Search Results (424)

We developed a laboratory-based setup to perform behavioral tests of the effect of the neonicotinoid insecticide Thiacloprid in the CALYPSO^® formulation on bumblebees. This setup simulates essential components of navigation and pollination under natural conditions. The behavioral components are exploration, exploratory learning, learning of a rewarded local cue in the context of a specific panorama, and retrieving the memory for this association. The walking bumblebees navigated under their own motivation between a fully functional colony and a training/test arena. They explored the arena and learned the association of a rewarded local cue in the context of a panorama. The rule of association was that the local cue was bound to a particular part of the panorama irrespective of where it appeared in its spatial relation to the entrance gate through which the animal came from the colony. Extinction tests were performed for two conditions, match and mismatch. The match condition resembled the training condition. In the mismatch condition the local cue appeared in a different part of the panorama. Solving this task requires the learning and remembering of a rule under variable conditions, mimicking the cognitive requirements faced by bumblebees under natural conditions. The control animals solved this task, whereas animals treated with Thiacloprid 400 ng CALYPSO^® diluted in 4 µL per animal were significantly compromised, as shown by several parameters of the walking trajectories under the match and mismatch conditions. No dose–response functions were established, but a volume of 800 ng CALYPSO^® diluted in 8 µL per animal did not show any significant differences from a volume of 4 µL CALYPSO^®. The setup and the experimental paradigm are suitable for routine quantitative tests on the effects of insecticides on the cognitive faculties of insects during navigation and pollination. Full article

Thiamethoxam is the main neonicotinoid insecticide used for controlling Riptortus pedestris (Fabricius) (Hemiptera: Alydidae). However, sublethal concentration stress may induce intergenerational transcriptional memory, leading to transcriptional patterns that may contribute to the intergenerational accumulation of metabolic tolerance, and evaluating only the toxicity of the current generation would underestimate the long-term risk. Therefore, this study investigated the effect of parental exposure on the expression of detoxification enzyme genes in offspring. Using transcriptome sequencing, we systematically identified three detoxification enzyme gene families (cytochrome P450 monooxygenases (CYPs), carboxylesterases (CCEs), and glutathione S-transferases (GSTs)) in R. pedestris and compared their differential expression patterns between the parental and filial generations after thiamethoxam treatment at three sublethal concentrations (LC₁₀, LC₃₀, and LC₅₀). In the parental generation, a Theta family GST was consistently upregulated, while in the filial generation, detoxification genes were predominantly downregulated, and the genes upregulated in the parents were not also upregulated in the offspring. Comparisons of parents and offspring at the same concentration revealed that the medium concentration induced the highest number of intergenerationally upregulated genes, exhibiting a non-linear response pattern. These results indicate that parental exposure to sublethal thiamethoxam leaves an intergenerational transcriptional imprint in the offspring, and the transmission pattern involves transcriptional reprogramming rather than simple replication of the parental response, the mechanism of which remains to be determined. This study provides transcriptomic evidence for understanding the metabolic adaptation and intergenerational resistance evolution of R. pedestris to thiamethoxam, offering important reference value for field resistance monitoring and rational insecticide application. Full article

The rapid evolution of metabolic resistance to chemical insecticides and the adaptation to plant allelochemicals in insect pests have become major challenges in global pest management. While the overexpression of cytochrome P450 monooxygenases (P450s) is a well-recognized classic detoxification mechanism, the upstream epigenetic and post-transcriptional regulatory networks governing this process have only recently been elucidated. In this narrative review, the latest research progress on microRNAs (miRNAs) as crucial “fine-tuners” in insect detoxification networks is systematically summarized. The classic regulatory model is highlighted: the induced or constitutive downregulation of specific miRNAs relieves the translational repression of their target P450 genes, thereby contributing to metabolic resistance to major insecticide classes, including neonicotinoids, diamides, and pro-insecticides. Furthermore, the evolutionary recruitment mechanisms of conserved miRNAs in host plant adaptation are explored, and how endocrine signals, such as juvenile hormone (JH) and 20-hydroxyecdysone (20E), synergistically regulate the miRNA–P450 axis is analyzed. The “sponge effect”, wherein highly expressed P450 mRNAs act as competitive endogenous RNAs (ceRNAs) to sequester miRNAs, and the consequent physiological trade-offs (fitness costs) resulting from the prioritization of metabolic resources toward the detoxification system are comprehensively discussed. Finally, the current core methodologies for miRNA functional validation are critically evaluated, and the application potential and ecological safety prerequisites of miRNA-based nanobiopesticides for targeted and sustainable pest management are discussed. By integrating mechanistic insights with translational perspectives, this review highlights miRNA–P450 regulatory networks as key determinants of insecticide resistance evolution and as promising targets for developing more precise, environmentally compatible pest-management strategies. Full article

