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Neonicotinoids, sometimes abbreviated as neonics, represent a class of neuro-active insecticides with chemical similarities to nicotine. Neonicotinoids are the most widely adopted group of insecticides globally since their discovery in the late 1980s. Their physiochemical properties surpass those of previously established insecticides, contributing to their popularity in various sectors such as agriculture and wood treatment. The environmental impact of neonicotinoids, often overlooked, underscores the urgency to develop tools for their detection and understanding of their behavior. Conventional methods for pesticide detection have limitations. Chromatographic techniques are sensitive but expensive, generate waste, and require complex sample preparation. Bioassays lack specificity and accuracy, making them suitable as preliminary tests in conjunction with instrumental methods. Aptamer-based biosensor is recognized as an advantageous tool for neonicotinoids detection due to its rapid response, user-friendly nature, cost-effectiveness, and suitability for on-site detection. This comprehensive review represents the inaugural in-depth analysis of advancements in aptamer-based biosensors targeting neonicotinoids such as imidacloprid, thiamethoxam, clothianidin, acetamiprid, thiacloprid, nitenpyram, and dinotefuran. Additionally, the review offers valuable insights into the critical challenges requiring prompt attention for the successful transition from research to practical field applications. [Display omitted] • The review investigates strategies for selecting and applying aptamers against common neonicotinoid in biosensors. • Various aptasensors are examined, with a focus on enhancing sensitivity through nanomaterial surface modifications. • The fundamental working principles and mechanisms underlying aptasensing strategies were discussed. • A comparison of different aptasensing strategies was highlighted. [ABSTRACT FROM AUTHOR]

Thiacloprid, a neonicotinoid insecticide, has become one of the major control agents for the pine sawyer beetle, Monochamus alternatus Hope, however, the mechanism of detoxification is unknown. We demonstrate that glutathione S-transferases (GSTs) and nicotinic acetylcholine receptors (nAChRs) are involved in the rapid detoxification of thiacloprid in M. alternatus larvae. The activity of detoxification enzyme GSTs was significantly higher, while the activity of acetylcholinesterase (AChE) was inhibited under thiacloprid exposure. The inhibition of AChE activity led to lethal over-stimulation of the cholinergic synapse, which was then released by the rapid downregulation of nAChRs. Meanwhile, GSTs were overexpressed to detoxify thiacloprid accordingly. A total of 3 nAChR and 12 GST genes were identified from M. alternatus , among which ManAChRα2 and MaGSTs1 were predicted to confer thiacloprid tolerance. RNA interference (RNAi) was subsequently conducted to confirm the function of ManAChRα2 and MaGSTs1 genes in thiacloprid detoxification. The successful knock-down of the ManAChRα2 gene led to lower mortality of M. alternatus under LC 30 thiacloprid treatment, and the suppression of the MaGSTs1 gene increased the mortality rate of M. alternatus. However, the mortality rate has no significant difference with controls when thiacloprid was fed together with both ds MaGSTs1 and ds ManAChRα2. Molecular docking modeled the molecular basis for interaction between Ma GSTs1/ Ma nAChR and thiacloprid. This study highlights the important roles that ManAChRα2 and MaGSTs1 genes play in thiacloprid detoxification through transcriptional regulation and enzymatic metabolization, and proposes a new avenue for integrated pest management that combines pesticides and RNAi technology as an efficient strategy for M. alternatus control. [Display omitted] • Enzyme activity of GST was significantly upregulated under thiacloprid treatment. • The rapid upregulation of MaGSTs1 promotes thiacloprid detoxification. • Enzyme activity of AChE were significantly inhibited under thiacloprid treatment. • The rapid downregulation of ManAChRα2 promotes thiacloprid detoxification. • RNAi confirmed the detoxification function of ManAChRα2 and MaGSTs1. [ABSTRACT FROM AUTHOR]

In January 2023, the derogation loophole was closed on “emergency authorisations” for the use of three out of five neonicotinoids in all EU states. In this study, we analysed the sorption/desorption behaviour and kinetic parameters of acetamiprid and thiacloprid, the two neonicotinoids that are still approved for use, either regularly or under emergency authorisations in the EU, and widely used worldwide. Sorption and desorption curves in four soils with different organic matter content were analysed using four kinetic models, namely, Lagergren’s pseudo first-order model, two-site model (TSM), Weber–Morris intraparticle diffusion model and Elovich’s model. Kinetic parameters were correlated to soil physico-chemical characteristics. To determine the mutual influence of soil characteristics and sorption/desorption parameters in the analysed soils, a factor analysis based on principal component analysis (PCA) was performed. Even though the two insecticides are very similar in size and chemical structure, the results showed different sorption/desorption kinetics. The model that best fits the experimental data was TSM. Thiacloprid showed a more rapid sorption compared to acetamiprid, and, in all soils, a higher proportion sorbed at equilibrium. Intra-particle diffusion seemed to be a relevant process in acetamiprid sorption, but not for thiacloprid. Desorption results showed that acetamiprid is more easily and more thoroughly desorbed than thiacloprid, in all soils. The kinetic behaviour differences stem from variations in molecular structure, causing disparate water solubility, lipophilicity, and acid–base properties.

Increasing usage and emission of neonicotinoid insecticides have caused severe risks to ecological environment and human health. The study aimed to explore a Fe2+/UV/peroxydisulfate (PDS) system for effective degradation of thiacloprid (TCP). The effects of various parameters involving the degradation efficiency including initial solution pH, PDS concentration, Fe2+ concentration, and UV power were investigated. Under the optimized conditions (pH 3.0, PDS concentration of 1 mmol L-1, Fe2+ concentration of 0.36 mmol L"* 1, and UV power of 45 W), it was observed that 97.5% of TCP was degraded with a pseudo-firstorder kinetics reaction constant of 5.63 × 10-2 min-1. The Fe2+/UV/PDS system demonstrated excellent performance on reaction stoichiometry efficiency (RSE) (31.25%, 60 min). Meanwhile, the effects of inorganic anions (CP-, NO3- and HCO3-) and natural organic matter (humic acid) on the removal of TCP were also investigated. In addition, the free radical scavenging experiments indicated that SOT' was dominant in the Fe2*/UV/PDS system. The intermediates were identified and their toxicity was notably lower than that of TCP. Therefore, the Fe2+/UV/PDS system is efficient and ecologically safe for TCP removal from wastewater. [ABSTRACT FROM AUTHOR]

Researchers globally identify pesticides as one of the main reasons for pollinator decline. In the European Union (EU), extensive legislation is implemented to protect pollinators from harmful pesticide exposure. The aim of our study was to discover whether the pesticide residue levels in honeybee matrices, such as nectar and pollen, exceeded the chronic or acute toxicity levels when beehives were located next to fields treated with specific insecticides. The insecticides were used according to the EU legislation and its national implementation. The experiments were conducted in turnip rape, oilseed rape, and caraway fields in southern Finland during the years 2019 and 2020. The pesticides used in the experiments contained the active substances lambda-cyhalothrin (2019), esfenvalerate (2020), and tau-fluvalinate (2020). However, the honeybee-collected pollen and nectar were analyzed for residues of more than 100 active substances. The results showed that the pesticide residue levels clearly remained under the oral acute toxicity for honeybees, although we found high levels of thiacloprid residues in the pollen collected in 2019. The pesticide residues in nectar were below LOQ values, which was most likely due to the rainy weather conditions together with the chosen sampling method. No statistically significant differences were observed between the insecticide-treated and untreated fields. In light of our research, the EU legislation protected honeybees from oral acute toxicity during the years 2019 and 2020. However, potential sublethal effects of thiacloprid and other pesticide compounds found in the collected pollen cannot be ruled out. In the future, constant monitoring of pesticide exposure of honeybees and wild pollinators should be established to ensure that pesticide legislation, and its implementation across the EU successfully protects pollinators and their services in agricultural environments. [ABSTRACT FROM AUTHOR]

