Pesticide News - Issue 126

August 2021 | ISSUE 126

PESTICIDE NEWS

An international perspective on the health & environmental effects of pesticides

CALL TO BAN URBAN PESTICIDES

By Professor Dave Goulson A new petition is calling for the UK Government to ban the use of pesticides in urban areas and end their sale for use in gardens. There is no need to spray poisons in our streets, parks and gardens for cosmetic purposes, where they harm vital insect populations and pose a risk to human health.

Insects have been around for more than 400 million years; they were already ancient when the dinosaurs appeared. They have been enormously successful, evolving into more than one million known species. These creatures pollinate, control pests, recycle organic material from dung to corpses, tree trunks and leaves, keep the soil healthy and disperse seeds. They provide food for many larger creatures such as birds, bats, lizards, amphibians and fish. Life on Earth would grind to a halt without insects.

It is a huge concern that insects appear to be undergoing massive declines. In Germany, flying insects have declined by 76% in the last 26 years. In the UK, our more common butterfly populations have fallen by 46% since 1976, the rarer ones by 77%, despite great efforts by conservation organisations. Thirteen UK bee species have gone extinct, and more look set to follow them. In the USA, the iconic monarch butterfly, famed for its annual migration between Mexico and Canada, has declined by more than 80% since the 1980s.

As a child, I vividly remember my parents having to stop the car on summer journeys to scrub clear the windscreen, which quickly became covered with splatted insects as we drove along. Today, our windscreens are disturbingly clean. This has all happened within our lifetime; on our watch. The causes of insect declines are many, but there is no doubt that the ever-growing blizzard of pesticides used by farmers and gardeners is a major contributor.

Do not despair. We can all get involved in halting and reversing insect declines.

Most insects have not yet gone extinct, and they could recover quickly if we gave them somewhere to live that was free from poison. A growing number of us are actively encouraging insects in our gardens, and it is astonishing how much life even a small garden can support. Biologist and wildlife gardener, Jenny Owen, spent 35 years obsessively cataloguing every plant and animal that she could find in her modest 1/8th of an acre garden in urban Leicester, eventually recording no less than 2,673 different species, 1,997 of which were different types of insect.

Britain has 22 million private gardens; just think how much life they could collectively support if they were all wildlife-friendly.

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Imagine every garden, park, cemetery, roundabout and road verge filled with swathes of wildflowers; we could create a national network of wildlife-rich habitat from Land’s End to John O’Groats.

Manchester, Derry in Northern Ireland and North Lanarkshire in Scotland.

These and other examples from around the world prove beyond doubt that these chemicals are not needed.

This will only work if we stop spraying pesticides in our streets, parks and gardens. Many councils spray pavements, edges of paths in parks, even the edges of children’s playgrounds. The most commonly used pesticide, glyphosate (usually sold as ‘Roundup’), is harmful to bees, damages soil health, and is strongly suspected of causing non-Hodgkin’s Lymphoma.

Similarly, many homeowners use pesticides in their gardens, with no training, and often without protective clothing. An extensive range of pesticides are sold by garden centres, DIY chains, and most supermarkets, including chemicals that are classified as carcinogens and neurotoxins.

The new petition is calling for the UK Government to clean up our towns by banning the use of pesticides in urban areas & ending their sale for use in gardens. The petition’s launch coincides with publication of “Silent Earth”, a new book which spells out how the decline of wild bees and other insects are a potential catastrophe for us all.

None of this pesticide use is necessary or desirable. Safe and sustainable alternatives for weed control are available, where necessary. France banned all use of synthetic pesticides in public spaces in 2017, and banned garden use from 2019. In Canada, 170 cities and towns are pesticide-free, some of them having been so for 30 years. Thanks to PAN UK, more than 70 towns and cities across the UK have already taken major steps towards going pesticide-free, including Brighton and Hove, boroughs of London and

Love them or loathe them, we all need insects. Three quarters of the crops we grow need pollinators. We have to learn to live in harmony with nature, seeing ourselves as part of it, not trying to rule and control it with an iron fist. Our survival, and that of our insect friends, depends upon it.

