Pesticides linked to bird declines

Non-conventional endpoints show higher sulfoxaflor toxicity to Chironomus riparius than conventional endpoints in a multistress environment

Evidence grows that standard toxicity testing might underestimate the environmental risk of neurotoxic insecticides. Behavioural endpoints such as locomotion and mobility have been suggested as sensitive and ecologically relevant additions to the standard tested endpoints. Possible interactive effects of chemicals and additional stressors are typically overlooked in standardised testing. Therefore, we aimed to investigate how concurrent exposure to environmental stressors (increased temperature and predation cues) and a nicotinic acetylcholine receptor (nAChR)-modulating insecticide ('sulfoxaflor') impact Chironomus riparius across a range of conventional and non-conventional endpoints. We used a multifactorial experimental design encompassing three stressors, sulfoxaflor (2.0-110 µg/L), predation risk (presence/absence of predatory cues), and elevated temperature (20 °C and 23 °C), yielding a total of 24 distinct treatment conditions. Additional stressors did not change the sensitivity of C. riparius to sulfoxaflor. To assess potential additive effects, we applied an Independent Action (IA) model to predict the impact on eight endpoints, including conventional endpoints (growth, survival, total emergence, and emergence time) and less conventional endpoints (the size of the adults, swimming abilities and exploration behaviour). For the conventional endpoints, observed effects were either lower than expected or well-predicted by the IA model. In contrast, we found greater than predicted effects of predation cues and temperature in combination with sulfoxaflor on adult size, larval exploration, and swimming behaviour. However, in contrast to the non-conventional endpoints, no conventional endpoints detected interactive effects of the neurotoxic insecticide and the environmental stressors. Acknowledging these interactions, increasing ecological context of ecotoxicological test systems may, therefore, advance environmental risk analysis and interpretation as the safe environmental concentrations of neurotoxic insecticides depend on the context of both the test organism and its environment.

Temporal and spatial trends of imidacloprid-related hazards in France

Neonicotinoids are the top-selling insecticides worldwide. Because of their method of use, mainly to coat seeds, neonicotinoids have been found to widely contaminate the environment. Their high toxicity has been shown to be a major concern in terms of impact on biodiversity, and the use of these insecticides has been associated with population declines of species in different countries. Despite the widespread recognition of the risk of neonicotinoids to biodiversity, their temporal and spatial use remains poorly known in many countries. Yet this information is essential to address the potential impacts of these pesticides on biodiversity and to inform measures to establish protected areas or biodiversity restoration. The present study relied a large publicly available dataset to characterise the temporal and spatial use in France of imidacloprid, the most widely used neonicotinoid worldwide, as well as analysed water contamination surveys between 2005 and 2022 to assess the contamination of the environment. The results show that imidacloprid was the main neonicotinoid used in France over the study period. This use was spatially structured, with higher use in northern and western France, particularly related to cereal and beet crops area. The water contamination survey indicated that imidacloprid has widely contaminated the environment and consequently increased the risk to biodiversity, especially in counties crossed by the Loire, Seine and Vilaine rivers. This risk increased between 2005 and 2018 due to the higher use of imidacloprid and decreased sharply after 2018 due to its ban, although it was reauthorized by derogation for sugar beet in 2021. This study is the first assessment of imidacloprid pressure on biodiversity in France and shows the spatial and temporal correlation between agricultural practices and the freshwater contamination level. These results will help to identify priority areas for mitigation and restoration measures.

Occurrence and fate of five representative neonicotinoid insecticides across different wastewater treatment plants and the impact on receiving water bodies

Neonicotinoids (NEOs), despite their widespread use as insecticides, exhibit a notable knowledge deficit in regards to their presence in wastewater treatment plants (WWTPs) and their surrounding environments. This study delves into the presence and disposition of 5 NEOs: Thiamethoxam (THM), Clothianidin (CLO), Imidacloprid (IMD), Acetamiprid (ACE), and Thiacloprid (THA) across 3 domestic WWTPs and their receiving waters. Notably, THM, CLO, and ACE were consistently detected in all water and sludge samples, with THM emerging as the most abundant compound in both influent and effluent. Among the 3 WWTPs, WWTP 2, employing a fine bubble oxidation process, achieved the highest removal efficiency, surpassing 68%, in contrast to WWTP 1 (CAST) at 37% and WWTP 3 (A/A/O) at 7%. Biodegradation played a pivotal role in NEO removal, accounting for 36.7% and 68.2% of the total removal in WWTP 1 and WWTP 2, respectively. Surprisingly, in WWTP 3, biotransformation process inadvertently increased ACE and CLO concentrations by approximately 4.1% and 4.5%, respectively. The total NEO concentration in the receiving surface waters ranged from 72.7 to 155.5 ng/L, while sediment concentrations were significantly lower, spanning between 0.10 and 1.53 ng/g. WWTPs serve as both a removal and concentration point for NEOs, thereby significantly influencing their transportation. Additionally, the concentration of most NEOs in the receiving waters progressively increased from upstream to downstream, highlighting the substantial impact of WWTP discharges on natural water environments. This research offers valuable insights into NEO pollution surrounding WWTPs in the Pearl River Delta, ultimately aiding in pollution control and environmental protection decisions.

Nanoparticle-specific transformations dictate nanoparticle effects associated with plants and implications for nanotechnology use in agriculture

Nanotechnology shows potential to promote sustainable and productive agriculture and address the growing population and food demand worldwide. However, the applications of nanotechnology are hindered by the lack of knowledge on nanoparticle (NP) transformations and the interactions between NPs and macromolecules within crops. In this Review, we discuss the beneficial and toxicity-relieving transformation products of NPs that provide agricultural benefits and the toxic and physiology-disturbing transformations that induce phytotoxicities. Based on knowledge related to the management of NP transformations and their long-term effects, we propose feasible design suggestions to attain nano-enabled efficient and sustainable agricultural applications.

Sensitivity Variations in Developmental Toxicity of Imidacloprid to Zebrafish Embryos at Different Neurodevelopmental Stages

Neonicotinoids are ubiquitous in global surface waters and pose a significant risk to aquatic organisms. However, information is lacking on the variations in sensitivity of organisms at different developmental stages to the neurotoxic neonicotinoids. We established a spectrum of toxicity to zebrafish embryos at four neurodevelopmental stages (1, 3, 6, and 8 h post fertilization [hpf]) and dechorionated embryos at 6 hpf based on external and internal exposure to imidacloprid as a representative neonicotinoid. Embryos at the gastrula stage (6 and 8 hpf) were more sensitive to imidacloprid than embryos at earlier developmental stages. Dechorionated embryos were more sensitive to imidacloprid than embryos with a chorion, suggesting that the chorion offers protection against pollutants. Nine sublethal effects were induced by imidacloprid exposure, among which uninflated swim bladder (USB) was the most sensitive. Water depth and air availability in the exposure chambers were critical factors influencing the occurrence of USB in zebrafish larvae. Internal residues of metabolites accounted for <10% of imidacloprid, indicating that imidacloprid was metabolized in a limited fashion in the embryos. In addition, acute toxicity of the main metabolite 5-hydroxy-imidacloprid was significantly lower than that of imidacloprid, indicating that the observed toxicity in embryos exposed to imidacloprid was mainly induced by the parent compound. Our research offers a fresh perspective on choosing the initial exposure time in zebrafish embryo toxicity tests, particularly for neurotoxicants. Environ Toxicol Chem 2024;00:1-11. © 2024 SETAC.

Sustainable approach for the expulsion of metaldehyde: risk, interactions, and mitigation: a review

All pests can be eliminated with the help of pesticides, which can be either natural or synthetic. Because of the excessive use of pesticides, it is harmful to both ecology and people's health. Pesticides are categorised according to several criteria: their chemical composition, method of action, effects, timing of use, source of manufacture, and formulations. Many aquatic animals, birds, and critters live in danger owing to hazardous pesticides. Metaldehyde is available in various forms and causes significant impact even when small amounts are ingested. Metaldehyde can harm wildlife, including dogs, cats, and birds. This review discusses pesticides, their types and potential environmental issues, and metaldehyde's long-term effects. In addition, it examines ways to eliminate metaldehyde from the aquatic ecosystem before concluding by anticipating how pesticides may affect society. The metal-organic framework and other biosorbents have been appropriately synthesized and subsequently represent the amazing removal of pesticides from effluent as an enhanced adsorbent, such as magnetic nano adsorbents. A revision of the risk assessment for metaldehyde residuals in aqueous sources is also attempted.

