Wildlife ecotoxicology of pesticides: can we track effects to the population level and beyond?

MCPA-Na exposure in aquatic systems: disruption of pathways and increased susceptibility to infection in fish

MCPA-Na (2-methyl-4-chlorophenoxyacetic acid) is a selective herbicide widely used in agricultural cultivation. Despite monitoring indicating risks to aquatic life, the specific organ effects and pathogen susceptibility are unclear. Therefore, we constructed a "compound-core target-signaling pathway" network using network toxicology methods, and the results showed that MCPA-Na interacted with multiple organs of loach (including intestine, liver, kidney, heart, gills, skin and blood). STRING and Cytoscape software were used to screen the core targets: PPAR (Peroxisome proliferator-activated receptor), ACE (angiotensin converting enzyme), REN (Renin), and CA9 (carbonic anhydrase). KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis showed that the core targets of each tissue were significantly enriched in the renin-angiotensin system, NF-κB signaling pathway, adherens junctions and cholinergic synapses. The relationship between the toxicology and molecular markers of MCPA-Na was further explored by using animal experiments, and the susceptibility of Misgurnus anguillicaudatus (loach) to opportunistic pathogens after toxic exposure was simulated by using opportunistic pathogen challenge Aeromonas hydrophila (A. hydrophila). It was found that the compound induced oxidative stress and triggered intestinal inflammation and promoted apoptosis. These processes undermine the intestinal barrier and increase the susceptibility of loach to the A. hydrophila, thereby exacerbating the challenge of aquaculture food safety.

Weak effects of chlorpyrifos at environmentally relevant concentrations on fitness-related traits in agile frogs

The widespread application of pesticides makes it important to understand the impacts of these chemicals on wildlife. Chlorpyrifos, an organophosphate insecticide that is still used en masse over large parts of the globe, can affect the development and behavior of non-target organisms and may thereby alter predator-prey interactions. To investigate whether environmentally relevant concentrations of chlorpyrifos affect survival, somatic, cerebral, and sexual development, as well as anti-predator behavior of the agile frog (Rana dalmatina), we exposed tadpoles to one of three treatments (0, 0.5, or 5 μg chlorpyrifos / L) either for three days (acute exposure) or throughout larval development (chronic exposure). We measured mortality, activity, and space use in the presence or absence of chemical cues of predatory fish, brain morphology, length of larval development, body mass at metamorphosis and two months later, and phenotypic sex. Compared to control individuals, tadpoles acutely exposed to 5 μg/L chlorpyrifos showed a shorter freezing response to predator cue on the first observation day. Also, chronic exposure to the same concentration decreased body mass at metamorphosis. Neither the chronically nor the acutely applied 0.5 μg/L chlorpyrifos concentration had any significant effect on the evaluated traits. Our results demonstrate that exposure to chlorpyrifos can induce changes in behavior and may result in lowered body mass of agile frog tadpoles, but only if the insecticide is present chronically at relatively high concentrations. Thus, agile frog tadpoles appear to be relatively tolerant to chlorpyrifos, but may suffer from its repeated high-dose application.

The impacts of pesticide exposure on fish conspecific interactions: A systematic review and meta-analysis

The production of chemical pesticides poses a critical threat to aquatic ecosystems worldwide, with sub-lethal impacts evident at even relatively low concentrations. Historically, ecotoxicologists have ignored an organism's social context when investigating the effects of pesticide exposure and, instead, have tended to focus on individual-level impacts. Recently, however, there has been a growing interest in understanding the impacts of pesticide exposure on social behaviour. Despite this shift, a holistic understanding of how pesticides impact conspecific interactions (i.e., social behaviour towards individuals of the same species) is lacking due to the multitude of behaviours, pesticides and species currently investigated. In this meta-analysis, we examine the effects of pesticide exposure on conspecific interactions in fish by using data collected from 37 studies on 31 pesticides and 11 species. Our results indicate that pesticide exposure generally reduces the expression of conspecific interactions, but it does not affect the variability of responses between individuals. Courtship behaviour was the most impaired, suggesting that pesticide exposure could weaken how matings are partitioned among individuals in a population. Triazoles and organochlorines were the most impactful pesticide classes for mean differences in behaviour, while triazoles and organophosphates had the greatest effects on response variability. These findings indicate that endocrine-disrupting and neurotoxic pesticides can impact fish conspecific interactions, regardless of their chemical class. Unfortunately, there is a large taxonomic bias in the literature, with most studies using zebrafish as a model, which, in turn, provides scope for studies using a broader range of fish species. We found little statistical evidence of publication biases in our dataset and our results were validated by sensitivity analyses. Overall, our synthesis suggests that pesticides broadly reduce the expression of social behaviours, though effects vary across behaviours, pesticide types, and fish species.

Chronic exposure to tebuconazole impairs offspring growth and survival in farmland birds: An experiment in captive house sparrows

European farmland bird populations have declined by over 60% in 40 years, with the use of pesticides suspected to be one of the main causes of this decline. However, it remains difficult to test the impact of these pesticides in field studies due to confounding environmental variables that can also affect avian wildlife (e.g., food resources, habitat fragmentation and alteration). Triazoles are a family of fungicides that are ubiquitous in agro-ecosystems due to their use on a wide range of crops. Triazoles are suspected to affect non-target avian species by disrupting key physiological mechanisms and by detrimentally affecting their reproduction. In this captive study, we experimentally investigated the effect of the most commonly used triazole fungicides (i.e., tebuconazole) on the reproduction of an avian species representative of farmlands, the house sparrow (Passer domesticus). We examined the impacts of tebuconazole at realistic concentrations (550 μg.L-1 in drinking water to achieve ∼ 60 pg g-1 in plasma of sparrows) under controlled conditions on multiple indicators of breeding performance (clutch size, hatching success, chick growth and survival). We found that chronic exposure to tebuconazole (9 months, including the breeding period) significantly altered the reproduction of sparrows. Although clutch size and hatching success were not affected by tebuconazole, chicks from the exposed group showed reduced growth and a higher mortality rate. Interestingly, these effects were exacerbated in female chicks, highlighting a sex-dependent effect of tebuconazole on sparrow offspring. This study demonstrates that tebuconazole can be detrimental to the reproduction of farmland birds. Further studies are now required to distinguish the direct effects of tebuconazole (toxic and sublethal effects on the developing chick/embryo) from the indirect ones (alteration of egg quality and parental care).

Pesticide Pollution Reduces the Functional Diversity of Macroinvertebrates in Urban Aquatic Ecosystems

Urbanization accelerates innovation and economic growth but imposes significant ecological challenges, particularly to aquatic biodiversity and ecosystem functionality. Among urban stressors, pesticide-driven chemical pollution represents a critical, yet under-recognized, global threat. Quantifying the causes and consequences of pesticides on biodiversity loss and ecosystem degradation is vital for ecological risk assessment and management, offering insights to promote sustainable societal development. This study evaluated anthropogenic stressors and macroinvertebrate communities at 42 sites across two major drainages in Beijing using chemical analysis and environmental DNA (eDNA), focusing on macroinvertebrate responses to pesticide exposure in the context of multiple anthropogenic stressors. Pesticides significantly impacted the α- and β-functional diversity of macroinvertebrates, accounting for 18.46 and 14.6% of the total observed variation, respectively, underscoring the role of functional groups in pesticide risk assessment. Land use and flow quantity directly influenced pesticide levels, which in turn affected macroinvertebrate functional diversity, while basic water quality had a less pronounced effect. These results provide empirical evidence of pesticide pollution's impact on macroinvertebrate functional diversity at the watershed scale under field conditions in a highly urbanized area. The findings highlight the importance of considering multiple stressors and sensitive taxa in pesticide risk assessment and management for urban aquatic ecosystems.

The neurotoxicity of pesticides: Implications for Parkinson's disease

Parkinson's disease (PD) is the fastest-growing neurodegenerative disorder worldwide, and no effective cure is currently available. Neuropathologically, PD is characterized by the selective degeneration of dopaminergic neurons in the substantia nigra and by the accumulation of alpha-synuclein (aSyn)-rich proteinaceous inclusions within surviving neurons. As a multifactorial disorder, approximately 85 % of PD cases are sporadic with unknown etiology. Among the many risk factors implicated in PD, exposure to neurotoxic pesticides stands out as a significant contributor. While the effects of many are still uncharacterized, it has already been shown that rotenone, paraquat, maneb, and dieldrin affect critical cellular pathways, including mitochondrial and proteasomal dysfunction, aSyn aggregation, autophagy dysregulation, and disruption of dopamine metabolism. With the constant rise in pesticide usage to meet the demands of a growing human population, the risk of environmental contamination and subsequent PD development is also increasing. This review explores the molecular mechanisms by which pesticide exposure influences PD development, shedding light on their role in the pathogenesis of PD and highlighting the need for preventative measures and regulatory oversight to mitigate these risks.