Neonicotinoids are systemic insecticides commonly used for pest control in agriculture and veterinary applications. Due to their widespread use, neonicotinoid insecticides (neonics) are found in different environmental compartments, including water, soils, and biota, in which their high toxicity towards non-target organisms is a matter of great concern. Given their widespread use and high toxicity, the development of strategies to remove neonics, while avoiding further environmental contamination is of high priority. In this work, ionic-liquid-based materials, comprising silica modified with tetraalkylammonium cations and the chloride anion, were explored as alternative adsorbent materials to remove four neonics insecticides, namely imidacloprid, acetamiprid, thiacloprid, and thiamethoxam, from aqueous media. These materials or supported ionic liquids (SILs) were first synthesized and chemically characterized and further applied in adsorption studies. It was found that the equilibrium concentration of the adsorbate in the solid phase decreases with the decrease in the SIL cation alkyl chain length, reinforcing the relevance of hydrophobic interactions between ionic liquids (ILs) and insecticides. The best-identified SIL for the adsorption of the studied insecticides corresponds to silica modified with propyltrioctylammonium chloride ([Si][N3888]Cl). The saturation of SILs was reached in 5 min or less, showing their fast adsorption rate towards all insecticides, in contrast with activated carbon (benchmark) that requires 40 to 60 min. The best fitting of the experimental kinetic data was achieved with the Pseudo Second-Order model, meaning that the adsorption process is controlled at the solid-liquid interface. On the other hand, the best fitting of the experimental isotherm data is given by the Freundlich isotherm model, revealing that multiple layers of insecticides onto the SIL surface may occur. The continuous removal efficiency of the best SIL ([Si][N3888]Cl) by solid-phase extraction was finally appraised, with the maximum adsorption capacity decreasing in the following sequence: imidacloprid > thiacloprid > thiamethoxam > acetamiprid. Based on real reported values, under ideal conditions, 1 g of [Si][N3888]Cl is able to treat at least 106 m3 of wastewater and water from wetland contaminated with the studied neonics. In summary, the enhanced adsorption capacity of SILs for a broad diversity of neonics was demonstrated, reinforcing the usefulness of these materials for their removal from aqueous matrices and thus contributing to preventing their introduction into the ecosystems and reducing their detrimental effects in the environment and human health. [ABSTRACT FROM AUTHOR]

The dissipation and residue levels of thiacloprid, spirotetramat and its four metabolites residues in cowpeas were investigated under field conditions. The QuEChERS technique with high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) was used to detect thiacloprid, spirotetramat and its four metabolites residues content in cowpeas. The recoveries were 81.3–95.1% at a spike level of 0.005–0.5 mg/kg, the relative standard deviations (RSDs) were 2.1–9.5%. The dissipation kinetics data showed that thiacloprid and spirotetramat in cowpeas were degraded with the half-lives of 1.14–1.54 days and 1.25–2.79 days. The terminal residues of thiacloprid and spirotetramat were 0.0255–0.4570 mg kg−1 and 0.0314–0.3070 mg kg−1 after application 2 times with a pre-harvest interval (PHI) of 3 days under the designed dosages. The chronic and acute dietary exposure assessment risk quotient (RQ) values of thiacloprid in cowpeas for different consumers were 2.44–4.41% and 8.72–15.78%, respectively, and those of spirotetramat were 1.03–1.87% and 0.18–0.32%, respectively, all of the RQ values were lower than 100%. The dietary risk of thiacloprid through cowpeas to consumers was higher than spirotetramat. The results from this study are important reference for Chinese governments to develop criteria for the safe and rational use of thiacloprid and spirotetramat, setting maximum residue levels (MRLs), monitoring the quality safety of agricultural products and protecting consumer health. [ABSTRACT FROM AUTHOR]

Simple Summary: The efficacy of crystalline contact insecticides is dependent foremost on the uptake of insecticide molecules by insect tarsi contacting crystal surfaces. Insecticide molecules, however, may organize in more than one way in the crystalline state, resulting in more than one crystalline form (also known as polymorph). We recently discovered that the lethality of contact insecticides increases with decreasing thermodynamic stability of the crystalline forms; the most stable crystalline form is invariably the least lethal/slowest acting. Polymorphism in contact insecticides, and its importance to efficacy, was largely unknown to the vector control community. It is argued that the crystallographic characterization of contact insecticide solids should be systematic to identify more active solid forms. Herein, we report seven new crystal structures, mostly pyrethroid insecticides recommended by the WHO for indoor residual spraying, as well as a new form of a neonicotinoid insecticide. These results further highlight polymorphism in contact insecticides and the importance of solid-state chemistry in the search for more active crystal forms. The active forms of contact insecticides used for combatting mosquito-borne infectious diseases are typically crystalline solids. Numerous molecular crystals are polymorphic, crystallizing in several solid forms characterized by different physicochemical properties, including bioavailability. Our laboratory recently found that the activity of crystalline contact insecticides is inversely dependent on the thermodynamic stability of their polymorphs, suggesting that efficacy can be enhanced by the manipulation of the solid-state structure. This paper argues that crystallography should be central to the development of contact insecticides, particularly because their efficacy continues to be compromised by insecticide resistance, especially among Anopheles mosquito populations that spread malaria. Although insecticidal compounds with new modes of action have been introduced to overcome resistance, new insecticides are expensive to develop and implement. The repurposing of existing chemical agents in metastable, more active crystalline forms provides an inexpensive and efficient method for 'evergreening' compounds whose risks are already well-established. We report herein seven new single-crystal structures of insecticides used for controlling infectious disease vectors. The structures reported herein include pyrethroid insecticides recommended by the WHO for indoor residual spraying (IRS)-bifenthrin, β-cyfluthrin, etofenprox, α-cypermethrin, and λ-cyhalothrin as well as the neonicotinoid insecticide thiacloprid. [ABSTRACT FROM AUTHOR]

The present study evaluated the relative susceptibility of insecticides viz., imidacloprid, thiamethoxam, thiacloprid, flonicamid, clothianidin, diafenthiuron, spiromesifen, thiodicarb and chlorpyriphos against field collected population of Amrasca (S.) biguttula. Out of nine insecticides, maximum susceptibility was observed with thiamethoxam. The descending order of susceptibility was observed as thiamethoxam> thiacloprid> diafenthiuron> spiromesifen> imidacloprid> clothianidin> flonicamid> thiodicarb> chlorpyriphos. Based on the relative toxicity value it was observed that the insecticides such as chlorpyriphos, thiodicarb, flonicamid and clothianidin were 14.04, 12.01, 9.43 and 9.41x, respectively less toxic as compared to thiamethoxam. The detoxification enzyme assay revealed that the activity of esterase was high in thiamethoxam and thiacloprid exposed leafhopper, while cytochrome p450 activity was high in spiromesifen, thiamethoxam and thiacloprid exposed ones. Elevated level of esterase and cytochrome p450 in the insecticide exposed leafhoppers indicates the probability of insecticide resistance development. [ABSTRACT FROM AUTHOR]