Usefulness of oxidative stress biomarkers in native species for the biomonitoring of pesticide pollution in a shallow lake of the Austral Pampas, Argentina

Pesticide contamination and its adverse effects on native freshwater species continue to be a worldwide major concern, mainly in developing countries. Passive biomonitoring of pesticide pollution in shallow lakes may be achieved by the simultaneous use of fish and wetland plants. Thus, the present study aimed to evaluate the occurrence of current-use pesticides in the surface water of a shallow lake of the Austral Pampas region (Buenos Aires Province, Argentina) surrounded by intensive agricultural activities and its relationship with a battery of biomarkers, including oxidative stress and genotoxicity, in two native species, the fish Oligosarcus jenynsii and the macrophyte Bidens laevis. A total of 26 pesticide residues were analyzed, and the main ones detected were glyphosate and its metabolite aminomethylphosphonic acid (AMPA), chlorpyrifos, and imidacloprid. In O. jenynsii, hydrogen peroxide (H2O2) content in the liver increased with chlorpyrifos occurrence, while malondialdehyde (MDA) levels in the brain and liver increased with the presence of both chlorpyrifos and glyphosate. In B. laevis, H2O2 and MDA levels in leaves and roots increased with AMPA occurrence. Also, leaf H2O2 contents and root MDA levels increased with chlorpyrifos concentration. In contrast, catalase and peroxidase activities in roots decreased with AMPA and chlorpyrifos occurrence. In both species, mainly H2O2 and MDA levels demonstrated their sensitivity to be used as biomarkers in the biomonitoring of current-use pesticide pollution in shallow lakes. Their use may provide information to plan strategies for environmental conservation by government institutions or decision-makers, and to assess the biota health status.

Imidacloprid exposure is detectable in over one third of wild bird samples from diverse Texas ecoregions

Avian decline is occurring globally with neonicotinoid insecticides posed as a potentially contributing factor. Birds can be exposed to neonicotinoids through coated seeds, soil, water, and insects, and experimentally exposed birds show varied adverse effects including mortality and disruption of immune, reproductive, and migration physiology. However, few studies have characterized exposure in wild bird communities over time. We hypothesized that neonicotinoid exposure would vary temporally and based on avian ecological traits. Birds were banded and blood sampled at eight non-agricultural sites across four Texas counties. Plasma from 55 species across 17 avian families was analyzed for the presence of 7 neonicotinoids using high performance liquid chromatography-tandem mass spectrometry. Imidacloprid was detected in 36 % of samples (n = 294); this included quantifiable concentrations (12 %; 10.8-36,131 pg/mL) and concentrations that were below the limit of quantification (25 %). Additionally, two birds were exposed to imidacloprid, acetamiprid (18,971.3 and 6844 pg/mL) and thiacloprid (7022.2 and 17,367 pg/mL), whereas no bird tested positive for clothianidin, dinotefuran, nitenpyram, or thiamethoxam, likely reflecting higher limits of detection for all compounds compared to imidacloprid. Birds sampled in spring and fall had higher incidences of exposure than those sampled in summer or winter. Subadult birds had higher incidences of exposure than adult birds. Among the species for which we tested more than five samples, American robin (Turdus migratorius) and red-winged blackbird (Agelaius phoeniceus) had significantly higher incidences of exposure. We found no relationships between exposure and foraging guild or avian family, suggesting birds with diverse life histories and taxonomies are at risk. Of seven birds resampled over time, six showed neonicotinoid exposure at least once with three showing exposures at multiple time points, indicating continued exposure. This study provides exposure data to inform ecological risk assessment of neonicotinoids and avian conservation efforts.

Climate Change, Extreme Temperatures and Sex-Related Responses in Spiders

Climatic extremes, such as heat waves, are increasing in frequency, intensity and duration under anthropogenic climate change. These extreme events pose a great threat to many organisms, and especially ectotherms, which are susceptible to high temperatures. In nature, many ectotherms, such as insects, may seek cooler microclimates and 'ride out´ extreme temperatures, especially when these are transient and unpredictable. However, some ectotherms, such as web-building spiders, may be more prone to heat-related mortality than more motile organisms. Adult females in many spider families are sedentary and build webs in micro-habitats where they spend their entire lives. Under extreme heat, they may be limited in their ability to move vertically or horizontally to find cooler microhabitats. Males, on the other hand, are often nomadic, have broader spatial distributions, and thus might be better able to escape exposure to heat. However, life-history traits in spiders such as the relative body size of males and females and spatial ecology also vary across different taxonomic groups based on their phylogeny. This may make different species or families more or less susceptible to heat waves and exposure to very high temperatures. Selection to extreme temperatures may drive adaptive responses in female physiology, morphology or web site selection in species that build small or exposed webs. Male spiders may be better able to avoid heat-related stress than females by seeking refuge under objects such as bark or rocks with cooler microclimates. Here, we discuss these aspects in detail and propose research focusing on male and female spider behavior and reproduction across different taxa exposed to temperature extremes.

ESASeedPARAM: A seed treatment model for threatened and endangered bird species in the United States

The USEPA, National Marine Fisheries Service, and Fish and Wildlife Service are required to assess the risks of pesticides undergoing registration or reregistration to threatened and endangered (i.e., listed) species. Currently, the USEPA lacks a refined model to assess the risks of seed treatments to listed bird species. We developed the Endangered Species Assessment Seed Treatment Probabilistic Avian Risk Assessment Model (ESASeedPARAM) to incorporate species-specific diets, body weights, and food ingestion rates for potentially exposed listed bird species. The model also incorporates information on dissipation of seed residues after planting, and metabolism and elimination by birds during exposure. The ESASeedPARAM estimates hourly intake from ingestion of treated seeds for up to 50 days after planting. For each simulated bird, maximum retained dose (= body burden) and maximum rolling average total daily intake are estimated for acute and chronic exposure, respectively. The model is probabilistic and estimates exposure and risk for 20 birds on each of 1000 fields. The model accounts for interfield variation in the amount of waste grain on the soil surface in tilled, reduced till, and untilled fields. To estimate the fate of each bird from acute exposure, a random value is selected from the appropriate dose-response relationship and compared with the maximum retained dose. If acute exposure exceeds the randomly chosen effects value, mortality is assumed. For chronic risk, the most sensitive No Observed Adverse Effects Level (NOAEL) and Lowest Observed Adverse Effects Level (LOAEL) for an apical endpoint (survival, growth, reproduction) are compared with maximum rolling average total daily intake. In this article, we describe a case study conducted with the ESASeedPARAM for imidacloprid used as a seed treatment on wheat and soybean. Integr Environ Assess Manag 2023;19:527-546. © 2022 SETAC.

Neonicotinoid exposure in Tricolored Blackbirds (Agelaius tricolor)

There is increasing awareness of the negative ecological and environmental effects of widespread use of pesticides on the landscape. Spillover or drift of pesticides from agricultural areas has been shown to impact species health, reproduction, and trophic dynamics through both direct and indirect mechanisms. Neonicotinoid insecticides are associated with observed declines of insectivorous and grassland birds, and these environmental pollutants are a significant conservation concern for many species that have experienced past or current population declines. Due to the high efficacy of these modern insecticides in depressing local insect populations, insectivorous birds can be negatively impacted by a pesticide-mediated reduction in food supply. Neonicotinoids may act synergistically with other stressors, such as habitat loss, to exacerbate threats to species or population viability. The Tricolored Blackbird is an insectivorous grassland bird of conservation concern in California, USA. Due to the high association of this species with agricultural habitats, we sought to quantify the amount of neonicotinoid residues in Tricolored Blackbird carcasses as a first step in assessing how this species may be impacted by pesticides. Out of 85 salvaged carcasses sampled (N = 24 adults, N = 3 fledglings, and N = 58 nestlings), only two contained detectable levels of target compounds. These were an adult and one nestling that contained clothianidin residue (40 ppb and 7 ppb, respectively); both of these birds were salvaged from breeding colonies associated with dairy farms in Kern County, California. We suggest that further work is needed to assess neonicotinoid exposure of Tricolored Blackbirds in dairy-associated breeding colonies.

