Harmful effects of pesticides in points

The impacts of pesticides on wildlife are extensive, and expose animals in urban, suburban, and rural areas to unnecessary risks. Beyond Pesticides defines "wildlife" as any organism that is not domesticated or used in a lab. This includes, but is not limited to, bees, birds, small mammals, fish, other aquatic organisms, and the biota within soil. Wildlife can be impacted by pesticides through their direct or indirect application, such as pesticide drift, secondary poisoning, runoff into local water bodies, or groundwater contamination. It is possible that some animals could be sprayed directly; others consume plants or prey that have been exposed to pesticides.

Click the links below to navigate our wildlife page:

Pesticide exposure can be linked to cancer, endocrine disruption, reproductive effects, neurotoxicity, kidney and liver damage, birth defects, and developmental changes in a wide range of species. Exposure to pesticides can also alter an organism’s behavior, impacting its ability to survive. In birds, for example, exposure to certain pesticides can impede singing ability, making it difficult to attract mates and reproduce. Pesticides can also affect birds' ability to care for offspring, causing their young to die.  For bees, even “near-infinitesimal” levels of systemic pesticides result in sublethal effects, impacting mobility, feeding behaviors, and navigation.  

Many deformations have been found after exposure to hormone-mimicking pesticides classified as endocrine disruptors. The impacts of these chemicals include hermaphroditic deformities in frogs, pseudo-hermaphrodite polar bears with penis-like stumps, panthers with atrophied testicles, and intersex fish in rivers throughout the U.S. Reproductive abnormalities have been observed in mammals, birds, reptiles, fish, and mollusks at exposure levels considered “safe” by the U.S. Environmental Protection Agency (EPA).

Visit our Pesticide Gateway for more information about specific pesticides and their impacts on wildlife.

Biodiversity is the web of life, including the complex array of organisms that live in the environment, and their interactions and interdependencies. The functionality of biodiversity has deep significance for the nurturance and protection of the many individual species in the environment that are part of a greater whole. The impacts of pesticides on wildlife directly relate back to the functional aspects of biodiversity. The Earth’s rich biological heritage of species, communities, and ecosystems, which have evolved across millions of years, is rapidly deteriorating and in many instances irreversibly disappearing. The impacts of pesticides on wildlife is a major cause of concern in the deterioration of biodiversity.

It has been documented that certain pesticides, when introduced to aquatic environments, cause a decline in species diversity in aquatic organisms and predatory insects. In Europe, it has been found that a 42% loss in species richness occurs due to pesticide exposure, even when such exposures are at concentrations deemed environmentally safe by current legislation. Species richness of beneficial insects, such as bees, spiders, and beetles, has been found to be much higher on untreated or organic fields than on those treated with insecticides. Use of insecticides is a common occurrence in chemical-dependent agriculture.

Organic pest management sharply contrasts with a chemical-intensive approach in terms of its impact on the stability and resiliency of ecosystems. This divergence has enormous consequences for biodiversity and survival of wild species. Various land management practices have different effects on the web of life; recognition of this is crucial to maintaining the intricate balance and life-sustaining benefits of nature. Utilizing organic pest management rather than chemical-intensive controls is the most critical step in mitigating negative impacts of pesticides on wildlife and preserving the Earth’s remaining biodiversity.

Economic Impacts of Pesticides on Wildlife

The estimated economic costs of losses to biodiversity — for the value of pollinator services, “beneficial” predators, and birds and aquatic life — are continually changing as more complex and comprehensive studies are published. Earlier studies estimated that the cost of losses to biodiversity might amount to more than $1.1 billion annually. Now, we know that the loss of biodiversity can cost hundreds of billions of dollars annually. Natural pest control, a fundamental agricultural service, is estimated to be worth $100 billion annually. The role of soil biota in increasing agricultural productivity is worth $25 billion annually. By 2009, the value of dependent crops attributed to all insect pollination was estimated to be worth $15.12 billion annually.

Other economic impacts are related to the recreational use of wildlife. U.S. citizens already spend over $60 billion annually on hunting, fishing, and observing wildlife; much of the wildlife at the center of those activities depends on insects as a food source. Researchers have found that there is a steady decline in these insects due to pesticide exposure and an overall decline in biodiversity. It could be concluded then that, as beneficial insect populations decline, their ability to provide ecosystem services will also decline, impacting the available wildlife for hunting, fishing and observing. The demand for these recreational activities will stay constant while the supply (availability) will decline, causing an increase in dollars spent by U.S. citizens for each year.

Organic Systems Protect Wildlife

Two ways to combat the negative impacts of pesticides on wildlife are: to implement organic practices for your own lawn and garden, and to support organic agriculture, rather than on conventional agriculture, which relies on pesticide use. Beyond Pesticides supports organic agriculture as effecting good land stewardship and reducing wildlife's hazardous chemical exposures. The pesticide reform movement, citing pesticide problems associated with chemical agriculture — from groundwater contamination and runoff to drift — views organic as the solution to these serious environmental threats.

Conventional agriculture relies on a “pick and choose” method when it comes to pesticide use — only treating the symptoms of bad land management instead of acknowledging the deeper problems and attempting to understand agriculture as a whole system, including impacts on wildlife. Adopting a whole-systems approach, starting with management methods that “feed-the-soil,” and thus, promote healthy land from the ground up, would result in the greatest systemic benefit. Beyond Pesticides has long supported a “feed-the-soil” approach to agricultural management. This systems approach, which centers on managing soil health and on proper fertilization, eliminates synthetic fertilizers and focuses on building the soil food web and nurturing soil microorganisms. Experience demonstrates that this approach develops a soil environment rich in microbiology, which will produce resilient, productive land and benefit wildlife.