Caging Gammarus roeseli to track pesticide contamination: How agricultural practices shape water quality in small waterbodies?

Contaminant monitoring in agroecosystems is increasingly revealing overlooked molecules, particularly within complex pesticide mixtures. This study assessed the effectiveness of chemical and ecotoxicological methods for evaluating contamination and biological responses in Gammarus roeseli exposed to pesticides and transformation products (TPs) in lentic small water bodies (LSWBs) near agricultural zones. We examined 7 LSWBs, finding variable contamination levels shaped by watershed composition differences. Analysis of 136 compounds identified key TPs, including chlorothalonil R471811, metazachlor ESA, and OXA, which collectively represented 86.2 % of the total quantified contaminants. These results underscore the persistence of both current and banned pesticides in the ponds studied. While G. roeseli showed favorable survival rates, significant reductions in locomotion and ventilation were observed at heavily contaminated sites, with biochemical analyses suggesting neurotoxic effects and activation of detoxification mechanisms in response to contaminants. Multivariate analyses revealed site-specific variations, highlighting the complex interactions between contamination levels and environmental conditions. Biomarker responses in gammarids served as sensitive indicators of residual toxicity in LSWBs, with frequent associations with historical contamination or current pesticide applications. This in situ caging approach across a contamination gradient demonstrates strong potential for biomonitoring and ecotoxicological assessments in agroecosystems. Extending exposure durations and including more heavily contaminated ponds could further enhance risk evaluation, thereby improving biomonitoring accuracy in headwater aquatic ecosystems. By integrating site-specific environmental conditions, contamination profiles, and biological responses, this study provides valuable insights into the influence of agricultural practices on LSWBs contamination and underscores the critical need to incorporate TPs into future risk assessment frameworks.

Additive Insecticidal Effects of Chitosan/dsRNA Nanoparticles Targeting V-ATPaseD and Emamectin Benzoate-Lufenuron Formulations Against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda, a lepidopteran pest from the family Noctuidae, has become a major invasive pest since 2016. Using RNAi methods to control S. frugiperda is currently under investigation. This study is the first to target the V-ATPaseD gene of S. frugiperda using RNAi. Injection of dsRNA-V-ATPaseD into the hemolymph of 4th-instar larvae significantly suppressed gene expression at 24 and 48 h post-injection. Treated larvae showed delayed development and reduced pupation after 7 days. Subsequently, V-ATPaseD silencing was achieved through topical or oral administration of chitosan/dsRNA-V-ATPaseD nanoparticles. Larvae fed these nanoparticles exhibited significant reductions in V-ATPaseD mRNA at 72 h, persisting until 96 h before normalizing. Additionally, the treated larvae displayed disrupted molting and impaired pupation. Furthermore, larvae fed chitosan/dsRNA-V-ATPaseD were more susceptible to emamectin benzoate-lufenuron at LC30 concentrations, resulting in 68% mortality-27% higher than the pesticide alone-72 h post-exposure. Combining chitosan/dsRNA-V-ATPaseD nanoparticles with emamectin benzoate-lufenuron significantly enhanced pest control efficacy, providing new insights into pesticide reduction and sustainable pest control methods for this invasive species.

A supramolecular bactericidal material for preventing and treating plant-associated biofilms

Treating bacterial biofilms on plants poses challenges due to biofilm induced resistance and poor agent adhesion on plant leaves. Here, we report on a host-guest self-assembled material which is biocompatible, has a lamellar supramolecular structure for leaf retention and prevents and treats bacterial biofilms. Phosphate/isopropanolamine-modified ferrocene forms a host-guest complex with β-CD which assembles into a lamella structure. The agent shows control efficacy against bacterial blight, bacterial leaf streak, and citrus canker in testing.

The relationship between diet, plasma glucose, and cancer prevalence across vertebrates

Birds have higher plasma glucose concentrations but lower cancer prevalence than other vertebrates. However, this inverse relationship between glucose and cancer may not hold within vertebrate groups. Given that diet affects blood sugar levels, and carnivores have higher cancer risk than herbivores, we also examined whether diet correlates with plasma glucose concentrations. We collected diet, mean plasma glucose concentration, and neoplasia data for up to 273 vertebrate species from existing databases. Across vertebrates, mean plasma glucose concentration negatively correlated with cancer prevalence, but that was mostly driven by differences in mean plasma glucose concentration and cancer prevalence between birds, mammals, and reptiles. Mean plasma glucose concentration was not correlated with diet across vertebrates nor with cancer prevalence within birds, mammals, or reptiles. Primary carnivores had higher neoplasia prevalence than herbivores when controlling for domestication. A hypothetical explanation for our results may be the evolutionary loss or downregulation of genes related to insulin-mediated glucose import in bird cells. This may have led to higher mean plasma glucose concentration, lower intracellular glucose concentrations in the form of glycogen, and production of fewer reactive oxygen species and inflammatory cytokines, potentially contributing to lower neoplasia prevalence in extant birds compared to mammals and reptiles.

An in-depth analysis of the effects of excessive acetochlor exposure on chicken liver health

Acetochlor, a commonly used herbicide, poses significant risks to ecosystem and organism health through contamination of the food chain. Despite its widespread use, there is a lack of comprehensive studies on its toxicological effects on avian species. This study investigates the impact of environmental acetochlor exposure on chicken liver health using metabolomics analysis and histopathological techniques. Microscopic examination revealed autophagy-like structures and endoplasmic reticulum (ER) expansion, with significant effects observed at higher exposure levels. Biochemical analysis and metabolomics also demonstrated acetochlor-induced ferroptosis, highlighting disruptions in liver function. Further, in vitro studies revealed that acetochlor stimulates autophagy, which regulates ferroptosis via ferritin degradation, mediated through the ER-CaMKII pathway. These findings emphasize the importance of understanding the molecular mechanisms involved in acetochlor toxicity, particularly the role of the Ca2+/CaMKII pathway, ER stress, and autophagy in ferroptosis. The study contributes to a deeper understanding of how environmental contaminants affect avian species, providing critical insights for better herbicide risk assessment, pollution control, and sustainable agricultural practices.

Pesticides have negative effects on non-target organisms

Pesticides affect a diverse range of non-target species and may be linked to global biodiversity loss. The magnitude of this hazard remains only partially understood. We present a synthesis of pesticide (insecticide, herbicide and fungicide) impacts on multiple non-target organisms across trophic levels based on 20,212 effect sizes from 1,705 studies. For non-target plants, animals (invertebrate and vertebrates) and microorganisms (bacteria and fungi), we show negative responses of the growth, reproduction, behaviour and other physiological biomarkers within terrestrial and aquatic systems. Pesticides formulated for specific taxa negatively affected non-target groups, e.g. insecticidal neonicotinoids affecting amphibians. Negative effects were more pronounced in temperate than tropical regions but were consistent between aquatic and terrestrial environments, even after correcting for field-realistic terrestrial and environmentally relevant exposure scenarios. Our results question the sustainability of current pesticide use and support the need for enhanced risk assessments to reduce risks to biodiversity and ecosystems.

Effects of plant protection products on ecosystem functions provided by terrestrial invertebrates

Plant protection products (PPP) are extensively used to protect plants against harmful organisms, but they also have unintended effects on non-target organisms, especially terrestrial invertebrates. The impact of PPP on ecosystem functions provided by these non-target invertebrates remains, however, unclear. The objectives of this article were to review PPP impacts on the ecosystem functions provided by pollinators, predators and parasitoids, and soil organisms, and to identify the factors that aggravate or mitigate PPP effects. The literature highlights that PPP alter several ecosystem functions: provision and maintenance of biodiversity, pollination, biotic interactions and habitat completeness in terrestrial ecosystems, and organic matter and soil structure dynamics. However, there are still a few studies dealing with ecosystem functions, with sometimes contradictory results, and consequences on agricultural provisioning services remain unclear. The model organisms used to assess PPP ecotoxicological effects are still limited, and should be expanded to better cover the wide functional diversity of terrestrial invertebrates. Data are lacking on PPP sublethal, transgenerational, and "cocktail" effects, and on their multitrophic consequences. In empirical assessments, studies on PPP unintended effects should consider agricultural-pedoclimatic contexts because they influence the responses of non-target organisms and associated ecosystem functions to PPP. Modeling might be a promising way to account for the complex interactions among PPP mixtures, biodiversity, and ecosystem functioning.