Environmental occurrence, toxicity concerns, and biodegradation of neonicotinoid insecticides

Neonicotinoids (NEOs) are fourth generation pesticides, which emerged after organophosphates, pyrethroids, and carbamates and they are widely used in vegetables, fruits, cotton, rice, and other industrial crops to control insect pests. NEOs are considered ideal substitutes for highly toxic pesticides. Multiple studies have reported NEOs have harmful impacts on non-target biological targets, such as bees, aquatic animals, birds, and mammals. Thus, the remediation of neonicotinoid-sullied environments has gradually become a concern. Microbial degradation is a key natural method for eliminating neonicotinoid insecticides, as biodegradation is an effective, practical, and environmentally friendly strategy for the removal of pesticide residues. To date, several neonicotinoid-degrading strains have been isolated from the environment, including Stenotrophomonas maltophilia, Bacillus thuringiensis, Ensifer meliloti, Pseudomonas stutzeri, Variovorax boronicumulans, and Fusarium sp., and their degradation properties have been investigated. Furthermore, the metabolism and degradation pathways of neonicotinoids have been broadly detailed. Imidacloprid can form 6-chloronicotinic acid via the oxidative cleavage of guanidine residues, and it is then finally converted to non-toxic carbon dioxide. Acetamiprid can also be demethylated to remove cyanoimine (=N-CN) to form a less toxic intermediate metabolite. A few studies have discussed the neonicotinoid toxicity and microbial degradation in contaminated environments. This review is focused on providing an in-depth understanding of neonicotinoid toxicity, microbial degradation, catabolic pathways, and information related to the remediation process of NEOs. Future research directions are also proposed to provide a scientific basis for the risk assessment and removal of these pesticides.

Residues of pesticides and veterinary drugs in diets of dairy cattle from conventional and organic farms in Austria

Modern agriculture depends highly on pesticides and pharmaceutical preparations, so controlling exposure to these substances in the feed and food chain is essential. This article presents the first study on residues of a broad spectrum of pesticides and veterinary drugs in the diets of dairy cattle. One hundred and two representative samples of the complete diets, including basal feed rations and additional fed concentrate, were collected in three Austrian provinces (Styria, Lower and Upper Austria) in 2019 and 2020. The samples were tested for >700 pesticides, veterinary drugs and related metabolites using a validated method based on liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). In total, 16 residues (13 pesticides and three veterinary drug residues) were detected. > 90% of the diets contained pesticide residues and <10% veterinary drug residues, whereas banned pesticides were not found. The most frequent pesticide residues were fluopyram (62%), piperonyl butoxide (39%) and diethyltoluamide (35%). The following pesticides exceed the default EU maximum residue level (MRL) (10 μg kg^-1) for products exclusively used for animal feed production: Benzovindiflupyr (proportion of samples > MRLs: 1%), bixafen (2%), fluopyram (6%), ipconazole (1%) and tebuconazole (3%). Three residues (dinitrocarbanilide, monensin and nicarbazin) of veterinary drugs were identified, all below the MRLs. Over 60% of the evaluated samples contained mixtures of two to six residues/sample. Only one pesticide (diethyltoluamide) presented a significant difference among regions, with higher concentrations in Upper Austria. Brewery's spent grains were the dietary ingredient that showed the strongest correlation to pesticide residues. These findings evidence the realistic scenario of highly occurrent low doses of pesticides cocktails in the feed/food chain, which may affect the animal, human and environmental health. Since the risk assessments are based on single pesticides, the potential synergistic effect of co-occurring chemicals ("cocktail effect") requires further investigations.

Toxicity of nitenpyram to silkworm (Bombyx mori L.) and its potential mechanisms

Silkworm (Bombyx mori L.), as an economic insect, occupies a certain position in the development of China's economy. The neonicotinoid insecticide nitenpyram is commonly used in farmland to control planthoppers and aphids. In China, mulberry orchards are often planted adjacent to fields or commercial crops, and mist drifts occur during application, which may affect the production safety of Bombyx mori. In this study, a risk assessment of nitenpyram was carried out, and the results showed that there were risks in spraying nitenpyram around the periphery and subperipheries of mulberry fields. However, few studies have reported the mechanism underlying nitenpyram's toxic effect on silkworms. Here, we validated 25 differentially expressed (DE) miRNAs in the nitenpyram treatment group of silkworms, and the significantly enriched mTOR signaling pathway, oxidative phosphorylation and FoxO signaling pathway were verified. Among them, bmo-miR-2766-5P was up-regulated by 2.122-fold, and the expression of its regulated target gene 101,741,287 was up-regulated. After the injection of bmo-miR-2766-5P inhibitor, the Log₂FC value of 101,741,287 was changed from 1.26 to -2.19. Bmo-miR-3326, bmo-miR-3378-5P and bmo-miR-2761-3P were down-regulated by 2.386-fold, 1.158-fold and 2.359-fold, respectively. After injecting miRNA mimics into silkworms, the Log₂FC values of the target genes 100,302,609, 101,740,730 and 101,746,319 were changed from 1.24 to -11.94, -1.12 changed to 2.84 and 1.93 changed to -0.37, respectively. In addition, nitenpyram induced oxidative damage in silkworms, and the degree of DNA damage increased with the increase of concentration and time. Meanwhile Imd was significantly up-regulated in IMD-related pathways (38.7-fold, p < 0.01). The results indicated that nitenpyram could affect the growth and development process of silkworms, and these DE-miRNAs may have an important impact on the stress response of silkworms to nitenpyram.

Risk aversion, marketing outlets, and biological control practice adoption: insight from pear farmers in China

Biological control (BC) is an important component of green control techniques, and its adoption in the production of fresh produce holds economic and ecological importance as an alternative to chemical pesticides, yet its current adoption rate is not high. To clarify the issue, this study analyzes the factors that influence growers' adoption of BC practices in China's orchard systems. We focus on how marketing outlets and risk attitudes affect farmers' adoption of BC practices. A field survey of 327 pear growers was conducted in three main pear-producing areas of Hebei, Shandong, and Hubei provinces of China between October and December 2020. Results show that farmers' risk aversion has a significant and negative impact on their adoption of BC practices. The market environment is another dramatic factor affecting farmers' adoption. Both green certification and cooperative marketing have a significant role in promoting farmers' adoption of BC practices. Our findings highlight the importance of risk reduction and market environment to BC adoption. Furthermore, it can provide critical information for policymakers in formulating strategies to promote the application and extension of BC practices among farmers in developing countries, such as China.

Imidacloprid Impairs Glutamatergic Synaptic Plasticity and Desensitizes Mechanosensitive, Nociceptive, and Photogenic Response of Drosophila melanogaster by Mediating Oxidative Stress, Which Could Be Rescued by Osthole

Background: Imidacloprid (IMD) is a widely used neonicotinoid-targeting insect nicotine acetylcholine receptors (nAChRs). However, off-target effects raise environmental concerns, including the IMD’s impairment of the memory of honeybees and rodents. Although the down-regulation of inotropic glutamate receptor (iGluR) was proposed as the cause, whether IMD directly manipulates the activation or inhibition of iGluR is unknown. Using electrophysiological recording on fruit fly neuromuscular junction (NMJ), we found that IMD of 0.125 and 12.5 mg/L did not activate glutamate receptors nor inhibit the glutamate-triggered depolarization of the glutamatergic synapse. However, chronic IMD treatment attenuated short-term facilitation (STF) of NMJ by more than 20%. Moreover, by behavioral assays, we found that IMD desensitized the fruit flies’ response to mechanosensitive, nociceptive, and photogenic stimuli. Finally, the treatment of the antioxidant osthole rescued the chronic IMD-induced phenotypes. We clarified that IMD is neither agonist nor antagonist of glutamate receptors, but chronic treatment with environmental-relevant concentrations impairs glutamatergic plasticity of the NMJ of fruit flies and interferes with the sensory response by mediating oxidative stress.

