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Risk assessment of plant protection products (PPPs) will be conducted before authorization for their possible effects on non-target organisms, including honey bees. Tank mixtures are often common practice by farmers, and mostly their effects on honey bees are not routinely assessed. To enable a realistic assessment of laboratory-reported effects of a combination of the insecticide thiacloprid and fungicide prochloraz on honey bees, a large-scale field study with spray application in winter oilseed rape was conducted in four regions in Germany. Several parameters were investigated, including mortality, flight activity, and colony development. Residue analysis of various materials (e.g., dead bees, nectar, and pollen) was conducted to assess exposure level. We observed several intoxication symptoms 2 h after application, including a high number of moribund bees and dead bees on the first day after application (DAA +1) compared to the control. Adverse effects were observed on the number of open brood cells, with a significant reduction of approximately 22% compared to control over the experimental period. High residue concentrations were detected on flowers and dead bees on the day of application, which decreased rapidly within six days. The residue concentrations detected were higher in bee-collected materials than in materials stored in the hive. In conclusion, exposure to a combination containing thiacloprid-prochloraz poses a high risk to honey bees. Thus, the application of such a mixture on flowering crops is restricted in Germany. [Display omitted] • Severe intoxication symptoms after application of thiacloprid-prochloraz mixture. • Increase bee mortality on the day of the application. • Reduction in the number of open brood cells. • Higher residue concentrations in bee-collected materials than in-hive stored one. • High risk under field conditions after exposure to thiacloprid-prochloraz mixture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Robust probe is designed by engineering biomimic MOFs with specific pockets. • The probe gives "key-lock" identification and sensitive quantitative information. • Innovatively integrating the probe with filter paper could avoid ring-like deposit. • The well-distributed interface is harvested to reduce colorimetric signal fluctuation. • Self-adaptive signal model allows for monitoring pesticide in colored matrices. Excessive residual pesticides have raised overall environmental damage and health hazard issues, thus the development of facile and sensitive means for pesticide monitoring in different environmental field is desperately needed but challenging. In this work, a flexible paper-based colorimetry beating coffee-ring effect is achieved toward sensing environmental pesticide exposure in user-friendly mode. First, to circumvent poor performance of biomolecules, robust probe is designed by imprinting metal-organic frameworks (MOFs) with specific pockets, enabling to provide "key-lock" identification and sensitive quantitative information under harsh environment. Innovatively, integrating the MOF-mediated probe with filter paper, a well-distributed sensing interface is harvested to reduce colorimetric signal fluctuation for reliable detection properties, which is ascribed to superior wetting behavior of filter paper for avoiding ring-like deposit formation. Additionally, the uniform profile is simulated by Fluent numerical software. Further exploiting smartphone-assisted image acquisition and self-adaptive signal model, the simple-to-perform system exhibits good accuracy toward ppb-level thiacloprid free of colored background interference. A low limit of detection of 0.04 μM thiacloprid (corresponding to 0.01 μg g−1 by weight) is achieved. Moreover, it allows for in-filed monitoring thiacloprid exposure in agricultural wastewater, soil, fresh vegetables with satisfactory recoveries ranging from 92.7 % to 109.0 %, verifying the broad potential applications for point-of-use tracking of environmental pesticide and eventually bringing benefits to ecosystem protection in resource-deficient settings. [ABSTRACT FROM AUTHOR]