The inclusion of bioaugmented low-cost biochar in current wastewater treatment technologies is a promising way to enhance the removal and degradation of emerging contaminants. In this paper, the properties of two wood waste biochars (wood waste mix - AB, and date palm fiber wood - PDF), and coffee bean husks (COF), produced at four temperatures (350, 450, 500, 550°C) were compared, and investigated in the presence of Geobacter sulfurreducens or a mixed freshwater stream bacterial culture to understand their potential for the adsorption and biotransformation of two types of pesticides (thiacloprid, pirimicarb), and two pharmaceuticals (ibuprofen, diclofenac). Biochar yield was similar for all three biochars and ranged between 30 and 35%. The ash content of PDF and COF was significantly higher than AB. pH and electrical conductivity (EC) were initially high for COF (pH: 7.4–8; EC: 3–4.27 mS/cm) and PDF (pH: 7.7–10.1; EC: 4–6.24 mS/cm) after 24 h, but stabilized at neutral pH and

Pistachio is an economically valuable crop, and Iran is among the biggest producers, exporters, and consumers of this product in the world. During the growing season, pistachios are subjected to multiple sprayings with various pesticides, which result in the accumulation of their residues in nuts. These residues have raised concerns regarding consumers' health. In this research, uptake and dissipation kinetics of insecticides imidacloprid (IMI), thiacloprid (THI), thiamethoxam (THX), and abamectin (ABA) were investigated in pistachio nuts. Field experiments were conducted in a pistachio orchard. Pistachio trees were sprayed with the recommended dose of each insecticide formulation and water as the control. Samplings were performed for up to 49 days. Based on the results, pesticides uptake and dissipation kinetics were best fitted to first-order exponential growth (FOEG) and single first-order kinetic (SFOK) models, respectively. Variations in pesticides uptake/dissipation rates were mostly related to their water solubility, pKa, and log Kow. THX showed a higher uptake rate (0.16 ± 0.04) compared to IMI (0.10 ± 0.01) and THI (0.06 ± 0.01). The fastest dissipation rates were observed for IMI (0.04 ± 0.002 day−1) and THX (0.03 ± 0.001 day−1), while the slowest belonged to THI (0.02 ± 0.003 day−1). ABA residues were below the quantification limit (LOQ) throughout the experiment. Based on FOEG and SFOK model predictions, multiple sprayings with THI and THX resulted in final concentrations exceeding the maximum residue limit (MRL). Hazard quotients for all pesticides were <1, indicating no risk to humans via consumption of the pistachio nut. [ABSTRACT FROM AUTHOR]

This study was conducted to introduce effective agent(s) among some novel and conventional insecticides in the management of Tuta absoluta (Meyrick, 1917), the most destructive insect pest of tomato throughout the world, in the lethal and sublethal terms of features. Toxicity of five chemical pesticides, including azadirachtin, emamectin benzoate, imidacloprid, lambda-cyhalothrin, and thiacloprid, was determined on 2nd-instar larvae of T. absoluta by leaf-dipping method in a growth chamber with 25 ± 2 °C, 65 ± 5% relative humidity, and a photoperiod of 16:8 h (L:D). The least LC50 value was attained with emamectin benzoate (0.52 mg A.I./L) among tested insecticides. Demographic parameters of the pest, including GRR (gross reproductive rate), R0 (net reproductive rate), rm (intrinsic rate of increase), T (mean generation time), and ? (finite rate of increase) along with larval, pupal, and pre-adult periods were more affected by emamectin benzoate and azadirachtin. Adult pre-oviposition period (APOP) (1.04 days), female longevity (18.17 days), male longevity (17.88 days), oviposition period (4.21 days), and fecundity (38.67 egg/female) were low by emamectin benzoate. In the treatments by emamectin benzoate and azadirachtin, the survival of fourth-instar larvae, pupae, and adults of insect was reduced in comparison to control. Accordingly, based on the highest adverse possessions of emamectin benzoate and azadirachtin on survival, life history, and demographic parameters of T. absoluta, the applicability of other tested insecticides imidacloprid, lambda-cyhalothrin, and thiacloprid may be limited. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during Ambia bahar - 2019 in the orchard of All India Coordinated Research Project on Arid Zone fruits, Department of Horticulture, Mahatma Phule Krishi Vidyapeeth (M.P.K.V.), Rahuri, Ahmednagar, to evaluate the efficacy of newer insecticides against pomegranate aphid, Aphis punicae. After the application of two sprays, the data revealed that spirotetramat + imidacloprid 240 SC @ 60+60 g a.i. ha-1 consistently proved to be the most promising insecticide by recording the lowest number of aphids per shoot (2.63). It was, however at par with fipronil 5 SC @ 100 g a.i. ha-1 and cyantraniliprole 10.26 OD @ 75 g a.i. ha-1, which recorded 2.83 and 3.18 aphids per shoot, respectively. This was followed by tolfenpyrad 15 EC @ 150 g a.i. ha-1 (4.86) and thiacloprid 240 SC @ 180 g a.i. ha-1 (4.94). [ABSTRACT FROM AUTHOR]

Aiming to evaluate the efficacy of constructed floating wetlands (CFW) in removing agrochemicals (nutrients and pesticides), a series of experiments were run continuously for a 16-week period in pilot-scale CFW systems to study the effect of two aquatic plant species (duckweed and water hyacinth) and climatic parameters. The CFW systems were loaded daily with agricultural polluted water containing a fertilizer and five pesticides, whose concentrations and removal efficiencies were measured in the experiments. Average nutrient and pesticide reductions varied from 27.4% to 83.6% and from 12.4% to 42.7%, respectively. The two plants performed almost equally well. High temperatures and increased solar radiation significantly contributed to increased removal performance. The results suggest the use of CFW systems as effective and low-cost agricultural pollution control technologies. [ABSTRACT FROM AUTHOR]

In this study, we present an inner filter effect-based immunoassay (IFE-IA) for the detection of acetamiprid with a turn off–on model. In the IFE-IA, the monoclonal antibody (mAb) conjugated with upconversion nanoparticles (UCNPs) were set as a fluorescence source, and the antigen conjugated with gold nanoparticles (AuNPs) were set as the fluorescence switch off reagent, while acetamiprid acts as the fluorescence turn-on reagent. After optimization, the concentration of acetamiprid producing 50% saturation of the signal (SC50) was 0.04 µg/L, and the detection range (SC10–SC90) was 0.002–0.58 µg/L. The IFE-IA showed no cross-reactivity with the analogues of acetamiprid except for thiacloprid (36.4%). The average recoveries of the immunoassay for spiked samples were in the range of 75.1–104.7%. In addition, the assay showed good correlation with high-performance liquid chromatography in the detection of blind samples. [ABSTRACT FROM AUTHOR]