Healthy, resilient soil reduces any need for pesticides; terrain free from pesticides benefits wildlife and promotes natural predators, who can then do what they were meant to do in nature — provide natural controls. Organic systems save wildlife from the dangerous impacts of pesticides, encourage them to flourish, and restores the natural balance that is unable to exist in a conventional agricultural system.

Utilizing the Endangered Species Act and Other Laws to Protect Wildlife

One way that groups like Beyond Pesticides have sought to protect wildlife from the threat of pesticides is by holding federal agencies accountable to the Endangered Species Act (ESA) of 1973, which provides for the conservation of ecosystems on which threatened and endangered species of fish, wildlife, and plants depend. EPA has routinely disregarded the ESA’s requirement to consult with federal wildlife agencies on how to implement conservation measures to protect threatened and endangered species from pesticides. After years of gridlock, federal wildlife agencies, EPA, and the U.S. Department of Agriculture (USDA) asked the National Academy of Sciences to study the issue and report on best ways to protect listed species (any species likely to become endangered or which is in danger of extinction) from the effects of toxic pesticides. The National Academy of Sciences report identified deficiencies for all the agencies involved in pesticide consultations, but singled out the EPA’s approach for its numerous analytical shortcomings. In response to the Academy’s recommendations, the agency announced several reforms, in the fall of 2013, designed to protect endangered species more effectively.

A stranded fish at Murray's Cauld near Selkirk
Photo by Walter Baxter

Though the ESA is one of the most important laws for protecting wildlife, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), Clean Water Act (CWA), and National Environmental Policy Act (NEPA) are other significant laws meant to keep wildlife safe. FIFRA regulates pesticides to prevent “unreasonable adverse effects” to humans and the environment, including wildlife. The stated objective of the CWA is to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters . . . for the protection and propagation of fish, shellfish, and wildlife.”

Finally, NEPA requires that any federal government action that may impact wildlife and the environment must review and evaluate those impacts before any action is taken. Each of these laws can be utilized to protect wildlife by holding federal agencies accountable to them. For more detailed information about each law and how it protects wildlife, read "Preserving Biodiversity As If Life Depends on It," from our winter 2011–2012 Pesticides and You newsletter.

See below for successful litigation regarding pesticides and wildlife:
EPA Agrees to Regulate Novel Nanotechnology Pesticides after Legal Challenge (March 2015)
Final Suit Routing Genetically Engineered Crops and Related Practices from Refuges (March 2015)
Following Lawsuit, EPA Restores Stream Buffers to Protect Salmon from Pesticides (August 2014)

See below for current litigation regarding pesticides and wildlife:
EPA’s Expansion of 2,4-D Enlist Duo Challenged (April 2015)
EPA Violates FIFRA, ESA and APA (March 2013)

Resources:

The Dangers of Pesticides to Wildlife
Getting the Drift on Chemical Trespass
Pesticides That Disrupt Endocrine System Still Unregulated by EPA
Preserving Biodiversity As If Life Depends On It
Environmental and Economic Costs of the Application of Pesticides Primarily in the United States
The Real Story of the Affordability of Organic Food
Protecting Life: From Research to Regulation

The Science:

• A contemporary survey of bumble bee diversity across the state of California.
  Bumble bees (genus Bombus) are important pollinators with more than 260 spe -cies found worldwide, many of which are in decline. Twenty-five species occur in California with the highest species abundance and diversity found in coastal, north -ern, and montane regions. No recent studies have examined California bumble bee di -versity across large spatial scales nor explored contemporary community composition patterns across the state. To fill these gaps, we collected 1740 bumble bee individuals, representing 17 species from 17 sites (~100 bees per site) in California, using an as -semblage monitoring framework. This framework is intended to provide an accurate estimate of relative abundance of more common species without negatively impact -ing populations through overcollection. Our sites were distributed across six ecore -gions, with an emphasis on those that historically hosted high bumble bee diversity. We compared bumble bee composition among these sites to provide a snapshot of California bumble bee biodiversity in a single year. Overall, the assemblage monitor-ing framework that we employed successfully captured estimated relative abundance of species for most sites, but not all. This shortcoming suggests that bumble bee biodiversity monitoring in California might require multiple monitoring approaches, including greater depth of sampling in some regions, given the variable patterns in bumble bee abundance and richness throughout the state. Our study sheds light on the current status of bumble bee diversity in California, identifies some areas where greater sampling effort and conservation action should be focused in the future, and performs the first assessment of an assembly monitoring framework for bumble bee communities in the state.
  [Fisher, K., Watrous, K.M., Williams, N.M., Richardson, L.L. and Woodard, S.H. Ecology and Evolution, 12(3), p.e8505.]
• Agriculture and climate change are reshaping insect biodiversity worldwide
  Several previous studies have investigated changes in insect biodiversity, with some highlighting declines and others showing turnover in species composition without net declines. Although research has shown that biodiversity changes are driven primarily by land-use change and increasingly by climate change, the potential for interaction between these drivers and insect biodiversity on the global scale remains unclear. Here we show that the interaction between indices of historical climate warming and intensive agricultural land use is associated with reductions of almost 50% in the abundance and 27% in the number of species within insect assemblages relative to those in less-disturbed habitats with lower rates of historical climate warming. These patterns are particularly evident in the tropical realm, whereas some positive responses of biodiversity to climate change occur in non-tropical regions in natural habitats. A high availability of nearby natural habitat often mitigates reductions in insect abundance and richness associated with agricultural land use and substantial climate warming but only in low-intensity agricultural systems. In such systems, in which high levels (75% cover) of natural habitat are available, abundance and richness were reduced by 7% and 5%, respectively, compared with reductions of 63% and 61% in places where less natural habitat is present (25% cover). Our results show that insect biodiversity will probably benefit from mitigating climate change, preserving natural habitat within landscapes and reducing the intensity of agriculture.
  [Outhwaite, C.L., McCann, P. and Newbold, T., Nature, pp.1-6.]
• Amine Volatilization from Herbicide Salts: Implications for Herbicide Formulations and Atmospheric Chemistry
  Amines are frequently included in formulations of the herbicides glyphosate, 2,4-D, and dicamba to increase herbicide solubility and reduce herbicide volatilization by producing herbicide–amine salts. Amines, which typically have higher vapor pressures than the corresponding herbicides, could potentially volatilize from these salts and enter the atmosphere, where they may impact atmospheric chemistry, human health, and climate. Amine volatilization from herbicide–amine salts may additionally contribute to volatilization of dicamba and 2,4-D. In this study, we established that amines applied in herbicide–amine salt formulations undergo extensive volatilization. Both dimethylamine and isopropylamine volatilized when aqueous salt solutions were dried to a residue at ∼20 °C, while lower-vapor pressure amines like diglycolamine and n,n-bis-(3-aminopropyl)methylamine did not. However, all four amines volatilized from salt residues at 40–80 °C. Because amine loss typically exceeded herbicide loss, we proposed that neutral amines dominated volatilization and that higher temperatures altered their protonation state and vapor pressure. Due to an estimated 4.0 Gg N/yr applied as amines to major U.S. crops, amine emissions from herbicide–amine salts may be important on regional scales. Further characterization of worldwide herbicide–amine use would enable this contribution to be compared to the 285 Gg N/yr of methylamines emitted globally.
  [Sharkey, S.M., Hartig, A.M., Dang, A.J., Chatterjee, A., Williams, B.J. and Parker, K.M., 2022. Environmental Science & Technology.]
• Assessing Marine Endocrine-Disrupting Chemicals in the Critically Endangered California Condor: Implications for Reintroduction to Coastal Environments.
  Coastal reintroduction sites for California condors (Gymnogyps californianus) can lead to elevated halogenated organic compound (HOC) exposure and potential health impacts due to the consumption of scavenged marine mammals. Using nontargeted analysis based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS), we compared HOC profiles of plasma from inland and coastal scavenging California condors from the state of California (CA), and marine mammal blubber from CA and the Gulf of California off Baja California (BC), Mexico. We detected more HOCs in coastal condors (32 ± 5, mean number of HOCs ± SD, n = 7) than in inland condors (8 ± 1, n = 10) and in CA marine mammals (136 ± 87, n = 25) than in BC marine mammals (55 ± 46, n = 8). ∑DDT-related compounds, ∑PCBs, and total tris(chlorophenyl)methane (∑TCPM) were, respectively, ∼7, ∼3.5, and ∼148 times more abundant in CA than in BC marine mammals. The endocrine-disrupting potential of selected polychlorinated biphenyls (PCB) congeners, TCPM, and TCPMOH was determined by in vitro California condor estrogen receptor (ER) activation. The higher levels of HOCs in coastal condors compared to those in inland condors and lower levels of HOC contamination in Baja California marine mammals compared to those from the state of California are factors to consider in condor reintroduction efforts.
  [Stack, Margaret E., Jennifer M. Cossaboon, Christopher W. Tubbs, L. Ignacio Vilchis, Rachel G. Felton, Jade L. Johnson, Kerri Danil, Gisela Heckel, Eunha Hoh, and Nathan G. Dodder. Environmental Science & Technology.]
• Ecosystem Services and Land Rental Markets: Producer Costs of Bat Population Crashes
  Non-market natural capital provides crucial inputs across the economy. In this paper, researchers use land rental market data to calculate the welfare impacts of a change in an unpriced natural capital using well-identified causal impact estimates while accounting for spatial spillovers. The researcher apply the welfare analysis to examine the cost of whitenose syndrome (WNS) in bats, which provide pest control services to agricultural producers. WNS, a disease that decimates infected bat populations, began spreading through the US starting in the mid-2000s. We find that the loss of bats in a county causes land rental rates.
  [Manning, D. and Ando, A.]
• Effects of Tick-Control Interventions on Tick Abundance, Human Encounters with Ticks, and Incidence of Tickborne Diseases in Residential Neighborhoods, New York, USA
