Several studies published this year by U.S. and European scientists appear to link neonicotinoides, a common class of insecticides, to colony collapse disorder in honeybees.
CCD is a phenomenon that causes worker bees to suddenly disappear from their colony and has been reported in both North America and Europe. These recent studies show effects ranging from bees being more likely to contract a known fungus to bees leaving the hive in winter.
The studies have come under fire from Bayer, who produces neonicotinoides, as well as several agricultural groups for flaws including dosage beyond the amount that the bees would be exposed to under normal conditions.
CCD is a major issue for agricultural production as many crops utilize bees to spread their pollen and it has been estimated that 20 to 40% of bee colonies in the U.S. have succumbed to CCD since 2006.
Although the exact cause is unknown, past studies have shown that a combination of a viral and fungal infection in the bee results in a condition of severe malnutrition that eventually leads to the death of the bee.