Dave Goulson is Professor of Biology at University of Sussex, specialising in bee ecology. He has published more than 300 scientific articles on the ecology and conservation of bumblebees and other insects. He founded the Bumblebee Conservation Trust in 2006, is a PAN UK trustee and an 'Ambassador' for the UK Wildlife Trusts.

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REASSEMBLING OUR CITIES

By Emma Pavans de Ceccatty, PAN UK Our recent series of talks Reassembling Our Cities: Creating pesticide-free urban spaces for people, plants and wildlife brought together 16 inspiring speakers to celebrate the diversity of nature in our cities and gardens, and the incredible projects that these speakers have set up to promote and protect it.

‘Our Resilient Neighbours’ and ‘Space for Us All’ gave botanists, mushroom enthusiasts, ecologists, biologists, and conservationists an opportunity to share their favourite urban plant and wildlife species and highlight how much there is to see, hear, smell, touch and even taste just on our doorsteps!

Our guests also highlighted how important it is to engage people with nature as ‘out of sight’ turns into ‘out of mind’ and that leaves our urban wildlife in an increasingly vulnerable position.

In view of this, ‘Connecting Communities’ and ‘Abundant Green Networks’ asked campaigners, community growers, urban designers and an environmental lawyer to explore the ways in which we can create more green spaces and ensure access to these spaces by different communities.

From the humble, but incredibly resilient dandelion, to rare orchids spotted on bank roofs and near fastfood restaurants, and mushrooms popping up in carparks there is an incredible wealth of plants and fungi to admire just on our walks to the bus stop.

Insects rely on these green networks to navigate our cities and to survive everincreasing conflicts for space. In turn, our urban birds, mammals, reptiles and amphibians feed on them and have a better chance to thrive.

Connecting to this local biodiversity in our daily lives has the potential to transform our days and bring wonder to mundane moments.

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There is a critical lack of access to green spaces for certain groups, most often people living in low-income areas, yet gardens and wild spaces have been shown to be crucial for our mental and physical wellbeing.

These spaces also build social connections and increase community resilience.

Our speakers demonstrated ways in which they have started to reclaim space through guerrilla gardening, growing food in community spaces, rewilding brown patches, or simply protecting an ancient tree from being chopped down. These are all initiatives where people have taken matters – in this case: soil, shovels and plants into their own hands to green what were previously forgotten corners.

Community gardens and green spaces aren’t true assets unless they are led and managed by their local communities, reflecting their diverse needs. These can then become flourishing spaces that residents are proud of, cultural assets where biodiversity becomes integral to the soul of a community.

This series of events has been an opportunity for PAN UK to highlight the fact that pesticide use on our pavements, playgrounds, parks and other green spaces, continues to undermine individual, group and community efforts to encourage urban biodiversity. UK cities are homes to increasing populations and it’s crucial that our cities are greener, wilder spaces that are inclusive to all. Going pesticidefree is the first step in protecting our green spaces and helping nature flourish.

Watch the series of talks online at: www.pan-uk.org/reassembling-our-cities Emma leads on the Pesticide-Free Towns Campaign. Find out more at: www.pan-uk.org/pesticide-free

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THE HAZARDS OF PESTICIDES TO SOIL INVERTEBRATES

By Tari Gunstone and Dr Aditi Dubey Soils are incredibly biodiverse ecosystems, containing millions of organisms that provide essential services for our survival. Thanks to the busy work of these unsung heroes, we are fed, have filtered water and recycled waste, and our planet’s temperature is regulated.

Unfortunately, soils are also the final resting place for the majority of agricultural pesticides. While threats like decreasing insect populations, human health risks, and water contamination highlight the dangers of our reliance on pesticides, we are just beginning to understand the toll they take on the world underfoot.

With compiled data from nearly 400 studies conducted in both the lab and field, researchers from The Center for Biological Diversity, Friends of the Earth, and University of Maryland conducted the most comprehensive review to date on how pesticides affect soil invertebrates. Recently published in Frontiers in Environmental Science, our review, Pesticides and Soil Invertebrates: A Hazard Assessment, found that pesticides negatively affect soil invertebrates in 71% of cases. The harmful effects of pesticides on soil organisms ranged from molecular to community levels, including impacts on mortality, reproductive function, richness

and diversity, abundance, behaviors like feeding, burrowing, and decomposition, growth, biochemical biomarkers, and body structure.