Neonicotinoid insecticides (NNIs) are the most widely used class of pesticides globally. However, NNIs may cause adverse health effects, including chronic liver disease, and perturbation of the gut microbiota. Thiacloprid (THI) is one of the NNIs widely used in agriculture. Therefore, it is essential to elucidate effects of THI on the microbiota–gut–liver axis to assess the risk of chronic liver disease following exposure to NNIs. This study aimed at investigating whether THI exposure promoted liver injury by altering the gut microbiota and related metabolites. In this study, healthy male quails were exposed to 2 or 4 mg/kg THI or 0.75 % (w/v) saline once daily for 6 weeks, respectively. Metabolomics, 16S rRNA sequencing, and transcriptomic methods were performed to analyze the toxic mechanisms of THI in Japanese quails. We found that THI evoked damage and disruption to intestinal barrier function, leading to increased harmful substances such as lipopolysaccharide (LPS) and phenylacetic acid entering the liver. Besides, our results showed significantly altered hepatic bile acid and cholesterol metabolism in THI-exposed quails, with abnormal liver lipid metabolism, showing severe liver injury, fibrosis, and steatosis compared with the control quails. In conclusion, THI exposure aggravates liver injury via microbiota–gut–liver axis. [Display omitted] • Multiomics was used to analyze the toxic mechanism of THI in quails. • Chronic THI exposure induces liver injury via disrupting intestinal flora in quails. • THI promotes endotoxin translocation by increasing intestinal mucosal permeability. • Microbiota–gut–liver axis provides a novel mechanism of THI toxicity. [ABSTRACT FROM AUTHOR]

Dissolved organic matter regulates the interaction between microplastics (MPs) and organic pollutants. Here, this paper investigated the effect and mechanism of humic acid (HA) on the adsorption behavior of thiacloprid at two microfibers (MFs)/water interface, and compared the differences in the performance of MFs and pure MPs. The results showed that 10 mg L−1 HA decreased the adsorption capacity and the partition coefficient K D of thiacloprid on MFs and pure MPs. Spectral analysis showed that HA could form hydrogen bonds and van der Waals forces with both MPs and thiacloprid, ultimately affecting the adsorption behavior of thiacloprid at MPs/water interface via competitive adsorption and bridging effect. Furthermore, two-dimensional correlation spectroscopy demonstrated that thiacloprid was preferentially adsorbed onto MPs compared with HA. Finally, density functional theory calculation demonstrated that phenolic-OH, –COOH, and alcoholic-OH played critical roles in competing adsorption and bridging effect. This study offers a theoretical foundation for a better comprehension of the adsorption behavior of organic pollutants at the MPs/water interface. [Display omitted] • HA reduced the partition coefficient K D of THIA at microfibers/water interface. • HA affected adsorption through both competitive adsorption and bridging effect. • THIA preferentially adsorbed on MPs compared with HA. • Phenolic-OH, –COOH, and alcoholic-OH acted through intermolecular hydrogen bonds. • Van der Waals forces also played significant roles in adsorption. [ABSTRACT FROM AUTHOR]

The use of agricultural neonicotinoid insecticides has sub-lethal chronic effects on bees that are more prevalent than acute toxicity. Among these insecticides, thiacloprid, a commonly used compound with low toxicity, has attracted significant attention due to its potential impact on the olfactory and learning abilities of honeybees. The effect of sub-lethal larval exposure to thiacloprid on the antennal activity of adult honeybees ( Apis mellifera L.) is not yet fully understood. To address this knowledge gap, laboratory-based experiments were conducted in which honeybee larvae were administered thiacloprid (0.5 mg/L and 1.0 mg/L). Using electroantennography (EAG), the impacts of thiacloprid exposure on the antennal selectivity to common floral volatiles were evaluated. Additionally, the effects of sub-lethal exposure on odor-related learning and memory were also assessed. The results of this study reveal, for the first time, that sub-lethal larval exposure to thiacloprid decreased honeybee antenna EAG responses to floral scents, leading to increased olfactory selectivity in the high-dose (1.0 mg/L) group compared to the control group (0 mg/L vs . 1.0 mg/L: p = 0.042). The results also suggest that thiacloprid negatively affected odor-associated paired learning acquisition, as well as medium-term (1 h) (0 mg/L vs . 1.0 mg/L: p = 0.019) and long-term memory (24 h) (0 mg/L vs . 1.0 mg/L: p = 0.037) in adult honeybees. EAG amplitudes were dramatically reduced following R-linalool paired olfactory training (0 mg/L vs . 1.0 mg/L: p = 0.001; 0 mg/L vs . 0.5 mg/L: p = 0.027), while antennal activities only differed significantly in the control between paired and unpaired groups. Our results indicated that exposure to sub-lethal concentrations of thiacloprid may affect olfactory perception and learning and memory behaviors in honeybees. These findings have important implications for the safe use of agrochemicals in the environment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ke, Chen, Dai and Liu.)