  Tickborne diseases (TBDs) such as Lyme disease result in ≈500,000 diagnoses annually in the United States. Various methods can reduce the abundance of ticks at small spatial scales, but whether these methods lower incidence of TBDs is poorly understood. We conducted a randomized, replicated, fully crossed, placebo-controlled, masked experiment to test whether 2 environmentally safe interventions, the Tick Control System (TCS) and Met52 fungal spray, used separately or together, affected risk for and incidence of TBDs in humans and pets in 24 residential neighborhoods. All participating properties in a neighborhood received the same treatment. TCS was associated with fewer questing ticks and fewer ticks feeding on rodents. The interventions did not result in a significant difference in incidence of human TBDs but did significantly reduce incidence in pets. Our study is consistent with previous evidence suggesting that reducing tick abundance in residential areas might not reduce incidence of TBDs in humans.
  [Keesing, F., Mowry, S., Bremer, W., Duerr, S., Evans Jr, A.S., Fischhoff, I.R., Hinckley, A.F., Hook, S.A., Keating, F., Pendleton, J. and Pfister, A., Emerging infectious diseases, 28(5), p.957.]
• Emerging Midges Transport Pesticides from Aquatic to Terrestrial Ecosystems: Importance of Compound- and Organism-Specific Parameters
  Emerging aquatic insects have the potential to retain aquatic contaminants after metamorphosis, potentially transporting them into adjacent terrestrial food webs. It is unknown whether this transfer is also relevant for current-use pesticides. We exposed larvae of the nonbiting midge, Chironomus riparius, to a sublethal pulse of a mixture of nine moderately polar fungicides and herbicides (logKow 2.5–4.7) at three field relevant treatment levels (1.2–2.5, 17.5–35.0, or 50.0–100.0 μg/L). We then assessed the pesticide bioaccumulation and bioamplification over the full aquatic–terrestrial life cycle of both sexes including the egg laying of adult females. By applying sensitive LC–MS/MS analysis to small sample volumes (∼5 mg, dry weight), we detected all pesticides in larvae from all treatment levels (2.8–1019 ng/g), five of the pesticides in the adults from the lowest treatment level and eight in the higher treatment levels (1.5–3615 ng/g). Retention of the pesticides through metamorphosis was not predictable based solely on pesticide lipophilicity. Sex-specific differences in adult insect pesticide concentrations were significant for five of the pesticides, with greater concentrations in females for four of them. Over the duration of the adults’ lifespan, pesticide concentrations generally decreased in females while persisting in males. Our results suggest that a low to moderate daily dietary exposure to these pesticides may be possible for tree swallow nestlings and insectivorous bats.
  [Roodt, A.P., Röder, N., Pietz, S., Kolbenschlag, S., Manfrin, A., Schwenk, K., Bundschuh, M. and Schulz, R., Environmental Science & Technology.]
• Evidence for the agricultural origin of resistance to multiple antimicrobials in Aspergillus fumigatus, a fungal pathogen of humans
  Pathogen resistance to clinical antimicrobial agents is an urgent problem. The fungus Aspergillus fumigatus causes 300,000 life-threatening infections in susceptible humans annually. Azoles, which are widely used in both clinical and agricultural settings, are currently the most effective treatment, but resistance to clinical azoles is emerging worldwide. Here, we report the isolation and analysis of azole-sensitive and azole-resistant A. fumigatus from agricultural environments in the southeastern United States (USA) and show that the USA pan-azole-resistant isolates form a clade with pan-azole-resistant isolates from the United Kingdom, the Netherlands, and India. We show that several pan-azole-resistant isolates from agricultural settings in the USA and India also carry alleles with mutations conferring resistance to agricultural fungicides from the benzimidazole (MBC) and quinone outside inhibitor (QoI) classes. We further show that pan-azole-resistant A. fumigatus isolates from patients in clinical settings in the USA, India, and the Netherlands also carry alleles conferring resistance to MBC and QoI agricultural fungicides. The presence of markers for resistance to agricultural-use fungicides in clinical A. fumigatus isolates is strong evidence for an agricultural origin of pan-azole resistance in patients. The presence of multiple fungicide-resistance alleles in agricultural and clinical isolates further suggests that the unique genetics of the pan-azole-resistant clade enables the evolution and/or persistence of antimicrobial resistance mutations leading to the establishment of multifungicide-resistant isolates.
  [Kang, S.E., Sumabat, L.G., Melie, T., Mangum, B., Momany, M. and Brewer, M.T. G3, 12(2), p.jkab427.]
• Feeding on grains containing pesticide residues is detrimental to offspring development through parental effects in grey partridge.
  Numerous toxicological studies have shown that ingestion of pesticides can induce physiological stress in breeding birds, with adverse consequences on egg laying parameters and offspring quality through parental effects. However, previous studies do not mimic current levels of pesticide residues in typical landscapes, and they do not consider potential cocktail effects of pesticides as they occur in the wild. Herein, we explored whether realistic pesticide exposure affected reproduction parameters and offspring condition through parental effects in Grey partridge. We fed 24 breeding pairs with either seeds from conventional agriculture crops treated with various pesticides during cropping, or organic grains without pesticide residues as controls. The conventional and organic grain diets mimicked food options potentially encountered by wild birds in the field. The results showed that ingesting low pesticide doses over a long period had consequences on reproduction and offspring quality without altering mortality in parents or chicks. Compared with organic pairs, conventional pairs yielded smaller chicks at hatching that had a lower body mass index at 24 days old. Additionally, these chicks displayed lower haematocrit when body mass index was higher. Therefore, ingestion of conventional grains by parents resulted in chronic exposure to pesticide residues, even at low doses, and this had detrimental consequences on offspring. These results demonstrate a sublethal effect of pesticide residues through parental effects. The consequences of parental exposure on chicks might partly explain the decline in wild Grey partridge populations, which raises questions for avian conservation and demography if current agrosystem approaches are continued.
  [Gaffard, A., Pays, O., Monceau, K., Teixeira, M., Bretagnolle, V. and Moreau, J. Environmental Pollution, p.120005.]
• Glyphosate impairs collective thermoregulation in bumblebees.
  Insects are facing a multitude of anthropogenic stressors, and the recent decline in their biodiversity is threatening ecosystems and economies across the globe. We investigated the impact of glyphosate, the most commonly used herbicide worldwide, on bumblebees. Bumblebee colonies maintain their brood at high temperatures via active thermogenesis, a prerequisite for colony growth and reproduction. Using a within-colony comparative approach to examine the effects of long-term glyphosate exposure on both individual and collective thermoregulation, we found that whereas effects are weak at the level of the individual, the collective ability to maintain the necessary high brood temperatures is decreased by more than 25% during periods of resource limitation. For pollinators in our heavily stressed ecosystems, glyphosate exposure carries hidden costs that have so far been largely overlooked.
  [Weidenmüller, A., Meltzer, A., Neupert, S., Schwarz, A. and Kleineidam, C. Science, 376(6597), pp.1122-1126.]
