New Study Shows Neonicotinoids Pose Little Practical Risk To Bees

New Study Shows Neonicotinoids Pose Little Practical Risk To Bees

While neonicotinoid pesticides can harm honeybees, a new study by Washington State University (WSU) researchers shows that the substances pose little risk to bees in real-world settings.

The team of WSU entomologists studied apiaries in urban, rural and agricultural areas in Washington, looking at potential honeybee colony exposure to neonicotinoid insecticides from pollen foraging. The results were published in the Journal of Economic Entomology.

Beebread packed into comb cells.

The research team collected samples of beebread, or pollen packed into comb cells, from 149 apiaries across the state.

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After calculating the risk based on a “dietary no observable adverse effect concentration” – the highest experimental point before there is an adverse effect on a species – of five parts per billion, the study’s results suggest low potential for neonicotinoids to harm bee behavior or colony health.

“Calculating risk, which is the likelihood that bad things will happen to a species based on a specific hazard or dose, is very different from calculating hazard, which is the potential to cause harm under a specific set of circumstances,” said co-author Allan Felsot, WSU Tri-Cities Professor of Entomology and Environmental Toxicology.

“Most of what has dominated the literature recently regarding neonicotinoids and honeybees has been hazard identification,” he said. “But hazardous exposures are not likely to occur in a real-life setting.”

Felsot said the study shows that the risk of bee exposure to neonicotinoids is small because bees aren’t exposed to enough of the pesticide to cause much harm in a real-world scenario.

Lead author Timothy Lawrence, Assistant Professor and Director of WSU-Island County Extension, said many sublethal toxicity studies, whether at the organism level or colony level, have not done formal dose-response analyses.

“The question we posed focused on the risk of exposure to actively managed honeybee colonies in different landscapes,” he said.

With the cooperation of 92 Washington beekeepers, the team collected samples of beebread, or stored pollen, from 149 apiaries across the state.

Throughout the one-year trial, neonicotinoid residues were detected in fewer than 5% of apiaries in rural and urban landscapes. Two neonicotinoids, clothianidin and thiamethoxam, were found in about 50% of apiaries in agricultural landscapes.

Although neonicotinoid insecticide residues were detectable, the amounts were substantially smaller than levels shown in other studies to not have effects on honeybee colonies. The WSU researchers referenced 13 studies to identify no observable adverse effect concentrations for bee populations, which they used to perform a risk assessment based on detected residues.

“Based on residues we found in apiaries around Washington state, our results suggest no risk of harmful effects in rural and urban landscapes and arguably very low risks from exposure in agricultural landscapes,” Felsot said.

While exposure levels were found to be small, Lawrence said it is still important to be careful with use of neonicotinoid insecticides and follow product label directions. For example, insecticides should not be used during plant flowering stages when bees are likely to be foraging.

“While we found that bees did not have chronic exposure to adverse concentrations of neonicotinoids, we are not saying that they are not harmful to bees – they are,” he said. “People need to be careful with pesticide use to avoid acute exposure.”

Other researchers on the study included Elizabeth Culbert, WSU Food and Environmental Quality Lab (GEQL) research technician; Vincent Hebert, WSU associate professor of entomology and laboratory research director; and Steven Sheppard, WSU professor and department chair of entomology.

 

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Nick says:

But then there is this study published today in Nature Communications
http://phys.org/news/2016-08-neonicotinoid-insecticides-linked-wild-bee.html

Randy Oliver says:

Actually, the UK study doesn’t really show much. If you look at their figures, there is only a small apparent negative effect upon a few species, based upon some fancy modeling that makes a lot of HUGE assumptions (one being that there are no other changes going on in the environment, and that the volunteer surveys actually detected every species present during each survey).

There is now plenty of evidence that neonics can have adverse effects upon some solitary and bumblebee species, but any such effect is very hard to quantify, with so much natural variation in populations, and changes in the environment.

As a professional beekeeper, bee researcher, and writer, I’ve objectively reviewed nearly all research, on the neonics, and correspond regularly with most of the researchers. Just as with any insecticide, neonics have the potential to cause problems. Seed treatments in general appear to be pretty safe for honey bees, but may affect some other pollinator species. Any other application of neonics needs to be done with caution to avoid off target effects on beneficials.

