Development of precise micro analytical tool to identify potential insecticide hazards to bees in guttation fluid using LC-ESI-MS/MS

Sublethal Effects of Four Insecticides Targeting Cholinergic Neurons on Partner and Host Finding in the Parasitic Wasp Nasonia vitripennis

Lethal and sublethal effects of pesticides on nontarget organisms are one of the causes of the current decline of many insect species. However, research in the past decades has focused primarily on pollinators, although other beneficial nontarget organisms such as parasitic wasps may also be affected. We studied the sublethal effects of the four insecticides acetamiprid, dimethoate, flupyradifurone, and sulfoxaflor on pheromone-mediated sexual communication and olfactory host finding of the parasitic wasp Nasonia vitripennis. All agents target cholinergic neurons, which are involved in the processing of chemical information by insects. We applied insecticide doses topically and tested the response of treated wasps to sex pheromones and host-associated chemical cues. In addition, we investigated the mating rate of insecticide-treated wasps. The pheromone response of females surviving insecticide treatment was disrupted by acetamiprid (≥0.63 ng), dimethoate (≥0.105 ng), and flupyradifurone (≥21 ng), whereas sulfoxaflor had no significant effects at the tested doses. Olfactory host finding was affected by all insecticides (acetamiprid ≥1.05 ng, dimethoate ≥0.105 ng, flupyradifurone ≥5.25 ng, sulfoxaflor ≥0.52 ng). Remarkably, females treated with ≥0.21 ng dimethoate even avoided host odor. The mating rate of treated N. vitripennis couples was decreased by acetamiprid (6.3 ng), flupyradifurone (≥2.63 ng), and sulfoxaflor (2.63 ng), whereas dimethoate showed only minor effects. Finally, we determined the amount of artificial nectar consumed by N. vitripennis females within 48 h. Considering this amount (∼2 µL) and the maximum concentrations of the insecticides reported in nectar, tested doses can be considered field-realistic. Our results suggest that exposure of parasitic wasps to field-realistic doses of insecticides targeting the cholinergic system reduces their effectiveness as natural enemies by impairing the olfactory sense. Environ Toxicol Chem 2023;42:2400-2411. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Residual levels and dietary intake risk assessment of 11 pesticides in apricots from different ecological planting regions in China

The frequent and massive use of pesticides has led to pesticide residues in apricot, threatening food safety and human health. A reliable and simple modified QuEChERS method with ultra-performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of 11 pesticides in apricot. Method validation indicated that satisfied linearity (R² ≥ 0.9959), accuracy (recoveries of 72-119%), sensitivity (limits of detection, 0.03-0.30 μg/kg; limits of quantification, 0.13-1.00 μg/kg), and precision (relative standard deviations ≤ 11.9%), and matrix effects were 0.89-1.13. Apricot samples from different ecological regions in China were collected and tested using the proposed methods. Monitoring results were used to assess the dietary intake risk of Chinese populations of different ages and genders. Dietary risk assessment revealed that the risk quotients were 0.003-1.184% for different gender and age groups in China, indicating none unacceptable public health risk for general population. This work was thus significant in developing a simpler, more efficient and economical analysis method and food safety risks of the 11 pesticides on apricot and facilitated the establishment of maximum residue limits.

Buffered fitness components: Antagonism between malnutrition and an insecticide in bumble bees

Global insect biodiversity declines due to reduced fitness are linked to interactions between environmental stressors. In social insects, inclusive fitness depends on successful mating of reproductives, i.e. males and queens, and efficient collaborative brood care by workers. Therefore, interactive effects between malnutrition and environmental pollution on sperm and feeding glands (hypopharyngeal glands (HPGs)) would provide mechanisms for population declines, unless buffered against due to their fitness relevance. However, while negative effects for bumble bee colony fitness are known, the effects of malnutrition and insecticide exposure singly and in combination on individuals are poorly understood. Here we show, in a fully-crossed laboratory experiment, that malnutrition and insecticide exposure result in neutral or antagonistic interactions for spermatozoa and HPGs of bumble bees, Bombus terrestris, suggesting strong selection to buffer key colony fitness components. No significant effects were observed for mortality and consumption, but significant negative effects were revealed for spermatozoa traits and HPGs. The combined effects on these parameters were not higher than the individual stressor effects, which indicates an antagonistic interaction between both. Despite the clear potential for additive effects, due to the individual stressors impairing muscle quality and neurological control, simultaneous malnutrition and insecticide exposure surprisingly did not reveal an increased impact compared to individual stressors, probably due to key fitness traits being resilient. Our data support that stressor interactions require empirical tests on a case-by-case basis and need to be regarded in context to understand underlying mechanisms and so adequately mitigate the ongoing decline of the entomofauna.