• Occurrence of Aculus mosoniensis (Ripka, 2014) (Acari; Prostigmata; Eriophyoidea) on tree of heaven (Ailanthus altissima Mill.) is expanding across Europe. First record in France confirmed by Barcoding
  In May 2020, populations of Eriophyid mites were detected on tree of heaven, Ailanthus altissima Mill., in a recreative park in the city of Colombes, near Paris, and later in August and September in four locations, in Southern France. Morphological examination supplemented with sequencing data for the cytochrome c oxidase subunit I (COI) assigned all collected mites to a single species, Aculus mosoniensis (Ripka) (Acari; Prostigmata; Eriophyoidea). This is the first record of this species in France and the first insights into its intraspecific variability based on a barcode dataset. In Europe, this species is considered one of the most promising biological control agents of tree of heaven. This new record provides encouraging evidence that the geographic occurrence of this species is expanding in Europe which may be indicative of its dispersal and establishment abilities, two key factors for a future biological control program.
  [Kashefi, J., Vidović, B., Guermache, F., Cristofaro, M. and Bon, M.C. Phytoparasitica, 50(2), pp.391-398.]
• Outside the Safe Operating Space of the Planetary Boundary for Novel Entities
  We submit that the safe operating space of the planetary boundary of novel entities is exceeded since annual production and releases are increasing at a pace that outstrips the global capacity for assessment and monitoring. The novel entities boundary in the planetary boundaries framework refers to entities that are novel in a geological sense and that could have large-scale impacts that threaten the integrity of Earth system processes. We review the scientific literature relevant to quantifying the boundary for novel entities and highlight plastic pollution as a particular aspect of high concern. An impact pathway from production of novel entities to impacts on Earth system processes is presented. We define and apply three criteria for assessment of the suitability of control variables for the boundary: feasibility, relevance, and comprehensiveness. We propose several complementary control variables to capture the complexity of this boundary, while acknowledging major data limitations. We conclude that humanity is currently operating outside the planetary boundary based on the weight-of-evidence for several of these control variables. The increasing rate of production and releases of larger volumes and higher numbers of novel entities with diverse risk potentials exceed societies’ ability to conduct safety related assessments and monitoring. We recommend taking urgent action to reduce the harm associated with exceeding the boundary by reducing the production and releases of novel entities, noting that even so, the persistence of many novel entities and/or their associated effects will continue to pose a threat.
  [Persson, L., Carney Almroth, B.M., Collins, C.D., Cornell, S., de Wit, C.A., Diamond, M.L., Fantke, P., Hassellöv, M., MacLeod, M., Ryberg, M.W. and Søgaard Jørgensen, P. Environmental science & technology, 56(3), pp.1510-1521.]
• Pesticide-induced disturbances of bee gut microbiotas.
  Social bee gut microbiotas play key roles in host health and performance. Worryingly, a growing body of literature shows that pesticide exposure can disturb these microbiotas. Most studies examine changes in taxonomic composition in Western honey bee (Apis mellifera) gut microbiotas caused by insecticide exposure. Core bee gut microbiota taxa shift in abundance after exposure but are rarely eliminated, with declines in Bifidobacteriales and Lactobacillus near melliventris abundance being the most common shifts. Pesticide concentration, exposure duration, season and concurrent stressors all influence whether and how bee gut microbiotas are disturbed. Also, the mechanism of disturbance—i.e. whether a pesticide directly affects microbial growth or indirectly affects the microbiota by altering host health—likely affects disturbance consistency. Despite growing interest in this topic, important questions remain unanswered. Specifically, metabolic shifts in bee gut microbiotas remain largely uninvestigated, as do effects of pesticide-disturbed gut microbiotas on bee host performance. Furthermore, few bee species have been studied other than A. mellifera, and few herbicides and fungicides have been examined. We call for these knowledge gaps to be addressed so that we may obtain a comprehensive picture of how pesticides alter bee gut microbiotas, and of the functional consequences of these changes.
  [Hotchkiss, M.Z., Poulain, A.J. and Forrest, J.R. FEMS Microbiology Reviews, 46(2), p.fuab056.]
• Rapid evolution of an adaptive taste polymorphism disrupts courtship behavior.
  The evolution of adaptive behavior often requires changes in sensory systems. However, rapid adaptive changes in sensory traits can adversely affect other fitness-related behaviors. In the German cockroach, a gustatory polymorphism, ‘glucose-aversion (GA)’, supports greater survivorship under selection with glucose-containing insecticide baits and promotes the evolution of behavioral resistance. Yet, sugars are prominent components of the male’s nuptial gift and play an essential role in courtship. Behavioral and chemical analyses revealed that the saliva of GA females rapidly degrades nuptial gift sugars into glucose, and the inversion of a tasty nuptial gift to an aversive stimulus often causes GA females to reject courting males. Thus, the rapid emergence of an adaptive change in the gustatory system supports foraging, but it interferes with courtship. The trade-off between natural and sexual selection under human-imposed selection can lead to directional selection on courtship behavior that favors the GA genotype.
  [Wada-Katsumata, A., Hatano, E., McPherson, S., Silverman, J. and Schal, C. Communications biology, 5(1), pp.1-10.]
• Standardized bioassays reveal that mosquitoes learn to avoid compounds used in chemical vector control after a single sub-lethal exposure
  Vector-borne diseases are worldwide public health issues. Despite research focused on vectorial capacity determinants in pathogen transmitting mosquitoes, their behavioural plasticity remains poorly understood. Memory and associative learning have been linked to behavioural changes in several insect species, but their relevance in behavioural responses to pesticide vector control has been largely overlooked. In this study, female Aedes aegypti and Culex quinquefasciastus were exposed to sub-lethal doses of 5 pesticide compounds using modified World Health Organization (WHO) tube bioassays. Conditioned females, subsequently exposed to the same pesticides in WHO tunnel assays, exhibited behavioural avoidance by forgoing blood-feeding to ensure survival. Standardized resting site choice tests showed that pre-exposed females avoided the pesticides smell and choose to rest in a pesticide-free compartment. These results showed that, following a single exposure, mosquitoes can associate the olfactory stimulus of pesticides with their detrimental effects and subsequently avoid pesticide contact. Findings highlight the importance of mosquito cognition as determinants of pesticide resistance in mosquito populations targeted by chemical control.
  [Sougoufara, S., Yorkston-Dives, H., Aklee, N.M., Rus, A.C., Zairi, J. and Tripet, F. Scientific Reports, 12(1), pp.1-12.]
• The chemical landscape of tropical mammals in the Anthropocene
