Improved Regulation Needed As Pesticides Found to Affect Genes in Bees

EurekAlert From: Queen Mary University of London March 6, 2019

Bumblebee Colony Credit: TJ Colgan

Bumblebee Colony Credit: TJ Colgan

Scientists are urging for improved regulation on pesticides after finding that they affect genes in bumblebees, according to research led by Queen Mary University of London in collaboration with Imperial College London.

For the first time, researchers applied a biomedically inspired approach to examine changes in the 12,000 genes that make up bumblebee workers and queens after pesticide exposure.

The study, published in Molecular Ecology, shows that genes which may be involved in a broad range of biological processes are affected.

They also found that queens and workers respond differently to pesticide exposure and that one pesticide they tested had much stronger effects than the other did.

Other recent studies, including previous work by the authors, have revealed that exposure even to low doses of these neurotoxic pesticides is detrimental to colony function and survival as it impairs bee behaviours including the ability to obtain pollen and nectar from flowers and the ability to locate their nests.

This new approach provides high-resolution information about what is happening at a molecular level inside the bodies of the bumblebees.

Some of these changes in gene activity may represent the mechanisms that link intoxification to impaired behaviour.

Lead author of the study Dr Yannick Wurm, from Queen Mary University of London, said: "Governments had approved what they thought were 'safe' levels but pesticides intoxicate many pollinators, reducing their dexterity and cognition and ultimately survival. This is a major risk because pollinators are declining worldwide yet are essential for maintaining the stability of the ecosystem and for pollinating crops.

"While newer pesticide evaluation aims to consider the impact on behaviour, our work demonstrates a highly sensitive approach that can dramatically improve how we evaluate the effects of pesticides."

The researchers exposed colonies of bumblebees to either clothianidin or imidacloprid at field-realistic concentrations while controlling for factors including colony social environment and worker age.

They found clothianidin had much stronger effects than imidacloprid - both of which are in the category of 'neonicotinoid' pesticides and both of which are still used worldwide although they were banned in 2018 for outdoor use by the European Union.

For worker bumblebees, the activity levels of 55 genes were changed by exposure to clothianidin with 31 genes showing higher activity levels while the rest showed lower activity levels after exposure.

This could indicate that their bodies are reorienting resources to try to detoxify, which the researchers suspect is what some of the genes are doing. For other genes, the changes could represent the intermediate effects of intoxification that lead to affected behaviour.

The trend differed in queen bumblebees as 17 genes had changed activity levels, with 16 of the 17 having higher activity levels after exposure to the clothianidin pesticide.

Dr Joe Colgan, first author of the study and also from Queen Mary University of London, said: "This shows that worker and queen bumblebees are differently wired and that the pesticides do not affect them in the same way. As workers and queens perform different but complementary activities essential for colony function, improving our understanding of how both types of colony member are affected by pesticides is vital for assessing the risks these chemicals pose."

The researchers believe that the approach they have demonstrated must now be applied more broadly. This will provide detailed information on how pesticides differ in the effects they have on beneficial species, and why species may differ in their susceptibility.

Dr Colgan said: "We examined the effects of two pesticides on one species of bumblebee. But hundreds of pesticides are authorised, and their effects are likely to substantially differ across the 200,000 pollinating insect species which also include other bees, wasps, flies, moths, and butterflies."

Dr Wurm added: "Our work demonstrates that the type of high-resolution molecular approach that has changed the way human diseases are researched and diagnosed, can also be applied to beneficial pollinators. This approach provides an unprecedented view of how bees are being affected by pesticides and works at large scale. It can fundamentally improve how we evaluate the toxicity of chemicals we put into nature."

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Research paper: 'Caste- and pesticide-specific effects of neonicotinoid pesticide exposure on gene expression in bumblebees'. Thomas J. Colgan, Isabel K. Fletcher, Andres N. Arce, Richard J. Gill, Ana Ramos Rodrigues, Eckart Stolle, Lars Chittka and Yannick Wurm. Molecular Ecology.

https://www.eurekalert.org/pub_releases/2019-03/qmuo-irn030519.php

The Neonicotinoids: An Objective Assessment

Scientific Beekeeping     By Randy Oliver     April 2018

(I wrote this article in response to a request following a presentation that I gave to the San Diego Master Gardeners. A revised version was later published by the University of California at http://ucnfa.ucanr.edu/files/280172.pdf)

Everyone’s heard about the claim that honey bees are going extinct due to the neonicotinoid insecticides. Although I’m glad that folk are concerned about the bees, the fact is that that claim is not accurate.