R. Rocha C, Teixeira JA, Pereira JAM. Green Extraction Techniques as Advanced Sample Preparation Approaches in Biological, Food, and Environmental Matrices: A Review

Green extraction techniques (GreETs) emerged in the last decade as greener and sustainable alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (μQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted.

Assessment of pesticide induced inhibition of Apis mellifera (honeybee) acetylcholinesterase by means of N-doped carbon dots/BSA nanocomposite modified electrochemical biosensor

This work describes the development and optimization of an electrochemical method to evaluate pesticide induced inhibition of honey bee (Apis mellifera) acetylcholinesterase (AChE) by means of acetylcholinesterase biosensor. The inhibition assay was based on the detection of changes in electrochemical activity of the enzyme caused by pesticide. As transducer, nitrogen doped carbon dots BSA (N-CD/BSA) nanocomposite electrodeposited on pencil graphite electrode was used to covalently immobilize AChE. The as-synthesized nanocomposite and fabricated electrodes were characterized for the structural, functional and electrochemical properties. Nanocomposite promoted the electron transfer reaction to catalyze the electro-oxidation of thiocholine and a large current response was obtained by cyclic voltammetry at 0.77 V, indicating successful immobilization of AChE. The sensitivity of Diazinon, an OP insecticide, for honeybee AChE was tested under optimal conditions and a linear response ranging 10-250 nM was obtained with a detection limit of 8.9 nM, and sensitivity 9 uA/nM/cm2. The method showed a good operational reproducibility and selectivity of biosensor. Further, the molecular docking provided additional support to the experimental data suggesting irreversible nature and contact toxicity of the pesticide for honey bee AChE. The developed biosensor has proved useful for the diazinon detection in wheat samples with 99% recovery rate.

Thiamethoxam as an inadvertent anti-aphrodisiac in male bees

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There is consensus that neonicotinoids can impact non-target animal fertility.

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Thiamethoxam reduced both mating success and sperm physiology in bumblebees.

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Queens mated by exposed males had 50% less total living sperm in their spermatheca.

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Thiamethoxam may act as anti-aphrodisiac, thereby limiting conservation efforts.

Sexual reproduction is common to almost all multi-cellular organisms and can be compromised by environmental pollution, thereby affecting entire populations. Even though there is consensus that neonicotinoid insecticides can impact non-target animal fertility, their possible impact on male mating success is currently unknown in bees. Here, we show that sublethal exposure to a neonicotinoid significantly reduces both mating success and sperm traits of male bumblebees. Sexually mature male Bombus terrestris exposed to a field-realistic concentration of thiamethoxam (20 ng g⁻¹) or not (controls) were mated with virgin gynes in the laboratory. The results confirm sublethal negative effects of thiamethoxam on sperm quantity and viability. While the latency to mate was reduced, mating success was significantly impaired in thiamethoxam-exposed males by 32% probably due to female choice. Gynes mated by exposed males revealed impaired sperm traits compared to their respective controls, which may lead to severe constraints for colony fitness. Our laboratory findings demonstrate for the first time that neonicotinoid insecticides can negatively affect male mating success in bees. Given that holds true for the field, this provides a plausible mechanism contributing to declines of wild bee populations globally. The widespread prophylactic use of neonicotinoids may therefore have previously overlooked inadvertent anti-aphrodisiac effects on non-target animals, thereby limiting conservation efforts.

Miniaturized multiresidue method for determination of 267 pesticides, their metabolites and polychlorinated biphenyls in low mass beebread samples by liquid and gas chromatography coupled with tandem mass spectrometry

Current work presents developed and validated miniaturized method for residue analysis of 261 pesticides and their metabolites as well as 6 congeners of non-dioxin like polychlorinated biphenyls (ndl-PCB) in a very low mass beebread sample. Sample preparation is based on modified QuEChERS protocol with all steps miniaturized to enable multiresidue analysis of sample with extremely low weight. Sample of beebread (0.3 g) was extracted with 1 mL of acetonitrile containing 5% formic acid and ammonium formate salt were added, then extract was subjected to clean-up by freezing and two-step dispersive solid phase extraction (dSPE) with a Supel QuE Verde sorbents (Supelclean ENVI-Carb Y; Supelclean PSA; Z-Sep+; magnesium sulfate). After 1st step dSPE a portion of extract was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) for 200 pesticide residues. Remaining extract was subjected to 2nd step dSPE clean-up by another Supel QuE Verde and then after concentration and solvent exchange it was analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS) for another 61 pesticide and 6 ndl-PCB residues. Method enables determination of residues of 101 insecticides, 72 herbicides, 67 fungicides, 10 acaricides, 6 growth regulators, 5 veterinary drugs and 6 ndl-PCB's. Particular attention was paid to the pesticides being active substances of plant protection products recommended for the protection of winter oilseed rape and apple orchards which during their blooming periods are one of the most attractive sources of food for pollinators and could serve as representatives of other economically important crops. Method was validated according to the Guidance document SANTE/12682/2019 at six concentration levels from 0.001 to 0.5 mg kg^-1. The analysis of beebread samples spiked at the level of 0.01 mg kg^-1showed mean recovery (trueness) value of about 98% and RSDr (precision) below 20%. The small weight of the sample did not adversely affect the limits of quantification and 75% of analytes could be quantified at least at concentration of 0.005 mg kg^-1. Developed mini-method was tested in the analysis of beebread samples, each extracted from individual cell of honeycomb. It is the first time when analyses at single comb cell level were possible.