  Sixty years ago, Rachel Carson published her book Silent Spring, which focused the world's attention on the dangers of pesticides. Since that time human impacts on the environment have accelerated and this has included reshaping the chemical landscape. Here we evaluate the severity of exposure of tropical terrestrial mammals to pesticides, pharmaceuticals, plastics, particulate matter associated with forest fires, and nanoparticles. We consider how these environmental contaminants interact with one another, with the endocrine and microbiome systems of mammals, and with other environmental changes to produce a larger negative impact than might initially be expected. Using this background and building on past conservation success, such as mending the ozone layer and decreasing acid rain, we tackle the difficult issue of how to construct meaningful policies and conservation plans that include a consideration of the chemical landscape. We document that policy solutions to improving the chemical landscape are already known and the path of how to construct a healthier planet is discernible.
  [Chapman, C.A., Steiniche, T., Benavidez, K.M., Sarkar, D., Amato, K., Serio-Silva, J.C., Venier, M. and Wasserman, M.D., Biological Conservation, 269, p.109522.]
• Turnover in floral composition explains species diversity and temporal stability in the nectar supply of urban residential gardens
  Residential gardens are a valuable habitat for insect pollinators worldwide, but differences in individual gardening practices substantially affect their floral composition. It is important to understand how the floral resource supply of gardens varies in both space and time so we can develop evidence-based management recommendations to support pollinator conservation in towns and cities.
  We surveyed 59 residential gardens in the city of Bristol, UK, at monthly intervals from March to October. For each of 472 garden surveys, we combined floral abundances with nectar sugar data to quantify the nectar production of each garden, investigating the magnitude, temporal stability, and diversity and composition of garden nectar supplies.
  We found that individual gardens differ markedly in the quantity of nectar sugar they supply (from 2 to 1,662 g), and nectar production is higher in more affluent neighbourhoods, but not in larger gardens. Nectar supply peaks in July (mid-summer), when more plant taxa are in flower, but temporal patterns vary among individual gardens. At larger spatial scales, temporal variability averages out through the portfolio effect, meaning insect pollinators foraging across many gardens in urban landscapes have access to a relatively stable and continuous supply of nectar through the year.
  Turnover in species composition among gardens leads to an extremely high overall plant richness, with 636 taxa recorded flowering. The nectar supply is dominated by non-natives, which provide 91% of all nectar sugar, while shrubs are the main plant life form contributing to nectar production (58%). Two-thirds of nectar sugar is only available to relatively specialised pollinators, leaving just one-third that is accessible to all.
  Synthesis and applications. By measuring nectar supply in residential gardens, our study demonstrates that pollinator-friendly management, affecting garden quality, is more important than the size of a garden, giving every gardener an opportunity to contribute to pollinator conservation in urban areas. For gardeners interested in increasing the value of their land to foraging pollinators, we recommend planting nectar-rich shrubs with complementary flowering periods and prioritising flowers with an open structure in late summer and autumn.
  [Tew, N.E., Baldock, K.C., Vaughan, I.P., Bird, S. and Memmott, J. Journal of Applied Ecology, 59(3), pp.801-811.]
• A15K-1789 - Greater Los Angeles Area dominates U.S. emissions of sulfuryl fluoride, a potent greenhouse gas
  Sulfuryl fluoride (SO2F2) is a synthetic pesticide and a potent greenhouse gas that has been steadily accumulating in the global atmosphere, rising from <0.5 parts per trillion (ppt) in the 1980's to over 2.5 ppt today. By 2015, the use of methyl bromide (CH3Br) for agricultural and structural fumigation was phased out under the Montreal Protocol. As a result, SO2F2 has been increasingly phased in as a replacement fumigant worldwide. Rising SO2F2 emissions are of notable concern because the gas has a relatively long atmospheric lifetime of ~36 ± 11 years, and a sizable global warming potential (GWP). However, there remains significant uncertainty about the magnitude and spatiotemporal distribution of SO2F2 emissions. In this study, we use a geostatistical inverse model (GIM) along with atmospheric measurements of SO2F2 from the NOAA Global Monitoring Laboratory to estimate SO2F2 emissions fluxes across North America. Atmospheric observations were collected via programmable flask packages (PFPs) from a network of tall towers, surface observatories, and vertical-profiling aircraft, and were measured via gas chromatography-mass spectrometry (GC-MS). To correlate surface emissions with downwind measurements, we use a Lagrangian particle dispersion model (STILT), with meteorology fields prescribed by the North American Mesoscale 12-km (NAM-12) data product. We construct our deterministic model using multiple predictor variables, including the SO2F2 county use inventory from the California Department of Pesticide Regulation and land cover classifications from the USGS National Land Cover Database. Our posterior GIM estimates indicate that the vast majority of U.S. SO2F2 emissions originate from California, and from the Greater Los Angeles Area in particular. Outside of California, emissions of SO2F2 are sparse or zero in most regions. In the context of recent global SO2F2 modeling work, the results presented here imply that California is the world-leading emitter of sulfuryl fluoride. Notably, SO2F2 was not included in AB-32, the California Global Warming Solutions Act of 2006, because its climate-warming properties were not known at the time. This work emphasizes the importance of considering SO2F2 in state and national greenhouse gas inventories and emissions reduction strategies.
  [Gaeta, D.C., Vimont, I.J., Miller, B.R., Zhang, M. and Miller, S.M. In AGU Fall Meeting 2021. AGU.]
• Agricultural Fast Food: Bats Feeding in Banana Monocultures Are Heavier but Have Less Diverse Gut Microbiota
  Habitat alteration for agriculture can negatively affect wildlife physiology and health by decreasing diet diversity and increasing exposure to agrochemicals for animals foraging in altered landscapes. Such negative effects may be mediated by the disruption of the gut microbiota (termed dysbiosis), yet evidence for associations between habitat alteration, wildlife health, and the gut microbiota remains scarce. We examine the association between management intensity of banana plantations and both the body condition and gut microbiota composition of nectar-feeding bats Glossophaga soricina, which commonly forage within banana plantations across Latin America. We captured and measured 196 bats across conventional monocultures, organic plantations, and natural forests in Costa Rica, and quantified gut microbiome bacterial phylogenetic diversity using 16S rRNA amplicon sequencing. We found that gut microbiota from bats foraging in conventional monocultures were overall less phylogenetically diverse than those from bats foraging in organic plantations or natural forests, both of which were characterized by diverse bacterial assemblages and individualized microbiota. Despite lower diversity, co-occurrence network complexity was higher in conventional monocultures, potentially indicating altered microbial interactions in agricultural landscapes. Bats from both organic and conventional plantations tended to be larger and heavier than their forest counterparts, reflecting the higher food supply. Overall, our study reveals that whilst both conventional monocultures and organic plantations provide a reliable food source for bats, conventional monocultures are associated with less diverse and potentially dysbiotic microbiota, whilst organic plantations promote diverse and individualized gut microbiota akin to their natural forest-foraging counterparts. Whilst the long-term negative effects of anthropogenically-altered microbiota are unclear, our study provides further evidence from a novel perspective that organic agricultural practices are beneficial for wildlife health.