Role of trophic interactions in transfer and cascading impacts of plant protection products on biodiversity: a literature review

Plant protection products (PPPs) have historically been one of the classes of chemical compounds at the frontline of raising scientific and public awareness of the global nature of environmental pollution and the role of trophic interactions in shaping the impacts of chemicals on ecosystems. Despite increasingly strong regulatory measures since the 1970s designed to avoid unintentional effects of PPPs, their use is now recognised as a driver of biodiversity erosion. The French Ministries for the Environment, Agriculture and Research commissioned a collective scientific assessment to synthesise the current science and knowledge on the impacts of PPPs on biodiversity and ecosystem services. Here we report a literature review of the state of knowledge on the propagation of PPP residues and the effects of PPPs in food webs, including biopesticides, with a focus on current-use PPPs. Currently used PPPs may be stronger drivers of the current biodiversity loss than the banned compounds no longer in use, and there have been far fewer reviews on current-use PPPs than legacy PPPs. We first provide a detailed overview of the transfer and propagation of effects of PPPs through trophic interactions in both terrestrial and aquatic ecosystems. We then review cross-ecosystem trophic paths of PPP propagation, and provide insight on the role of trophic interactions in the impacts of PPPs on ecological functions. We conclude with a summary of the available knowledge and the perspectives for tackling the main gaps, and address areas that warrant further research and pathways to advancing environmental risk assessment.

Wildlife ecotoxicology of plant protection products: knowns and unknowns about the impacts of currently used pesticides on terrestrial vertebrate biodiversity

Agricultural practices are a major cause of the current loss of biodiversity. Among postwar agricultural intensification practices, the use of plant protection products (PPPs) might be one of the prominent drivers of the loss of wildlife diversity in agroecosystems. A collective scientific assessment was performed upon the request of the French Ministries responsible for the Environment, for Agriculture and for Research to review the impacts of PPPs on biodiversity and ecosystem services based on the scientific literature. While the effects of legacy banned PPPs on ecosystems and the underlying mechanisms are well documented, the impacts of current use pesticides (CUPs) on biodiversity have rarely been reviewed. Here, we provide an overview of the available knowledge related to the impacts of PPPs, including biopesticides, on terrestrial vertebrates (i.e. herptiles, birds including raptors, bats and small and large mammals). We focused essentially on CUPs and on endpoints at the subindividual, individual, population and community levels, which ultimately linked with effects on biodiversity. We address both direct toxic effects and indirect effects related to ecological processes and review the existing knowledge about wildlife exposure to PPPs. The effects of PPPs on ecological functions and ecosystem services are discussed, as are the aggravating or mitigating factors. Finally, a synthesis of knowns and unknowns is provided, and we identify priorities to fill gaps in knowledge and perspectives for research and wildlife conservation.

Beyond the field: How pesticide drift endangers biodiversity

Airborne pesticide drift poses a substantial environmental threat in agriculture, affecting ecosystems far from the application sites. This process, in which up to 25% of applied pesticides are carried by air currents, can transport chemicals over hundreds or even thousands of kilometers. Drift rates peak during the summer months, reaching as high as 60%, and are influenced by various factors, including wind speed, temperature, humidity, and soil type. Pesticide volatilization is a significant concern, occurring 25 times more frequently than surface runoff. Under certain conditions, it can result in chemical losses of compounds like metolachlor and atrazine that are up to 150 times higher. These drifting pesticides have profound impacts on biodiversity, harming non-target plants, insects, fungi, and other organisms both near application sites and in distant ecosystems. Pesticide drift has been linked to over 50% reductions in wild plant diversity within 500 m of fields, reducing floral resources for pollinators. Despite growing evidence of these effects, the long-term consequences of airborne pesticides on biodiversity remain poorly understood, especially in complex field conditions with multiple pesticide applications. Addressing this requires urgent measures, such as improved meteorological tracking during applications, adoption of biopesticides, and integrated pest management strategies. This review highlights the pressing need for research to quantify airborne pesticides' ecological impacts, advocating for sustainable practices to mitigate environmental damage.

Testing the Population-Level Effects of Stress-Induced Susceptibility in the Ranavirus-Wood Frog System

Chronic exposure to physical, chemical, and biotic stressors can make animals more susceptible to infections. Such stress-induced susceptibility is widely expected to make disease-and epidemics-more likely and more severe. However, whether the impacts of stressors on individuals scale up to population-level outcomes is uncertain, both theoretically and empirically. We initiated ranavirus epidemics in replicate mesocosm populations of larval wood frogs (Lithobates sylvaticus) exposed to conditions known to impact their individual susceptibility to ranavirus infections: low and high salinity crossed factorially with ambient or elevated temperatures. Contrary to expectations, epidemics were no more likely or more severe in stressful conditions, although increased temperatures did speed their progression. We discuss several potential reasons why the effects of stressors did not scale up to epidemics, but our results suggest caution in assuming the individual-level effects of even well-studied stressors necessarily scale simply to population-level outcomes.

Dimethomorph induces heart and vascular developmental defects by disrupting thyroid hormone in zebrafish embryos

Dimethomorph (DMT) is a widely-used selective active fungicide that effectively controls downy mildew, crown rot, and late blight in crops. The extensive application of DMT raises concerns about its ecological impact on non-target organisms in the environment. However, there is limited understanding of the toxicological properties of DMT on these organisms. In this study, we utilized zebrafish as an animal model to assess the toxicity of DMT induced by exposure 5.5-72 hours post-fertilization (hpf). During this period, we monitored and evaluated the development of the zebrafish heart and vascular system. Additionally, embryo samples were collected to perform molecular-level detection of PCNA, oxidative stress, and related genes. The results showed a concentration-dependent decrease in survival rate and hatching rate, shortened body length, slowed heart rate, and pericardial edema, body curvature and reduced eye size as DMT exposure concentration increased. Furthermore, DMT exposure led to impairments in the development of the heart, vascular, along with change in the expression levels of relevant genes. It also caused a decrease in cell proliferation and an increase in oxidative stress levels. Moreover, DMT disrupts the normal development of thyroid follicular cells, leading to a reduction in T3 levels. Thyroid hormone supplementation partially reverses the toxicity induced by DMT, increasing eye size, restoring body length, reducing spine curvature, and reducing pericardial edema. Therefore, we speculate that DMT likely affects the development of zebrafish embryos by disrupting normal thyroid follicle development.

Acanthocephalans as pollutant sinks? Higher pollutant accumulation in parasites may relieve their crustacean host

Increasing chemical pollution calls for a closer look at ecologically highly relevant host-parasite interactions to understand the persistence of organisms and populations in a polluted environment. The impact of chemical exposure within the host-parasite interactions - particularly the distinctive bioaccumulation behavior of organic micropollutants - can substantially influence the persistence of a species. This significance has been emphasized by previous research showing a higher tolerance of Gammarus roeselii (Amphipoda, Crustacea) infected with acanthocephalans during acute exposure to a pyrethroid. This suggests the presence of infection-related benefits within polluted environments. The present study addressed this complex relationship by investigating the chemical body burden and internal pollutant concentrations of both G. roeselii and its acanthocephalan parasites across a pollution gradient. Specifically, we analyzed 405 organic micropollutants and identified 123 of these in gammarids and their acanthocephalan parasites. Among the detected compounds, 22 are either banned or are no longer permitted for use in Germany. Remarkably, we discovered that the concentrations of pollutants were up to 35 times higher in the acanthocephalan parasites than in their crustacean intermediate hosts. The log KOW, the most frequently used measure of chemical hydrophobicity, could not explain the accumulation. Instead, the accumulation is likely explained by the unique physiology and high absorption capacity of acanthocephalans, combined with potentially limited biotransformation and excretion ability. This results in a redistribution of micropollutants within the host-parasite system, reducing the burden on the host up to 13.9 % and potentially explaining the observed helpful effects of parasitized G. roeselii in polluted environments. Our study underscores the often overlooked but significant role of host-parasite interactions in human-altered ecosystems, revealing how these relationships can mediate and amplify the impacts of micropollutants within aquatic communities. These insights stress the need to consider the pervasive influence of metazoan parasites in environmental assessments and pollution management strategies.

Landscape influences bat suppression of pine processionary moth: Implications for pest management

Bats provide important ecosystem services, particularly in agriculture, yet integrating bat management into conservation plans remains challenging. Some landscape features considerably influence bat presence, diversity, and ecosystem service provision. Understanding the relationship between landscape structure, composition, pest suppression, and ecosystem services is crucial. We modelled areas where bats most effectively suppress pine processionary moths (Thaumetopoea pityocampa), considering landscape characteristics to predict ecosystem services and optimise pest suppression in Serra da Estrela, Portugal. Faecal samples collected during fieldwork were analysed for pine processionary moth presence in bat diets. Lasso regression assessed spatial landscape variables to create an "optimal landscape" for predation. Landscape structure and composition influenced pest suppression differently, with the greatest impact within a 5000-m buffer. "Riparian edge" and "tree cover density" were key habitat structure variables supporting bat navigation and access to hunting areas, while "other forest" and "vineyard/orchard" areas were important composition variables. Optimising landscape composition involves incorporating diverse forest within agroforestry systems to enhance pest suppression by creating habitats reflecting bats' foraging preferences. We recommend strategies focusing on riparian edge conservation, selective canopy reduction, and promoting diverse forest compositions. These strategies aim to create mosaic landscapes balancing land uses, fostering optimal conditions for bat foraging. Our study shows edges provide the highest rates of bats-pine processionary moth interactions. However, caution is needed to avoid excessive fragmentation, which may reduce habitat suitability and increase pest presence before effective bat predation. A balanced approach, focusing on edge creation without over-fragmenting the landscape, is key to promoting sustainable pest management.