Aims: Aims of this study are to elucidate the molecular mechanism of copper‐improved thiacloprid (THI) degradation by Ensifer adhaerens TMX‐23 and characterize copper resistance of this strain. Methods and Results: Resting cells of E. adhaerens TMX‐23 were used to degrade THI, with formation of THI amide and 98·31% of 0·59 mmol l−1 THI was degraded in 100 min. The addition of copper improved the degradation of THI and showed little inhibitory effects on the growth of E. adhaerens TMX‐23. E. adhaerens TMX‐23 degraded THI to THI amide by nitrile hydratases (NhcA and NhpA). QPCR analysis indicated that the expression of nhpA was up‐regulated in the presence of copper. E. adhaerens TMX‐23 nitrile hydratases were purified, and enzyme assay of NhpA exhibited the highest NHase activity toward THI. The addition of copper activated the activity of NhcA. Soil degradation experiment indicated that E. adhaerens TMX‐23 could quickly eliminate THI residual in copper‐added soil. Conclusions: Copper improved THI degradation by E. adhaerens TMX‐23 was attributed to the induced expression of nhpA and activated NhcA. Significance and Impact of the Study: This study broadens the investigation of regulatory mechanism of NHase expression and provided theoretical basis for using metal‐resistant microbes to degrade pesticide in heavy metal co‐contaminated environments. [ABSTRACT FROM AUTHOR]

The tomato leaf miner, Tuta absoluta (Meyrick), is one of the serious insect pests in tomato and potato farms. Along with acute toxicity, effects of emamectin benzoate alone and mixed with some conventional insecticides on esterase enzymes and the protein content of T. absoluta second‐instar larvae were assessed in the current study. After 72 h exposure time, emamectin benzoate had the most toxicity (LC50 = 0.52 mg a.i. L−1), followed by azadirachtin (LC50 = 5.19 mg a.i. L−1), indoxacarb (LC50 = 7.13 mg a.i. L−1), imidocloprid (LC50 = 44.63 mg a.i. L−1), thiacloprid (LC50 = 293.92 mg a.i. L−1) and lambda‐cyhalothrin (LC50 = 610.08 mg a.i. L−1). Although emamectin benzoate mixed with either azadirachtin or indoxacarb at LC15: LC15 (Lethal Concentration to kill 15% tested insects) ratio had synergistic effects, its combination with imidacloprid or thiacloprid showed additive interactions. However, emamectin benzoate mixed with imidacloprid at both LC25: LC25 and LC50: LC50 ratios showed synergistic effects. Lambda‐cyhalothrin mixed with emamectin benzoate showed an antagonistic interaction in all tested ratios. α‐esterase activity of larvae increased when emamectin benzoate was mixed with thiacloprid in comparison with emamectin benzoate alone and the control. Combinations of emamectin benzoate with either azadirachtin or indoxacarb significantly reduced the total protein content of larvae. Generally, it can be concluded that the combination of emamectin benzoate with either azadirachtin, indoxacarb, or imidacloprid resulted in more negative impacts against T. absoluta larvae. [ABSTRACT FROM AUTHOR]

A field study was conducted in coconut at farmer's field in Halebudanuru village in Mandya district, Karnataka during 2017-2018. The frond injection, a novel method of insecticide application was evaluated against the black headed caterpillar Opisina arenosella Walker. The insecticides evaluated include: imidacloprid 17.8% SL, acetamiprid 20% SP, clothianidin 50% WG, thiacloprid 21.7% SC, emamectin benzoate 5% SG, spinosad 45% SC, cartap hydrochloride 50% SP and standard check monocrotophos 36% SL. Among these, it was observed that cartap hydrochloride 50%SP and monocrotophos 36% SL gave 100% mortality; all other treatments also gave significant mortality over control. The frond injection method advocated now is an easy, quicker and accurate method, without any secondary infection/damage to the frond tissues. [ABSTRACT FROM AUTHOR]

Field studies were conducted in two villages viz., Mambattu and Salai in Tamil Nadu to assess the toxicity of five neonicotinoids viz., imidacloprid 17.8 SL, acetamiprid 20 SP, thiacloprid 21.7 SC, thiamethoxam 25 WDG and clothianidin 50 WDG to coccinellid predators in Bt cotton. At 1, 3, 7 and 14 days after treatment, standard check monocrotophos recorded maximum reduction of 78.8, 83.5, 70.4 and 62.6% respectively. Among neonicotinoids, clothianidin was found to be comparatively more toxic to coccinellids, followed by thiamethoxam and thiacloprid. Acetamiprid was found to be safest among chemical treatments with population reduction of 45.6, 53.9, 36.5 and 24.7% respectively at 1, 3, 7 and 14 days after treatment followed by imidacloprid and thiacloprid. Two rounds of spray of neonicotinoids on Bt cotton had significant impact on the coccinellids, when compared with untreated control plots. However, monocrotophos recorded relatively lowest population of coccinellids compared to untreated control and neonicotinoids. With significant population built-up after 7 days after acetamiprid and imidacloprid sprays, the 2 neonicotinoids may be suitable candidates for inclusion in integrated pest management of sucking insect pests in major Bt cotton growing areas as these insecticides are comparatively less toxic to predators as compared to other neonicotinoids like thiacloprid, thiamethoxam and clothianidin and non-selective insecticide like monocrotophos. [ABSTRACT FROM AUTHOR]

Lethal effects of thiacloprid were determined on Schizaphis graminum (Rondani) and Hippodamia variegata (Goeze) at 27 ± 1 °C, 65 ± 10% RH, and 16:8 (L:D) h. The effect of sublethal concentrations (LC10 and LC30) was estimated by the International Organization for Biological Integrated Control (IOBC). The LC50 values of thiacloprid for H. variegata and S. graminum were 730.3 and 212.7 mg a.i.L−1, respectively. Both tested sublethal concentrations negatively affected the demography of H. variegata and S. graminum. The LC30 treatments had a higher negative effect on demographic parameters of both tested insects compared to the LC10 one. Based on the IOBC classification, the LC10 and LC30 treatments were found to be harmless for H. variegata and slightly harmful for S. graminum. Therefore, thiacloprid can be suggested to be used in cereal fields where S. graminum and its predators are active. [ABSTRACT FROM AUTHOR]

Abstract Background Trunk-boring pests (TBPs) are an important type of forest pest, TBPs not only feed on the branches and trunks of trees, but also spread quarantine diseases in forests. However, because the larvae of TBPs live inside the trunk and are well concealed, prevention and control are difficult. The lack of effective control methods leads to the death of many trees in forests. In this study, a novel nanopesticide featuring high bioactivity and slow-release properties was developed to control TBPs. Thiacloprid (THI), which is commonly used to control Coleoptera species, was used as a model pesticide. Results The oleophobic properties of bovine serum albumin (BSA) were exploited to encapsulate the hydrophobic pesticide THI by self-assembly, and the size of the obtained nanoparticles, THI@BSA·NPs, was approximately 23 nm. The loading efficiency reached 70.4%, and THI@BSA·NPs could be released continuously for over 15 days, with the cumulative release reaching 93.5%. The fluorescein isothiocyanate (FITC)-labeled nanoparticles were evenly distributed in the digestive tract and body surface of a typical TBPs, M. alternatus, and the stomach and contact toxicities increased by 33.7% and 25.9%, respectively, compared with those of free THI. Furthermore, the results showed that the transport efficiency of THI@BSA·NPs was highest at a concentration of 50 μg/mL, and the THI@BSA·NPs content in the trunk, from to lower to higher layers, was 8.8, 8.2, 7.6, and 5.8 μg/g. At the same time, THI@BSA·NPs also exhibited high transport efficiency in dead trees. Conclusion The transport efficiency and toxicity of the active ingredients are the key factors for the control of TBPs. This work provided idea for the application of biological delivery system encapsulated hydrophobic pesticides. The novel self-assembled THI@BSA·NPs have promising potential for sustainable control of TBPs.