The biodiversity of our soils is vast, containing nearly a quarter of our planet’s taxa. We analyzed the effects of pesticide on just a small percentage of these that spend all or most of their developmental stages in the soil, making them the most vulnerable to this route of pesticide exposure: 275 non-target species or mixed groups, including earthworms, ground beetles, springtails, centipedes, millipedes, nematodes, mites, isopods, ground nesting bees, and parasitic wasps.

Insecticides were predictably toxic, causing harm to invertebrates in 80% of cases. More surprisingly, other pesticides such as amide/anilide herbicides and benzimidazole and inorganic fungicides were among the most damaging pesticide classes overall. While our review covered a large number of pesticides currently not banned in the United States (284 different pesticide active ingredients or unique mixtures of pesticides), there are many commonly used pesticides and fumigants that have not been adequately represented in relevant soil studies and require further research.

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In addition to the pesticides themselves, non-active ingredients in pesticide formulas fly under the regulation radar.

Surfactants in Roundup were recently found to cause 94% mortality in bumble bees within 24 hours (Straw et al. 2021).

Pesticides can also have long half-lives in the soil; with a recent large-scale study finding up to 16 different pesticide residues in soils after 20 years of organic production (Riedo et al. 2021).

Most agricultural pesticide regimens utilise a mix of pesticides throughout the year, leaving few windows of opportunity for soil communities to recover. While changes to pesticide delivery methods are increasingly utilised to reduce pollinator exposure, contamination of water sources and aerial deposition in neighboring crops or residential areas, the switch from foliar spray to seed coating and soil drenching

Images in this article credited to Tari Gunstone www.tarigunstone.com

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further increases exposure for soil organisms. Soil preservation strategies have focused on reduced or no tillage, which greatly benefits both soil invertebrates and soil structure, but often relies on increased herbicide application to kill cover crops, counteracting the benefits to soil organisms.

Oral pesticide toxicity for the European honey bee in the US increased 48-fold between 1992 and 2014, driven largely by increased neonicotinoid use in corn and soybean (Dibartolomeis et al. 2019).

Given that virtually all neonicotinoid application in those crops is through seed treatments, toxicity for soil organisms is likely even higher (Lewis and Tooker, 2015).

While neonicotinoid seed treatments are among the worst offenders in terms of pesticide impacts on soil invertebrates, they do not provide economic benefits in many, if not most cases (Tooker et al., 2017).

Tari Gunstone worked as an environmental research assistant at the Center for Biological Diversity where she co-authored Pesticides and Soil Invertebrates: A Hazard Assessment.

Despite the alarming extent of exposure of pesticides to soil organisms, soil organisms are not accounted for in pesticide risk assessment in the United States. While the European Food Safety Authority (EFSA) requires standard tests for several soil organisms (an earthworm, mite, and springtail species), the U.S. EPA uses the European honey bee as a proxy for all terrestrial invertebrates — needless to say, this is woefully inadequate.

In the U.S., water and air receive regulated protection while soils are the forgotten sponge of our pollution.

The inextricable link between below and above ground communities means that hazards to soil invertebrates not only disrupt the important ecosystem services provided by healthy, diverse soil communities, but also indirectly impact the essential contributions of aboveground organisms, from pollination services to biological pest control. How much soil damage are we causing through our agricultural practices and what damage is irreversible? Scientists agree that it takes roughly 100 years to build just an inch of topsoil, while disturbed soil communities may require more than 15 years to recover (Menta, 2012). We must acknowledge that protecting soil organisms is vital for maintaining a healthy planet, and take urgent measures to halt the damage being done.

Aditi Dubey is a PhD graduate in Entomology from the University of Maryland and an Entomological Society of America Science Policy Fellow. Her interests include Integrated Pest Management, sustainable agriculture and environmental justice.

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IMPACTS OF CHEMICAL POLLUTION ON FRESHWATER & MARINE WILDLIFE IN THE UK

By Dr Julie Schneider and Dr Francesca Bevan Chemical pollution is a big concern for aquatic wildlife in the UK. Agricultural pesticides and road runoff, household and industrial wastewater, as well as leachates from landfills and past industrial sites, all end up as mixtures of chemical contaminants in our rivers, as they make their way to the sea. The chemical pollution levels are a major concern as, in England, not a single one of the 4,679 rivers, lakes or estuaries achieved good chemical status according to the Environment Agency 2019 assessment.