A Multifunctional Tb(III)-Based Metal-Organic Framework for Chemical Conversion of CO2, Fluorescence Sensing of Trace Water and Metamitron

The utilization of metal-organic frameworks (MOFs) as fluorescent sensors for the detection of environmental and chemical reagent pollutants as well as heterogeneous catalysis for CO2 conversion represents a crucial avenue of research with significant implications for the protection of human health. In this work, a Tb(III)-based three-dimensional metal-organic framework, [Tb(L)·4DMF]n (Tb-MOF) (H3L = 5'-(4-carboxy-3-hydroxyphenyl)-3,3″-dihydroxy-[1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid), has been structurally conformed by single-crystal X-ray crystallography. It possesses a 1D rhombus channel along the [010] direction, featuring a pore size of 6.02 × 9.13 Å. Tb-MOF was proved to be a multifunctional material for a fluorescent sensor and CO2 cycloaddition heterogeneous catalyst material. Fluorescence sensing studies revealed that Tb-MOF demonstrates high sensitivity, selectivity, and favorable regeneration properties, making it an effective chemosensor for detecting the metamitron (MMT) pesticide and trace water in organic solvents. The mechanism of fluorescence quenching by MMT and water was elucidated by a combination of XRD, UV-vis absorption spectra, IR spectra, theoretical calculations, and fluorescence lifetimes. The material was also utilized for the sensing of MMT and water in paper strips. Additionally, the open Tb3+ site as Lewis acidic centers makes Tb-MOF achieve efficiently catalytic conversion for CO2 and epoxides to cyclic carbonates. Moreover, a possible catalytic mechanism for the conversion of carbon dioxide to cyclic carbonates was proposed by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments. It also exhibited recyclability for up to five cycles without noticing an appreciable loss in sensing or catalytic efficiency.

Nano-enabled strategies in sustainable agriculture for enhanced crop productivity: A comprehensive review

The global food demand is increasing with the world population, burdening agriculture with unprecedented challenges. Agricultural techniques that ushered in the green revolution are now unsustainable, owing to population growth and climate change. The agri-tech revolution that promises a robust, efficient, and sustainable agricultural system while enhancing food security is expected to be greatly aided by advancements in nanotechnology, which have been reviewed here. Nanofertilizers and nanoinsecticides can benefit agricultural practices economically without major environment impact. Owing to their unique size and features, nano-agrochemicals provide enhanced delivery of active ingredients and increased bioavailability, and posing lesser environment hazard. Nano-agrochemicals should be improved for increased efficiency in the future. In this context, nanocomposites have drawn considerable interest with regard to food security. Nanocomposites can overcome the drawbacks of chemical fertilizers and improve plant output and nutrient bioavailability. Similarly, metallic and polymeric nanoparticles (NPs) can potentially improve sustainable agriculture via better plant development, increased nutrient uptake, and soil healing. Hence, they can be employed as nanofertilizers, nanopesticides, and nanoherbicides. Nanotechnology is also being used to enhance crop production via genetic modification of traits for efficient use of soil nutrients and higher yields. Furthermore, NPs can help plants overcome salinity stress-induced oxidative damage. We also review the fate of NPs in the soil system, plants, animals, and humans, highlight the shortcomings of previous research, and offer suggestions for toxicity studies that would aid regulatory bodies and benefit the agrochemical sector, consequently promoting efficient and sustainable use of nano-agrochemicals.

Stress biomarker response in Aporrectodea caliginosa earthworms exposed to single and combined pesticide treatments (Prosaro and Decis)

This study aims to assess the impact of two pesticides commonly used in Algeria (Prosaro XRT and Decis 25 EC), as well as their combinations at recommended doses, on a non-target species bioindicator of soil pollution, the earthworm Aporrectodea caliginosa, using physiological (mortality and growth) and biochemical parameters (proteins, glutathione, catalase activity and glutathione S-transferase, acetylcholine esterase, lipoxygenase). The recommended dose and its double were tested individually and in combination for this. It should be noted that the protocol used and the initial concentrations selected are the same as those used in the field. After 7 and 14 days (7D/14D) of exposure, all dosages were administered. Our findings show that the pesticides tested had no effect on earthworm survival. However, a significant decrease in their growth rates depending on the different concentrations was observed for the different treatments over the entire exposure period of 7 or 14 D. The greatest reductions (31.62%, 35.04%) are reported after 14D for the high concentrations of Decis alone (D2) as well as for the combined treatment Prosaro/Decis (P2/D2). At the same time, an increase in total protein contents (more than 50% after 14D) as well as a decrease in acetylcholine esterase activity were reported for all treatments. We were also able to identify the induction of oxidative stress after xenobiotic exposure, which is more pronounced at the end of the treatment (14D), resulting in the stimulation of the antioxidant system (gluthione, glutathione S-transférase, catalase) as well as the induction of lipoxygenase, which is responsible for the oxidation of polyunsaturated fatty acids as well as the generation of reactive oxygen species (ROS) involved in the inflammatory phenomenon. Finally, it turns out that the species Aporrectodea caliginosa is sensitive to the different concentrations applied, even those used in the open field, and that Decis (deltamethrin) seems to be more toxic than Prosaro and that the combinaison P2/D2 is as toxic as Decis alone (D2).

The role of marine bacteria in modulating the environmental impact of heavy metals, microplastics, and pesticides: a comprehensive review

Bacteria assume a pivotal role in mitigating environmental issues associated with heavy metals, microplastics, and pesticides. Within the domain of heavy metals, bacteria exhibit a wide range of processes for bioremediation, encompassing biosorption, bioaccumulation, and biotransformation. Toxigenic metal ions can be effectively sequestered, transformed, and immobilized, hence reducing their adverse environmental effects. Furthermore, bacteria are increasingly recognized as significant contributors to the process of biodegradation of microplastics, which are becoming increasingly prevalent as contaminants in marine environments. These microbial communities play a crucial role in the colonization, depolymerization, and assimilation processes of microplastic polymers, hence contributing to their eventual mineralization. In the realm of pesticides, bacteria play a significant role in the advancement of environmentally sustainable biopesticides and the biodegradation of synthetic pesticides, thereby mitigating their environmentally persistent nature and associated detrimental effects. Gaining a comprehensive understanding of the intricate dynamics between bacteria and anthropogenic contaminants is of paramount importance in the pursuit of technologically advanced and environmentally sustainable management approaches.

Discovery of Enantiopure (S)-Methoprene Derivatives as Potent Biochemical Pesticide Candidates

(S)-Methoprene has been widely applied as a powerful biochemical pesticide to control disease vectors and other pestiferous arthropods of economic importance. As a juvenile hormone analogue, many products based on (S)-methoprene are developed and commercialized in the USA, Europe, and elsewhere. However, the agricultural use of (S)-methoprene and its analogues remains underexplored. Here, based on an intermediate derivatization strategy and structural modification, a series of enantiopure (S)-methoprene derivatives were designed for their expected bioactivity against two crop-threatening pests. Six compounds showed more than 2-fold stronger inhibition of emergence against Plutella xylostella than (S)-methoprene, among which one that was designated as B2 showed even superior activity to the conventional chemical pesticide and biopesticide with IE50 of 0.02 mg/L. Nine compounds exhibited over 2-fold higher bioactivity against Aphis craccivora growth than (S)-methoprene. The physicochemical property evaluation and toxicological test showed that the potent (S)-methoprene derivatives were low toxic to the nontarget organism and the environment. Molecular docking studies further demonstrated that the high bioactivity of B2 may be partially attributed to its great affinity for binding to juvenile hormone receptors of P. xylostella. The current study suggests that B2 is a biochemical pesticide candidate with potency to be developed as a new agrochemical for lepidopteran control.

The combined effect of herbicide and Bacillus thuringiensis exposure delays development in the red flour beetle

The use of herbicides and their long persistence in the environment have raised concerns about potential harm to ecosystems and human health. However, there is a gap in the knowledge regarding the effects of continuous exposure to residues or admitted field doses on non-target organisms such as insects that inhabit croplands and play key ecological roles. Furthermore, the potential impact of this exposure on host-pathogen interactions remains largely unstudied. This study adopted an eco-immunological perspective, investigating the influence of herbicides on an organism's interaction with natural pathogens. The impact of this combination of multiple stressors was studied in larvae of the red flour beetle, Tribolium castaneum Herbst, 1797, previously treated with a pendimethalin-based commercial formulation (PND) and exposed to the natural entomopathogen Bacillus thuringiensis (1x109, 1x1010 cells/mL). The effects of three PND concentrations (i.e. a recommended field rate, a soil contaminant concentration and the maximum residue limit admitted in grain in EU countries: 4L/ha, 13 and 0.05 ppm, respectively) on life history traits such as developmental time, pupation rate and survival rate and the expression levels of antimicrobial peptides (AMPs) were assessed. The results showed that even at doses considered safe for human consumption or field application, exposure to PND had an impact on beetle larvae, affecting their vulnerability to B. thuringiensis. The combined experience of exposure to PND and B. thuringiensis at the larval stage resulted in a delay of larval development, a reduction in the number of pupae and emerging adults, and alterations in their body condition. Moreover, changes in the expression levels of the analysed AMPs, including Attacin 1, Defensin 2 and Coleoptericin 2, were recorded as markers for immune activity against the bacterium. The findings of this study highlight the general need for further studies on the effects of commonly used herbicides on the physiology of non-target organisms and on host-pathogen interactions at the community level. Additionally, there is a need for the establishment of revised residual levels that are deemed non-toxic to soil organisms and humans.