Thiacloprid (TH) is a neurotoxic agricultural insecticide and potential food contaminant. The purpose of this study was to investigate the relationship between TH exposure and memory dysfunction in rats, as well as the potential protective effect of piracetam and piracetam-loaded magnetic chitosan nanoparticles (PMC NPs). Rats were divided into five equal groups (six rats/group). The control group received saline. Group II was treated with PMC NPs at a dose level of 200 mg/kg body weight (Bwt); Group III was treated with 1/10 LD 50 of TH (65 mg/kg Bwt); Group IV was treated with TH (65 mg/kg Bwt) and piracetam (200 mg/kg Bwt); Group V was co-treated with TH (65 mg/kg Bwt) and PMC NPs (200 mg/kg Bwt). All animal groups were dosed daily for 6 weeks by oral gavage. Footprint analysis, hanging wire test, open field test, and Y-maze test were employed to assess behavioral deficits. Animals were euthanized, and brain tissues were analyzed for oxidative stress biomarkers, proinflammatory cytokines, and gene expression levels of glial fibrillary acidic protein (GFAP), amyloid-beta precursor protein (APP), B-cell lymphoma 2 (Bcl-2), and caspase-3. Brain and sciatic nerve tissues were used for the evaluation of histopathological changes and immunohistochemical expression of tau protein and nuclear factor kappa B (NF-κB), respectively. The results revealed that TH-treated rats suffered from oxidative damage and inflammatory effect on the central and peripheral nerves. The administration of PMC NPs considerably protected against TH-induced neuronal damage, increased antioxidant enzyme activity, decreased inflammatory markers, and improved behavioral performance than the group treated with piracetam. The neuroprotective effect of PMC NPs was mediated through the inhibition of GFAP, APP, caspase-3, Tau, and NF-κB gene expression with induction of Bcl-2 expression. In conclusion, TH could induce oxidative stress, inflammatory and neurobehavior impairment in rats. However, PMC NPs administration markedly mitigated TH-induced brain toxicity, possibly via oxidative and inflammatory modulation rather than using piracetam alone., (© 2023. The Author(s).)

Although pesticides are often discharged into surface waters in pulses as opposed to a sustained release, the effect of episodic pollution events on freshwater crayfish is largely unknown. We monitored change in heart rate and distance moved to assess the response of signal crayfish Pacifastacus leniusculus to short-term exposure to environmentally relevant concentrations of metazachlor (MTZ), terbuthylazine (TER), and thiacloprid (TCL). Crayfish exposed to 20 µg/L of MTZ exhibited a significant increase in mean heart rate and distance moved. Increased heart rate was detected at 118 ± 74 s post-exposure to MTZ. There were no significant differences in mean heart rate and distance moved in crayfish exposed to 6 µg/L of TCL and 4 µg/L of TER. A significant correlation between heart rate and distance moved was found in all exposed groups. These results suggest that pulse exposure to MTZ impact crayfish physiology and behavior during short-term period. With pulse exposure to TCL and TER, crayfish not exhibiting a locomotor response may continue to be exposed to lower, but potentially harmful, levels of pollutants. Evidence of the impacts of pesticide pulse at environmentally relevant concentrations on crayfish is scarce. Further study is required to determine the ecological effects of such events on freshwater crayfish., (© 2023. The Author(s).)

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.

In accordance with Article 43 of Regulation (EC) No 396/2005, the European Commission requested EFSA to assess whether existing maximum residue levels (MRLs) based on codex maximum residue limits (CXLs) and import tolerances for thiacloprid are safe for consumers in light of the lowered toxicological acute reference value established following the non-renewal of approval of the active substance thiacloprid. Based on the assessment, EFSA identified a potential acute concern for the CXL on peaches and sweet peppers. EFSA did not identify a consumer health risk for all the other remaining commodities of plant and animal origin., (© 2023 European Food Safety Authority. EFSA Journal published by Wiley‐VCH GmbH on behalf of European Food Safety Authority.)