  [Alpízar, P., Risely, A., Tschapka, M. and Sommer, S. Frontiers in Ecology and Evolution, p.608.]
• An evaluation of biological soil health indicators in four long-term continuous agroecosystems in Canada
  The soil microbial community (SMC) and soil organic matter (SOM) are inherently related and are sensitive to land-use changes. Microorganisms regulate essential soil functions that are key to SOM dynamics, whereas SOM dynamics define the SMC. To expand our understanding of soil health, we evaluated biological and SOM indicators in long-term (18-yr) continuous silage corn (Zea mays L.), continuous soybean [Glycine max (L.) Merr.], and perennial grass ecosystems in Ontario, Canada. The SMC was evaluated via ester-linked fatty acid methyl ester (EL-FAME) and amplicon sequencing. Soil organic matter was evaluated via a new combined enzyme assay that provides a single biogeochemical cycling value for C, N, P, and S cycling activity (CNPS), as well as loss-on-ignition, permanganate oxidizable C (POXC), and total C and N. Overall, soil health indicators followed the trend of grasses > corn > soybean. Grass systems had up to 8.1 times more arbuscular mycorrhizal fungi, increased fungal/bacteria ratios (via EL-FAME), and higher microbial diversity (via sequencing). The POXC was highly variable within treatments and did not significantly differ between systems. The novel CNPS activity assay, however, was highly sensitive to management (up to 2.2 and 3.2 times higher under grasses than corn and soybean, respectively) and was positively correlated (ρ > .92) to SOM, total C, and total N. Following the “more is better” model, where higher values of the measured parameters indicate a healthier soil, our study showed decreased soil health under monocultures, especially soybean, and highlights the need to implement sustainable agriculture practices that maintain soil health.
  [Pérez‐Guzmán, L., Phillips, L.A., Seuradge, B.J., Agomoh, I., Drury, C.F. and Acosta‐Martínez, V. Agrosystems, Geosciences & Environment, 4(2), p.e20164.]
• Anticoagulant rodenticide exposure and toxicosis in bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos) in the United States
  Raptors, including eagles, are geographically widespread and sit atop the food chain, thereby serving an important role in maintaining ecosystem balance. After facing population declines associated with exposure to organochlorine insecticides such as dichlorodiphenyltrichloroethane (DDT), bald eagles (Haliaeetus leucocephalus) have recovered from the brink of extinction. However, both bald and golden eagles (Aquila chrysaetos) are exposed to a variety of other toxic compounds in the environment that could have population impacts. Few studies have focused on anticoagulant rodenticide (AR) exposure in eagles. Therefore, the purpose of this study was to determine the types of ARs that eagles are exposed to in the USA and better define the extent of toxicosis (i.e., fatal illness due to compound exposure). Diagnostic case records from bald and golden eagles submitted to the Southeastern Cooperative Wildlife Disease Study (University of Georgia) 2014 through 2018 were reviewed. Overall, 303 eagles were examined, and the livers from 116 bald eagles and 17 golden eagles were tested for ARs. The percentage of AR exposure (i.e., detectable levels but not associated with mortality) in eagles was high; ARs were detected in 109 (82%) eagles, including 96 (83%) bald eagles and 13 (77%) golden eagles. Anticoagulant rodenticide toxicosis was determined to be the cause of mortality in 12 (4%) of the 303 eagles examined, including 11 bald eagles and 1 golden eagle. Six different AR compounds were detected in these eagles, with brodifacoum and bromadiolone most frequently detected (81% and 25% of eagles tested, respectively). These results suggest that some ARs, most notably brodifacoum, are widespread in the environment and are commonly consumed by eagles. This highlights the need for research to understand the pathways of AR exposure in eagles, which may help inform policy and regulatory actions to mitigate AR exposure risk.
  [Niedringhaus, K.D., Nemeth, N.M., Gibbs, S., Zimmerman, J., Shender, L., Slankard, K., Fenton, H., Charlie, B., Dalton, M.F., Elsmo, E.J. and Poppenga, R. Plos one, 16(4), p.e0246134.]
• ASSESSMENT OF POTENTIAL RISK TO HUMAN HEALTH FOLLOWING USE OF AZAMETHIPHOS, DELTAMETHRIN AND HYDROGEN PEROXIDE IN FISH FARMS
  The objective of this project was to assess the potential health risk to open-water swimmers in the vicinity of fish farms in Scotland in relation to medicinal treatments applied for the control of sea lice on salmon. The three substances assessed were azamethiphos, deltamethrin and hydrogen peroxide; these substances forming the active ingredients of products licensed for medicinal use on fish farms. The risk characterisation ratios for azamethiphos and deltamethrin were determined to be 0.8 and 0.0007, respectively. As these values were both below 1, it can be concluded that the concentrations of azamethiphos and deltamethrin used to treat fish are below the concentrations predicted by SWIMODEL to present no hazard to swimmers (on a worst-case basis). This demonstrates that the concentrations used to treat fish are safe for open-water swimmers, even before dilution and dispersion occurs in open waters. However, for hydrogen
  peroxide, the risk characterisation ratio was determined to be 27.7. As this value is above 1, this indicates a risk associated with the concentrations of hydrogen peroxide used in the fish treatment baths. Therefore, characterisation of dilution and dispersion factors are likely to be required to be taken into account to demonstrate that discharges of hydrogen peroxide are safe for open-water swimmers
  [WCA Environment Ltd.]
• Birds feeding on tebuconazole treated seeds have reduced breeding output
  Drilled seeds are an important food resource for many farmland birds but may pose a serious risk when treated with pesticides. Most compounds currently used as seed treatment in the EU have low acute toxicity but may still affect birds in a sub-chronic or chronic way, especially considering that the sowing season lasts several weeks or months, resulting in a long exposure period for birds. Tebuconazole is a triazole fungicide widely used in agriculture but its toxicity to birds remains largely unknown. Our aim was to test if a realistic scenario of exposure to tebuconazole treated seeds affected the survival and subsequent reproduction of the red-legged partridge (Alectoris rufa). We fed captive partridges with wheat seeds treated with 0%, 20% or 100% of tebuconazole application rate during 25 days in late winter (i.e. tebuconazole dietary doses were approximately 0.2 and 1.1 mg/kg bw/day). We studied treatment effects on the physiology (i.e. body weight, biochemistry, immunology, oxidative stress, coloration) and reproduction of partridges. Exposed birds did not reduce food consumption but presented reduced plasmatic concentrations of lipids (triglycerides at both exposure doses, cholesterol at high dose) and proteins (high dose). The coloration of the eye ring was also reduced in the low dose group. Exposure ended 60 days before the first egg was laid, but still affected reproductive output: hatching rate was reduced by 23% and brood size was 1.5 times smaller in the high dose group compared with controls. No significant reproductive effects were found in the low dose group. Our results point to the need to study the potential endocrine disruption mechanism of this fungicide with lagged effects on reproduction. Risk assessments for tebuconazole use as seed treatment should be revised in light of these reported effects on bird reproduction.
  [Lopez-Antia, A., Ortiz-Santaliestra, M.E., Mougeot, F., Camarero, P.R. and Mateo, R., 2021. Environmental Pollution, 271, p.116292.]
• Can Glyphosate-Based Herbicides Contribute to Sustainable Agriculture?