Identification of coastal pesticide pollutants as potent inhibitors of Bacillus pasteurii urease mediated calcium carbonate precipitation: a computational approach

Microbially induced calcite precipitation (MICP) through urease enzyme has attained a lot of recognition in various fields of civil engineering and geotechnology for stabilizing the strength of soil and various concrete materials. The activity of urease has been found to be affected by various factors like temperature, substrate concentrations, pH of the medium, presence of inhibitors, etc. Through this study, the outcome of the interaction of pesticides (commonly found in Indian coastal regions) on Bacillus pasteurii urease, a major organism reported for MICP studies has been investigated in silico. The results from the study revealed that the enzyme has higher interactions of -4.1, -3.2, and -3.4 kJ/mol with common pesticides like dichloro diphenyl dichloro ethane(DDD), dichloro diphenyl trichloroe thane (DDT), and methyl parathion of organochlorides and organophosphates class. From the molecular dynamics simulation analysis, complex 1 (DDD -receptor) has been found to have the highest and more compact structure followed by methyl parathion -receptor. Prime MM-GBSA analysis also revealed the highest binding energy of -27.8 kcal/mol with the protein and DDD. Thus, it can be inferred from the current study that pesticides, particularly, DDD, DDT, and methyl parathion present in the coastal areas may have an impact on urease. This interaction can result in the inhibition of the urease activity of B. pasteurii, thus preventing the biomineralization process. This study would be the first report on the computational approach to understanding the interaction of prominent pesticides on the coastal region and B. pasteurii urease.Communicated by Ramaswamy H. Sarma.

Field and Laboratory Evidence That Chlorpyrifos Exposure Reduced the Population Density of a Freshwater Snail by Increasing Juvenile Mortality

Pesticides have been frequently detected in global freshwater ecosystems, but attempts to document changes in population dynamics of organisms upon exposure to pesticides, establish a causal relationship between exposure and population effects, and identify the key toxic events within individuals under natural field conditions remain rare. Here, we used a field survey, a reciprocal cross-transplant experiment, and a laboratory toxicity experiment to build a compelling case that exposure to the insecticide chlorpyrifos was responsible for differences in snail (Bellamya aeruginosa) densities in eastern (ELL) and western basins of Liangzi Lake in China. Our field survey and reciprocal cross-transplant experiment revealed significant differences in snail densities, juvenile percentage, survival, and relative telomere length (RTL) in the two basins. The insecticide chlorpyrifos detected in snail tissues was negatively correlated with snail densities, the percentage of juvenile snails, and RTL and had an extremely high risk quotient in ELL. In the laboratory experiment, tissue concentrations of chlorpyrifos detected in ELL were associated with reduced RTL and increased juvenile mortality in B. aeruginosa. These results support the hypothesis that chlorpyrifos exposure in ELL reduced the density of snails by reducing juvenile survival and, consequently, recruitment to the adult population.

Exposure to Cyantraniliprole Adversely Impacts Fitness of Harmonia axyridis: Acute Toxicity and Sublethal Effects on Development, Fecundity and Antioxidant Responses

Extensive utilization of pesticides and their persistent residues inadvertently pose threats to the effectiveness and fitness of biocontrol agents in agroecosystems. However, these ecological consequences are generally disregarded when executing integrated pest management strategies (IPM). Cyantraniliprole (CNAP) serves as a wide-spectrum diamide insecticide and its sublethal effects have been well characterized on multiple insect pests, whereas its impacts on beneficial natural enemies remain unfathomed. Herein we exposed Harmonia axyridis, a predacious generalist, to lethal and sublethal concentrations of CNAP via dipping treatment (egg stage) and topical applications (1st-instar stage + adult stage). The acute toxicity tests revealed that LC50 of CNAP were 90.11, 86.11 and 240.50 mg/L against embryos, 1st instar nymphs and female adults, respectively, with safety factors ranging from 1.14 to 5.34, suggesting its medium toxicity for H. axyridis and larval stage was the most susceptible. The embryonic, larval and pupal durations of coccinellids ecdysed from CNAP-treated eggs and 1st instars were all elongated under sublethal concentrations, of which LC30 triggered more pronounced and significant retardations relative to control. Besides, exposed coccinellids displayed substantially diminished pupal mass and pupation rate, most notably for insects molted from the 1st-instar stage upon CNAP sublethal treatments. With respect to reproductive performance, LC10 and LC30 of CNAP all significantly suppressed female fecundity, as evidenced by reduced vitellin content, a prolonged pre-oviposition period (POP), mitigated laid eggs and the egg hatching rate. Specifically, there existed positive correlations between vitellin level (Vn) and number of eggs deposited by per female, indicative of CNAP affecting fecundity by regulation of Vn. In addition, the antioxidant system was also profoundly disrupted by CNAP, with compromised POD activity at different concentrations over time and induced hormesis of SOD/CAT activities post LC10 exposure. Activities of SOD and TAC were enhanced to exert protective functions during the first 48 h, while defense collapsed at 72 h following LC30 treatments that depleted all enzymatic activities. We speculated that fitness trade-offs may occur between reproductive capacity and antioxidant defenses to sustain physiological homeostasis in response to CNAP stress. Collectively, this study evaluated the ecological risk of CNAP and unmasked its adverse implications for overall fitness of H. axyridis, which highlighted rational application of agrochemicals to conserve biocontrol agents when implementing IPM strategies for sustainable pest control.

Water temperature governs organophosphate ester dynamics in the aquatic food chain of Poyang Lake

Organophosphate esters (OPEs) are increasingly recognized as pervasive environmental contaminants, primarily from their extensive application in flame retardants and plasticizers. Despite their widespread presence, the intricacies of OPE bioaccumulation within aquatic ecosystems remain poorly understood, particularly the environmental determinants influencing their distribution and the bioaccumulation dynamics across aquatic food chains. Here we show that water temperature plays a crucial role in modulating the dispersion of OPE in the aquatic environment of Poyang Lake. We quantified OPE concentrations across various matrices, uncovering levels ranging from 0.198 to 912.622 ng L-1 in water, 0.013-493.36 ng per g dry weight (dw) in sediment, 0.026-41.92 ng per g wet weight (ww) in plankton, 0.13-2100.72 ng per g dw in benthic invertebrates, and 0.31-3956.49 ng per g dw in wild fish, highlighting a pronounced bioaccumulation gradient. Notably, the intestines emerged as the principal site for OPE absorption, displaying the highest concentrations among the seven tissues examined. Among the various OPEs, tris(chloroethyl) phosphate was distinguished by its significant bioaccumulation potential within the aquatic food web, suggesting a need for heightened scrutiny. The propensity for OPE accumulation was markedly higher in benthic invertebrates than wild fish, indicating a differential vulnerability within aquatic biota. This study lays a foundational basis for the risk assessment of OPEs as emerging contaminants and underscores the imperative to prioritize the examination of bioaccumulation effects, particularly in benthic invertebrates, to inform future environmental safeguarding strategies.

Moderate evidence for the sex-dependent effect of poisoning on adult survival in a long-lived raptor species

Survival rate is usually the greatest contributor to population growth in long-lived species, and its accurate estimation along with the evaluation of the factors influencing it is therefore essential for effective conservation. Here, we studied the survival of breeding eastern imperial eagles Aquila heliaca in Hungary between 2011 and 2022 and investigated the effect of poisoning, the leading known anthropogenic cause of mortality. We used the Cormack-Jolly-Seber mark-recapture model to estimate annual apparent survival and encounter probabilities based on the capture histories of 208 males and 411 females. We obtained encounter data from the DNA profiles of shed feathers collected at the nest sites, which we also supplemented with presences inferred from parentage analysis. The most supported model estimated a constant 91.6% annual survival over the study period, but models including the effect of sex and poisoning rate on survival had similar support. Sex difference in survival was less than 1% on average, but the survival of males decreased more with poisoning rate than the survival of females. However, due to smaller encounter probabilities, the estimates for males were less precise compared to females. Males may be more at risk from poisoning than females not only due to their more active foraging behaviour during incubation and chick-rearing but also due to their smaller body size. Apart from providing direct practical information for the conservation management of imperial eagles, our results also highlight the importance of long-term studies for estimating population parameters of birds of prey.