[Display omitted] • MXene/MIL(Fe) with Fe-protoporphyrin bridging was applied as photo-Fenton catalyst. • Biomimetic Fe-protoporphyrin showed high O 2 -carrying capacity for H 2 O 2 generation. • Schottky barrier enhanced charge transfer and O 2 reduction for H 2 O 2 generation. • MXene/MIL(Fe)-POR exhibited 12 times higher H 2 O 2 production rate than MIL(Fe) • MXene/MIL(Fe)-POR showed 60 times higher TCL removal rate than reported catalysts. Efficient and deep degradation for organic contaminants in the absence of externally supplied H 2 O 2 is still a challenge and research hotspot for photo-Fenton catalysis. In this work, a novel Ti 3 C 2 MXene/MIL-100(Fe) hybrid via Fe-protoporphyrin bridging was proposed to in-situ generate H 2 O 2 for photo-Fenton catalytic degradation of thiacloprid (TCL). The generated Schottky junction between MXene and MIL-100(Fe) and biomimetic oxygen-carrying from Fe-protoporphyrin constructed a synergistic system to promote H 2 O 2 generation and photo-Fenton reaction. As expected, MXene/MIL-100(Fe) exhibited 12 times higher of H 2 O 2 generation rate (reaching 1175.2 μmol/L under air-bubble), and 24 times of degradation rate and 3.7 times of mineralization rate for TCL compared to MIL-100(Fe). In addition, MXene/MIL-100(Fe) possessed 21–60 times higher TCL degradation rate than many of reported photo-Fenton catalysts in H 2 O 2 -free system. MXene/MIL-100(Fe) realized > 80 % TOC removal of TCL (80 mg/L) within 120 min, and exhibited excellent catalytic stability (>97 % TCL degradation) for 10 successive reuses. [ABSTRACT FROM AUTHOR]

Due to worldwide production, sales and application, neonicotinoids dominate the global use of insecticides. While, neonicotinoids are considered as pinpoint neurotoxicants that impair cholinergic neurotransmission in pest insects, the sublethal effects on nontarget organisms and other neurotransmitters remain poorly understood. Thus, we investigated long-term neurological outcomes in the decomposer nematode Caenorhabditis elegans. In the adult roundworm the neonicotinoid thiacloprid impaired serotonergic and dopaminergic neuromuscular behaviors, while respective exposures to thiamethoxam showed no effects. Thiacloprid caused a concentration-dependent delay of the transition between swimming and crawling locomotion that is controlled by dopaminergic and serotonergic neurotransmission. Age-resolved analyses revealed that impairment of locomotion occurred in young as well as middle-aged worms. Treatment with exogenous serotonin rescued thiacloprid-induced swimming deficits in young worms, whereas additional exposure with silica nanoparticles enhanced the reduction of swimming behavior. Delay of forward locomotion was partly caused by a new paralysis pattern that identified thiacloprid as an agent promoting a specific rigidity of posterior body wall muscle cells and peripheral neuropathy in the nematode (lowest-observed-effect-level 10 ng/ml). On the molecular level exposure with thiacloprid accelerated protein aggregation in body wall muscle cells of polyglutamine disease reporter worms indicating proteotoxic stress. The results from the soil nematode Caenorhabditis elegans show that assessment of neurotoxicity by neonicotinoids requires acknowledgment and deeper research into dopaminergic and serotonergic neurochemistry of nontarget organisms. Likewise, it has to be considered more that different neonicotinoids may promote diverse neural end points. [Display omitted] • In C. elegans thiacloprid impaired serotonin- and dopamine-controlled locomotion. • Thiacloprid generated a new type of paralysis that represents peripheral neuropathy. • Thiacloprid-induced defects correlated with proteotoxic stress in body wall muscle cells. • Pre-treatment with serotonin counteracted thiacloprid-induced reduction of locomotion. • Silica nanoparticles added to thiacloprid-induced reduction of C. elegans fitness. [ABSTRACT FROM AUTHOR]