Imidacloprid (IMI), the commonly used neonicotinoid pesticide, has emerged as a persistent aquatic contaminant due to its high solubility and stability, posing risks to non-target organisms and ecosystem health. In this study, a MnZnFe₂O₄/SrWO₄ ferrite–tungstate nanocomposite was synthesized via a hydrothermal process and its ability to photocatalytically degrade IMI under UV light was assessed. SEM, XRD and FT-IR were used to characterize the composite to confirm its structural and morphological features. Photocatalytic performance was systematically investigated by examining the effects of operational factors, including initial pollutant concentration, catalyst dosage, pH, and irradiation time. The MnZnFe₂O₄/SrWO₄ nanocomposite exhibited significantly enhanced activity, achieving up to 87% degradation of IMI within 30 min at pH 9, outperforming individual components (SrWO₄: 37%; MnZnFe₂O₄: 75%) under identical conditions. The degradation kinetics followed a pseudo-first-order model consistent with the Langmuir–Hinshelwood mechanism. Effective interfacial charge transfer between the ferrite and tungstate phases, which suppresses electron-hole recombination and increases the production of reactive species, is responsible for the enhanced performance. Furthermore, the composite demonstrated good stability and reusability across several cycles, indicating its practical applicability. Overall, the results demonstrate the potential of MnZnFe₂O₄/SrWO₄ nanocomposites as efficient and sustainable photocatalysts for removing imidacloprid and similar organic contaminants from aqueous systems. Full article

Megalurothrips usitatus is a major pest of cowpea in tropical regions, where frequent insecticide use has promoted the development of resistance. In this study, field populations of M. usitatus were collected from five major cowpea-producing areas in Hainan from 2023 to 2025, and their susceptibility to five commonly used insecticides was evaluated using a modified leaf-tube residual film method. Resistance levels varied among regions and insecticides, with southern populations generally showing higher LC₅₀ values than central and northern populations. The tested neonicotinoid insecticide, acetamiprid, showed the highest resistance levels. By 2025, the resistance ratios of the Ledong, Sanya, and Lingshui populations to acetamiprid reached 298.48-, 139.60-, and 130.25-fold, respectively. Spinosyn resistance also increased rapidly, particularly in southern Hainan. The resistance ratio to spinetoram reached 110.78-fold in the Ledong population, while resistance to spinosad reached 37.06-fold in the Lingshui population. However, the absolute LC₅₀ values of spinosad and spinetoram remained relatively low compared with those of acetamiprid and chlorfenapyr, indicating that these two spinosyn insecticides retained relatively high bioassay activity in laboratory bioassays. A significant positive correlation was detected between the LC₅₀ values of spinosad and spinetoram across field populations (r = 0.8972, p < 0.0001), suggesting cross-resistance within the spinosyn class. These results indicate that resistance management for M. usitatus in Hainan should prioritize reducing the use of high-resistance-risk insecticides, avoiding consecutive applications of spinosyns, and designing region-specific rotation programs based on local resistance monitoring. Full article

Neonicotinoids are among the most widely used classes of insecticides worldwide. However, growing evidence links their exposure to metabolic disturbances, including DNA damage, endocrine disruption, and hepatic dysfunction. In this study, transcriptomic analyses were applied to investigate the gene expression changes induced by two neonicotinoids, clothianidin and thiacloprid. Our results revealed distinct treatment-driven transcriptional signatures, characterized by the upregulation of gene sets enriched in pathways associated with mitochondrial regulation, neuronal signaling, and neurodegeneration-related molecular processes, alongside the downregulation of genes involved in core metabolic processes. In addition, neonicotinoid exposure modulated gene sets associated with xenobiotic detoxification, immune response, cell proliferation, and cell adhesion. Notably, clothianidin and thiacloprid induced compound-specific transcriptional profiles, despite sharing a common mechanism of action. Furthermore, combined exposure resulted in gene expression patterns that differed from those observed with individual treatments. Together, these findings demonstrate that neonicotinoids can elicit divergent molecular responses, highlighting the importance of compound-specific toxicological assessment in non-target species. Full article