Thiacloprid, a neonicotinoid insecticide, is widely used to control various species of pests in the current agriculture of today. The potential genotoxic effects of thiacloprid on human peripheral blood lymphocytes were investigated in vitro by chromosome aberrations (CA), and double-strand breaks (DSB), which were detected by the phosphorylation of γH2AX histone. Human peripheral blood lymphocytes were exposed to 30, 60, 120, 240, 480 µg.ml−1 doses for the last 24 and 48 hours of culture. Thiacloprid increased CA at the concentrations of 240, 480 μg.ml−1 (P < 0.05), but these results did not confirm genotoxicity. The mitotic index (MI) was important to us; it served as a basis for the confirmation of the cytotoxicity of this insecticide. During 48 hours of culture, at the concentration of 480 µg.ml−1, its value rapidly decreased (0.42) (P < 0.001), which did not allow us to analyse the results because of the high cytotoxic response.

Pesticides are widely used to maintain tea yields. For achieving satisfactory effects on pests, multiple pesticides in a low application dose have been the trend at present. In this study, we investigated the dissipation and dietary risk assessment of thiacloprid and tolfenpyrad. A method for the determination of thiacloprid and tolfenpyrad was developed. The recoveries ranged from 73% to 105% with standard deviations between 0.7% and 8.3%. Limits of quantification were 0.01 mg/kg for both pesticides. Field trials were conducted in China in 2021. The half-lives were in ranges of 3.22 to 8.45 days for thiacloprid and 2.91 to 10.50 days for tolfenpyrad. The terminal residues were in the range of 0.04–2.55 mg/kg for thiacloprid and

This article discusses the potential toxic impact of neonicotinoid pesticides on male reproductive functions. Neonicotinoids are commonly used agrochemicals that are effective against crop pests but may pose a risk to aquatic ecosystems. The study examined the effect of two neonicotinoids, acetamiprid and thiacloprid, on mouse Sertoli cells in vitro. The results showed that higher doses of acetamiprid and thiacloprid significantly decreased the metabolic activity and cell membrane integrity of the exposed cells. The authors emphasize the need for further research to better understand the risks associated with reproductive health. [Extracted from the article]

Neonicotinoids are pesticides that act as agonists of nicotinic receptors for acetylcholine in insects' central nervous system (CNS). Chronic exposure to neonicotinoids in humans is related to autism, memory loss, and finger tremor. In this article, we evaluate the effect of subchronic oral administration of two neonicotinoids in the same mixture: clothianidin and thiacloprid. Decreasing doses of both pesticides were administered to rats starting from the lethal dose 50 (LD50) reported by the manufacturer. Our results indicate that the administration of three doses of decreasing amounts of LD50 (5/10, 4/10, and 3/10 LD50) resulted in 100% death in all cases. Ten administration times of 2/10 LD50 of the mixture caused only 20% of death cases after twenty-seven days, which was determined as a subchronic administration scheme. The animals administered 2/10 LD50 showed behavioral alterations after the first and second administration. Electrographic studies showed abnormal discharge patterns in the CNS. 72 h after the tenth dose, learning and memory tests were performed in the Morris water maze. Our results revealed significant decreases in permanence at the quadrant and the number of crosses (P = 0.0447 , P = 0.0193 , respectively), which represent alterations in the short-term memory test, but there were no significant changes in a long-term memory test. Likewise, the brains of these animals showed tissue architecture loss, nucleosomal retraction, and a significant increase in the pycnosis of the granular neurons of the dentate gyrus analyzed at 72 h after the last dose (P = 0.0125). Toxic effects and cognitive deterioration that have been found in communities living near contaminated areas are probably related to the agricultural use of neonicotinoids. [ABSTRACT FROM AUTHOR]

Polar organic chemical integrative sampler (POCIS) devices have been suggested for measuring time‐weighted averages (TWAs) of contaminant concentrations resulting from chemical leak accidents in aquatic environments. However, the response of the POCIS device in the emergency condition in natural water remains unclear. The response of the POCIS device to contaminant fluctuation was investigated using a chamber test with tap water and a channel test with natural water. The fluctuation in the chamber and the channel simulated the condition of river water under a chemical leak scenario (maximum concentration: 1–10 μg L–1, half‐life: 1 day). The target chemicals were neonicotinoid pesticides (dinotefuran, clothianidin, thiamethoxam, imidacloprid, acetamiprid, and thiacloprid) and bisphenol A. The ratio of the POCIS measured value to the TWA values of grab samplings (POCIS/TWA) for the channel test (temperature: 15 °C, flow velocity: 15 cm s–1) ranged from 61% (clothianidin) to 133% (thiacloprid). The results indicated that the POCIS device could be effectively used as a monitoring device in an aquatic environment under the chemical leak scenario over a time period of more than14 days. In addition, the POCIS/TWA ratios obtained from the chamber test and the channel test were in the range of 50–150%. Thus, the chamber test could be used to evaluate the POCIS device at a low cost. Environ Toxicol Chem 2021;40:3010–3018. © 2021 SETAC [ABSTRACT FROM AUTHOR]

BACKGROUND The aerial application of insecticides is a primary method used to prevent the spread of pine wilt disease by reducing the population density of Monochamus beetles, the vector insects of pine wood nematodes (PWNs). This study investigated the mortality of vector insects and the ratio of PWN‐infected trees according to systemically remaining thiacloprid residues in Pinus densiflora. To do this, thiacloprid was sprayed on a nursery of 5‐year‐old P. densiflora in meshed cages. Then Monochamus alternatus adults carrying PWNs were placed into meshed cages 1 and 15 days post‐treatment (T1 and T15 groups for thiacloprid spraying, and N1 and N15 groups for nonsprayed groups) and tree mortality was monitored. We also measured the thiacloprid residues in pine branches in each treatment. RESULTS: In pine trees, more thiacloprid residues were found in the T1 group than in the T15 group, but most M. alternatus adults died in the T1 and T15 groups and PWNs were detected in 51.3% of all recaptured beetles. In the 16th week after each treatment, the average tree mortalities in T1 and T15 were 0% and 16.7%, respectively, whereas mortality of ≈50–60% of all tested trees in the nonsprayed groups was observed. CONCLUSION: The current aerial application of insecticides may have a limitation in preventing PWN transmission from dying M. alternatus adults when they are exposed to low thiacloprid residues in pine trees. [ABSTRACT FROM AUTHOR]

Pesticide exposure is thought to be one of the common reasons for the decline in amphibian populations, a phenomenon that is a major threat to global biodiversity. Although the single effects of pesticides on amphibians have been well studied, the effects of mixtures are not well known. The present study aimed to evaluate the acute toxicity of the insecticide thiacloprid and the fungicide trifloxystrobin on early developmental stages of Xenopus laevis using various biochemical markers (glutathione S‐transferase, glutathione reductase, acetylcholinesterase, carboxylesterase, glutathione peroxidase, catalase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, Na+K+‐adenosine triphosphatase [ATPase], Ca2+‐ATPase, Mg2+‐ATPase, and total ATPase). The median lethal concentrations (LC50s) of thiacloprid and trifloxystrobin were determined to be 3.41 and 0.09 mg a.i. L–1, respectively. Tadpoles were exposed to the LC50, LC50/2, LC50/10, LC50/20, LC50/50, and LC50/100 of these pesticides. Both pesticides significantly affected (inhibited/activated) the biomarkers even at low concentrations. The pesticides showed a synergistic effect when applied as a mixture and altered the biomarkers more than when applied individually. In conclusion, we can assume that tadpoles are threatened by these pesticides even at environmentally relevant concentrations. Our findings provide important data to guide management of the ecotoxicological effects of these pesticides on nontarget amphibians. Environ Toxicol Chem 2021;40:2846–2860. © 2021 SETAC [ABSTRACT FROM AUTHOR]