Abstract In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS), Belgium, compiled an application to modify the existing maximum residue level (MRL) for the active substance thiacloprid in Jerusalem artichokes. In order to accommodate for the intended use of thiacloprid Belgium proposed to raise the value of the existing MRL from the limit of quantification (LOQ) of 0.02 mg/kg to 0.05 mg/kg. Belgium drafted an evaluation report in accordance with Article 8 of Regulation (EC) No 396/2005, which was submitted to the European Commission and forwarded to EFSA. EFSA concludes to derive a MRL proposal of 0.05 mg/kg on Jerusalem artichokes by extrapolation of data from carrots. Adequate analytical enforcement methods are available to monitor the residues of thiacloprid on the commodity under consideration. Based on the risk assessment results, EFSA concludes that the proposed use of thiacloprid on Jerusalem artichokes will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk.

Background: Neonicotinoid insecticides (NNIs) have been routinely used in arable crop protection since their development in the early 1990s. These insecticides have been subject to the same registration procedures as other groups of pesticides, thus meet the same environmental hazard standards as all crop protection products. However, during the last 10 years the debate regarding their possible detrimental impact on non-target organisms, particularly pollinators, has become increasingly contentious and widely debated. Against this background, legislators and politicians in some countries, have been faced with a need to make decisions on the future registration of some or all of this class of insecticides, based on published evidence that in some areas is incomplete or limited in extent. This has created much concern in agricultural communities that consider that the withdrawal of these insecticides is likely to have significant negative economic, socio-economic and environmental consequences. Methods: The proposed systematic map aims to address the following primary question: What is the available evidence for the effects of neonicotinoids used in arable crop production on non-target organisms and concentrations of residues in relevant matrices? The primary question will be divided into two sub-questions to gather research literature for (1) the effect of NNIs on non-target organisms (2) the occurrence of concentrations of NNIs in matrices of relevance to non-target organisms (i.e. exposure routes). The systematic map will focus on NNIs used in arable crop production: imidacloprid, clothianidin, thiamethoxam, acetamiprid, thiacloprid and dinotefuran. Separate inclusion criteria have been developed for each sub-question. Traditional academic and grey literature will be searched for in English language and a searchable databases containing extracted meta-data from relevant included studies will be developed. [ABSTRACT FROM AUTHOR]

An efficient, high throughput and cost-effective direct aqueous injection approach for the analysis of neonicotinoid pesticides and a common metabolite in environmental water has been described here. The method determines eight neonicotinoid pesticides (acetamiprid, clothianidin, dinotefuran, flonicamid, imidacloprid, nitenpyram, thiacloprid, thiamethoxam) and 6-chloronicotinic acid (a common metabolite of the first generation neonicotinoids, acetamiprid, imidacloprid, nitenpyram and thiacloprid) without any sample enrichment/cleanup steps. The method detection limits are 2–8 ng/L for the neonicotinoids and 93 ng/L for 6-chloronicotinic acid. The performance of the QTRAP ® 5500 mass spectrometer was compared against a 4000QTRAP ® , and a QTRAP ® 6500, to provide insights for future method transfer among different generations of instrumentations. Critical mass spectrometric parameters such as collision energy were quite consistent among the three instruments evaluated. However, increased chemical background levels for some target compounds on the more sensitive instruments were observed. The application of differential ion mobility spectrometry combined with tandem mass spectrometry was demonstrated to have great potential in reducing chemical background and/or isobaric interferences inherited in sample matrices. This ISO 17025 accredited method was employed to quantitate neonicotinoids in Ontario stream water samples. Good correlation for analytical results of this direct aqueous injection approach and a previously published solid phase extraction approach warrant high confidence in data quality. [ABSTRACT FROM AUTHOR]