The toxic effects of combined exposure of chlorpyrifos and p, p'-DDE to zebrafish (Danio rerio) and tissue bioaccumulation

Pesticides are widely used and frequently detected in the environment. The evaluation on the toxic effects of the co-exposure of two or more pesticides or related metabolites could reflect the real situation of the exposing risks. In this study, zebrafish was used as a model to investigate the potential toxic interactions of chlorpyrifos and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) on the survival rate, oxidative stress response and neurotoxicity, as well as their bioaccumulation and distribution in tissues. Co-exposure of chlorpyrifos and p,p'-DDE resulted in significant additive acute toxic effects on adult zebrafish with model deviation ratio (MDR) = 1.64. Both 7-day short-term at 1% LC₅₀ and 35-day long-term at 0.5% LC₅₀ co-exposure of chlorpyrifos with p,p'-DDE (50 and 100 µg/L) significantly reduced the survival rate of zebrafish colony to 75 and 82.5%. Co-exposure of chlorpyrifos and p,p'-DDE contributed to increased activity of antioxidant enzyme CAT, SOD and GST and excessive MDA generation, and decreased activity of CarE, CYP450 and AChE, compared with either single exposure of them. In co-exposure, the bioaccumulation of chlorpyrifos and p,p'-DDE was significantly different from the single exposure group. Overall, this study unraveled the potential toxic interaction of chlorpyrifos and p,p'-DDE on zebrafish and provided reference for environmental risk assessment of pesticide mixture.

Avoidance of neonicotinoid-treated seeds and cotyledons by captive eared doves (Zenaida auriculata, Columbidae)

Farmland birds can be exposed to neonicotinoids through the ingestion of treated unburied seeds and cotyledons. The aim of this study was to evaluate the avoidance of sorghum with imidacloprid, clothianidin or thiamethoxam, soybean with imidacloprid, and soybean cotyledons with imidacloprid or thiamethoxam on eared doves (Zenaida auriculata). Doves were fed with test food (untreated and neonicotinoid-treated sorghum, soybean or soybean cotyledons) and maintenance food (seed mix) for 3-5 days to study the repellency (primary repellency and conditioned aversion) and anorexia caused by neonicotinoid-treated food, followed by a 7-day period on maintenance food to study the persistence of the anorexic effect after neonicotinoid exposure. Immediately afterward, the same doves were exposed to treated test food during a second period of 3-5 days to study the potential reinforcement of food avoidance. Finally, doves were fed with untreated test food to test the capacity of the pesticide to induce conditioned food aversion against untreated food in subsequent encounters. Intoxication signs and differences of body weight were determined. With sorghum, the three neonicotinoids produced a decrease in the consumption of treated seeds by >97% compared to control birds. However, this was not enough to prevent the death of 3/8 and 1/8 of the doves exposed to imidacloprid and clothianidin, respectively. Anorexia was clearly observed with neonicotinoid-treated sorghum. The birds did not avoid the untreated sorghum after exposure to the treated sorghum, indicating that avoidance is not generalized to the type of food without an associated sensory cue. The results obtained with soybean seeds and cotyledons were less conclusive because captive doves hardly consumed these foods, even without neonicotinoid treatment. The avoidance of sorghum seeds treated with neonicotinoids was insufficient to prevent poisoning and death of eared doves.

Amyloid-Like Protein Aggregation Toward Pesticide Reduction

Pesticide overuse is a major global problem and the cause of this problem is noticeable pesticide loss from undesired bouncing of sprayed pesticide droplets and rain erosion. This further becomes a primary source of soil and groundwater pollution. Herein, the authors report a method that can enhance pesticide droplet deposition and adhesion on superhydrophobic plant leave surfaces by amyloid-like aggregation of bovine serum albumin (BSA). Through the reduction of the disulfide bond of BSA by tris(2-carboxyethyl) phosphine hydrochloride (TCEP), the amyloid-like phase transition of BSA is triggered that rapidly affords abundant phase-transitioned BSA (PTB) oligomers to facilitate the invasion of the PTB droplet into the nanostructures on a leaf surface. Such easy penetration is further followed by a robust amyloid-mediated interfacial adhesion of PTB on leaf surface. As a result, after mixing with pesticides, the PTB system exhibits a remarkable pesticide adhesion capacity that is more than 10 times higher than conventional fixation of commercial pesticides. The practical farmland experiments show that the use of PTB aggregation could reduce the use of pesticides by 70-90% while ensuring yield. This work demonstrates that current pesticide dosage in actual agriculture production may be largely reduced by utilizing eco-friendly amyloid-like protein aggregation.

Emerging frontiers in microbe-mediated pesticide remediation: Unveiling role of omics and In silico approaches in engineered environment

The overuse of pesticides for augmenting agriculture productivity always comes at the cost of environment, biodiversity, and human health and has put the land, water, and environmental footprints under severe threat throughout the globe. Underpinning and maximizing the microbiome functions in pesticide-contaminated environments has become a prerequisite for a sustainable environment and resilient agriculture. It is imperative to elucidate the metabolic network of the microbial communities and environmental variables at the contaminated site to predict the best strategy for remediation and soil microbe-pesticide interactions. High throughput next-generation sequencing and in silico analysis allow us to identify and discern the members and characteristics of core microbiomes at the contaminated site. Integration of modern high throughput multi-omics investigations and informatics pipelines provide novel approaches and pathways to capitalize on the core microbiomes for enhancing environmental functioning and mitigation. The role of eco-genomics tools in visualising the microbial network, taxonomy, functional potential, and environmental variables in contaminated habitats is discussed in this review. The integrated role of the potential microbe identification as individual or consortia, mechanistic approach for pesticide degradation, identification of responsible enzymes/genes, and in silico approach is emphasized for the prospects of the area.

The ubiquity of neonicotinoid contamination: Residues in seabirds with different trophic habits

Neonicotinoids are one of the most diffusely used classes of pesticides whose level of danger toward non-target invertebrate and vertebrate species has raised increasing concern in the last decades. Among vertebrates, birds are particularly susceptible to unintentional neonicotinoid poisoning since they can be exposed through different pathways, including ingestion of dressed seeds, sucking of contaminated pollen, ingestion of sprayed insects, predation on contaminated aquatic and terrestrial preys. In the present study, we investigated the possible exposure of seabirds by measuring the residues of five neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) in samples of pooled feathers collected from fledglings of the strictly piscivorous Sandwich tern (Thalasseus sandvicensis) and the mixotrophic species Mediterranean gull (Ichthyaetus melanocephalus). At least one neonicotinoid was quantified in all the Mediterranean gull samples (n = 11) and 89% of the analysed Sandwich tern samples (n = 36). The active principles with the highest quantification rates were imidacloprid (100% in Mediterranean gulls and 58% in Sandwich terns) and clothianidin (100% in Mediterranean gulls and 61% in Sandwich terns), while thiacloprid was the less frequently detected pesticide (<20% of samples in both species). Mean concentrations ± standard error for imidacloprid, clothianidin and thiamethoxam were 8.8 ± 1.4, 4.5 ± 0.19 and 0.16 ± 0.02 ng g^-1 for the Mediterranean gull, and 5.8 ± 0.55, 0.60 ± 0.08 and 0.36 ± 0.03 ng g^-1for the Sandwich tern, respectively. Our data evidenced the exposure of seabirds to neonicotinoids and the further need to investigate the extent of neonicotinoid contamination in non-agricultural ecosystems.

Regard and protect ground-nesting pollinators as part of soil biodiversity

While the Convention on Biological Diversity employs a habitat-oriented definition of soil biodiversity including all kinds of species living in soil, the Food and Agriculture Organization, since 2002 assigned to safeguard soil biodiversity, excludes them by focusing on species directly providing four ecosystem services contributing to soil quality and functions: nutrient cycling, regulation of water flow and storage, soil structure maintenance and erosion control, and carbon storage and regulation of atmospheric composition. Many solitary wasps and 70% of wild bees nest below ground and require protection during this long and crucial period of their lifecycle. Recent research has demonstrated the extent of threats to which ground-nesting pollinators are exposed, for example, chemicals and deep tillage. Ground-nesting pollinators change soil texture directly by digging cavities, but more importantly by their indirect contribution to soil quality and functions: 87% of all flowering plants require pollinators. Without pollinators, soil would lose all ecosystem services provided by these flowering plants, for example, litter, shade, roots for habitats, and erosion control. Above- and belowground biota are in constant interaction. Therefore, and in line with the Convention's definition, the key stakeholder, the Food and Agriculture Organization should protect ground-nesting pollinators explicitly within soil biodiversity conservation.

