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Journal of Economic Entomology Dec 2020The nutritional status of host plants can have direct impacts on herbivore physiology and insect-plant interactions. We investigated the effect of micronutrients,...
The nutritional status of host plants can have direct impacts on herbivore physiology and insect-plant interactions. We investigated the effect of micronutrients, including manganese, iron, zinc, and copper, on cucumber plant physiology, and on the biology and physiology of a strain of Aphis gossypii Glover selected over 12 generations to be resistant to pirimicarb. The micronutrient treatment increased the activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase in cucumber plants, and also increased levels of total phenolics, hydrogen peroxide, salicylic acid, and total chlorophyl, whereas malondialdehyde levels were unaffected. Pirimicarb-resistant cotton aphids that fed on micronutritient-amended cucumber plants expressed significantly decreased levels of acetylcholinesterase and detoxifying enzymes, specifically glutathione S-transferase, and carboxylesterase. Analysis of energy reserves in resistant A. gossypii fed on micronutritient-amended plants revealed decreases in the lipid and protein contents of aphids, whereas glycogen and carbohydrate contents showed no response. Resistant cotton aphids fed on micronutritient-amended plants showed significantly reduced fecundity, longevity, and reproductive periods, and a 1.7-fold reduction in pirimicarb LC50 compared with those fed on control plants. We conclude that micronutrient amendment negatively impacts the biological performance of insecticide-resistant cotton aphids, and diminishes their resistance to pirimicarb. Both direct effects on plant health, such as enhanced inducible defenses, and indirect effects on aphid fitness, such as reduced biological performance and detoxification abilities, were implicated. Therefore, optimization of micronutrient amendments could be a useful complement to other tactics for managing insecticide-resistant A. gossypii on cucumbers, and warrants exploration in other contexts.
Topics: Animals; Aphids; Carbamates; Cucumis sativus; Fertilization; Micronutrients; Pyrimidines
PubMed: 32964224
DOI: 10.1093/jee/toaa202 -
Food Chemistry: X Mar 2022Dynamics of pesticides decomposition in sweet cherry fruits at different technologies of long-term storage, ultra-low oxygen and modified atmosphere packing, and after...
Dynamics of pesticides decomposition in sweet cherry fruits at different technologies of long-term storage, ultra-low oxygen and modified atmosphere packing, and after post-harvesting application of 1-methylcyclopropen and ozone has been studied. We assumed that type of pesticide and fruit storage conditions may have a profound effect on pesticide residues content. Therefore, levels of residues after applying combinations of active ingredients including acetamiprid, boscalid, cyprodinil, fenhexamid, fenpyrazamine, fludioxonil, fluopyram, pyraclostrobin, pirimicarb, tebuconazole, thiacloprid, and trifloxystrobin were monitored. We found these contents below tolerated maximum residue limits when applied at recommended times and depended on period prior to withdrawal. Low contents of acetamiprid, boscalid, fenpyrazamine, thiacloprid, pirimicarb, and fludioxonil were found when fruit were stored in modified atmosphere packages. Ozone affected degradation of tebuconazole, pyraclostrobin, and cyprodinil. However, differences between storage regimens were not statistically significant (p ≥ 0.05). Kinetic of degradation was studied with fruits stored after treatment with 1-methylcyclopropen and ozone.
PubMed: 35499021
DOI: 10.1016/j.fochx.2021.100185 -
Pesticide Biochemistry and Physiology Jun 2024Sitobion miscanthi is a destructive wheat pest responsible for significant wheat yield losses. Pirimicarb, one of the most important representatives of N,...