Occurrence and distribution of pesticides and transformation products in ambient air in two European agricultural areas

Pesticides present a significant risk for both humans and the environment. However, quantitative data for a broad range of airborne pesticides in agricultural areas are missing. During or after the application, pesticides can reach the atmosphere and partition between the particulate and gaseous phase. As part of the EU project SPRINT, weekly ambient air samples were collected from two agricultural areas in Portugal (vineyard) and the Netherlands (potatoes, onions, and sugarbeet) between April 2021 and June 2022 using high-volume air samplers. The samples were analysed for 329 pesticides, of which 99 were detected. The most frequently detected compounds included the fungicides folpet, fenpropidin and mandipropamid, the insecticide chlorpyrifos-methyl, the herbicide terbuthylazine, and the metabolite prothioconazole-desthio, which were found with detection frequencies between 40 and 57 %. Pesticide concentrations ranged between 0.003 ng/m3 and 10 ng/m3. Remarkably, 97 % of the samples contained at least one pesticide and in 95 % of the samples, pesticide mixtures were present. The calculated particle phase fractions correlated with the octanol-air partitioning coefficient for most of the investigated compounds. Furthermore, calculated daily inhalation rates for individual pesticides and pesticide mixtures were far below the Acceptable Daily Intake (ADI) with a margin of exposure (MOE) of >1000 for the highest calculated daily inhalation rate for a child. However, as this value only includes pesticide intake from food and drinking water and considering that 91 % of the detected pesticides are associated with potential adverse human health effects. These findings highlight the broad range of airborne pesticides in agricultural areas and the need for quantitative data to include the intake of mixtures of highly hazardous pesticides by inhalation in human risk assessment.

Long-term exposure to aryl hydrocarbon receptor agonist neburon induces reproductive toxicity in male zebrafish (Danio rerio)

Neburon is a phenylurea herbicide that is widely used worldwide, but its toxicity is poorly studied. In our previous study, we found that neburon has strong aryl hydrocarbon receptor (AhR) agonist activity, but whether it causes reproductive toxicity is not clear. In the present study, zebrafish were conducted as a model organism to evaluate whether environmental concentrations of neburon (0.1, 1 and 10 µg/L) induce reproductive disorder in males. After exposure to neburon for 150 days from embryo to adult, that the average spawning egg number in high concentration group was 106.40, which was significantly lower than 193.00 in control group. This result was mainly due to the abnormal male reproductive behavior caused by abnormal transcription of genes associated with reproductive behavior in the brain, such as secretogranin-2a. The proportions of spermatozoa in the medium and high concentration groups were 82.40% and 83.84%, respectively, which were significantly lower than 89.45% in control group. This result was mainly caused by hormonal disturbances and an increased proportion of apoptotic cells. The hormonal disruption was due to the significant changes in the transcription levels of key genes in the hypothalamus-pituitary-gonadal axis following neburon treatment. Neburon treatment also significantly activated the AhR signaling pathway, causing oxidative stress damage and eventually leading to a significant increase in apoptosis in the exposed group. Together, these data filled the currently more vacant profile of neburon toxicity and might provide information to assess the ecotoxicity of neburon on male reproduction at environmentally relevant concentrations.

Toxicity and speciation of inorganic arsenics and their adverse effects on in vivo endpoints and oxidative stress in the marine medaka Oryzias melastigma

Here, we investigate the effects of acute and chronic exposure to arsenate (AsV) and arsenite (AsIII) in the marine medaka Oryzias melastigma. In vivo effects, biotransformation, and oxidative stress were studied in marine medaka exposed to the two inorganic arsenics for 4 or 28 days. An investigation of embryonic development revealed no effect on in vivo parameters, but the hatching rate increased in the group exposed to AsIII. Exposure to AsIII also caused the greatest accumulation of arsenic in medaka. For acute exposure, the ratio of AsV to AsIII was higher than that of chronic exposure, indicating that bioaccumulation of inorganic arsenic can induce oxidative stress. The largest increase in oxidative stress was observed following acute exposure to AsIII, but no significant degree of oxidative stress was induced by chronic exposure. During acute exposure to AsV, the increase in the enzymatic activity of glutathione-S-transferase (GST) was twice as high compared with exposure to AsIII, suggesting that GST plays an important role in the initial detoxification process. In addition, an RNA-seq-based ingenuity pathway analysis revealed that acute exposure to AsIII may be related to cell-cycle progression. A network analysis using differentially expressed genes also revealed a potential link between the generation of inflammatory cytokines and oxidative stress due to arsenic exposure.

Identifying pesticides of high concern for ecosystem, plant, animal, and human health: A comprehensive field study across Europe and Argentina

The widespread and excessive use of pesticides in modern agricultural practices has caused pesticide contamination of the environment, animals, and humans, with confirmed serious health consequences. This study aimed to identify the 20 most critical substances based on an analysis of detection frequency (DF) and median concentrations (MC) across environmental and biological matrices. A sampling campaign was conducted across 10 case study sites in Europe and 1 in Argentina, each encompassing conventional and organic farming systems. We analysed 209 active substances in a total of 4609 samples. All substances ranked among the 20 most critical were detected in silicon wristbands worn by humans and animals and indoor dust from both farming systems. Five of them were detected in all environmental matrices. Overall, higher values of DF and MC, including in the blood plasma of animals and humans, were recorded in samples of conventional compared to organic farms. The differences between farming systems were greater in the environmental samples and less in animal and human samples. Ten substances were detected in animal blood plasma from conventional farms and eight in animal blood plasma from organic farms. Two of those, detected in both farming systems, are classified as hazardous for mammals (acute). Five substances detected in animal blood plasma from organic farms and seven detected in animal blood plasma from conventional farms are classified as hazardous for mammals (dietary). Three substances detected in human blood plasma are classified as carcinogens. Seven of the substances detected in human blood plasma are classified as endocrine disruptors. Six substances, of which five were detected in human blood plasma, are hazardous for reproduction/development. Efforts are needed to elucidate the unknown effects of mixtures, and it is crucial that such research also considers biocides and banned substances, which constitute a baseline of contamination that adds to the effect of substances used in agriculture.

Ecological implications and drivers of emerging contaminants in Dongting Lake of Yangtze River Basin, China: A multi-substance risk analysis

Emerging contaminants (ECs) are increasingly recognized as a global threat to biodiversity and ecosystem health. However, the cumulative risks posed by ECs to aquatic organisms and ecosystems, as well as the influence of anthropogenic activities and natural factors on these risks, remain poorly understood. This study assessed the mixed risks of ECs in Dongting Lake, a Ramsar Convention-classified Typically Changing Wetland, to elucidate the major EC classes, key risk drivers, and magnitude of anthropogenic and natural impacts. Results revealed that ECs pose non-negligible acute (30% probability) and chronic (70% probability) mixed risks to aquatic organisms in the freshwater lake ecosystem, with imidacloprid identified as the primary pollutant stressor. Redundancy analysis (RDA) and structural equation modeling (SEM) indicated that cropland and precipitation were major drivers of EC contamination levels and ecological risk. Cropland was positively associated with EC concentrations, while precipitation exhibited a dilution effect. These findings provide critical insights into the ecological risk status and key risk drivers in a typical freshwater lake ecosystem, offering data-driven support for the control and management of ECs in China.

Concentration-dependent effects of spinetoram on nontarget freshwater microalgae: A comparative study on Chlorella vulgaris and Microcystis aeruginosa

The rising global demand for agricultural products is leading to the widespread application of pesticides, such as spinetoram, resulting in environmental pollution and ecotoxicity to nontarget organisms in aquatic ecosystems. This research focused on assessing the toxicity of spinetoram at various concentrations (0, 0.01, 0.1, 0.5, 1.0, and 3.0 mg L-1) on two common freshwater microalgae, Chlorella vulgaris and Microcystis aeruginosa, to shed light on the ecotoxicological effects of insecticides. Our findings demonstrate that M. aeruginosa is more sensitive to spinetoram than is C. vulgaris, with a concentration-dependent reduction in the growth rate observed for M. aeruginosa, whereas only the highest concentration of spinetoram adversely affected C. vulgaris. At a concentration of 0.01 mg L-1, the growth rate of M. aeruginosa unexpectedly increased beginning on day 7, indicating a potential hormetic effect. Although initial exposure to spinetoram improved the photosynthetic efficiency of both microalgae strains at all concentrations, detrimental effects became apparent at higher concentrations and with prolonged exposure. The photosynthetic efficiency of C. vulgaris recovered, in contrast to that of M. aeruginosa, which exhibited limited recovery. Spinetoram more significantly inhibited the effective quantum yield of PSII (EQY) in M. aeruginosa than in C. vulgaris. Although spinetoram is not designed to target phytoplankton, its toxicity can disrupt primary productivity and modify phytoplankton-consumer interactions via bottom-up control mechanisms. This study enhances our understanding of spinetoram's ecotoxicity and potential effects on aquatic ecosystems.