People have every reason to be concerned about our human impact upon the environment, and many species face extinction due to habitat conversion, pollution, overharvesting, and climate change. But the honey bee is not one of them. In actuality, the number of managed hives of bees has been increasing in recent years in nearly every country in the world. Colony numbers reflect the profitability of beekeeping as a business, as reflected in the graph below.

The largest number of hives in the U.S. occurred during World War II, due to the Army’s demand for beeswax, and the public’s demand for honey. After the War, beekeeping was less profitable, and the number of hives decreased. We then got hit by the introduction of two parasitic mites in the late 1980’s, and hive numbers declined further as it became tougher to keep our colonies alive. In recent years, the offered price for hive rental for almond pollination tripled, so colony numbers are on the rise.

In the early 2000’s, our bees got hit by yet another invasive pathogen (Nosema ceranae), and the term “CCD” was used to describe the sudden collapse of colonies. But at the time we didn’t know what was happening, which allowed the claim that a new class of insecticides—the neonicotinoids—were responsible. It was a compelling narrative—was this a repeat of DDT causing the near extinction of the pelicans and raptors? I immediately started researching the subject, but found to my surprise, that the narrative didn’t fit the evidence. But that didn’t stop the anti-neonic bandwagon, and researchers switched from working on our main problem—the varroa mite—to trying to pin the blame on the neonics.

Although varroa was a hot topic upon its arrival in Europe and North America, scientific interest in the parasite was eclipsed during the CCD epidemic in the mid 2000’s by the sexier claim that the neonics were to blame.

Why The Neonics?

Growers have long used insecticides, many of which we now know are not at all environmentally friendly.

Since the founding of the EPA in the post Silent Spring era, we are taking a better look at the impacts of pesticides upon off-target organisms, the environmental fates of the products, and their long-term sublethal effects—especially upon humans. EPA has thus phased out the “Dirty Dozen” Persistent Organic Pollutants. And in recent years has revoked or restricted the use of a number of others. For example, the previously commonly-used organophosphate chlorpyrifos is no longer registered for use as a household bug spray.

The problem is, that as we limit the number of insecticides available to growers, pests develop resistance to regularly-applied products. That, and the fact that the vast majority of a sprayed insecticide never actually hits the intended pest—thus ending up in the air, water, and rest of the environment. Growers thus put pressure on the chemical companies to continually develop new types of pesticides, while the consumer demands safer products.

Enter The Neonicotinoids

The neonicotinoids (meaning new, nicotine-like) are synthetic derivatives of the natural plant alkaloid nicotine. The neonics affect specific receptors in the nervous system of insects that are less prevalent in vertebrate animals, so they are thus much safer for humans, other mammals, birds, and fish. In fact, the most commonly-used neonic, imidicloprid, is less toxic to humans than is caffeine.

The second advantage of the neonics is that they are systemic—they can be absorbed through a plant’s roots, and get carried via the xylem to the rest of the plant. Thus, if they are applied as a seed treatment, the only organisms exposed to the chemical are the pests that take a bite out of the plant, or consume the pollen or nectar (this is where bees enter the picture).

Because of these advantages, neonics quickly became the most widely-used insecticides in the world.

Effects Of Neonics On Bees

Neonics are ideally applied as seed treatments, where the amount per seed can be carefully controlled, so that by the time that a plant produces nectar and pollen, the residues are too diluted to harm pollinators.

Unfortunately, during the introduction of the neonics, there were some serious incidents of inadvertent bee kills when the seed coating rubbed off in pneumatic seed planters, and the dust killed bees. In most countries, this issue has now been resolved.