CHEM Trust and the Marine Conservation Society joined forces to answer the question: what impact is chemical pollution having on aquatic wildlife in the UK? The results of our investigation, based on exchanges with 15 UK academics throughout 2020, are covered in our joint briefing: “State of

What is clear from our investigation is that: 1. There is strong and clear evidence of the impact of legacy persistent organic pollutants (POPs) on aquatic wildlife in the UK, in particular, marine mammals.

2. There are major data gaps regarding the trends of emerging contaminants in freshwater and marine environments as well as their impact on aquatic wildlife in the UK, including for pesticides.

3. Chemical pollution contributes to the biodiversity crisis in the UK and the Government should take urgent actions to address it in a context where aquatic wildlife is subjected to many other stressors such as climate change and habitat loss.

play of the impact of chemical pollution on freshwater and marine wildlife in the UK”.

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Legacy POPs, such as the pesticide DDT, are human made synthetic substances that have been largely phased out globally in the past decades.

These “poisons from the past” are highly persistent in the environment, which is why they are still impacting aquatic wildlife decades after being phased out.

In the marine environment, these legacy chemicals, in particular polychlorinated biphenyls (PCBs), have been found to negatively affect the immune system, reproductive system and lipid metabolism of marine mammals in the UK (e.g. killer whales, harbour porpoises, grey seals). This is a source of concern for the long-term impact of chemical pollution on marine mammal populations, with clear evidence that killer whale populations are in decline.

In freshwater, POPs are thought to be responsible for the fact that specific freshwater species, such as certain fish and invertebrates, have only partially recovered from their decline in the 20th century.

An incomplete picture: major data gaps on other contaminants The chemical landscape has evolved significantly in the past decades, with thousands of new substances put on the market and a strong diversification of compounds. Emerging contaminants of concern include, PFAS also known as the ‘forever chemicals', new generations of flame retardants, neonicotinoid insecticides and pharmaceuticals.

Unfortunately, the scarcity of data on other contaminants makes it difficult to derive their trends and impacts on aquatic wildlife in the UK. For instance, the potential role of pesticides in the decline of amphibian populations due to infectious disease in the UK has yet to be fully investigated.

By focussing on only a handful of well-known chemicals, environmental monitoring in the UK paints a very incomplete picture of the true pollution burden of aquatic wildlife and ecosystems. Real-world chemical exposure is a complex mixture of known and unknown natural and anthropogenic substances. Academics mentioned that in several instances, it cannot be ruled out that adverse effects ascribed to specific legacy contaminants could, in reality, result from a combination effect of legacy and emerging pollutants.

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12 Key Asks for the UK Chemicals Strategy The UK Government should aim at minimising emissions of all synthetic substances into the water environment, including pesticides. All new synthetic substances emitted are adding to the existing chemical pollution burden. This burden includes persistent chemicals such as POPs and PFAS for which the impacts will be felt for generations.

UK academics are calling for chemical regulation to be much more proactive by preventing new ‘problem’ chemicals from entering widespread use to avoid having to mitigate the impacts retrospectively.

This is an important message for the UK Government to take onboard, as a consultation of their new Chemicals Strategy is expected in late 2021.

Dr Julie Schneider is a campaigner at CHEM Trust, a charity working to prevent human-made chemicals from causing long-term damage to humans and wildlife. Her work focuses on persistent synthetic chemicals, in particular PFAS.

27 UK NGOs, including CHEM Trust, MCS and PAN UK, have written to the UK Government to outline 12 Key Asks that should be prioritised for the UK Chemicals Strategy. The key asks include among others: 1. Phasing out the use of the most hazardous chemicals, including very persistent chemicals such as PFAS. 2. Identifying and remediating hot spots of legacy POPs contamination.

3. Developing legislation that addresses combined exposure to chemicals, or the cocktail effect.

4. Developing an effective monitoring and alert system.

To protect our aquatic biodiversity, we urge the UK Government to listen to the concerns raised by the academics and implement our 12 Key Asks.