The present study was carried out to evaluate the hematological, biochemical, and histopathological changes due to thiacloprid toxicity, and the potential protective role of flaxseed oil in male Wistar albino rats. Subacute thiacloprid intoxication induced a significant increase in RBCs, Hb, PCV, and WBCs count, and bone marrow micronucleus (MN) formation. Moreover, there was a significant increase in serum biochemical parameters related to hepatic injury: alanine aminotransferase (ALT) and alkaline phosphatase (ALP). Serum total protein and albumin levels were significantly reduced. Thiacloprid increases tumor necrosis factor-alpha (TNF-α) and interleukine-2(IL-2). There was a significant decrease in glutathione-S-transferase, while the lipid peroxidation (MDA) and cytochrome P450 activity were significantly increased. Flaxseed oil coadministration partially retrieved the changes in all studied parameters. Thiacloprid induced histopathological liver damage, which was minimized as a result of flaxseed oil treatment. In general, it was concluded that, flaxseed oil able to protect against thiacloprid-induced hepatoxicity. [ABSTRACT FROM AUTHOR]

Honey bees, Apis mellifera, are markedly less sensitive to neonicotinoid insecticides containing a cyanoimino pharmacophore than to those with a nitroimino group. Although previous work has suggested that this results from enhanced metabolism of the former by detoxification enzymes, the specific enzyme(s) involved remain to be characterized. In this work, a pretreatment of honey bees with a sublethal dose of thiacloprid resulted in induced insensitivity to the same compound immediately following thiacloprid feeding. A longer pretreatment time resulted in no, or increased, sensitivity. Transcriptome profiling, using microarrays, identified a number of genes encoding detoxification enzymes that were over-expressed significantly in insecticide-treated bees compared with untreated controls. These included five P450s, CYP6BE1, CYP305D1, CYP6AS5, CYP315A1, CYP301A1, and a carboxyl/cholinesterase (CCE) CCE8. Four of these P450s were functionally expressed in Escherichia coli and their ability to metabolize thiacloprid examined by liquid chromatography-mass spectrometry (LC-MS) analysis. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS), Germany, compiled an application to modify the existing maximum residue level (MRL) for the active substance thiacloprid in honey. Germany proposed to raise the existing MRL from the limit of quantification of 0.05 mg/kg to 0.2 mg/kg. No guidance document for the setting of MRL in honey is currently available at EU level and therefore, in addition to the EMS evaluation, EFSA proposed additional alternative MRL values based on monitoring data. An MRL proposal of 0.2 mg/kg was derived from field trials where honey was collected in hives positioned close to rapeseed plots treated with thiacloprid. In addition MRLs of 0.15 and 0.2 mg/kg were derived considering data from national monitoring programs and the approaches recommended by the Food and Agriculture Organization (FAO). EFSA proposes to risk managers to decide which approach should be taken into account for the setting of an MRL in honey. Adequate analytical enforcement methods are available to control the residues of thiacloprid in honey. Based on the risk assessment results, EFSA concludes that the proposed MRLs of 0.15 or 0.2 mg/kg in honey will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk. [ABSTRACT FROM AUTHOR]

This article is concerned with the kinetics of the photocatalytic degradation of four neonicotinoids insecticides as active ingredients (AIs) in their commercial formulations by using the annular slurry reactor (ASR). For all AIs, more effective photodegradation was achieved by UVA than by visible light irradiation. The most efficient degradation was observed in the case of thiacloprid, which degraded completely after two hours of irradiation using UVA, and 59% using visible light irradiation. On the other hand, the most stable appeared to be acetamiprid, whereby during the same time of irradiation it was degraded 42% using UVA, and only 4% using visible light irradiation. Because of that the efficiency of a number of advanced oxidation processes was examined in the case of acetamiprid. It was found that the presence of H 2 O 2 in ZnO, 7.8Fe/ZnO, and 7.2Fe/TiO 2 systems using UVA did not bring significant changes in the efficiency of degradation. However, using visible light irradiation the presence of H 2 O 2 in ZnO and 7.8Fe/ZnO systems significantly increases efficiency of acetamiprid degradation. Also, by adjusting pH to 2.80 in the system 7.2Fe/TiO 2 /H 2 O 2 using both type of irradiation resulted in a significant increase of the degradation efficiency. For the first time, for ZnO/H 2 O 2 system a general reaction mechanism in the dark, as well as in the presence of visible light irradiation was proposed. The electrical energy consumption of ASR was estimated for the most efficient visible light irradiation system using the figure-of-merit electrical energy per order and compared with batch and laminar falling film slurry reactor. [ABSTRACT FROM AUTHOR]