The Decline of Common Birds Exemplified by the Western Jackdaw Warns on Strong Environmental Degradation

Bird populations associated with agricultural ecosystems have declined markedly in Europe during the last quarter of the 20th century due to land-use intensification. This has meant that some very common species, in some cases even species considered as pests, are now threatened or subject to management programs to ensure their conservation. Considered pests of crops and predators of small game species, corvids are among the most persecuted common farmland birds. The consideration that these birds are pests lacks any scientific evaluation and is justified by the subjective impression that they are abundant. Here, using estimates of absolute and relative abundances of both the total and the breeding population, we show how jackdaws Corvus monedula have shown a marked negative population trend in central Spain during the last 40 years. Decline involves the loss of multiple colonies, the apparent absence of the species as a breeder in riverside forests, and an overall numerical decrease of about 75% (from 35,000 to 9000 individuals) according to counts in communal roosts. The population decline seems to be more pronounced in areas where land use has been intensified, probably in response to the reduction in the availability of once-abundant food (i.e., invertebrates and weed seeds) but also due to more direct effects such as intoxication and medium to long-term accumulation of agricultural pollutants which may have also affected reproduction and survival. Intensive hunting over decades has undoubtedly contributed to this decline and should therefore be made forbidden urgently. Generally, it seems that high-intensity agricultural management more drastically affects smaller and less adaptable common species, which are expected to decline before and at a higher extent and magnitude than jackdaws. Given that global population estimates based on direct counts of individuals are readily achievable through simultaneous counts in communal roosts, the jackdaw can serve as a model for assessing temporal trends potentially linked to large-scale anthropogenic modifications of open and agricultural environments.

Bird exposure to fungicides through the consumption of treated seeds: A study of wild red-legged partridges in central Spain

Sown seeds are a key component of many farmland birds' diets due to natural food shortages in autumn and winter. Because these seeds are often treated with pesticides, their ingestion by birds can result in toxic effects. For risk assessment, data on treated seed toxicity should be combined with information about exposure risk for wild birds and the factors that modulate it. We characterized the exposure of red-legged partridges to pesticide-treated seeds through the analysis of digestive contents of birds shot by hunters (n = 194) in an agricultural region in central Spain. We measured the contribution of sown seeds to the partridges' diet and how it related to pesticide exposure. Moreover, we evaluated the influence of landscape composition on the intake of sown seeds and pesticides by partridges. During peak sowing time, seeds constituted half (50.7%) of the fresh biomass ingested by partridges, which consumed mostly winter cereal seeds (42.3% of biomass). Residues of seven fungicides and one insecticide (active ingredients) were detected in 33.0% of birds. The presence of pesticides in digestive contents was linked to the ingestion of cereal sown seeds. Moreover, dietary exposure of birds to pesticides was modulated by landscape characteristics, being lower in areas with heterogeneous landscapes, greater habitat mosaic and more natural vegetation. The estimated dietary intake of pesticides resulting from our field observations, in combination with experimental data on pesticide toxicity, raise concerns about the risks that pesticide-treated cereal seeds pose to granivorous bird populations. Our results highlight the importance of farming landscape composition and diversification, which should be considered as a priority in the agricultural policy to mitigate pesticide risks to farmland birds through the consumption of treated seeds.

Selected transformation products of neonicotinoid insecticides (other than imidacloprid) in drinking water

Several transformation products (or metabolites) of neonicotinoid insecticides (NNIs) have been detected in drinking water, such as desnitro-imidacloprid and imidacloprid-urea. However, data on the occurrences of the metabolites of NNIs (mNNIs) in drinking water are mainly limited to the imidacloprid metabolites. To identify whether the potential metabolites of other widely used NNIs (such as acetamiprid, clothianidin, and thiamethoxam) occur in drinking water and to characterize their distribution profiles, twelve selected (mainly urea and desnitro/decyano) metabolites of NNIs were measured in drinking water samples (n = 884, including n = 789 for tap water, and n = 95 for shallow groundwater) that were collected from 32 provinces in mainland China and Hong Kong. Nearly 90% of the drinking water samples contained the detected mNNI residues. Among the selected mNNIs, thiamethoxam-urea (THM-urea: 76%) and decyano-acetamiprid (decyano-ACE: 73%) were frequently detected (median: 0.94 and 0.25 ng/L, respectively), which were followed by clothianidin-urea (CLO-urea: 45%), desnitro-thiamethoxam (DN-THM: 38%), and other mNNIs (detected in less than 30% of the water samples). Surface-water-sourced tap water had an approximately 8-10 times higher median cumulative concentration (ng/L) of the selected mNNIs (ΣmNNIs: 3.88) than the deep groundwater-sourced tap water (0.53) and groundwater that was directly used as drinking water (0.38). Higher ratios of THM-urea accounted for ΣTHM in north and northwest China than in south China could be partly explained by the decreasing soil pH values from north to south in China. The higher ratios of decyano-ACE accounted for ΣACE in south China than in north and northwest China could be attributable to the lower soil pH levels, higher temperatures, and greater light intensities in south China. The THM-urea, decyano-ACE, and ΣmNNIs levels in cities were found to be significantly higher than those in nonurban areas. The THM-urea levels in seven drinking water samples from Guangxi and Henan Provinces exceeded the guideline limit (100 ng/L) of the European Union. This is the first study to identify THM-urea, decyano-ACE, CLO-urea, and DN-THM in drinking water. To better assess the mass loadings of NNIs in drinking water, mNNIs should be considered in further studies.

Assessment of Cholinesterase inhibition activity of birds inhabiting pesticide exposed croplands and protected area in hot semi-arid region of Pakistan

Acetylcholinesterase (AChE) activity levels can be used as an indicator for AChE inhibition due to pesticide poisoning in bird species. We assessed the comparative brain cholinesterase (AChE) activity level of five bird species inhabiting pesticide exposed croplands and Protected Area i.e. Deva Vatala National Park (DVNP), Bhimber by using a spectrophotometric method. AChE activity levels ranged from 56.3 to 85.9 µmol/min/g of brain tissue of birds representing DVNP. However, AChE activity levels ranged from 27.6 to 79.9 µmol/min/g of brain tissue of birds representing croplands. AChE activity levels observed in Jungle babbler, Common babbler, and Red-vented bulbul showed significant differences (P < 0.05) at two sites. However, White wagtail and Black drongo demonstrated non-significant differences (P > 0.05). Maximum inhibition was recorded in Jungle babbler (53%) followed by Common babbler (35%), Red-vented bulbul (18%), White wagtail (15%), and Black drongo (7%). The brain cholinesterase inhibition levels under-protected ecosystems (DVNP, Bhimber) and agricultural landscape suggest insecticidal contamination and its impact on avifauna diversity. The study also emphasizes on the importance of pesticide-free zones to protect the biodiversity of birds.

Seroprevalences of specific antibodies against avian pathogens in free-ranging ring-necked pheasants (Phasianus colchicus) in Northwestern Germany

Infectious diseases in captive pheasants (Phasianus colchicus) are well known, but there is a lack of knowledge about occurrence and distribution of pathogens in free-ranging pheasants in Germany. We investigated 604 sera from hunted pheasants and 152 sera from wild caught pheasants between 2011 to 2015, with the aim to determine the prevalence of specific antibodies against different viruses: Avian influenza virus (AIV) of subtypes H5, H7, H9, paramyxovirus type 1 (PMV-1), avian encephalomyelitis virus (AEV), infectious bursitis disease virus (IBDV), infectious bronchitis virus (IBV), infectious laryngotracheitis virus (ILTV), avian metapneumovirus (aMPV) and Salmonella sp., Mycoplasma synoviae (MS) and Mycoplasma gallisepticum (MG). In addition, 178 caeca were investigated for Histomonas meleagridis. The study reveals an ongoing circulation of IBV in the wild pheasant population during the study. Also high seroprevalences of specific antibodies against aMPV depending on the area and a strong increase in prevalence of IBDV antibodies in sera of pheasants in Lower Saxony were detected. ILTV antibody prevalences differed between areas and AEV antibody detection differed between years significantly, whereas specific antibodies against PMV-1 could not be detected and antibodies against AIV-H5, -H7 and -H9 and Mycoplasma spp. were detected in very few cases.