  Glyphosate-based herbicides (GBHs) have become the leading agricultural herbicides used globally since the development of genetically engineered herbicide-tolerant crops. This paper investigates whether GBHs are consistent with or supportive of sustainable agriculture. Agricultural sustainability is defined by generally agreed upon goals: (1) promoting agroecology; (2) protecting soils and the Earth’s natural resources; (3) protecting biodiversity; and (4) enhancing the quality of life and health of farmers, farm workers, and society. Through an in-depth examination of the scholarly literature, the paper explores whether the scientific studies of GBHs are consistent with their sustainable applications in agriculture in the areas of human health, non-tillage agriculture, soil quality, aquatic ecosystems and beneficial, non-target species. Based on the four generally agreed upon goals listed above for agricultural sustainability, the paper finds that GBHs are not consistent with sustainability goals.

  What are the harmful effects of pesticides?

  Hazards of pesticides.

  Direct impact on humans. ... .

  Impact through food commodities. ... .

  Impact on environment. ... .

  Surface water contamination. ... .

  Ground water contamination. ... .

  Soil contamination. ... .

  Effect on soil fertility (beneficial soil microorganisms) ... .

  Contamination of air, soil, and non-target vegetation..

  What are the 3 major problems of pesticides?

  Pesticides can also contaminate our food, harm pollinators, and threaten our ecosystems.

  What are 2 effects of pesticides on humans?

  Severe exposure to pesticides can cause 2 types of poisoning: Acute poisoning. Chronic poisoning.

  What are the negative effects of pesticides on the environment?

  The main environmental concerns related to pesticides are soil, water or air pollution and damage to non-target organisms including plants, birds, wildlife, fish and crops.