Neonicotinoid pesticides are a typical category of emerging hazardous micropollutants, and chlorine (Cl₂) is a widely used disinfectant that readily induces the chlorination of organic micropollutants. This study systematically investigated the chlorination kinetics and transformation pathways of a representative neonicotinoid pesticide (clothianidin, CLO) and evaluated the cytotoxicity variation via Chinese Hamster Ovary (CHO) cell assays. CLO chlorination followed second-order kinetics, with a first-order dependence on both CLO and Cl₂ concentrations, and the apparent rate constant (k_app) value was measured to be 1.758 × 10⁻⁴ μM⁻¹ h⁻¹, at a pH of 7.0. The CLO chlorination initially accelerated and then retarded with the increase in pH. The same tendency was involved in the yield of disinfection byproducts (i.e., trihalomethanes and haloacetic acids). Dissolved organic matter was also a crucial factor inhibiting the chlorination of CLO. The reaction of CLO⁺ with HOCl was more prevalent than between CLO⁺ with ClO⁻, wherein HOCl likely exerts electrophilic attack either after 2-nitroguanidine hydrolysis or directly at the nitrogen sites of secondary amines. Cell exposure results revealed that the chronic cytotoxicity of CLO decreased significantly after chlorination. This study helps to the mechanistic understanding of neonicotinoid transformation during water disinfection, and provides a valuable reference for the control of neonicotinoid pesticides in drinking water. Full article

Neonicotinoid insecticides (NEOs) are widely used globally, leading to human exposure including pregnant women, and may pose risks of neurocognitive toxicity. In this study, we analyzed 114 mother–child pairs from the Guangxi Zhuang birth cohort. Umbilical cord plasma concentrations of 10 NEOs were measured using ultra-high-performance liquid chromatography–mass spectrometry (UPLC–MS), and child neurocognitive development was assessed using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) and the Ages and Stages Questionnaire, Third Edition (ASQ-3). NEOs were frequently detected, with detection rates ranging from 15.8% to 96.5%, and dinotefuran (DIN) showed the highest prevalence. Prenatal exposure to several NEOs was associated with lower neurocognitive scores. Specifically, DIN and clothianidin (CLO) exposure were associated with lower Full-Scale Intelligence Quotient (FSIQ), while thiacloprid (THIA) exposure was linked to poorer communication performance. In addition, imidacloprid (IMI) and THIA exposure were associated with reduced gross motor function, and thiamethoxam (TMX) was further associated with reduced fine motor development. Mixed exposure analysis suggested a negative but non-significant association between overall NEO exposure and FSIQ or fine motor outcomes. These findings suggest a potential association between prenatal exposure to NEOs and neurocognitive development in preschool children, highlighting the need for further research to inform public health strategies. Full article

Chirality has emerged as a critical determinant in the design, efficacy, and environmental behavior of modern insecticides. While a significant proportion of agrochemicals are inherently chiral, most are still commercialized as racemic mixtures, despite well-documented differences in biological activity, toxicity, and degradation pathways between enantiomers. In this review, we provide a comprehensive and critical analysis of advances in the stereoselective synthesis and resolution of chiral insecticides, with particular emphasis on neonicotinoids, pyrethroids, and oxadiazines, including indoxacarb. A systematic survey of the literature (1985–2025), including peer-reviewed articles and patents, reveals that multiple strategies have been developed to access enantiomerically enriched compounds, including asymmetric organocatalysis, transition-metal catalysis, chiral-pool approaches, biocatalytic transformations, and chromatographic resolution techniques. Among these, recent developments in photoredox catalysis, recyclable metal complexes, and enzyme-mediated processes have significantly improved enantioselectivity and scalability, bridging the gap between academic methodologies and industrial applications. Despite these advances, challenges remain in achieving cost-effective, sustainable, and universally applicable asymmetric processes. Importantly, the relationship between stereochemistry and biological performance underscores the need for integrating synthetic chemistry with toxicological and environmental studies. Future directions point toward the incorporation of green chemistry principles, continuous-flow processes, and computational tools, including machine learning and molecular modeling, to accelerate the rational design of enantiopure agrochemicals. This review highlights both the progress achieved and the critical gaps that must be addressed to realize the potential of stereoselective insecticide development fully. Full article