Dr Francesca Bevan is the policy and advocacy manager for chemicals at the Marine Conservation Society. Francesca concentrates on the chemical pollutants that are impacting our seas including PFAS and other persistent organic pollutants.

Read the full briefing: Bevan, F. & Schneider, J., 2021. State of play of the impact of chemical pollution on freshwater and marine wildlife in the UK. A joint CHEM Trust and MCS briefing.

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SMALL STREAMS IN AGRICULTURAL ECOSYSTEMS ARE HEAVILY POLLUTED WITH PESTICIDES In a German nationwide monitoring programme, a consortium of scientists led by the Helmholtz Centre for Environmental Research (UFZ) has shown that the governmental thresholds for pesticides are generally too high and that even these excessively high levels are still exceeded in over 80% of water bodies.

Loss of biodiversity can only be halted if the environmental risk assessment of pesticides is radically revised.

For two years, researchers studied pesticide contamination at more than 100 monitoring sites on streams flowing through predominantly agricultural lowland regions in 12 federal states in Germany. They found significant exceedances of the RAC value - the concentration of an active ingredient specified in the official approval procedure for a pesticide, which should not be exceeded in the water body in order to prevent negative effects on aquatic organisms. In most of the small streams investigated, the RAC values were exceeded (81%). In 18% of the streams, such exceedances were detected for more than 10 pesticides.

"We have detected a significantly higher pesticide load in small water bodies than we originally expected", says Prof. Matthias Liess, ecotoxicologist at the UFZ and coordinator of the small water monitoring project. For example, in three water bodies, the insecticide thiacloprid exceeded the RAC value by

more than 100-fold. In 27 streams the insecticides clothianidin, methiocarb, and fipronil as well as herbicides such as terbuthylazine, nicosulfuron, and lenacil exceeded the RAC value 10- to 100-fold.

Because of the extensive data set, the researchers were able to reveal that pesticides affect aquatic invertebrate communities at much lower concentrations than previously assumed by the pesticide risk assessment.

The concentrations depend on which species are to be conserved. For example, sensitive insect species such as caddisflies and dragonflies require much lower (1.000-fold) threshold values than snails and worms. "For sensitive insect species, the pesticide concentration in the small lowland streams is the most relevant factor that determines their survival. In contrast, other environmental problems such as watercourse expansion, oxygen deficiency, and excessive nutrient content are less important. For the first time this study allows a ranking of environmental problems", says Liess.

For the current approval of pesticides, the high sensitivity of species in the ecosystem context is grossly underestimated. Until now, the ecological risk of pesticides in the field has been predicted based on laboratory studies, artificial ecosystems, and simulation models.

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However, according to Liess, the results from the laboratory do not reflect reality. "In addition to pesticides, many other stressors act on organisms in the ecosystem. These make them much more sensitive to pesticides. Natural stressors such as predation pressure or competition between species are not sufficiently taken into account in the risk assessment. But these obvious problems often go unnoticed because the degree of pesticide contamination and the effect of this have not been validated in the field - neither in Germany nor in other countries", he says.

In the course of the project, the scientists also found that the type of sampling has a drastic influence on the concentrations of pesticides measured.

In addition to the scoop sample specified as standard by the EU Water Framework Directive, they also took an "event sample". Here, an automatically controlled sampler takes water samples from the water body after a rain event.

"The event sample provides much more realistic results because the pesticides enter the water bodies as a result of the increased surface run-off from

the field, especially during rain", says Liess. Compared to the scoop samples, the event-related samples show a 10fold higher pesticide load. "In order to realistically depict the water pollution, samples must therefore be taken after rainfall events. That’s why we need an official regular environmental monitoring to be able to assess the amount and the effects of pesticides," says Matthias Liess.

Liess and his colleagues also demand that new scientific findings be incorporated into the approval process for new pesticides more quickly. "We are still using pesticides that were approved many years ago based on an outdated risk assessment. This must therefore change as soon as possible. Only in this way can we preserve the biodiversity in our waters and with it the services that these biotic communities provide for our ecosystems."

Prof. Dr Matthias Liess is Head of Dept SystemEcotoxicology at UFZ - Helmholtz Center for Environmental Research. The full article is in the journal Water Research.

