Scientists uncover why millions of bees are dying
Monday, July 29, 2013, 10:55 - Since 2006, millions of bees in North America have been dying and scientists have struggled to determine why - but new research might have an answer.
Scientists finally believe they know why millions of bees across North America have been dying off.
Since 2006, numbers have dropped dramatically due to Colony Collapse Disorder (CCD), a paradox that occurs when most worker bees suddenly abandon the hive, leaving the queen and an inadequate number of workers behind.
Factors such as malnutrition, pesticide use, and habitat loss have been cited as possible factors before, but none could be pinpointed as the cause -- until now.
A study published in the journal PLOS ONE, says scientists at the University of Maryland and the U.S. Department of Agriculture have found that CCD is caused by a combination of factors.
When researchers collected pollen from hives in seven major crops and measured the pesticides type and concentration from within the samples, what they discovered was a mishmash of chemicals.
These chemicals, which are found in widely-used fungicides were previously believed to be harmless to bees, but in fact they increase a bee's susceptibility to Nosema cerenae -- a parasite linked to CCD.
Bee's found in colonies with high concentrations of those chemicals were three times as likely to be infected by Nosema.
Labels on pesticides warn farmers not to spray their crops when pollinating bees are in the area, but such precautions do not apply to fungicides.
"Our results highlight a need for research on sub-lethal effects of fungicides and other chemicals that bees placed in an agricultural setting are exposed to," said one researcher in the report, released on July 24, 2013.
Last year, Health Canada's Pest Management Regulatory Industry began taking samples from dead bees in Ontario and Quebec. The agency is now "re-evaluating" the pesticides status while analyzing more samples this year.
To read The University of Maryland and the U.S. Department of Agriculture's full report, click here.
With files from QZ.com