Acute toxicity effects of pesticides on beneficial organisms - Dispelling myths for a more sustainable use of chemicals in agricultural environments

Agricultural practitioners, researchers and policymakers are increasingly advocating for integrated pest management (IPM) to reduce pesticide use while preserving crop productivity and profitability. Using selective pesticides, putatively designed to act on pests while minimising impacts on off-target organisms, is one such option - yet evidence of whether these chemicals control pests without adversely affecting natural enemies and other beneficial species (henceforth beneficials) remains scarce. At present, the selection of pesticides compatible with IPM often considers a single (or a limited number of) widely distributed beneficial species, without considering undesired effects on co-occurring beneficials. In this study, we conducted standardised laboratory bioassays to assess the acute toxicity effects of 20 chemicals on 15 beneficial species at multiple exposure timepoints, with the specific aims to: (1) identify common and diverging patterns in acute toxicity responses of tested beneficials; (2) determine if the effect of pesticides on beetles, wasps and mites is consistent across species within these groups; and (3) assess the impact of mortality assessment timepoints on International Organisation for Biological Control (IOBC) toxicity classifications. Our work demonstrates that in most cases, chemical toxicities cannot be generalised across a range of beneficial insects and mites providing biological control, a finding that was found even when comparing impacts among closely related species of beetles, wasps and mites. Additionally, we show that toxicity impacts increase with exposure length, pointing to limitations of IOBC protocols. This work challenges the notion that chemical toxicities can be adequately tested on a limited number of 'representative' species; instead, it highlights the need for careful consideration and testing on a range of regionally and seasonally relevant beneficial species.

Broad-scale pesticide screening finds anticoagulant rodenticide and legacy pesticides in Australian frogs

Pesticide contamination poses a significant threat to non-target wildlife, including amphibians, many of which are already highly threatened. This study assessed the extent of pesticide exposure in dead frogs collected during a mass mortality event across eastern New South Wales, Australia between July 2021 and March 2022. Liver tissue from 77 individual frogs of six species were analysed for >600 legacy and contemporary pesticides, including rodenticides. More than a third (36 %) of the liver samples contained at least one of the following pesticides: brodifacoum, dieldrin, DDE, heptachlor/heptachlor epoxide, fipronil sulfone, and 2-methyl-4-chlorophenoxyacetic acid (MCPA). Brodifacoum, a second-generation anticoagulant rodenticide, was found in four of the six frog species analysed: the eastern banjo frog (Limnodynastes dumerilii), cane toad (Rhinella marina), green tree frog (Litoria caerulea) and Peron's tree frog (Litoria peronii). This is the first report of anticoagulant rodenticide detected in wild amphibians, raising concerns about potential impacts on frogs and extending the list of taxa shown to accumulate rodenticides. Dieldrin, a banned legacy pesticide, was also detected in two species: striped marsh frog (Limnodynastes peronii) and green tree frog (Litoria caerulea). The toxicological effects of these pesticides on frogs are difficult to infer due to limited comparable studies; however, due to the low frequency of detection the presence of these pesticides was not considered a major contributing factor to the mass mortality event. Additional research is needed to investigate the effects of pesticide exposure on amphibians, particularly regarding the impacts of second-generation anticoagulant rodenticides. There is also need for continued monitoring and improved conservation management strategies for the mitigation of the potential threat of pesticide exposure and accumulation in amphibian populations.

Transfer and bioaccumulation of pesticides in terrestrial arthropods and food webs: State of knowledge and perspectives for research

Arthropods represent an entry point for pesticide transfers in terrestrial food webs, and pesticide accumulation in upper chain organisms, such as predators can have cascading consequences on ecosystems. However, the mechanisms driving pesticide transfer and bioaccumulation in food webs remain poorly understood. Here we review the literature on pesticide transfers mediated by terrestrial arthropods in food webs. The transfer of pesticides and their potential for bioaccumulation and biomagnification are related to the chemical properties and toxicokinetic of the substances, the resistance and detoxification abilities of the contaminated organisms, as well as by their effects on organisms' life history traits. We further identify four critical areas in which knowledge gain would improve future predictions of pesticides impacts on terrestrial food webs. First, efforts should be made regarding the effects of co-formulants and pesticides mixtures that are currently understudied. Second, progress in the sensitivity of analytical methods would allow the detection of low concentrations of pesticides in small individual arthropods. Quantifying pesticides in arthropods preys, their predators, and arthropods or vertebrates at higher trophic level would bring crucial insights into the bioaccumulation and biomagnification potential of pesticides in real-world terrestrial food webs. Finally, quantifying the influence of the trophic structure and complexity of communities on the transfer of pesticides could address several important sources of variability in bioaccumulation and biomagnification across species and food webs. This narrative review will inspire future studies aiming to quantify pesticide transfers in terrestrial food webs to better capture their ecological consequences in natural and cultivated landscapes.

The Pacific oyster reproduction is affected by early-life exposure to environmental pesticide mixture: A multigenerational study

Pesticides threat marine organisms worldwide. Among them, the Pacific oyster is a bivalve mollusc model in marine ecotoxicology. A large body of literature already stated on the multiple-scale effects pesticides can trigger in the Pacific oyster, throughout its life cycle and in a delayed manner. In particular, reproductive toxicity is of major concern because of its influence on population dynamics. However, past studies mostly investigated pesticide reprotoxicity as a direct effect of exposure during gametogenesis or directly on gametes and little is known about the influence of an early embryo exposure on the breed capacity. Therefore, we studied delayed and multigenerational consequences through gametogenesis features (i.e. sex ratio, glycogen content, gene expression) and reproductive success in two consecutive oyster generations (F0 and F1) exposed to an environmentally-relevant pesticide mixture (sum nominal concentration: 2.85 μg.L-1) during embryo-larval development (0-48 h post fertilization, hpf). In the first generation, glycogen content increased in exposed individuals and the expression of some gametogenesis target genes was modified. The reproductive success measured 48 hpf was higher in exposed individuals. A multigenerational influence was observed in the second generation, with feminisation, acceleration of gametogenesis processes and the sex-specific modification of glycogen metabolism in individuals from exposed parents. This study is the first to highlight the delayed effects on reproduction induced by an early exposure to pesticides, and its multigenerational implications in the Pacific oyster. It suggests that environmental pesticide contamination can have impacts on the recruitment and the dynamics of natural oyster populations exposed during their embryo-larval phase.

Organophosphate toxicity patterns: A new approach for assessing organophosphate neurotoxicity

Organophosphorus compounds or organophosphates (OPs) are widely used as flame retardants, plasticizers, lubricants and pesticides. This contributes to their ubiquitous presence in the environment and to the risk of human exposure. The persistence of OPs and their bioaccumulative characteristics raise serious concerns regarding environmental and human health impacts. To address the need for safer OPs, this study uses a New Approach Method (NAM) to analyze the neurotoxicity pattern of 42 OPs. The NAM consists of a 4-step process that combines computational modeling with in vitro and in vivo experimental studies. Using spherical harmonic-based cluster analysis, the OPs were grouped into four main clusters. Experimental data and quantitative structure-activity relationships (QSARs) analysis were used in conjunction to provide information on the neurotoxicity profile of each group. Results showed that one of the identified clusters had a favorable safety profile, which may help identify safer OPs for industrial applications. In addition, the 3D-computational analysis of each cluster was used to identify meta-molecules with specific 3D features. Toxicity was found to correspond to the level of phosphate surface accessibility. Substances with conformations that minimize phosphate surface accessibility caused less neurotoxic effect. This multi-assay NAM could be used as a guide for the classification of OP toxicity, helping to minimize the health and environmental impacts of OPs, and providing rapid support to the chemical regulators, whilst reducing reliance on animal testing.

Development of an analytical method for the determination of more than 300 pesticides and metabolites in the particulate and gaseous phase of ambient air

Pesticides can enter the atmosphere during spraying or after application, resulting in environmental or human exposure. The study describes the optimisation and validation of analytical methods for the determination of more than 300 pesticides in the particulate and gaseous phases of the air. Pesticides were sampled with high-volume air samplers on glass-fibre filters (GFFs) and glass columns filled with polyurethane foam (PUF) and XAD-2 resin. Comparing different extraction methods, a QuEChERS extraction with acetonitrile was selected for the GFFs. For the PUF/XAD-2 columns, a cold-column extraction with dichloromethane was used. Instrumental determination was performed using liquid chromatography/electrospray ionisation-time-of-flight mass spectrometry (LC/ESI-QTOF) and gas chromatography/electron impact ionisation-tandem mass spectrometry (GC/EI-MS/MS). Recovery experiments showed recovery rates between 70 and 120% for 263 compounds on the GFFs and 75 compounds on the PUF/XAD-2 columns. Semi-quantitative determination was performed for 39 compounds on the GFFs and 110 compounds on the PUF/XAD-2 columns. Finally, 27 compounds on the GFFs and 138 compounds on the PUF/XAD-2 columns could be determined only qualitatively. For the determination of the PUF/XAD-2 samples, signal suppression (LC) or signal enhancement (GC) due to matrix effects were determined. Method quantification limits of the optimised methods ranged from 30 to 240 pg/m3 for the target compounds on the GFFs, and from 8 to 60 pg/m3 on the PUF/XAD-2 columns. The applicability of the method was demonstrated by means of environmental air samples from an agricultural area in the Netherlands.

