Do Neonicotinoid Pesticides Affect Bees? 2 Studies Say YES

Are neonicotinoid pesticides killing bees in the wild? (Image: Pixabay/CC0 Public Domain)
Are neonicotinoid pesticides killing bees in the wild? (Image: Pixabay/CC0 Public Domain)

Can you really argue with these two studies that were published in Nature? The studies were conducted over concerns about whether neonicotinoid pesticides adversely affect bee health.

Newest pesticide research wades into debate over bee decline:

In the first study, led by neuroscientist Geraldine A. Wright, of Newcastle University, England, shows that bees are drawn to neonicotinoids, possibly because the insects catch a “buzz” from the pesticides similar to the one human’s get from nicotine.

The team gave bumblebees and honeybees a choice between drinking a sugar solution laced with low doses of a neonicotinoid— either clothianidin, imidacloprid, or thiamethoxam—and a sugar solution without any pesticides. The scientists found that the bees actually preferred the pesticide-laced solutions, wrote C&EN (Chemical & Engineering News).

Electrophysiology experiments conducted by Wright’s team showed that bees cannot taste neonicotinoids, so something else is attracting them to the pesticides, Wright said. “The fact that bees show a preference for food containing neonicotinoids is concerning as it suggests that, like nicotine, neonicotinoids may act like a drug to make foods containing these substances more rewarding,” Wright says. “We don’t have evidence that they are addicted, but they could be.” If neonicotinoid-treated plants coax bees to return to a crop field over and over, it could have a “negative impact on whole colonies and on bee populations.”

Bees get buzz from pesticides:

The second study suggests that neonicotinoids affect bee behavior and growth under realistic conditions in a crop field.

Unlike previous studies, which have been criticized for artificially feeding bee’s neonicotinoids in the lab, the second Nature study, conducted by Maj Rundlöf, of Lund University, Sweden, and colleagues examined how neonicotinoids affect bees in agricultural fields. The team monitored colonies of honeybees and wild bees, including bumblebees, in 16 fields in southern Sweden. Half the fields contained an oilseed rape crop grown from seeds coated with clothianidin and a fungicide, and half the fields were planted with seeds coated only with fungicide, wrote C&EN.

Unique field study shows that pesticide harms wild bees:

In the fields planted with clothianidin-treated seeds, the team observed a reduced density of wild bees and reduced colony growth in bumblebees specifically. However, the researchers saw no significant impact on honeybee colonies.

The Rundlöf study “is the first fully field-realistic, well-replicated trial so far,” says David Goulson, a biologist at the University of Sussex, England.

“It is no longer credible to argue that agricultural use of neonicotinoids does not harm wild bees,” he notes in the study.

The new studies may have huge implications for future policies on neonicotinoids, mainly in the European Union, where there are three neonicotinoids that are under a temporary ban while the regulators review all the risks of the pesticides to bees. The moratorium is due to expire at the end of year, and has been criticized for relying on studies that were conducted under unrealistic conditions.

Neonics and pollinators:

Both studies are being hailed by environmental groups, which have been pushing regulatory agencies worldwide to ban neonicotinoids because of their harmful effects on bees. But pesticide manufacturers and some researchers argue that the data are insufficient to end the debate over the role of neonicotinoids in declining bee populations, wrote C&EN.

Pesticide manufacturers, however, still contend that neonicotinoids are vital to controlling pests.

A pesticide trade group in England, the Crop Protection Association, rejects the Rundlöf paper, saying that “the only effect of the restriction on neonicotinoids in Europe so far has been a steady stream of reports from farmers that their crops are suffering serious losses,” C&EN added.

While there is big money to be had or lost in the pesticide industry, similar to the tobacco industry, passions will run high on both sides of the question.


Is This the World's Oldest Murder Mystery?
Founder of 'Silk Road' Sentenced to Life in Prison