Despite the controversies surrounding the accuracy of previous reports on the effects of neonicotinoids on the bee population, a large scale study now shows the pesticide's negative impact on the health of honeybee populations.

Neonicotinoids And Honeybee Health

In the past, reports of neonicotinoids being detrimental to certain insect populations were seen by some critics as controversial mainly because they were thought to be unrealistic, suggesting that the bees in the studies were exposed to the chemical far longer than they would have been exposed in realistic situations.

Now, after the largest scale field research on the effects of neonicotinoids on bee populations, researchers from the York University in Toronto found that neonicotinoids do in fact harm the health of bee colonies. In fact, they found that honeybees exposed to realistic levels of neonicotinoids were more susceptible to early death and queenlessness, thereby harming the health of an entire colony.

Toxic To Honeybees

The research team went about with the study by observing five bee colonies in close proximity to neonicotinoid-treated corn fields, and six colonies that are far from agriculture. These colonies were observed, sampled, and tested between the months of May and September.

Through this process, however, researchers found that the pollen containing neonicotinoids did not originate from the adjacent corn fields, but from the pollen of other plants that bees are attracted to.

"This indicates that neonicotinoids, which are water soluble, spill over from agricultural fields into the surrounding environment, where they are taken up by other plants that are very attractive to bees," said Nadia Tsvetkov, PhD student from York University and coauthor of the study.

What's more, they also found that the combination of neonicotinoids and boscalid, a commonly used fungicide, has a dangerous effect on bees. Together with the fungicide, neonicotinoids are twice more toxic to honeybees.

Results of the study can be found in the journal Science.


Neonicotinoids are a widely used group of insecticides, and are often used to treat farm crops as well as ornamental plants for pest control. Though significantly less toxic on humans and other mammals, they have proven to be highly toxic to small insects such as honeybees.

Despite manufacturers' skepticism over results showing the negative impacts of neonicotinoids on bees, countries such as the United States and Canada are taking steps to protect insects such as bees. By January of 2016, the U.S. Fish and Wildlife Service has banned all use of neonicotinoids on National Wildlife Refuges.

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