This leaves the question of neonic residues in nectar and pollen. In general, the residues in the nectar and pollen of properly-treated agricultural crops (typically less than 3 ppb) do not appear to cause significant adverse effects on honey bee colonies. I’ve personally visited beekeepers in corn, soy, and canola growing areas, and they report that since the Bt genetically-engineered crops and the neonic seed treatments, that the pesticide issues that they suffered from in the 1960’s and ‘70’s have largely gone away. That said…

The Neonics Are Not Without Problems

Insecticides by definition are designed to kill insects. No insecticide is environmentally harmless, and as we learn more about unintended effects, our regulators must revise the approved allowable applications.

We have now found that the honey bee colony is a special case, and is able to “buffer” the sublethal effects of the neonics on the colony. So although properly-applied neonics appear to generally cause minimal measureable adverse effects on honey bee colonies, they may have more deleterious effects upon bumblebees and solitary native bees. This is a serious concern, of which the EPA is well aware.


Another concern is that with the widespread prophylactic use of neonic seed treatment, more and more residues are ending up at the field margins and in aquatic ecosystems. We’re recently finding out that certain uncultivated plants in the field margins concentrate neonic residues in their nectar and/or pollen. A recent study in Saskatchewan found residues up to 20 ppb in some flowers—enough to start causing problems in bee hives (serious problems occur at 50 ppb), and strong adverse effects upon some native pollinators. These unintended effects upon native pollinators and aquatic invertebrates need to be addressed, and the universal use of treated seed should be restricted.

 

I’m heartened by a recent Court ruling regarding a challenge to EPA, which apparently did not consult with the FWS or the NMFS regarding its approval of some registrations of clothianidin–see https://www.courthousenews.com/wp-content/uploads/2017/05/epa-pesticides-ruling.pdf

Uses Other Than As Seed Treatments

Neonics can also be applied as sprays, drenches, or other foliar applications, or by chemigation. There is far more room for misapplication by these methods. And perhaps worst of all would be misapplication by homeowners, who think that “if a little is good, more might be better.” Luckily, in the studies I’ve seen, urban and suburban bee-collected pollen and nectar normally does not contain toxic levels of neonics.

And this brings us to neonic applications in nursery stock. Nurserymen, in order to ship stock across state lines, must produce pest-free plants. This requires insecticides. But nurserymen do not want to expose their employees and customers to residues of organophosphates such as chlorpyrifos. They can avoid this by placing a measured amount of a neonic in the potting soil, which then, due to its systemic action, results in “clean” plants, and no human-harmful residues. Ideally, by the time a pollinator-attractive plant produces flowers, the residues would be diluted enough so as not to cause harm. The problem is, that no one has individually tested the thousands of cultivars of nursery plants. Plus there is no list of which cultivars attract pollinators.

There have been consumer protests at the big box nurseries, and nurserymen are scrambling to figure out answers.

Jim Bethke and I are currently involved in an IR-4 Project at Rutgers University to address this issue. Currently, we can’t really say which nursery plants might be problematic for pollinators. However, you can generally check a garden book to see if a cultivar is attractive to bees or butterflies; if so, at this time you may wish to avoid pollinator-attractive neonic-treated potted plants, and plant from seed instead.

Wrap Up

No insecticide is harmless. All of agriculture should shift towards Integrated Pest Management to reduce its reliance upon pesticides. California is the most proactive state in the Nation as far as safe pesticide use. The ag community and chemical companies have gotten the message loud and clear that the consumer wants them to reduce pesticide use and develop more eco-friendly pesticides—both of which they are doing.

Write to your representatives to support the EPA, which our current administration is attempting to shut down. Support local eco-friendly growers. Buying “organic” may help, but the best future will be the adoption of agro-ecology, which goes beyond “certified organic.” The field of agroecology is based upon biology, soil improvement, and sustainability, rather than upon “certified organic’s” arbitrary rules that exclude precision breeding and environmentally-friendly synthetic pesticides, fertilizers, and practices. Keep in mind that it is the housewife who spends her dollars at the grocery store who can effect the most rapid change—even the largest agribusinesses respond immediately to consumer demand.

http://scientificbeekeeping.com/the-neonicotinoids-an-objective-assessment/

More Reading

http://scientificbeekeeping.com/the-extinction-of-the-honey-bee/

http://scientificbeekeeping.com/neonicotinoids-trying-to-make-sense-of-the-science/

http://scientificbeekeeping.com/neonicotinoids-trying-to-make-sense-of-the-science-part-2/

 

EU Nations Back Ban On Insecticides To Protect Honey Bees

REUTERS    By Philip Blenkinsop     April 2017 2018

BRUSSELS (Reuters) - European Union countries backed a proposal on Friday to ban all use outdoors of insecticides known as neonicotinoids that studies have shown can harm bees.