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AGROECOLOGY: CORE COMPONENT IN TACKLING CLIMATE CHANGE AND BIODIVERSITY LOSS

By Prof Dr Josef Settele The fight against global warming and for sustainable development can only succeed if all political decisions take the issues of climate protection, biodiversity and social justice into account equally.

This is the core message in the recent peer-reviewed workshop report, Biodiversity and Climate Change, by 50 of the world’s leading biodiversity and climate change experts and assembled by the Intergovernmental SciencePolicy Platform on Biodiversity and Ecosystem Services (IPBES) and the Intergovernmental Panel on Climate Change (IPCC). They conclude that healthy ecosystems can make longterm contributions to climate protection.

The report regards agroecology and agroforestry, including diversification of planted crop and forest species, as core components for the enhancement of biodiversity conservation and climate mitigation. Addressing insect diversity loss through conventional agricultural practices may be better communicated through improved integration of insect conservation practices with climatesmart agricultural practices. What is clear though, is that the body of evidence regarding the ability of the adoption of agroecological principles to achieve multiple benefits within

agricultural landscapes (including improved conservation) is strong and growing. Sustainable agricultural and forestry practices can improve adaptive capacity, enhance biodiversity, increase carbon storage in farmland and forest soils and vegetation, and reduce greenhouse gas emissions. Improved management of cropland and grazing systems, such as soil conservation and the reduction of pesticide and fertiliser use, is jointly estimated by the report to offer annual climate change mitigation potential of at least 3-6 gigatonnes of carbon dioxide equivalent.

This increased adaptive capacity is especially important in view of extreme events such as heatwaves, droughts, fires, insect, pest and disease outbreaks, which are expected to become more frequent and severe under climate change.

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Overall, agricultural pathway choices are about quality vs. quantity, and high yield agriculture based on high inputs of fertilizers or pesticides is to some extent obsolete. Outcomes of comparisons between intensive vs less intensive agriculture are very system dependent and, in addition, intensive high-yield systems may move the provision of nonmaterial benefits (aesthetics, sense of place etc.) further from people’s centres of livelihood, in contrast to less intensive and often more biodiverse agriculture.

Biodiversity-based measures aim to increase resistance and resilience of agricultural ecosystems and reduce environmental impacts by mobilizing biodiversity to replace chemical inputs with ecological functions. These measures often increase climate adaptation capacity. One adaptive strategy is the improvement of soil biodiversity and health, characterised by reduced tillage, use of less pesticides and increased organic material input, which enhances the abundance and diversity of soil organisms, and participates in making soils more resistant and resilient in the face of climate change. If done wisely, soil conservation measures can have large benefits for soil and non-soil biodiversity.

The authors also reveal the extent to which pesticide and fertiliser use in one-sided climate protection concepts like the large-scale cultivation of energy crops in monocultures can negatively affect biodiversity and ecosystem services, including in adjacent land, freshwater and marine ecosystems.

The Governments of the United Kingdom and Norway co-hosted the virtual workshop. “This is an absolutely critical year for nature and climate,” said Lord Zac Goldsmith, UK Minister of State for Pacific and the Environment.

“With the UN Biodiversity Conference in Kunming, and the Glasgow Climate Change Conference in the UK, we have an opportunity and responsibility to put the world on a path to recovery. This hugely valuable report by the experts of IPBES and IPCC makes it clear that addressing biodiversity loss and climate change together offers our best chance of doing so.”

Access the report at: https://ipbes.net/events/launch-ipbesipcc-co-sponsored-workshop-reportbiodiversity-and-climate-change; report in full: DOI:10.5281/zenodo.4659158; synopsis of report: DOI:10.5281/zenodo.4782538

Prof Dr Josef Settele is Head of the Dept of Conservation Biology and Social-Ecological Systems at the Helmholtz Centre for Environmental Research and is professor of ecology at the Martin-Luther-University of Halle-Wittenberg.

He was co-chair of the Global Assessment of IPBES from 20162019 and co-author of the IPBES-IPCC co-sponsored workshop report on biodiversity and climate change, published in 2021.