A global study of pesticides in bees: QuEChERS as a sample preparation methodology for their analysis - Critical review and perspective

To this day, it remains unknown what the cause of decline of honey bee populations is and how to prevent this phenomenon efficiently. Poisonings with pesticides are assumed to be among the main causes for the decline of the honey bee population. Despite the significant progress observed in analytics over recent years, research aimed at improving methods applied in diagnostics of bee poisoning is still in progress. This is no easy task, since determination of the content of trace amounts (often equal to sublethal doses) of a wide range of compounds with diverse physico-chemical properties in honey bee samples with a complex matrix composition poses a serious challenge to modern analytics. This overview is the first to include a comprehensive critical assessment of analytical methods proposed for quantification of pesticides in honey bees over the last decade. Since the QuEChERS method is currently of great significance to ensuring accurate and reliable results of pesticide quantification in honey bees, the present overview focuses on the major aspects of this method, which will provide a comprehensive reference for scientists. The review focuses on the limitations of methods and on potential future prospects. It also contains information on the detection of pesticides in honey bees between 2010 and 2020 and characterizes the pesticide classes which are most toxic to these insects. This is extremely important, not just in the context of understanding the potential adverse impact of pesticides, manifesting as losses in bee colonies; it is also intended to facilitate decision-making in future research related to this difficult yet very important subject.

Graphene and its derivatives: understanding the main chemical and medicinal chemistry roles for biomedical applications

Over the past few years, there has been a growing potential use of graphene and its derivatives in several biomedical areas, such as drug delivery systems, biosensors, and imaging systems, especially for having excellent optical, electronic, thermal, and mechanical properties. Therefore, nanomaterials in the graphene family have shown promising results in several areas of science. The different physicochemical properties of graphene and its derivatives guide its biocompatibility and toxicity. Hence, further studies to explain the interactions of these nanomaterials with biological systems are fundamental. This review has shown the applicability of the graphene family in several biomedical modalities, with particular attention for cancer therapy and diagnosis, as a potent theranostic. This ability is derivative from the considerable number of forms that the graphene family can assume. The graphene-based materials biodistribution profile, clearance, toxicity, and cytotoxicity, interacting with biological systems, are discussed here, focusing on its synthesis methodology, physicochemical properties, and production quality. Despite the growing increase in the bioavailability and toxicity studies of graphene and its derivatives, there is still much to be unveiled to develop safe and effective formulations.

Graphic abstract

Exposure of wild boars (Sus scrofa L) to neonicotinoid insecticides

The aim was to determine, for the first time, concentrations of 7 neonicotinoids (NEOs) and 5 metabolites in Sus scrofa from hunting areas in north-eastern Poland and assess the risk to consumers eating boar meat. 42 wild boar muscle samples were collected over a one-year period. The concentrations of 12 NEOs were determined by a fully validated LC-ESI-MS/MS protocol based on ultrasonic, freezing and cleanup EMR-lipid sample preparation. NEOs were present in over 83% of samples, 17% had no residue, and one pesticide was present in 36% of samples. Most often found were: clothianidin (35%), acetamiprid and imidacloprid (33%), thiacloprid (31%), thiamethoxam (9%), and the average concentrations were (ng g^-1): thiacloprid 6.2 > imidacloprid 5.7 > acetamiprid 4.6 > clothianidin 2.2 > thiacloprid 1.6 > thiamethoxam 1.0. Multi-residue samples were found, one with 7 and one with 5 NEOs. Two NEOs were present in 24%; 3 in 39% and 4 in 10% of samples. In the metabolic degradation of acetamiprid, imidacloprid and thiacloprid, it was observed that metabolites account for no more than 8.5% of the measured parent substance. Acetamiprid-n-desmethyl was noted most often (21%). Due to the detection of NEOs in a large proportion of samples, chronic and acute risk assessment were performed. The estimated chronic and acute risk for consumers from NEOs neonicotinoids through the consumption of wild boar was very low and amounted to respectively 0.02% of ADI and 0.86% of ARfD.