Bee colonies had a decline in 2006, and a decade earlier, and lots of times going back as far as people kept count of bees, but activists most recently blamed a group of pesticides called neonicotinoids, and ignored climate and parasites, the thing that scientists said made the difference in periodic blips.
Regardless of the consensus, a team of scholars in Environmental Science&Technology blame these "neonics" and claim past studies may have underestimated the bees' exposure to the compounds.
They say past research on neonicotinoids has focused mainly on bees' exposure through crops treated with the pesticides, that is why they have been discounted as issues - Australia, for example, had no declines of any kind but use neonics as much as anyone, while one region of Europe had a large decline but had more climate difference. Cristina Botías and colleagues claim wildflowers could be exposing bees to more pesticides and being the missing link between bee deaths and science.
The researchers analyzed pollen samples from plants growing in areas close to arable fields and from beehives on five farms in the U.K. They found that pollen from wildflowers growing in these locations often contains neonicotinoid residues. In addition, 97 percent of neonicotinoids in the pollen that bees brought back to honey bee hives was from wildflowers, which were not directly treated with the pesticides.
They say that neonicotinoids are likely leaching through the soil and being taken up by the nearby wildflowers. The team says their results suggest that exposure is likely to be higher and more prolonged than currently recognized and so activists may have a point in trying to get them banned.