He is also a member of the German Advisory Council on the Environment. (Image: Prof Dr Josef Settle by Sebastian Wiedling)

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INTERACTIONS BETWEEN PESTICIDES INCREASE BEE MORTALITY

By Dr Harry Siviter A doctor will always ask if you are on any other medication before they write you a prescription. This is because pharmaceuticals can interact with each other and potentially disrupt treatment, or even harm the patient. But when agrochemicals, such as pesticides, are licensed for use on farms, little attention is paid to how they interact with one another, and so their environmental impact is underestimated.

We analysed data gathered in scientific studies from the last two decades and found that when bees are exposed to a combination of pesticides, parasites and poor nutrition, the negative impact of each is exacerbated. We say that the cumulative effect of all these things is synergistic, meaning that the number of bees that are killed is more than we would predict if the negative effects were merely added together.

When bees were exposed to multiple agrochemicals, the effects were worse.

When we consider the prevalence of these substances in the environment, the picture begins to look very worrying.

Crops are rarely ever treated with just one chemical. Insecticides control insect pests, such as aphids. Herbicides, such as glyphosate, kill unwanted weeds, and fungicides are used to control moulds such as mildew. Crops will often be treated with different agrochemical combinations repeatedly throughout the year.

Many agrochemicals, such as neonicotinoids, are systemic, meaning they accumulate in the environment over several months, and in some cases years. For pollinating insects, exposure to multiple agrochemicals is the norm, not the exception. But when new agrochemicals are licensed for use by regulatory bodies, such as the US Environmental Protection Agency (EPA) or the European Food Safety Authority (EFSA), how they interact is seldom considered.

In some ways this is understandable.

Thousands of different agrochemicals have been licensed for use globally and assessing how each one interacts with each other would be difficult. But commercial pesticide formulas, sold en-masse to farmers, regularly contain many different chemicals. Assessing how each of them interacts before they are licensed for use should be mandatory.

And once an agrochemical is licensed for use, regulators should continually monitor its potential harm in case prelicensing assessments failed to detect something important. These postlicensing observations could be akin to those carried out with pharmaceuticals in humans, which would offer better protection for both wildlife and food security.

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Dr Harry Siviter is a postdoctoral research fellow at The University of Texas at Austin and formerly a PhD student at Royal Holloway, University of London. This article is an excerpt from the The Conversation and can be read in full at: https://theconversation.com/pesticides-interactionsbetween-agrochemicals-increase-their-harm-to-bees-165626

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PESTICIDE TOXICITY ON POLLINATORS HAS INCREASED OVER THE YEARS

By Professor Parthiba Basu A reduction in the volume of pesticide consumption in certain countries is often cited as a success of anti-pesticide use campaigns. The pesticide industry also cites such declines as evidence for positive and pro-environment progress.

It is true that the use of pesticides (insecticides, herbicides and fungicides) in agriculture has undergone significant changes globally and in many countries, the use rate (Kg/ha) or bulk volume of pesticides used (Kg/Year) has declined.

But the picture is not uniform and consumption has increased in some areas.

The changes in pesticide volumes, is only part of the picture. The key point is to understand the effects these consumption changes have had on the environment and human health. One factor that is often overlooked is that the toxicities of different kinds of pesticides and their impacts on different non-target species groups vary greatly. As a result, weight-based measures are inadequate in assessing the environmental impacts of these pesticides. Therefore, it is crucial to have a toxicity-weighted pesticide impact assessment on different vulnerable species groups for effective conservation management strategies. Unfortunately, such information has been unavailable so far.

Pollinators in agroecosystems face a grave threat from pesticides, and there is mounting evidence on the scale and intensity of their impacts. The gap in our understanding of the toxicity-weighted impacts of different pesticides on pollinators and other vulnerable species groups has been bridged by a recent research article by Ralph Schultz and his colleagues (Schultz et al. 2021) at the University of Koblenz-Landau in Germany.

The study used 1,591 different substance-specific regulatory threshold levels (RTL) ‘indicative of potential biodiversity impacts’ to examine 381 pesticides for a period of twenty-five years (1991 – 2016) on their effects on eight different non-target organismal groups. The RTL values indicate the pesticide toxicity on an organism at the predicted exposure level and is part of a regulatory procedure before a pesticide is allowed for application. The RTL data was taken from the US Environmental Protection Agency (EPA) and the pesticide consumption data source was the US Geological Survey (USGS). From these data sets, they calculated the Total Applied Toxicity (TAT) index- an indicator of the environmental impact for the non-target faunal groups for each year.