The ban, championed by environmental activists, covers the use of three active substances - imidacloprid developed by Bayer CropScience, clothianidin developed by Takeda Chemical Industries and Bayer CropScience as well as Syngenta’s thiamethoxam.

“All outdoor uses will be banned and the neonicotinoids in question will only be allowed in permanent greenhouses where exposure of bees is not expected,” the European Commission said in a statement.

Bayer called the ban “a sad day for farmers and a bad deal for Europe” and said it would not help bees. Many farmers, it said, had no other way of controlling pests and that the result was more spraying and a return to older, less effective chemicals.

The use of neonicotinoids in the European Union has been restricted to certain crops since 2013, but environmental groups have called for a total ban and sparked a debate across the continent about the wider use of chemicals in farming.

Campaign group Friends of the Earth described the decision of EU governments a “tremendous victory” for bees and for the environment.

“The European Commission must now focus on developing a strong pollinator initiative that boosts bee-friendly habitat and helps farmers cut pesticide-use,” it said.

Both Bayer and Syngenta have challenged the 2013 partial ban at the European Court of Justice. A verdict is due on May 17.

https://www.reuters.com/article/us-eu-environment-bees/eu-to-fully-ban-neonicotinoid-insecticides-to-protect-bees-idUSKBN1HY11W

NOTE: From SumofUs

I'm writing quickly to let you know some breaking news: WE WON! The EU neonics ban just passed.

A majority of European governments voted in favour of the European Commission's proposal.

This is a massive win for the bees -- and you and SumOfUs members around the world have helped make this happen. Thank you so much for your incredible support!

I'll be in touch in the coming days with a more detailed report back.

In the meantime, let's celebrate!

Wiebke and rest of the SumOfUs team

P.S. It’s only thanks to SumOfUs members like you that we won this amazing and historic bee-saving ban. But the battle to save the bees is far from over. Bayer and co will not give up now and neither can we. To keep the bees safe from pesticide giants we need sustained support from members like you -- it’s the most powerful form of support. Please can you set up a small monthly donation today so that we can keep fighting for and saving the bees.

EU Agrees Total Ban On Bee-Harming Pesticides

The Guardian      By Damian Carrington     April 27, 2018

The world’s most widely used insecticides will be banned from all fields within six months, to protect both wild and honeybees that are vital to crop pollination.

People protest ahead of the historic EU vote on a full neonicotinoids ban at Place Schuman in Brussels, Belgium. Photograph: Olivier Matthys/AP The European Union will ban the world’s most widely used insecticides from all fields due to the serious danger they pose to bees.

The ban on neonicotinoids, approved by member nations on Friday, is expected to come into force by the end of 2018 and will mean they can only be used in closed greenhouses.

Bees and other insects are vital for global food production as they pollinate three-quarters of all crops. The plummeting numbers of pollinators in recent years has been blamed, in part, on the widespread use of pesticides. The EU banned the use of neonicotinoids on flowering crops that attract bees, such as oil seed rape, in 2013.

But in February, a major report from the European Union’s scientific risk assessors (Efsa) concluded that the high risk to both honeybees and wild bees resulted from any outdoor use, because the pesticides contaminate soil and water. This leads to the pesticides appearing in wildflowers or succeeding crops. A recent study of honey samples revealed global contamination by neonicotinoids.

Vytenis Andriukaitis, European commissioner for Health and Food Safety, welcomed Friday’s vote: “The commission had proposed these measures months ago, on the basis of the scientific advice from Efsa. Bee health remains of paramount importance for me since it concerns biodiversity, food production and the environment.”

The ban on the three main neonicotinoids has widespread public support, with almost 5 million people signing a petition from campaign group Avaaz. “Banning these toxic pesticides is a beacon of hope for bees,” said Antonia Staats at Avaaz. “Finally, our governments are listening to their citizens, the scientific evidence and farmers who know that bees can’t live with these chemicals and we can’t live without bees.”