Background: Alveolar echinococcosis (AE) is a chronic zoonosis caused by the larval form of Echinococcus multilocularis (E. multilocularis). Current chemotherapy against AE has relied on albendazole and mebendazole, which only exhibit parasitostatic and not parasiticidal efficacy. Therefore, novel compounds for the treatment of this disease are needed. Methods: Phosphoglucose isomerase (PGI) assays were used for compound screening of seven neonicotinoids. The anti-parasitic effects of thiacloprid were then evaluated on E. multilocularis metacestode vesicles, germinal cells and protoscoleces in vitro. Human foreskin fibroblasts (HFF) and Reuber rat hepatoma (RH) cells were used to assess cytotoxicity. Glucose consumption in E. multilocularis protoscoleces and germinal cells was assessed by measuring uptake of 2-deoxyglucose (2-DG). Molecular docking was used to evaluate the potential binding sites of thiacloprid to acetylcholine receptors. In vivo efficacy of thiacloprid was evaluated in mice by secondary infection with E. multilocularis. In addition, ELISA and flow cytometry were used to evaluate the effects of cytokines and T lymphocyte subsets after thiacloprid treatment. Furthermore, collagen deposition and degradation in the host lesion microenvironment were evaluated. Results: We found that thiacloprid is the most promising compound, with an IC50 of 4.54 ± 1.10 μM and 2.89 ± 0.34 μM, respectively, against in vitro-cultured E. multilocularis metacestodes and germinal cells. Thiacloprid was less toxic for HFF and RH mammalian cell lines than for metacestodes. In addition, thiacloprid inhibited the acetylcholinesterase activity in protoscoleces, metacestodes and germinal cells. Thiacloprid inhibited glucose consumption by protoscoleces and germinal cells. Subsequently, transmission electron microscopy revealed that treatment with thiacloprid damaged the germinal layer. In vivo, metacestode weight was significantly reduced following oral administration of thiacloprid at 15 and 30 mg/kg. The level of CD4+ T lymphocytes in metacestodes and spleen increased after thiacloprid treatment. Anti-echinococcosis-related cytokines (IL-2, IL-4, IL-10) were significantly increased. Furthermore, thiacloprid inhibited the expression of matrix metalloproteinases (MMPs 1, 3, 9, 13) and promoted collagen deposition in the host lesion microenvironment. Conclusions: The results demonstrated that thiacloprid had parasiticidal activity against E. multilocularis in vitro and in vivo, and could be used as a novel lead compound for the treatment of AE. [ABSTRACT FROM AUTHOR]

Agricultural and apicultural practices expose honeybees to a range of pesticides that have the potential to negatively affect their physiology, neurobiology, and behavior. Accumulating evidence suggests that these effects extend to the honeybee gut microbiome, which serves important functions for honeybee health. Here we test the potential effects of the pesticides thiacloprid, acetamiprid, and oxalic acid on the gut microbiota of honeybees, first in direct in vitro inhibition assays and secondly in an in vivo caged bee experiment to test if exposure leads to gut microbiota community changes. We found that thiacloprid did not inhibit the honeybee core gut bacteria in vitro , nor did it affect overall community composition or richness in vivo. Acetamiprid did also not inhibit bacterial growth in vitro , but it did affect community structure within bees. The eight bacterial genera tested showed variable levels of susceptibility to oxalic acid in vitro. In vivo , treatment with this pesticide reduced amplicon sequence variant (ASV) richness and affected gut microbiome composition, with most marked impact on the common crop bacteria Lactobacillus kunkeei and the genus Bombella. We conducted network analyses which captured known associations between bacterial members and illustrated the sensitivity of the microbiome to environmental stressors. Our findings point to risks of honeybee exposure to oxalic acid, which has been deemed safe for use in treatment against Varroa mites in honeybee colonies, and we advocate for more extensive assessment of the long-term effects that it may have on honeybee health. [ABSTRACT FROM AUTHOR]

BackgroundNeonicotinoids, a widely used class of insecticide, have attracted much attention because of their widespread use that has resulted in the decline of the bee population. Accumulating evidence suggests potential animal and human exposure to neonicotinoids, which is a cause of public concern.ObjectivesIn this study, we examined the effects of a neonicotinoid, thiacloprid (thia), on the male reproductive system.MethodsThe pregnant outbred Swiss female mice were exposed to thia at embryonic days E6.5 to E15.5 using “0,” “0.06,” “0.6,” and “6” mg/kg/day doses. Adult male progeny was analyzed for morphological and cytological defects in the testes using hematoxylin and eosin (H&E) staining. We also used immunofluorescence, Western blotting, RT-qPCR and RNA-seq techniques for the analyses of the effects of thia on testis.ResultsWe found that exposure to thia causes a decrease in spermatozoa at doses “0.6” and “6” and leads to telomere defects at all tested doses. At doses “0.6” and “6,” thia exposure leads to an increase in meiotic pachytene cells and a decrease in lumen size, these changes were accompanied by increased testis-to-body weight ratios at high dose. By using RNA-seq approach we found that genes encoding translation, ATP production, ATP-dependent proteins and chromatin-modifying enzymes were deregulated in testes. In addition, we found that exposure to thia results in a decrease in H3K9me3 levels in spermatocytes. The changes in H3K9me3 were associated with a dramatic increase in activity of retroelements.ConclusionOur study suggests that gestational exposure to thia affects epigenetic mechanisms controlling meiosis which could lead to deleterious effects on male spermatogenesis.

Neonicotinoid insecticides (NNIs) are now popular in many agricultural systems across Africa; however, the extent of human exposures to NNIs in African countries is scarcely reported. The present study evaluates neonicotinoid exposures in the consumer population of Kumasi, a cosmopolitan city in Ghana. A total of 75 human urine samples were collected from healthy volunteers (nonfarmers, aged 13–80 yr) and analyzed with a liquid chromatography electrospray ionization tandem mass spectrometry system. Seven NNIs and 3 NNI metabolites were detected in the following pattern (frequency, median concentration, maximum concentration): N‐dm‐acetamiprid (94.7%, 0.41 µg/L, 8.79 µg/L) > imidacloprid (70.7%, 0.15 µg/L, 211.62 µg/L) > N‐(6‐chloro‐3‐pyridylmethyl)‐N‐ethyl‐N′‐methylformamidine (62.2%, 0.43 µg/L, 53.85 µg/L) > 2‐[N‐(6‐chloro‐3‐pyridylmethyl)‐N‐ethylamino]‐2‐(methylimino)acetic acid (56.8%, 0.10 µg/L, 3.53 µg/L) > clothianidin (40%, >limit of quantification [LOQ], 0.45 µg/L) > nitenpyram (18.7%, >LOQ, 0.14 µg/L) ≈ thiamethoxam (18.7%, >LOQ, 0.21 µg/L) > dinotefuran (12.0%, >LOQ, 1.01 µg/L) > acetamiprid (2.7%, >LOQ, 0.08 µg/L) ≈ thiacloprid (2.7%, >LOQ, 0.14 µg/L). Approximately 92% of the subjects were found to be exposed to multiple neonicotinoids simultaneously. The mean, median, and maximum imidacloprid equivalent of the relative potency factor of NNIs were found to be 1.6, 0.5, and 22.52, respectively. The median estimated daily intakes of acetamiprid, imidacloprid, and nitenpyram were 0.47, 1.27, and 0.02 µg/kg/d for females and 0.91, 0.66, and 0.08 µg/kg/d for males, respectively. The maximum daily intakes of all the NNIs were <1% of their chronic reference doses (cRfDs), except for imidacloprid and thiacloprid which recorded maximum daily intakes corresponding to 17.97 and 8.28% of cRfDs, respectively. To the best of our knowledge, the present study is the first biomonitoring report on neonicotinoid insecticides in Africa. Environ Toxicol Chem 2021;40:2306–2318. © 2021 SETAC [ABSTRACT FROM AUTHOR]