Lysiphlebus fabarum Marshall is the main parasitoid of the black bean aphid, Aphis fabae Scopoli. Lethal and sublethal effects of insecticides, thiacloprid+deltamethrin, pirimicarb and pymetrozine were evaluated on the parasitoid under laboratory conditions. One-day-old mummies were exposed to the recommended field concentration of either insecticides via dipping method. Adult emergences were reduced by 82.67, 19.98 and 10.67 % for thiacloprid+deltamethrin, pirimicarb and pymetrozine treatments, respectively. Thiacloprid+deltamethrin had the most adverse effect on the fecundity of the emerged females, while pirimicarb and pymetrozine did not have such effects. According to International organization for biological control (IOBC) insecticide toxicity classification, thiacloprid+deltamethrin resulted to be moderately harmful (E = 97.39%), whereas pirimicarb (E = 15.78%) and pymetrozine (E = 5.15%) were harmless. Thiacloprid+deltamethrin negatively affected five of the estimated demographic parameters ( GRR, R , r, λ and T ). Pirimicarb negatively affected GRR, R and T, while it had no adverse effects on r and λ. None of the studied demographic parameters were affected by pymetrozine. Our results suggest that pirimicarb and pymetrozine can be considered as safe for L. fabarum, but that thiacloprid+deltamethrin can have serious detrimental of this parasitoid in the field. [ABSTRACT FROM AUTHOR]

Chemometric tools equipped with a Plackett–Burman (P–B) design, a central composite design (CCD) and a desirability profile were employed to optimise the QuEChERS (quick, easy, cheap, effective, rugged and safe) method for the quantification of thiacloprid, spirotetramat and spirotetramat’s four metabolites in pepper. The average recoveries were in the range of 71.6–119.5%, with relative standard deviations ⩽12.1%. The limit of quantification for the method was less than 0.01 mg/kg. The method was applied to field samples to evaluate the residual characteristics of thiacloprid and spirotetramat. The data showed that the first + first-order model is a better fit than the first order model for the dissipation of thiacloprid and spirotetramat in pepper. The half-lives of thiacloprid and spirotetramat in pepper are 0.81 and 1.21 days, respectively. The final residues were between 0.016 mg/kg and 0.13 mg/kg for thiacloprid and 0.08 mg/kg and 0.12 mg/kg for spirotetramat. [ABSTRACT FROM AUTHOR]

Cacopsylla pyricola(Förster) (Hemiptera: Psyllidae) is an important pest of commercial pear in all pear-growing regions of Iran. In the scope of an integrated pest management, a research was carried out on the impact of treatment with biorational compounds in comparison with conventional chemical insecticides for controlling the pear psyllid. The experiments were done with five treatments consisted of diflubenzuron and lufenuron as biorational insecticides and thiacloprid and diazinon as conventional chemical insecticides and untreated check. The trials were set up in a randomised complete block design. The treatments were replicated four times. Samplings were carried out one day before spraying and 3, 7, 15, 30 and 45 days after spraying through clipping 15 leaves in each replicate and counting the number of pear psyllid live nymphs. Mortality percentage was calculated using Henderson–Tilton formula. The data were subjected to analysis of variance (ANOVA) and the means comparison was performed using Duncan’s multiple range test. The results indicated that the highest mortality in diflubenzuron and lufenuron treatments occurred after 15 days, with 82.09% and 71.01% mortality, respectively. In comparison with conventional chemical insecticides, the efficacy of biorational compounds was higher or not significantly different. The results of the trials are discussed in terms of improving management of the populations of pear psylla. [ABSTRACT FROM PUBLISHER]