Martin Dermine, at Pesticide Action Network Europe, said: “Authorising neonicotinoids a quarter of a century ago was a mistake and led to an environmental disaster. Today’s vote is historic.”

However, the pesticide manufacturers and some farming groups have accused the EU of being overly cautious and suggested crop yields could fall, a claim rejected by others. “European agriculture will suffer as a result of this decision,” said Graeme Taylor, at the European Crop Protection Association. “Perhaps not today, perhaps not tomorrow, but in time decision makers will see the clear impact of removing a vital tool for farmers.”

The UK’s National Farmers’ Union (NFU) said the ban was regrettable and not justified by the evidence. Guy Smith, NFU deputy president, said: “The pest problems that neonicotinoids helped farmers tackle have not gone away. There is a real risk that these restrictions will do nothing measurable to improve bee health, while compromising the effectiveness of crop protection.”

A spokesman for the UK Department of Environment, Food and Rural Affairs welcomed the ban, but added: “We recognise the impact a ban will have on farmers and will continue to work with them to explore alternative approaches.” In November, UK environment secretary Michael Gove overturned the UK’s previous opposition to a full outdoor ban.

Neonicotinoids, which are nerve agents, have been shown to cause a wide range of harm to individual bees, such as damaging memory and reducing queen numbers.

But this evidence has strengthened recently to show damage to colonies of bees. Other research has also revealed that 75% of all flying insects have disappeared in Germany and probably much further afield, prompting warnings of “ecological armageddon”.

Prof Dave Goulson, at the University of Sussex, said the EU ban was logical given the weight of evidence but that disease and lack of flowery habitats were also harming bees. “Also, if these neonicotinoids are simply replaced by other similar compounds, then we will simply be going round in circles. What is needed is a move towards truly sustainable farming,” he said.

Some experts are worried that the exemption for greenhouses means neonicotinoids will be washed out into water courses, where they can severely harm aquatic life.

Prof Jeroen van der Sluijs, at the University of Bergen, Norway, said neonicotinoids will also continue to be used in flea treatments for pets and in stables and animal transport vehicles, which account for about a third of all uses: “Environmental pollution will continue.”

The EU decision could have global ramifications, according to Prof Nigel Raine, at the University of Guelph in Canada: “Policy makers in other jurisdictions will be paying close attention to these decisions. We rely on both farmers and pollinators for the food we eat. Pesticide regulation is a balancing act between unintended consequences of their use for non-target organisms, including pollinators, and giving farmers the tools they need to control crop pests.”

https://www.theguardian.com/environment/2018/apr/27/eu-agrees-total-ban-on-bee-harming-pesticides

Young, Hive-Bound Bees Befuddled By Common Chemicals

COSMOS    By Tanya Loos     April 12, 2018

Even bees that never leave the hive can be exposed to insecticides and herbicides that affect their sense of taste and reduce their ability to learn. Tanya Loos reports.

Young worker bees exposed to neonicotinoids and glyphosate suffered an impaired sense of taste and damage to their memories. Credit: JESUS INES / EYEEMHive-bound young honey bees (Apis mellifera) are being poisoned by insecticide and weed killer gathered by their foraging hive mates, according to new research published in the Journal of Experimental Biology. The chemicals cause brain damage in young worker bees, affecting both their ability to taste and to learn, placing the future of the colony at risk.

Recent research in Europe and the USA has demonstrated that insecticides known as neonicotinoids have a substantial impact on honey bee health. Glyphosate, a commonly used herbicide, has also been shown to have effects on non-target species such as bees. In agricultural landscapes it is expected that honey bees would be exposed to both of these agrochemicals.

Carolina Goñalons and Walter M. Farina from the Universidad de Buenos Aires decided to examine the effects of field-realistic concentrations of these common farm chemicals on young worker bees.

The role of worker bees is related to age. Young worker bees perform vital tasks such nest maintenance and care of the eggs and pupae. Later in life they become field or forager bees, and gather nectar and pollen for the colony. These skills involve behavioural plasticity, memory and discernment, so the Goñalons and Farina believe the young bees serve as important bioindicators to study the effects of these chemicals on colony health.