Neonicotinoids are selective modulators of insect nicotinic acetylcholine receptors (nAChRs). These widely deployed insecticides interact with the orthosteric sites of nAChRs, not only to activate nAChRs on their own, but also to block the desensitizing component of nAChR responses. To date recombinant vertebrate or insect/vertebrate hybrid nAChRs have been deployed to understand the mechanism of selectivity and diversity of neonicotinoid actions as well as to show that both α/α and α/non‐α interfaces are involved in the interactions with neonicotinoids. However, many of the fine details of insecticide interactions with sites on nAChRs remain to be resolved. The breakthrough of functional expression of insect nAChRs allows such questions to be addressed, not only for neonicotinoids but for other insecticides targeting insect nAChRs. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The Shot-hole borer (SHB), Xylosandrus compactus Eichhoff (Coleoptera: Scolytidae) is one of the serious pests of coffee with a higher infestation in robusta coffee than arabica. This study includes both laboratory and field experiments to assess the efficacy of five different insecticides for the control of SHB. In the laboratory, insecticides were evaluated at two different doses and the insecticide concentrations that generated the highest mortality percentage were subsequently tested in the field. Such, insecticides were sprayed on the SHB infested twigs in the field and the efficacy was assessed by percentage mortality on insect stages. The highest percent adult mortality at tunnel entry hole (92 %) was recorded for Chlorpyrifos 20 EC @ 3 ml/l and Chlorpyrifos 50 EC + Cypermethrin 5 EC @ 1.2 ml/l followed by Emamectin benzoate 5 SG @ 0.4 g/l (71%), Thiacloprid 21.7 SC @ 1 ml/l (70%) and Imidacloprid 17.8 SL @ 1 ml/l (64%). The study revealed that Chlorpyrifos 20 EC and Chlorpyrifos 50 EC + Cypermethrin 5 EC combination insecticides were effective in killing SHB adults at the entrance hole and these insecticides could be integrated as an IPM component in the management of SHB in the young robusta coffee plantations. [ABSTRACT FROM AUTHOR]

Malnutrition and pesticide exposure are severe factors contributing to the current losses of honeybee colonies. As these stressors often occur combined, we studied the synergistic effects of different diets and pesticide exposure on food choice and mobility of Apis mellifera. We fed beehives with different food sources and exposed the bees to sublethal doses of thiacloprid. After that three different types of honey and pollen were offered in separate choice assays and behaviour towards food was recorded. Thiacloprid significantly affected the food choice in the honey assay, increasing the bees' preference of polyfloral honey, while pre-pesticide diet had no influence. The pollen choice remained similar regardless of treatments, as bees always preferred polyfloral pollen. Interestingly, pesticide exposure affected bee mobility differently, depending on the previous diet. These results indicate that the diet is an important factor influencing the susceptibility to pesticides. [ABSTRACT FROM AUTHOR]

Ecotoxicological profiles of the 3 insecticides imidacloprid, thiacloprid, and flupyradifurone in terms of acute and chronic effects were analyzed in Chironomus riparius. Toxicokinetic–toxicodynamic modeling revealed that chironomids would die from starvation as a result of prolonged feeding inhibition under chronic exposures. The starvation effect is an indirect cause for mortality, which, for the neonicotinoids, adds to the direct/acute mortality, although the results suggests that this additional effect is not relevant for flupyradifurone. Environ Toxicol Chem 2021;40:1706–1712. © 2021 Bayer Inc. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Neonicotinoids are widely used insecticides that have raised considerable concerns for both environmental and human health. However, there lack of comprehensive evaluation of their accumulation in surface water ecosystems and exposure to various human groups. Additionally, there's a distinct lack of scientific evidence describing the carcinogenic and non-carcinogenic impacts of neonicotinoids from surface water. Using an integrated approach employing the Relative Potency Factor (RPF), Hazard Index (HI), and Monte Carlo Simulation (MCS), the study assessed neonicotinoid exposure and risk to four demographic groups via dermal contact and mistaken oral intake pathways in the Yangtze River Basin (YRB), China. Neonicotinoid concentrations range from 0.1 to 408.12 ng/L, indicating potential risk (10−3 to 10−1) across the studied demographic groups. The Incremental Lifetime Cancer Risk (ILCR) for dermal contact was within a moderate range of 2.00 × 10−3 to 1.67 × 10−2, while the mistaken oral intake was also within a moderate range of 3.07 × 10−3 to 7.05 × 10−3. The Hazard Index (HI) for dermal exposure ranged from 1.49 × 10−2 to 0.125, while for mistaken oral intake, it varied between 2.69 × 10−2 and 0.14. The findings highlight the importance of implementing specific interventions to address neonicotinoid exposure, especially among demographic groups that are more susceptible. This research underscores the urgent need for targeted strategies to address neonicotinoid risks to vulnerable populations within the YRB while contributing to insights for effective policies to mitigate neonicotinoid exposure in surface water ecosystems globally. [Display omitted] • Develop an integrated method to assess human risk of neonicotinoids in surface water. • Combine the Relative Potency Factor, Hazard Index, and Monte Carlo Simulation. • The carcinogenic risk value of thiacloprid ranged from 2.00 × 10−3 to 1.67 × 10−2. • Children and adolescents are more sensitive groups to neonicotinoids. • Females generally had a higher risk than males. [ABSTRACT FROM AUTHOR]

The effectiveness of selected insecticides against capsule weevils (Neoglocianus maculaalba) and capsule midges (Dasineura papaveris), which are the main pests of breadseed poppy, was verified in a small-plot field experiment in 2015-2017. The effect of foliar application was evaluated according to boreholes on capsule surfaces caused by the feeding of capsule weevil adults and larvae numbers in capsules collected approximately 4 weeks after application. Biological efficacy of the tested biological formulations Spintor (active ingredient spinosad 240 g/l) in dosage 0.4 l/ha and NeemAzal T/S (active ingredient azadirachtin A 10.6 g/l) in dosage 3 l/ha against N. maculaalba larvae in individual years of monitoring ranged from 46.4% to 77.7% and from 67.7% to 82.9%, respectively. The effect of the formulation Prev B2 (boron ethanolamine corresponding to 2.1% of water-soluble boron) in 0.3% dosage was in the range of 59.5-81.9%. Their efficacy did not differ significantly compared to the registered chemical standards Biscaya 240 OD (active ingredient thiacloprid 240 g/l) and Decis Mega (active ingredient deltamethrin 50 g/l). Therefore, these biological insecticides are potentially useful for the effective control of N. maculaalba and D. papaveris population densities and reduction of damage they cause to breadseed poppy.