Susceptibility of Tribolium castaneum (Coleoptera: Tenebrionidae) to the Fumigation of Two Essential Satureja Oils: Optimization and Modeling

Due to the numerous side effects of synthetic pesticides, including environmental pollution, threats to human health, harmful effects on non-target organisms and pest resistance, the use of alternative healthy, available and efficient agents in pest management strategies is necessary. In this paper, the susceptibility of the cosmopolitan, polyphagous, stored-product pest Tribolium castaneum (red flour beetle) to the fumigation of the essential oils of two important medicinal and food additive plants, Satureja hortensis and S. intermedia, was investigated. The insecticidal properties of the essential oils were modeled and optimized using response surface methodology. It was found that a maximum significant mortality of 94.72% and 92.97% could be achieved within 72 h with the applications of 55.15 µL/L of S. hortensis (with the linear model) and 58.82 µL/L of S. intermedia (with the quadratic model), respectively. There were insecticidal terpenes and phenylpropanoids in both essential oils, including thymol (50.8%), carvacrol (11.2%) and p-cymene (13.4%), in the S. intermedia and estragole (68.0%) and methyl eugenol (5.6%) in the S. hortensis. It was suggested that the essential oils of S. hortensis and S. intermedia could be offered as promising pesticidal agents against T. castaneum for further studies in the management of such pests instead of detrimental synthetic pesticides.

Retention and distribution of pesticides in planted filter microcosms designed for treatment of agricultural surface runoff

Pesticides in agricultural surface water runoff cause a major threat to freshwater systems. Installation of filter systems or constructed wetlands in areas of preferential run-off is a possible measure for pesticides abatement. To develop such systems, combinations of filter materials suitable for retention of both hydrophilic and hydrophobic organic pesticides were tested for pesticide removal in planted microcosms. The retention of six pesticides frequently detected in surface waters (bentazone, MCPA, metalaxyl, propiconazole, pencycuron, and imidacloprid) was evaluated in unplanted and planted pot experiments with novel bed material mixtures consisting of pumice, vermiculite, water super-absorbent polymer (SAP) for retention of ionic and water soluble pesticides, and synthetic hydrophobic wool for adsorption of hydrophobic pesticides. The novel materials were compared to soil with high organic matter content. The highest retention of the pesticides was observed in the soil, with a considerable translocation of pesticides into the plants, and low leaching potential, in particular for the hydrophobic compounds. However, due to the high retention of pesticides in soil, environmental risks related to their long term mobilization cannot be excluded. Mixtures of pumice and vermiculite with SAP resulted in high retention of i) water and ii) both hydrophilic and hydrophobic pesticides but with much lower leaching potential compared to the mineral systems without SAP. Mixtures of such materials may provide near natural treatment options in riparian strips and also for treatment of rainwater runoff without the need for water containment systems.

Feeding partridges with organic or conventional grain triggers cascading effects in life-history traits

Farmland birds are declining across Europe and North America and the research of factors behind is the subject of extensive researches. Agricultural intensification is now recognized as a major factor governing the loss of biodiversity with strong evidence that pesticides induced direct bird mortality at a high dose. However, less attention has been given to the long-term effects of chronic exposure to low dose of pesticides. Here, we used an experimental procedure in which grey partridges were fed with untreated grains obtained from either organic (no pesticide) or conventional agriculture (with pesticide) for 26 weeks, thus strictly mimicking wild birds foraging on fields. We then examined a suite of life-history traits (ecophysiological and behavioural) that may ultimately, influence population dynamics. We show for the first time that ingesting low pesticide doses over a long period has long-term consequences on several major physiological pathways without inducing differential mortality. Compared to control partridges, birds exposed to chronic doses i) had less developed carotenoid-based ornaments due to lower concentrations of plasmatic carotenoids, ii) had higher activated immune system, iii) showed signs of physiological stress inducing a higher intestinal parasitic load, iv) had higher behavioural activity and body condition and v) showed lower breeding investment. Our results are consistent with a hormetic effect, in which exposure to a low dose of a chemical agent may induce a positive response, but our results also indicate that breeding adults may show impaired fitness traits bearing population consequences through reduced breeding investment or productivity. Given the current scale of use of pesticides in agrosystems, we suggest that such shifts in life-history traits may have a negative long-term impact on wild bird populations across agrosystems. We stress that long-term effects should no longer be ignored in pesticide risk assessment, where currently, only short-term effects are taken into account.

Isolation and Identification of Antibacterial Bioactive Compounds From Bacillus megaterium L2

Bacterial metabolites exhibit a variety of biologically active compounds including antibacterial and antifungal activities. It is well known that Bacillus is considered to be a promising source of bioactive secondary metabolites. Most plant pathogens have an incredible ability to mutate and acquire resistance, causing major economic losses in the agricultural field. Therefore, it is necessary to use the natural antibacterial compounds in microbes to control plant pathogens. This study was conducted to investigate the bio-active compounds of Bacillus megaterium L2. According to the activity guidance of Agrobacterium tumefaciens T-37, Erwinia carotovora EC-1 and Ralstonia solanacearum RS-2, five monomeric compounds, including erucamide (1), behenic acid (2), palmitic acid (3), phenylacetic acid (4), and β-sitosterol (5), were fractionated and purified from the crude ethyl acetate extract of B. megaterium. To our knowledge, all compounds were isolated from the bacterium for the first time. To understand the antimicrobial activity of these compounds, and their minimum inhibitory concentrations (MICs) (range: 0.98∼500 μg/mL) were determined by the broth microdilution method. For the three tested pathogens, palmitic acid exhibited almost no antibacterial activity (>500 μg/mL), while erucamide had moderate antibacterial activity (MIC = 500 μg/mL). Behenic acid showed MICs of 250 μg/mL against T-37 and RS-2 strains with an antibacterial activity. β-sitosterol showed significant antimicrobial activity against RS-2. β-sitosterol showed remarkable antimicrobial activity against RS-2 with an MIC of 15.6 μg/mL. In addition, with the antimicrobial activity, against T-37 (62.5 μg/mL) and against EC-1 (125 μg/mL) and RS-2 (15.6 μg/mL) strains notably, phenylacetic acid may be interesting for the prevention and control of phytopathogenic bacteria. Our findings suggest that isolated compounds such as behenic acid, β-sitosterol, and phenylacetic acid may be promising candidates for natural antimicrobial agents.

Assessing surface and subsurface transport of neonicotinoid insecticides from no-till crop fields

Increased use of neonicotinoid-coated crop seeds introduces greater amounts of insecticides into the environment, where they are vulnerable to transport. To understand the transport of neonicotinoids from agricultural fields, we planted maize (Zea mays L.) seeds coated with thiamethoxam in lysimeter plots in central Pennsylvania. Over the next year, we sampled water generated by rainfall and snowmelt and analyzed these samples with mass spectrometry for the neonicotinoids thiamethoxam and clothianidin (metabolite), which originated from the coated seeds. For surface and subsurface transport, thiamethoxam exhibited "first-flush" dynamics, with concentrations highest during the first events following planting and generally decreasing for the remainder of the study. The metabolite clothianidin, however, persisted throughout the study. The mass of thiamethoxam and clothianidin exported during the study period accounted for 1.09% of the mass applied, with more than 90% of the mass transported in subsurface flow and less than 10% in surface runoff. These results suggest that surface runoff, at least for our site, is a relatively small contributor to the overall fate and transport of these insecticides and that the delivery ratio (i.e., mass exported/mass applied) observed for these compounds is similar to those of other trace-level emerging contaminants known to negatively influence aquatic ecosystems.

Clothianidin decomposition in Missouri wetland soils

Neonicotinoid pesticides can persist in soils for extended time periods; however, they also have a high potential to contaminate ground and surface waters. Studies have reported negative effects associated with neonicotinoids and nontarget taxa, including aquatic invertebrates, pollinating insect species, and insectivorous birds. This study evaluated factors associated with clothianidin (CTN) degradation and sorption in Missouri wetland soils to assess the potential for wetland soils to mitigate potential environmental risks associated with neonicotinoids. Solid-to-solution partition coefficients (K_d ) for CTN sorption to eight wetland soils were determined via single-point sorption experiments, and sorption isotherm experiments were conducted using the two most contrasting soils. Clothianidin degradation was determined under oxic and anoxic conditions over 60 d. Degradation data were fit to zero- and first-order kinetic decay models to determine CTN half-life (t_0.5 ). Sorption results indicated CTN sorption to wetland soil was relatively weak (average K_d , 3.58 L kg^-1 ); thus, CTN has the potential to be mobile and bioavailable within wetland soils. However, incubation results showed anoxic conditions significantly increased CTN degradation rates in wetland soils (anoxic average t_0.5 , 27.2 d; oxic average t_0.5 , 149.1 d). A significant negative correlation was observed between anoxic half-life values and soil organic C content (r²  = .782; p = .046). Greater CTN degradation rates in wetland soils under anoxic conditions suggest that managing wetlands to facilitate anoxic conditions could mitigate CTN presence in the environment and reduce exposure to nontarget organisms.