Mayfly nymphs are among the most sensitive taxa to neonicotinoids. The present study presents the acute and chronic toxicity of 3 neonicotinoids (imidacloprid, thiacloprid, and thiamethoxam) to a mayfly species (Cloeon dipterum) and some notes on the seasonality of the toxicity of imidacloprid to C. dipterum and 5 other invertebrate species. Imidacloprid and thiamethoxam showed equal acute and chronic toxicity to a winter generation of C. dipterum, whereas thiacloprid was approximately twice as toxic. The acute and chronic toxicity of imidacloprid was much higher for the C. dipterum summer generation than for the winter one. The acute toxicity differs by a factor of 20 for the 96-h 50% effective concentration (EC50) and by a factor of 5.4 for the chronic 28-d EC50. Temperature had only a slight effect on the sensitivity of C. dipterum to imidacloprid because we only found a factor of 1.7 difference in the 96-h EC50 between tests performed at 10 °C and 18 °C. The difference in sensitivity between summer and overwintering generations was also found for 3 other insect species. The results indicate that if the use and environmental fate of the 3 neonicotinoids are comparable, replacing imidacloprid by another neonicotinoid might not reduce the environmental impact on the mayfly nymph C. dipterum. The results also show the importance of reporting which generation is tested because sensitivity values of insects in the summer might be underestimated by the experiments performed with neonicotinoids and an overwintering population. [ABSTRACT FROM AUTHOR]

The binding of thiaclopride (THI), a neonicotinoid insecticide, with Aplysia californica acetylcholine binding protein ( Ac-AChBP), the surrogate of the extracellular domain of insects nicotinic acetylcholine receptors, has been studied with a QM/QM′ hybrid methodology using the ONIOM approach (M06-2X/6-311G(d):PM6). The contributions of Ac-AChBP key residues for THI binding are accurately quantified from a structural and energetic point of view. The importance of water mediated hydrogen-bond (H-bond) interactions involving two water molecules and Tyr55 and Ser189 residues in the vicinity of the THI nitrile group, is specially highlighted. A larger stabilization energy is obtained with the THI- Ac-AChBP complex compared to imidacloprid (IMI), the forerunner of neonicotinoid insecticides. Pairwise interaction energy calculations rationalize this result with, in particular, a significantly more important contribution of the pivotal aromatic residues Trp147 and Tyr188 with THI through CH···π/CH···O and π-π stacking interactions, respectively. These trends are confirmed through a complementary non-covalent interaction (NCI) analysis of selected THI- Ac-AChBP amino acid pairs. [ABSTRACT FROM AUTHOR]

Background & objectives: Due to ever growing insecticide resistance in mosquitoes to commonly used insecticides in many parts of the globe, there is always a need for introduction of new insecticides for the control of resistant vector mosquitoes. In this study, larvicidal and adulticidal efficacies of three neonicotinoids (imidacloprid, thiacloprid and thiamethoxam) were tested against resistant and susceptible populations of Anopheles stephensi Liston 1901, Aedes (Stegomyia) aegypti Linnaeus, and Culex quinquefasciatus Say (Diptera: Culicidae). Methods: Laboratory-reared mosquito species were used. Insecticide susceptibility tests were done using standard WHO procedures and using diagnostic dosages of insecticide test papers and larvicides. Adulticidal efficacy of candidate insecticides was assessed using topical application method and larval bioassays were conducted using standard WHO procedure. Results: The results of topical application on 3-5 day old female mosquitoes indicated that resistant strain of An. stephensi registered lower LC50 values than the susceptible strain. Among the three insecticides tested, thiacloprid was found more effective than the other two insecticides. Culex quinquefasciatus registered lowest LC50 for imidacloprid than the other two mosquito species tested. In larval bioassays, the LC50 values registered for imidacloprid were in the order of Cx. quinquefasciatus