Anyone can read my reviews on the neonics at ScientificBeekeeping.com.

Although I wrote the above reviews four years ago, none of the recent flurry of research findings has changed my assessments.

Randy Oliver
California

Steve Savage says:

Randy. I agree. Regions without varroa mites can have lots of seed treatment acres and healthy bees

Robert H Keggan says:

Who paid for this research???
A report without disclosure of interested parties, is misleading. Were wax and honey also tested……or was pollen cherry picked for this study because the amounts of the pesticide were already known to be low?????

couch says:

What did one of the authors state in the second to last paragraph of this article? Did he say that neonicotoinoids aren’t harmful AT ALL? Or did you just ignore that, bc it’s not convenient for your anti-neonicotoinoid narrative? And are you people claiming that this science isn’t legit? Why? Because you have credentials? Or because you don’t want growers using pesticides? Go away. You add nothing to a discussion of a serious topic that requires serious answers from experts.

crush davis says:

Right? I love how every do-gooder activist sitting at a desk can post some links supposedly debunking this peer-reviewed study but offer no solutions to growers trying to produce crops. So what would you tell growers who are looking for practical and economical insecticide options Laura and Nick? How many acres are you consulting on?

First, this is one study. It is nothing to hang our hats on.

The gist of the research quoted in this article seems to be their model is more predictive of the risk to bees from neonics than the models used by the bulk of the mainstream literature. You asked the right question: why. The answer they gave might have been probed further.

For example, based on 2014 numbers provided by the Washington Dept. of Ag’s Honey Bee Work Group (of which the lead author of this article is a member), the sample size of this study represents only 15 percent of the state’s industry. How generalizable are their results?

Some questions I might have asked:

(1) Co-author Alan Felsot states: “But hazardous exposures are not likely to occur in a real-life setting.”
Why not?

(2) Another Felsot quote: “Calculating risk, which is the likelihood that bad things will happen to a species based on a specific hazard or dose, is very different from calculating hazard, which is the potential to cause harm under a specific set of circumstances.”
What was the specific set of circumstances they used in their study and how generalizable are those circumstances?

Lastly, I would note the headline of this piece seems to fly in the face of the last Felsot quote in the story: “While we found that bees did not have chronic exposure to adverse concentrations of neonicotinoids, we are not saying that they are not harmful to bees – they are,” he said.

Shawn says:

Both of the other articles Laura and Nick quoted didn’t really prove anything. As the original article stated neonicotinoids have a risk, but in real world they haven’t been detrimental. The article Laura quoted said it was probably synergistic effect of many factors and stopped very short of blaming neonicotinoids.

grapedoc says:

The article talks about the difference between hazard and risk and that is the key. We all use electricity which can be extremely hazardous. The risk depends on the potential for exposure. Same with these products.

The big question is- did the researchers collect samples for analysis from dead and dying colonies. Every bee keeper loses significant numbers of colonies every year. It would also be interesting to know who funded the study.

keithsrv says:

Then there is this article on the pesticides used to protect the bees may harm them: https://vtnews.vt.edu/articles/2016/08/080816-fralin-honeybees.html

I would also like to know if the pesticides are more concentrated in the nectar realizing this study looked at broswing for pollen.

David Headrick says:

It’s science people; no one study is fully definitive. And please, what’s with the who funded it conspiracy theory stuff? The Journal of Economic Entomology looks at the science by way of peer review. If that’s not good enough, then you’re stuck in a belief system and shouldn’t be commenting on science. The links to Nature articles are great and deserve thoughtful comparison.

If the study only looked a living, healthy bee colonies, then it was flawed from the beginning. The big question is, did their study include dead and/or dying colonies???

keithp says:

Anytime a political aspect or monetary investment in materials are involved there is reason to question. Often researchers have a motivation to receive continued funding in many cases. In many areas peer review is valid. But when the bulk of the researchers have a vested interest in some facet or continued funding then peer review is corrupt. It is a fact of life, and people are people and have many motivations and agendas.