that the United States Department of Agriculture is researching, the facts in this case are not consistent with what is known about CCD. CCD is characterized by a relatively rapid decline in the adult bee population of a hive; typically only the queen, a few nurse bees and brood remain in the CCD-affected hive. Reported incidents of CCD have detected few if any dead adult bees. The recent incident in Germany, however, was associated with large numbers of dead adult bees in and around the hives. Additionally, clothianidin residues were detected in the dead bees and their hives.
According to German authorities, the May 2008 incident resulted from inadvertent exposure of the bees to clothianidin, an insecticide used for corn seed treatment, resulting from a combination of factors. These factors include the specific formulation of the pesticide used, weather conditions and type of application equipment:
- The formulation of the pesticide clothianidin used to protect seed corn from corn root worm did not include a polymer seed coating known as a "sticker." This coating makes the pesticide product stick to the seed. Although the formulation used in the US also does not require a “sticker” on corn seed, it is typical practice to use “stickers” on corn seed in the US.
- Normally, corn is planted before canola blooms and attracts bees. Because early, heavy rains delayed the corn planting in Germany, the seeds were sown later than usual when nearby canola crops were in bloom and bees were present.
- A particular type of air-driven equipment used to sow the seeds apparently blew clothianidin-laden dust off the seeds and into the air as the seeds were ejected from the machine and into the ground.
- Finally, dry and windy conditions at the time of planting blew the dust into the neighboring canola fields that were in bloom and where honey bees were foraging.
Together, these factors helped create the circumstances under which this incident occurred.
While this incident is not related to CCD, EPA is examining its practices with respect to label requirements for seed treatment pesticides and will revise them as necessary to prevent the types of exposure that led to the bee deaths. Our initial focus will be on seed treatment pesticides that we know are toxic to bees and whether the use of stickers or coatings should be required. In many situations, the use of pesticide-treated seeds results in less human and environmental exposure than would the use of the pesticide later, after the crop is growing. We want to make sure that seed treatment is done according to best practices that minimize human and environmental exposure.