To accurately measure the effects of neonicotinoids and glyphosate on young bees, Goñalons and Farina raised broods of young bees, and exposed them to various concentrations of the chemicals.

As the concentrations of the chemicals are too low to kill the bees outright, the only way to test their effects is by training the bees to carry out tasks, and then measuring the bees’ performance under various levels of exposure to the chemicals. The bee responses were assessed at 5, 9, and 14 days old.

The bees were fitted with tiny, bee-sized harnesses and trained to respond to various concentrations of sucrose solution and smells. The indicators included antennae movement and extension of their mouthparts.

Both chemicals had a negative effect on the young bees’ olfactory learning, and reduced sucrose responsiveness or sense of taste. Glyphosate also reduced food uptake during rearing.

The paper demonstrates that neonicotinoids and glyphosate adversely affect memory, taste and smell in young bees – the very senses and skills required by worker bees for nectar foraging. The authors are concerned that compromised foraging behaviour may threaten the survival of the colony, especially at the end of the summer season.

https://cosmosmagazine.com/biology/young-hive-bound-bees-befuddled-by-common-chemicals

How Bees Defend Against Some Controversial Insecticides

ScienceNews.org     By Dan Garisto    March 22, 2018

Researchers have discovered enzymes that can help resist some neonicotinoids

WHAT’S THE BUZZ Honeybees (shown) and bumblebees can resist a type of neonicotinoid insecticide thanks to a family of enzymes that metabolize toxic compounds.

Honeybees and bumblebees have a way to resist toxic compounds in some widely used insecticides.

These bees make enzymes that help the insects break down a type of neonicotinoid called thiacloprid, scientists report March 22 in Current Biology. Neonicotinoids have been linked to negative effects on bee health, such as difficulty reproducing in honeybees (SN: 7/26/16, p 16). But bees respond to different types of the insecticides in various ways. This finding could help scientists design versions of neonicotinoids that are less harmful to bees, the researchers say.

Such work could have broad ramifications, says study coauthor Chris Bass, an applied entomologist at the University of Exeter in England. “Bees are hugely important to the pollination of crops and wild flowers and biodiversity in general.”

Neonicotinoids are typically coated on seeds such as corn and sometimes sprayed on crops to protect the plants from insect pests. The chemicals are effective, but their use has been suspected to be involved in worrisome declines in numbers of wild pollinators (SN Online: 4/5/12).  

Maj Rundlöf, of Lund University in Sweden, helped raise the alarm about the insecticides. In 2015, she reported that neonicotinoid-treated crops reduced the populations of bees that fed from the plants. Rundlöf, who was not involved with the new study, says the new research is important because it clarifies differences between the insecticides. “All neonicotinoids are not the same,” she says. “It’s a bit unrealistic to damn a whole group of pesticides.”

Bass and his colleagues, which include scientists from Bayer, one of the main producers of neonicotinoids, investigated resistance to thiacloprid by looking at bees’ defense systems. The team focused on enzymes known as P450s, which can metabolize toxic chemicals, breaking them down before they affect the bee nervous system. The researchers used drugs to inhibit groups of P450 enzymes. When the family enzymes called CYP9Q was inhibited, bees became 170 times as sensitive to thiacloprid, dying from a much smaller dose, the researchers found. Discovering the enzymes’ protective power could lead to more effective ways to simultaneously avoid harming bees and help crops.

“We live in an era that uses pesticides,” Rundlöf says. “We need to figure out the ones that are safest.”

Citations:
C. Manjon et al. Unravelling the molecular determinants of bee sensitivity to neonicotinoid insecticides. Current Biology. Published online March 22, 2018. doi:10.1016/j.cub.2018.02.045.

Further Reading:
L. Hamers. Much of the world’s honey now contains bee-harming pesticides. Science News. Vol. 192, October 28, 2017, p. 16.

S. Milius. Neonicotinoids are partial contraceptives for male honeybees. Science News. Vol. 190, August 20, 2016, p. 16.

S. Milius. Bees may like neonicotinoids, but some may be harmed. Science News. Vol. 187, May 16, 2015, p. 13.

J. Raloff. Yet another study links insecticide to bee losses. Science News Online, April 5, 2012.

https://www.sciencenews.org/article/how-bees-defend-against-some-controversial-insecticides