The annual TAT values were summed up for different sets of substances (e.g., pesticide use types, chemical classes of respective pesticides and their modes of action).

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This analysis shows that the TAT values for pollinators have significantly increased even though the total applied amounts of pesticides have fallen considerably. The TAT for pollinators more than doubled and rose approximately by 8% per year during the decade following 2005. Neonicotinoids, whose usage rose sharply in place of organophosphates and carbamates over the last decade, are increasingly responsible for this rise in TAT for bees (social and solitary).

The TAT for non-target plants from herbicides has also increased significantly post 2006. This concomitant rise in toxicity on plants in parallel with that for pollinators poses an additional risk on the plant-pollinator interactions.

The adverse impacts of neonicotinoids on pollinator health have been extensively studied during recent years, and some have been banned in EU countries. The adverse impacts of herbicides on pollinator health are only unravelling now, and a recent meta-analysis (Battisti et al. 2021) published in May this year has shown that the mortality in bees from glyphosate exposure has increased significantly.

While the pesticide usage data used by Shultz and his colleagues are from the USA, it is quite possible that TAT values would be higher for the agroecosystems of different global regions like Asia, South America and certain EU countries where pesticide sales increased during this period along with the expansion of croplands. It is not possible to calculate the TAT for many countries due to the non-availability of open access pesticide usage data for such and global regions, e.g., China, Russia, South America and the EU. Hopefully, a global assessment will be possible soon – before it is too late.

Professor Parthiba Basu has a Ph.D. in Ecology and a research career spanning nearly thirty years. He heads the Centre for Agroecology and Pollination Studies at the University of Calcutta. His research interest is broadly on biodiversity and ecosystem functioning along ecological degradation gradients.

A major research focus has been the status of pollinators and natural enemies of pests in the agro-ecosystems and their restoration.

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MORE TO POLLINATOR DECLINES THAN NEONICOTINOIDS

By Nick Mole, Policy Officer, PAN UK Many thought that the recent ban on neonicotinoids in the UK would mean an end to the harmful effects of pesticides on our pollinators. But this is far from the truth. The interactions between different pesticides can increase harm to pollinators as chemicals combine to become more toxic (the 'cocktail effect').

Also, studies have shown that other classes of pesticides, and particularly herbicides, can harm pollinators directly and indirectly.

Indirect impacts of herbicides include a decrease in the variety and abundance of wildflower species upon which they forage. The UK has lost 97% of its wildflower meadows since 1930.

Intensification of agriculture, the creation of monocultures, and the increased use of herbicides has led to massive declines in native wild plant species. 20% of British wildflowers are under serious threat of extinction. According to a recent study, each and every square kilometre in the UK lost an average of 11 species of bee and hoverfly between 1980 and 2013.

An increasing body of evidence shows that herbicides can also directly impact the health of bees and pollinators. The majority of the research has focused on the impact of glyphosate as it is the most widely used herbicide in the world.

The use of glyphosate in UK agriculture between 1996 and 2016 rose from approx.

0.5 million kgs to 2.5 million kgs, an increase of 400%. Of particular concern are the effects of glyphosate on the gut bacteria of bees making them more susceptible to certain pathogens which are often lethal. Other studies have found that glyphosate exposure negatively affects the ability of bees to detect and remember both the location of food sources and navigation abilities.

It is clear that there is an urgent need for more research into the impacts of herbicides and other pesticides on pollinators and that we must not view the banning of neonicotinoids as the answer to bee-declines. PAN UK will shortly be publishing a report that explores the impacts of herbicides on pollinators.

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Pesticide Action Network UK

ISSN 2514-5770

We are the only UK charity focused solely on tackling the problems caused by pesticides and promoting safe and sustainable alternatives in agriculture, urban areas, homes and gardens.

The Brighthelm Centre North Road Brighton BN1 1YD

We work tirelessly to apply pressure to governments, regulators, policy makers, industry and retailers to reduce the impacts of harmful pesticides to both human health and the environment.

Telephone: 01273 964230 Email: admin@pan-uk.org

Find out more about our work at: www.pan-uk.org