Climate change-mediated temperature extremes and insects: From outbreaks to breakdowns

Insects are among the most diverse and widespread animals across the biosphere and are well-known for their contributions to ecosystem functioning and services. Recent increases in the frequency and magnitude of climatic extremes (CE), in particular temperature extremes (TE) owing to anthropogenic climate change, are exposing insect populations and communities to unprecedented stresses. However, a major problem in understanding insect responses to TE is that they are still highly unpredictable both spatially and temporally, which reduces frequency- or direction-dependent selective responses by insects. Moreover, how species interactions and community structure may change in response to stresses imposed by TE is still poorly understood. Here we provide an overview of how terrestrial insects respond to TE by integrating their organismal physiology, multitrophic, and community-level interactions, and building that up to explore scenarios for population explosions and crashes that have ecosystem-level consequences. We argue that TE can push insect herbivores and their natural enemies to and even beyond their adaptive limits, which may differ among species intimately involved in trophic interactions, leading to phenological disruptions and the structural reorganization of food webs. TE may ultimately lead to outbreak-breakdown cycles in insect communities with detrimental consequences for ecosystem functioning and resilience. Lastly, we suggest new research lines that will help achieve a better understanding of insect and community responses to a wide range of CE.

Mining the effect of the neonicotinoids imidacloprid and clothianidin on the chemical homeostasis and energy equilibrium of primary mouse neural stem/progenitor cells using metabolomics

The projection of plant protection products' (PPPs) toxicity to non-target organisms at early stages of their development is challenging and demanding. Recent developments in bioanalytics, however, have facilitated the study of fluctuations in the metabolism of biological systems in response to treatments with bioactives and the discovery of corresponding toxicity biomarkers. Neonicotinoids are improved insecticides that target nicotinic acetylocholine receptors (nAChR) in insects which are similar to mammals. Nonetheless, they have sparked controversy due to effects on non-target organisms. Within this context, mammalian cell cultures represent ideal systems for the development of robust models for the dissection of PPPs' toxicity. Thus, we have investigated the toxicity of imidacloprid, clothianidin, and their mixture on primary mouse (Mus musculus) neural stem/progenitor (NSPCs) and mouse neuroblastoma-derived Neuro-2a (N2a) cells, and the undergoing metabolic changes applying metabolomics. Results revealed that NSPCs, which in vitro resemble those that reside in the postnatal and adult central nervous system, are five to seven-fold more sensitive than N2a to the applied insecticides. The energy equilibrium of NSPCs was substantially altered, as it is indicated by fluctuations of metabolites involved in energy production (e.g. glucose, lactate), Krebs cycle intermediates, and fatty acids, which are important components of cell membranes. Such evidence plausibly suggests a switch of cells' energy-producing mechanism to the direct metabolism of glucose to lactate in response to insecticides. The developed pipeline could be further exploited in the discovery of unintended effects of PPPs at early steps of development and for regulatory purposes.

The Human Cost of Anthropogenic Global Warming: Semi-Quantitative Prediction and the 1,000-Tonne Rule

Greenhouse-gas emissions are indirectly causing future deaths by multiple mechanisms. For example, reduced food and water supplies will exacerbate hunger, disease, violence, and migration. How will anthropogenic global warming (AGW) affect global mortality due to poverty around and beyond 2100? Roughly, how much burned fossil carbon corresponds to one future death? What are the psychological, medical, political, and economic implications? Predicted death tolls are crucial for policy formulation, but uncertainty increases with temporal distance from the present and estimates may be biased. Order-of-magnitude estimates should refer to literature from diverse relevant disciplines. The carbon budget for 2°C AGW (roughly 1012 tonnes carbon) will indirectly cause roughly 109 future premature deaths (10% of projected maximum global population), spread over one to two centuries. This zeroth-order prediction is relative and in addition to existing preventable death rates. It lies between likely best- and worst-case scenarios of roughly 3 × 108 and 3 × 109, corresponding to plus/minus one standard deviation on a logarithmic scale in a Gaussian probability distribution. It implies that one future premature death is caused every time roughly 1,000 (300-3,000) tonnes of carbon are burned. Therefore, any fossil-fuel project that burns millions of tons of carbon is probably indirectly killing thousands of future people. The prediction may be considered valid, accounting for multiple indirect links between AGW and death rates in a top-down approach, but unreliable due to the uncertainty of climate change feedback and interactions between physical, biological, social, and political climate impacts (e.g., ecological cascade effects and co-extinction). Given universal agreement on the value of human lives, a death toll of this unprecedented magnitude must be avoided at all costs. As a clear political message, the "1,000-tonne rule" can be used to defend human rights, especially in developing countries, and to clarify that climate change is primarily a human rights issue.

Timing of sub-lethal insecticide exposure determines parasite establishment success in an insect-helminth model

Environmental toxicants are pervasive in nature, but sub-lethal effects on non-target organisms and their parasites are often overlooked. Particularly, studies on terrestrial hosts and their parasites exposed to agricultural toxicants are lacking. Here, we studied the effect of sequence and timing of sub-lethal exposures of the pyrethroid insecticide alpha-cypermethrin on parasite establishment using the tapeworm Hymenolepis diminuta and its intermediate insect host Tenebrio molitor as a model system. We exposed T. molitor to alpha-cypermethrin (LD20) before and after experimental H. diminuta infection and measured the establishment success of larval tapeworms. Also, we conducted in vitro studies quantifying the direct effect of the insecticide on parasite viability. Our results showed that there was no direct lethal effect of alpha-cypermethrin on H. diminuta cysticercoids at relevant concentrations (LD10 to LD90 of the intermediate host). However, we observed a significantly increased establishment of H. diminuta in beetles exposed to alpha-cypermethrin (LD20) after parasite infection. In contrast, parasite establishment was significantly lower in beetles exposed to the insecticide before parasite infection. Thus, our results indicate that environmental toxicants potentially impact host-parasite interactions in terrestrial systems, but that the outcome is context-dependent by enhancing or reducing parasite establishment depending on timing and sequence of exposure.

Experimental and empirical evidence shows that reducing weed control in winter cereal fields is a viable strategy for farmers

Modern agriculture needs a paradigm shift to make the world’s food production sustainable while mitigating social and environmental externalities. Although various policies to limit the use of agrochemicals have recently been implemented in the European Union, the use of both herbicides and fertilizers has remained fairly constant. Farmers are assumed to behave optimally, producing the best they can, given the agronomic constraints of their fields. Based on this assumption, reducing agrochemicals should inevitably have negative effects on food production, or reduce farmers’ incomes. Coupling empirical analysis based on field surveys and experimental trials where weed management and nitrogen input were manipulated in the same production fields and under real farming conditions, we demonstrate that high use of N fertiliser or intense weed control slightly increase yields, but that this increase is not enough to offset the additional costs incurred by their use. Our experimental design allowed inputs to be varied in a two-factor design, along a gradient spanning from organic to highly intensive farming, while holding all other conditions constant and thus avoiding confounding effects. Quantification of crop yields and gross margins from winter cereal farming showed that reducing dependence on weed management may not hamper cereal production in this system, and is economically profitable at the field level on the short term. Our study thus contributes to addressing a key gap in our economic knowledge, and gives hope for implementing win-win strategies for farmers and the environment.

Analysis of insecticide exposure in California hummingbirds using liquid chromatography-mass spectrometry

External feather rinses and homogenized whole-carcass tissue matrix from two hummingbird species found in California (Calypte anna and Archilochus alexandri) were analyzed for the presence of nine insecticides commonly used in urban settings. Using a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analytical method, samples were quantitatively tested for the following neonicotinoids: dinotefuran, nitenpyram, thiamethoxam, acetamiprid, thiacloprid, clothianidin, imidacloprid, and sulfoxaflor. This analytical method was also used to qualitatively screen for the presence of approximately 150 other pesticides, drugs, and natural products. Feather rinsates from both hummingbird species had detectable concentrations of carbamate and neonicotinoid classes of insecticides. Combined results of the rinsate and homogenized samples (n = 64 individual hummingbirds) showed that 44 individuals (68.75%) were positive for one to four target compounds. This study documented that hummingbirds found in California are exposed to insecticides. Furthermore, feather rinsates and carcass homogenates are matrices that can be used for assessing pesticide exposure in small bird species. The small body size of hummingbirds limits traditional sampling methods for tissues and whole blood to evaluate for pesticide exposure. Thus, utilization of this analytical method may facilitate future research on small-sized avian species, provide insight into pesticide exposure, and ultimately lead to improved conservation of hummingbirds.