Intensive pesticide application sustains global agriculture but poses poorly characterized risks to complex soil ecosystems. Here, we quantitatively evaluated pesticide residues and utilized high-resolution environmental DNA (eDNA) metagenomics to decode multi-trophic community responses across a typical major grain-producing region located in China. Among 39 targeted pesticides, 26 were detected with total concentrations ranging from 27.9 to 478.8 ng/g. While herbicides and fungicides dominated the residual mass, insecticides posed the most severe ecological threat. Notably, the neonicotinoid imidacloprid exhibited high-risk levels (RQ = 1.78 ± 1.49) at >61.1% of the sampling sites. eDNA profiling and Procrustes analyses revealed a clear trophic-dependent sensitivity gradient (p < 0.01). Lower-trophic microbial communities were significantly altered in composition; pesticide stress was strongly associated with profound non-target suppression on keystone plant-beneficial bacteria (e.g., Nocardioides). Concurrently, the fungal eDNA profiles indicated that the soil mycobiome harbored an alarming 34.7% of potential phytopathogenic fungi (e.g., Aspergillus and Colletotrichum), intrinsically driving the massive fungicide reliance. In contrast, higher-trophic soil metazoa (Rotifera, 40.4%) and weed communities (e.g., Digitaria sanguinalis) exhibited significant spatial stability, reflecting robust environmental buffering and herbicide-driven ecological escapes. Furthermore, co-occurrence networks decoupled target from non-target toxicities, uniquely revealing that persistent herbicide metabolites (desethylatrazine) induce prolonged legacy toxicities on specific soil fauna. Collectively, this study unveils the deep, cross-kingdom ecological disruptions caused by current pesticide regimes, underscoring the urgency of integrating eDNA biomonitoring to guide precision pest management and safeguard soil health in vital agricultural hubs. Full article

The ban on neonicotinoid seed treatments in the EU has created major challenges for maize and sugar beet production, as these chemicals have been highly effective in controlling early-season pests, including wireworms (Agriotes spp.), sugar beet weevil (Asproparthenis punctiventris Germar) (SBW) and sugar beet flea beetles (Chaetocnema tibialis Illiger) (SBFB). However, adequate alternatives have not yet been introduced. The aim of this research was to get insights on the biological activity of insecticides with distinct modes of action and comparatively more favorable ecotoxicological profiles than neonicotinoids, chlorantraniliprole, spinosad, and azadirachtin, applied as seed treatments in maize and sugar beet against wireworms in maize and against SBW and SBFB in sugar beet. In laboratory trials, each insecticide was tested as a seed treatment at three different doses. Thiamethoxam was included as the standard treatment (positive control). Among the tested insecticides, spinosad seed treatment showed the highest efficacy against wireworms and was superior to both the standard insecticide and chlorantraniliprole, while azadirachtin showed no effect. None of the tested insecticides provide satisfactory control of SBW. In contrast, SBFB responded to all three insecticide treatments, with efficacy comparable to, or even better than, the standard insecticide. These results suggest that chlorantraniliprole, azadirachtin, and spinosad may all represent promising candidates for sugar beet seed treatment to protect young plants against SBFB. Future research should focus on developing seed treatment formulations and field and semi-field trials as well as evaluating combinations of active ingredients and their suitability for integration into IPM programs. These findings provide a basis for further development of seed treatment strategies aimed at reducing dependence on neonicotinoids in maize and sugar beet production. Full article

A comprehensive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous quantification of 50 pesticide biomarkers across nine current-use chemical classes in human urine. These classes include organophosphorus insecticides (which encompass dialkyl phosphates and specific metabolites), pyrethroid insecticides, fungicides, neonicotinoid insecticides, herbicides, insect repellents, organochlorine pesticide metabolites, and plant growth regulators. The method employs solid-phase extraction (SPE) for sample preparation, requiring only 0.2 mL of urine. Chromatographic separation was optimized using a Hypersil Gold AQ column, achieving a total run time of 18 min. Mass spectrometric detection utilized polarity switching in electrospray ionization mode with multiple reaction monitoring. Method validation demonstrated satisfactory linearity (R² > 0.99), high sensitivity with limits of detection ranging from 0.01 to 0.88 ng/mL, and extraction efficiencies between 85% and 113%. Precision and accuracy were within acceptable ranges, with relative standard deviations generally below 15%. The method’s robustness was confirmed through participation in external quality assessment schemes. Application to real samples revealed significant inter-individual variability in pesticide biomarker concentrations, with total measured biomarker levels ranging from 89 to 1242 ng/mL across the 10 individuals analyzed. This method offers comprehensive coverage of current-use pesticide chemical classes, including 30 biomarkers from the U.S. National Health and Nutrition Examination Survey (NHANES) biomonitoring program, and demonstrates improved sensitivity and broader analyte coverage compared to existing methods. The developed assay provides a valuable tool for large-scale biomonitoring studies and environmental health research. Full article