Thiacloprid (THI) is a widely used neonicotinoid insecticide where concerns have been raised regarding low absorption by crops, substantial distribution in surrounding areas, and potential adverse effects to terrestrial and aquatic organisms. Prior to this study, there was very limited information addressing the ex vivo (precision-cut liver slices) metabolism of THI by fish species and the metabolic pathways regulating its potential for adverse effects. The in vitro and ex vivo biotransformation pathway of THI is defined by the formation of three primary metabolites (TM1, TM2 and TM3) via separate paths differentiated by reductive decyanation, reductive dechlorination with hydration and dealkylation processes, respectively. Kinetic rates were calculated for the rat microsomal decyanation of THI into TM1 (Km = 299.2 µM and Vmax = 5.3 pmol/min/mg), and for the dealkylation of THI into TM3 (Km = 368.9 µM and Vmax = 3.95 pmol/min/mg). Formation confirmation and identity inference of THI metabolites in absence of standards were achieved by LC-UV and High Resolution-MS strategies. The in vitro and ex vivo metabolic products of THI are conserved both across species (rat and Rainbow trout) and levels of biological organization (microsomes and liver slices), as previously reported for the neonicotinoid insecticides Imidacloprid and Acetamiprid. [ABSTRACT FROM AUTHOR]

The objective of this study was to find out if useful insects - in this case, harlequin ladybirds (Harmonia axyridis) - are affected by plant protection products (PPP) to the same extent as pests and if this species shows any levels of resistance to chosen active substances in insecticides. Harlequin ladybirds were collected in selected localities during the 2019 vegetation season. Their resistance to active substances (lambda-cyhalothrin and thiacloprid in various concentrations) was then tested. In the thiacloprid test, the commercial formulation of Biscaya 240 OD was used. Testing was performed pursuant to the Insecticide Resistance Action Committee (IRAC) methods using the adult-vial-test. The efficiency of the active substance used was assessed, and tested individuals were divided into groups (Alive, Dead, or Tremor) according to their physical condition. From the values obtained, mortality was calculated at 100% of the dose of each active substance. Subsequently, the results were elaborated using the specialised program of POLO PLUS 2.0, which calculates the values of a lethal dose - LD50, LD90 and LD95. Mortality was assessed depending on the dose increase of tested active substances. According to the mortality assessed and calculated lethal doses, it was observed that populations of the harlequin ladybird are sensitive to the affect of tested active substances. Since these are one-year results, it is difficult to determine if a selection of resistant populations will occur. [ABSTRACT FROM AUTHOR]

Neonicotinoid insecticides have become of global concern for the aquatic environment. Harpacticoid copepods are among the organisms most sensitive to neonicotinoids. We exposed the brackish copepod Nitocra spinipes to 4 neonicotinoid insecticides (clothianidin, imidacloprid, thiacloprid, and thiamethoxam) to investigate acute toxicity on adults (96‐h exposure) and effects on larval development (7‐d exposure). We used these results in combination with publicly available ecotoxicity data to derive environmental quality standards (EQS). These EQS were ultimately used in a single‐substance and mixture risk assessment for the Belgian part of the North Sea. Acute toxicity testing revealed that immobilization is a more sensitive endpoint than mortality, with 96‐h median effect concentration (EC50) values of 6.9, 7.2, 25, and 120 µg L–1 for clothianidin, thiacloprid, imidacloprid, and thiamethoxam, respectively. In addition, the larval development tests resulted in 7‐d no‐observed‐effect concentrations (NOECs) of 2.5, 2.7, 4.2, and >99 µg L–1 for clothianidin, thiacloprid, imidacloprid, and thiamethoxam, respectively. The derived saltwater annual average (AA‐)EQS were 0.05, 0.0048, 0.002, and 0.016 µg L–1 for clothianidin, thiacloprid, imidacloprid, and thiamethoxam, respectively. Finally, the risk characterization revealed some exceedances of the AA‐EQS in Belgian harbors for imidacloprid (number of exceedances, n = 2/4), for thiacloprid (n = 1/4), for thiamethoxam (n = 1/4), and for the mixture of the 4 neonicotinoids (n = 4/4), but not at the open sea. At the open sea site, the toxic unit sums relative to the AA‐EQS were 0.72 and 0.22, suggesting no mixture risk, albeit with a relatively small margin of safety. Including short‐term EC10 (96‐h) values of N. spinipes for the AA‐EQS derivation led to a refinement of the AA‐EQS for clothianidin and thiamethoxam, suggesting their use for the AA‐EQS derivation because one of the overarching goals of the definition of EQS is to protect species at the population level. Environ Toxicol Chem 2021;40:1353–1367. © 2021 SETAC [ABSTRACT FROM AUTHOR]

To promote exports, import tolerance (IT) of thiacloprid in strawberry was proposed using the Organization for Economic Cooperation and Development (OECD) maximum residue limit (MRL) calculator after conducting three different field trials. The pre‐harvest interval of residual pattern and degradation dynamics of thiacloprid in strawberry were determined using ultra‐performance liquid chromatography–tandem mass spectrometry. Samples were extracted with acetonitrile and a mixture of salts and dilution was performed for purification. A six‐point matrix‐matched calibration curve was constructed which provided excellent linearity with coefficient of determination (R2) of 0.9998 or more. Detection and quantification limits were 0.003 and 0.01 mg/kg, respectively. The method was validated in quintuplicate at three different concentrations, which resulted in acceptable recovery ranging from 80.86% to 101.71% with relative standard deviation of 6.50 or less among the three field sites. The developed method was applied to the field‐treated sample harvested at different intervals. In the pre‐harvest interval trial, the amount of thiacloprid residues ranged from 0.24 to 0.70 mg/kg in field site 1 (Nonsan), 0.16 to 0.50 mg/kg in field site 2 (Sunchang), and 0.36 to 0.50 mg/kg in field site 3 (Sacheon). By contrast, in the degradation trial, the observed residues were 0.03–0.81 mg/kg in field site 1 and 0.02–0.48 mg/kg in field site 2. Consequently, the IT of thiacloprid in strawberry using the OECD MRL calculator was proposed as 2 mg/kg, which is exactly the same as the MRL established by the Republic of Korea. In conclusion, the residue study proposes 2.0 mg/kg as the MRL of thiacloprid in strawberries. [ABSTRACT FROM AUTHOR]

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The weevil, Datonychus melanostictus, is one of the most damaging insect pest of mint crop Mentha spicata L. in Morocco. This insect causes significant damage by larval feeding on mint rhizomes. The effectiveness of systemic and contact insecticides for controlling larvae and adults of D. melanostictus was investigated in spearmint field trials, during three cropping seasons in the Chaouia region. The contact insecticide lambda-cyhalothrin (250 ml/ha) caused the highest mortality (87.5%) against adult weevils three days after treatment, reducing the damaged rhizomes by 61% and significantly increased the fresh yield by 48.7% over the check. However, the use of neonicotinoid insecticides imidacloprid and thiacloprid after mint cuts showed a negative effect to reduce the larval infestation on rhizomes. These findings revealed that the use of lambda-cyhalothrin as foliar application in early summer, could be an excellent candidate to control the adult weevils D. melanostictus on mint crop. [ABSTRACT FROM AUTHOR]