The enantioselective environmental behavior and toxicological effects of pyriproxyfen in soil

We synthesized nine pyriproxyfen (PYR) metabolites and developed a chiral residual analysis method for PYR with its metabolites in five soils using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Soil degradation research showed that higher organic matter content and bigger soil particle size were conducive to the degradation of PYR and metabolites. Metabolite A 4'-OH-PYR was mainly found in five soils. PYR and metabolite A performed enantioselective degradation in soil with half-lives ranging from 2.11 d to 9.69 d and 2.80 d to 13.30 d, respectively. The activity of dehydrogenase, sucrase was inhibited and catalase activity was promoted under the disturbance of PYR. Urease was more sensitive to PYR with uncertain influences. Most soil enzymes were not restored to their initial active state after 120 d. The toxicity of metabolites to earthworms was greater than that of the parent compound PYR. This study provides the basic degradation and toxicity data of chiral pesticide PYR and its main metabolites in soil ecosystem, which is of great significance for guiding safe use and comprehensive evaluation of PYR on environmental risk.

Anthropocene Crisis: Climate Change, Pollinators, and Food Security

In this paper, we propose a new approach—understood as a whole-of-community approach—to address a dualistic and dysfunctional human/nature relationship. Of particular concern is the decline in health and numbers of the insects that pollinate an estimated 90 percent of the Earth’s flora and an estimated 35 percent of global crop volume. Specifically, bees provide the majority of biotic pollination and play a critical role in food crop pollination. Multiple factors are contributing to this growing problem including a changing climate. In 2016, the International Commission on Stratigraphy agreed that the concept of the Anthropocene—the human epoch—is of sufficient scale to be considered part of the geological time scale. This indicates that these crises are not random or passive—they are largely the direct result of human activities. Despite decades of awareness of these socio-ecological issues, they continue to worsen. In addition, the growing awareness of the critical role of pollinators is creating a new understanding of our interconnectedness with the “natural” world. We introduce the Bee City movement as a way to operationalize a whole-of-community approach. Individual action is critical, but addressing pollinator health in these forums legitimizes and provides an institutional space for otherwise fringe, or even marginalized, activities and more coherent spaces for habitat creation.

Oral acute toxicity of imidacloprid, thiamethoxam and clothianidin in eared doves: A contribution for the risk assessment of neonicotinoids in birds

Neonicotinoids have recently been demonstrated to cause direct negative impacts on birds from North America and Europe. To further understand the impact of these compounds on bird species and to improve risk assessment capacities, the current study determined the acute toxicities of imidacloprid, clothianidin, and thiamethoxam formulations on South American eared doves (Zenaida auriculata). Insecticides were administered by gavage to adult doves to determine median lethal doses (LD50) according to a standardized sequential procedure. The acute toxicity of formulated imidacloprid (LD50=59mg active ingredient, a.i./kg body weight, b.w.) was much higher than that of the tested formulations of clothianidin (LD50=4248mga.i./kg b.w.) and thiamethoxam (LD50=4366mga.i./kg b.w.). Imidacloprid also differed from the other two neonicotinoids in terms of the onset and intensity of intoxication signs and the times of death and recovery. All three insecticides induced a reduction in food consumption that led to body weight loss. An average weight dove of 127g would obtain a dose equivalent to the LD50 of imidacloprid by consuming 1.7g of treated sorghum seeds. As eared doves offered non-treated sorghum seeds 5h per day consumed on average 6.4±1.8g (mean±S.D.), it is concluded that these doves could feasibly be exposed to lethal doses in the field. This work is the first to describe intoxication signs and report oral neonicotinoid LD50s in a wild South-American bird species.

Dose-related impacts of imidacloprid oral intoxication on brain and liver of rock pigeon (Columba livia domestica), residues analysis in different organs

Available data regarding Imidacloprid (IMI) insecticide hazards to birds are still being scare. Our study aimed to investigate toxic impacts of IMI oral gavage by different dose levels on the brain and liver of Rock pigeon (Columba livia domestica). Forty mature male birds were divided equally into four groups. A control group (C) was orally dosed Mazola corn oil and other three groups; the low dose (LD), the medium dose (MD), and the high dose (HD) groups were orally dosed IMI in Mazola corn oil by three dose levels corresponding to 1/15^th, 1/10^th, 1/5^th IMI oral LD₅₀ respectively. IMI exposure induced a significant decrease in serum levels of glutathione (GSH), superoxide dismutase (SOD) enzyme activity. On the other hand; malondialdehyde (MDA) levels were elevated. The levels of serum total protein, albumin, globulin, and A/G ratio showed a non-significant changes in all IMI dosed groups except levels of total protein in the HD IMI dosed group showed a significant decrease compared to the C group. Serum levels of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), uric acid, plasma tumor necrosis factor α (TNFα) and plasma acetylcholinesterase (AChEs) enzyme activities showed a significant dose related increase in all IMI exposed groups compared to the C group; except the levels of ALT, LDH, and uric acid showed a non significant decrease in the LD IMI dosed group only. Residues of IMI were detected in the pectoral muscles, liver, brain, and kidney of all dosed rock pigeon. Moreover; pectoral muscles were the highest tissue for IMI residues detection. This is the first study reports accumulation of IMI in tissues other than crop, liver, and kidney of rock pigeon including brain and muscles. Moreover, the examined brain and liver tissues of all IMI dosed groups showed dosed related alterations in their structural and ultra-structural morphology. It is concluded that IMI oral administration to pigeon induced oxidative stress and detrimental effects in brain and liver of exposed pigeons. Additionally; IMI bio-accumulated in different organs being muscles is the highest tissues for IMI residues, thus monitoring of IMI residues in food is very essential.

Convolutional Neural Networks for the Automatic Identification of Plant Diseases

Deep learning techniques, and in particular Convolutional Neural Networks (CNNs), have led to significant progress in image processing. Since 2016, many applications for the automatic identification of crop diseases have been developed. These applications could serve as a basis for the development of expertise assistance or automatic screening tools. Such tools could contribute to more sustainable agricultural practices and greater food production security. To assess the potential of these networks for such applications, we survey 19 studies that relied on CNNs to automatically identify crop diseases. We describe their profiles, their main implementation aspects and their performance. Our survey allows us to identify the major issues and shortcomings of works in this research area. We also provide guidelines to improve the use of CNNs in operational contexts as well as some directions for future research.

Brood size is reduced by half in birds feeding on flutriafol-treated seeds below the recommended application rate

Despite the efforts of the European Commission to implement measures that offset the detrimental effects of agricultural intensification, farmland bird populations continue to decline. Pesticide use has been pointed out as a major cause of decline, with growing concern about those agro-chemicals that act as endocrine disruptors. We report here on the effects of flutriafol, a ubiquitous systemic fungicide used for cereal seed treatment, on the physiology and reproduction of a declining gamebird. Captive red-legged partridges (Alectoris rufa; n = 11-13 pairs per treatment) were fed wheat treated with 0%, 20% or 100% of the flutriafol application rate during 25 days in late winter. We studied treatment effects on the reproductive performance, carotenoid-based coloration and cellular immune responsiveness of adult partridges, and their relationship with changes in oxidative stress biomarkers and plasma biochemistry. We also studied the effect of parental exposure on egg antioxidant content and on the survival, growth and cellular immune response of offspring. Exposed partridges experienced physiological effects (reduced levels of cholesterol and triglycerides), phenotypical effects (a reduction in the carotenoid-based pigmentation of their eye rings), and most importantly, severe adverse effects on reproduction: a reduced clutch size and fertile egg ratio, and an overall offspring production reduced by more than 50%. No effects on body condition or cellular immune response of either exposed adult or their surviving offspring were observed. These results, together with previous data on field exposure in wild partridges, demonstrate that seed treatment with flutriafol represents a risk for granivorous birds; they also highlight a need to improve the current regulation system used for foreseeing and preventing negative impacts of Plant Protection Products on wildlife.