Thermal sensitivity of Rhinella arenarum tadpole at low concentrations of dimethoate pesticides

One of the main causes of contamination of aquatic environments, which affects biotic communities, is the use of pesticides in agricultural regions. Amphibians are considered good bio-indicators of aquatic pollution, because they are one of the most susceptible groups to pollution. Several studies suggest that both pollution and climate change produce synergistic effects in amphibians which amplify the toxicity afecting survival, and malformations with an increase in temperature. We studied the sensitivity of sublethal concentrations of dimethoate in Rhinella arenarum tadpoles on two fitness related thermal traits including locomotor swimming performance and thermal tolerance limits (CTmax = critical thermal maximum and CTmin = critical thermal minimum). The locomotor performance of R. arenarum tadpoles decreased with increasing sublethal dimethoate concentrations up to ∼60 % at intermediates dimethoate concentration. The tadpoles showed a tendency to decrease their tolerance to high temperatures (CTmax) with increasing dimethoate concentration around ∼0.5 °C, however no significant differences were found among treatments. Similarly, tadpoles showed decreases in their cold resistance (CTmin) with dimethoate concentrations, around 1 °C the high concentrations of dimethoate. The increase of atypical climatic events, such as heat waves may put R. arenarum tadpoles at greater risk when exposed to dimethoate. Our results show that the sublethal concentrations of the dimethoate pesticide may affect the fitness and survival of the larvae of R. arenarum in natural, and seminatural enviroments.

Regulatory framework for the assessment of the impacts of plant protection products on biodiversity: review of strengths and limits

The placing of plant protection products (PPPs) on the market in the European Union is governed by numerous regulations. These regulations are among the most stringent in the world, however they have been the subject of criticisms especially because of the decline in biodiversity. The objectives of this work were to review (1) the functioning and actors involved in the PPP framework processes, (2) the construction of the environmental risk assessment focused on biodiversity, and (3) the suggested ways to respond to the identified limits. Both literature from social sciences and ecotoxicology were examined. Despite the protective nature of the European regulation on PPPs, the very imperfect consideration of biodiversity in the evaluation process was underlined. The main limits are the multiplicity of applicable rules, the routinization of the evaluation procedures, the lack of consideration of social data, and the lack of independence of the evaluation. Strengths of the regulation are the decision to integrate a systemic approach in the evaluation of PPPs, the development of modeling tools, and the phytopharmacovigilance systems. The avenues for improvement concern the realism of the risk assessment (species used, cocktail effects…), a greater transparency and independence in the conduct of evaluations, and the opening of the evaluation and decision-making processes to actors such as beekeepers or NGOs. Truly interdisciplinary reflections crossing the functioning of the living world, its alteration by PPPs, and how these elements question the users of PPPs would allow to specify social actions, public policies, and their regulation to better protect biodiversity.

Systematic approaches to machine learning models for predicting pesticide toxicity

Pesticides play an important role in modern agriculture by protecting crops from pests and diseases. However, the negative consequences of pesticides, such as environmental contamination and adverse effects on human and ecological health, underscore the importance of accurate toxicity predictions. To address this issue, artificial intelligence models have emerged as valuable methods for predicting the toxicity of organic compounds. In this review article, we explore the application of machine learning (ML) for pesticide toxicity prediction. This review provides a detailed summary of recent developments, prediction models, and datasets used for pesticide toxicity prediction. In this analysis, we compared the results of several algorithms that predict the harmfulness of various classes of pesticides. Furthermore, this review article identified emerging trends and areas for future direction, showcasing the transformative potential of machine learning in promoting safer pesticide usage and sustainable agriculture.

First evidence of widespread positivity to anticoagulant rodenticides in grey wolves (Canis lupus)

Second-generation Anticoagulant Rodenticides (ARs) can be critical for carnivores, due to their widespread use and impacts. However, although many studies explored the impacts of ARs on small and mesocarnivores, none assessed the extent to which they could contaminate large carnivores in anthropized landscapes. We filled this gap by exploring spatiotemporal trends in grey wolf (Canis lupus) exposure to ARs in central and northern Italy, by subjecting a large sample of dead wolves (n = 186) to the LC-MS/MS method. Most wolves (n = 115/186, 61.8 %) tested positive for ARs (1 compound, n = 36; 2 compounds, n = 47; 3 compounds, n = 16; 4 or more compounds, n = 16). Bromadiolone, brodifacoum and difenacoum, were the most common compounds, with brodifacoum and bromadiolone being the ARs that co-occurred the most (n = 61). Both the probability of testing positive for multiple ARs and the concentration of brodifacoum, and bromadiolone in the liver, systematically increased in wolves that were found at more anthropized sites. Moreover, wolves became more likely to test positive for ARs through time, particularly after 2020. Our results underline that rodent control, based on ARs, increases the risks of unintentional poisoning of non-target wildlife. However, this risk does not only involve small and mesocarnivores, but also large carnivores at the top of the food chain, such as wolves. Therefore, rodent control is adding one further conservation threat to endangered large carnivores in anthropized landscapes of Europe, whose severity could increase over time and be far higher than previously thought. Large-scale monitoring schemes for ARs in European large carnivores should be devised as soon as possible.

Pesticides in small volume plasma samples: Method development and application to smallmouth bass (Micropterus dolomieu) from the Chesapeake Bay watershed, USA

Nontarget organisms are exposed to pesticides following applications in agricultural and urban settings, potentially resulting in deleterious effects. Direct measurements of pesticides in biological tissues may aid in characterizing exposure, accumulation, and potential toxicity versus analyses in environmental media alone (e.g., water, soil, and air). Plasma represents a nonlethal sampling medium that can be used to assess recent exposures to contaminants. Herein, a method was developed to test the extraction of 210 pesticides and their transformation products in small volume plasma samples (100 μL). Plasma samples were protein precipitated with 0.5 % formic acid in acetonitrile added to the sample (ratio of 3.5:1). Pass-through solid phase extraction was used for sample matrix and lipid removal and samples were analyzed by liquid chromatography and gas chromatography with tandem mass spectrometry. Recoveries of 70.0-129.8 % were achieved for 182 pesticides and degradates across the low (25 ng mL-1), medium (100 ng mL-1), and high (250 ng mL-1) spike levels. Method detection levels ranged 0.4-13.0 ng mL-1. Following development, the method was applied to smallmouth bass (Micropterus dolomieu) plasma samples (n = 10) collected from adults in the Chesapeake Bay watershed. Individual plasma samples resulted in four to seven analytes detected with summed concentrations ranging 16.4-95.0 ng mL-1. Biological multiresidue pesticide methods help elucidate recent exposures of bioactive compounds to nontarget organisms.

Bat diversity boosts ecosystem services: Evidence from pine processionary moth predation

Coniferous forests contribute to the European economy; however, they have experienced a decline since the late 1990s due to an invasive pest known as the pine processionary moth, Thaumetopoea pityocampa. The impacts of this pest are increasingly exacerbated by climate change. Traditional control strategies involving pesticides have had negative effects on public health and the environment. Instead, forest managers seek a more ecological and sustainable approach to management that promotes the natural actions of pest control agents. This study aims to evaluate the role of bats in suppressing pine processionary moths in pine forests and examine how the bat community composition and abundance influence pest consumption. Bats were sampled in the mountainous environment of the Serra da Estrela in central Portugal to collect faecal samples for DNA meta-barcoding analysis. We assessed the relationship between a) bat richness, b) bat relative abundance, c) bat diet richness, and the frequency of pine processionary moth consumption. Our findings indicate that sites with the highest bat species richness and abundance exhibit the highest levels of pine processionary moth consumption. The intensity of pine processionary moth consumption is independent of insect diversity within the site. The highest occurrence of pine processionary moth presence in bat diets is primarily observed in species that forage in cluttered habitats. A typical predator of pine processionary moths among bats is likely to be a forest-dwelling species that specialises in consuming Lepidoptera. These species primarily use short-range echolocation calls, which are relatively inaudible to tympanate moths, suitable for locating prey in cluttered environments, employing a gleaning hunting strategy. Examples include species from the genera Plecotus, Myotis, and Rhinolophus. This study enhances our understanding of the potential pest consumption services provided by bats in pine forests. The insights gained from this research can inform integrated pest management practices in forestry.