Brazil hosts the world’s greatest stingless bee diversity but remains a leading pesticide consumer. This study evaluated the effects of thiamethoxam on Melipona scutellaris (Apidae) and Scaptotrigona postica (Apidae) larvae using standardized in vitro protocols and patented biomimetic technologies. Larvae were exposed to a field-realistic dose (RD) of 0.02292 ng a.i./larva—calculated using the BeeRex model for citrus crops—and two lower doses: RD/10 and RD/100. Thiamethoxam exposure resulted in significant mortality and developmental alterations, even at 100-fold dilutions. In M. scutellaris, mortality was dose-dependent; RD and RD/10 induced body malformation and reduced food consumption, resulting in >98% mortality. At RD/100, surviving individuals showed significant reductions in body size. In S. postica, all tested doses induced larval darkening and accelerated fungal growth, leading to 100% mortality during the feeding period, including at RD/100. This pattern contrasts with the greater tolerance reported for the adult stage of this species. Overall, the results suggest that larval stages may be more sensitive to thiamethoxam exposure than adults, highlighting the importance of considering different life stages in pesticide risk assessment. These findings also emphasize the need for validated experimental approaches to support environmental risk evaluation for Neotropical pollinators. Full article

Despite the undisputable ecosystem importance of honeybees, human activities have a substantial impact on their health. Since foraging is directly linked to a wide range of crops and bee-attracting flowers, plant protection products are at the forefront of chemical scrutiny, along with contamination of pollen, nectar, beehive components and water by other xenobiotics. In this study, a non-targeted Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) screening was applied to 25 honeybee samples collected after reported death incidents in Greece. This approach led to the tentative annotation of over 50 compounds across various chemical classes, including pesticides, PFAS candidates not included in the EFSA “PFAS-4”, pharmaceuticals, antibiotics, industrial chemicals, and natural product constituents. In parallel, targeted pesticide residue analysis using liquid and gas chromatography coupled to tandem mass spectrometry (LC-MS/MS and GC-MS/MS) was performed, covering more than 250 active substances and providing direct quantitative results, revealing 11 active substances in concentrations ranging from <limit of quantification (LOQ) to 0.95 mg/kg, overlapping substantially with the HRMS detection. Overall, this study does not allow concrete causal attribution of mortality to specific chemicals; however, it documents complex co-occurrence patterns (pesticides together with other xenobiotics and plant bioactives), not excluding sublethal and mixture-toxicity effects. Quantified pesticide concentrations were below acute LD50-based thresholds, yet selected samples combined neonicotinoid/pyrethroid/fungicide signatures and other contaminants, supporting the need for mixture-toxicity frameworks and effect-based follow-ups. Full article

Neonicotinoids are widely used pesticides that have caused a catastrophic decrease in bee and bumblebee populations worldwide. In addition to insects, neonicotinoids induce toxic effects in other species, including lizards, birds, and mammals. Previous studies have shown that gestational exposure to thiacloprid promotes transgenerational effects in the testes and thyroid. In this project, we described the epigenetic effects of thiacloprid on prostate tissue in directly exposed F1 and non-directly exposed F3 outbred Swiss male mice. We used paraffin sections for morphological analysis and frozen tissue for immunofluorescence analysis, RT–qPCR, and protein analysis. We purified histones and analyzed them through Western blot. We used ChIP–qPCR for histone H3K4me3 occupancy analysis. A tendency to increase in epithelial hyperplasia in F1 but not in F3 prostate was detected. Elevated levels of phosphorylated histone H3 at serine 10, a marker of mitosis, in both the F1 and F3 prostates were noted. A significant increase in the level of the Ki-67 marker of proliferation was detected in the F1 but not in the F3 anterior prostate. Hox gene expression was upregulated in the F1 and downregulated in the F3 prostate. The changes in gene expression were positively associated with histone H3K4me3 alterations at the promoters of the Hoxa and Hoxb13 genes. We determined that regions of Hox genes that play important roles in prostate development had altered DNA methylation in the sperm of F1 and F3. These alterations in DNA methylation were negatively related to gene expression. This is an observational study, as it was part of our previous research on the effects of thiacloprid on the testis and thyroid. Our analysis revealed that gestational exposure to thiacloprid induced an increase in cell proliferation in the prostates of directly exposed F1. Some persistent epigenetic alterations in the prostate of F3 males were not associated with phenotypic changes. Full article