Sitobion miscanthi is a destructive wheat pest responsible for significant wheat yield losses. Pirimicarb, one of the most important representatives of N, N-dimethylcarbamate insecticides, is widely used to control wheat aphids. In present work, heterozygous S431F mutation of acetylcholinesterase 1 (AChE1) was identified and verified in three pirimicarb-resistant S. miscanthi populations (two field populations (HA and HS, >955.8-fold) and one lab-selected population (PirR, 486.1-fold)), which has not been reported in S. miscanthi yet. The molecular docking results revealed that AChE1 containing the S431F mutation of S. miscanthi (SmAChE1) showed higher free binding energy to three insecticides (pirimicarb, omethoate, and methomyl) than wild-type AChE1 of S. miscanthi (SmAChE1). Enzyme kinetic and inhibition experiments showed that the recombinant SmAChE1 was more insensitive to pirimicarb and omethoate than the recombinant SmAChE1. Furthermore, two overexpression P450 genes (CYP6K1 and CYP6A14) associated with pirimicarb resistance of S. miscanthi were verified by RNAi. These results suggested both target alteration and enhanced metabolism contributed to high pirimicarb resistance of S. miscanthi in the field and laboratory. These findings lay a foundation for further elucidating the mechanism of pirimicarb resistance in S. miscanthi, and have important implications for the resistance management of S. miscanthi control.
Topics: Acetylcholinesterase; Animals; Insecticide Resistance; Aphids; Insecticides; Carbamates; Cytochrome P-450 Enzyme System; Mutation; Pyrimidines; Molecular Docking Simulation; Triticum; Dimethoate
PubMed: 38879339
DOI: 10.1016/j.pestbp.2024.105957 -
Polymers Jan 2023An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly...
An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) and gold nanoparticles (AuNPs) to enhance electrochemical proprieties. Electrode characterizations were performed using scattering electron microscopy (SEM) and cyclic voltammetry (CV). With the SPCE/PEDOT:PSS/AuNPs modified electrode, a new peak at 1.0 V appeared in the presence of PMC related to the PMC oxidation. To elucidate the mechanism of PMC oxidation, Gas Chromatography-Mass Spectrometry (GC-MS), where two major peaks were identified, evidencing that the device can both detect and degrade PMC by an electro-oxidation process. Exploring this peak signal, it was possible the sensor development, performing detection from 93.81-750 µmol L, limits of quantification (LOQ) and detection (LOD) of 93.91 µmol L and 28.34 µmol L, respectively. Thus, it was possible to study and optimization of PMC degradation, moreover, to perform detection at low concentrations and with good selectivity against different interferents using a low-cost printed electrode based on graphite modified with conductive polymer and AuNPs.
PubMed: 36772040
DOI: 10.3390/polym15030739 -
The Science of the Total Environment Feb 2022Greenhouse and other covered cultivation systems have increased globally over the past several decades, leading to considerably improved product quality and productivity...
Greenhouse and other covered cultivation systems have increased globally over the past several decades, leading to considerably improved product quality and productivity per land area unit. However, there is a paucity in information regarding the environmental impacts of covered production systems, especially regarding pesticides entering the surrounding environment. Aiming to address this knowledge gap, we collected grab samples downstream of greenhouses from seven Swedish streams every 14 days during a 12 month period. In three of the streams, samples were also taken upstream of the greenhouses and in four of the streams time-integrated samples were collected by TIMFIE samplers in the period between grab sampling occasions. The samples were analyzed for 28 substances (27 that were permitted for use in greenhouse production systems in Sweden and one degradation product to a permitted substance). Pesticide use journals were collected from the greenhouse producers for the 12 month period. The results were examined for indications of greenhouse contributions to detection frequencies, maximum and average concentrations, and potential ecotoxicicity in several ways: (1) comparing locations downstream of greenhouses with registered use of a substance with those without registered use, (2) comparing results from this study with those from the Swedish environmental monitoring program of pesticides in surface water from catchments with no greenhouses from the same period and region, (3) comparing concentration trends with registered pesticide application times in the greenhouses, and (4) comparing up- and downstream concentrations. The results strongly suggest that greenhouse applications do contribute to pesticide occurrences, maximum and median concentrations for most of the pesticides included in this study, and to potential toxicity to aquatic organisms for several of them, most notably imidacloprid, acetamiprid, carbendazim, and pirimicarb.
Topics: Environmental Monitoring; Pesticides; Sweden; Water Pollutants, Chemical
PubMed: 34890678
DOI: 10.1016/j.scitotenv.2021.152215 -
Environmental Science and Pollution... Mar 2022To determine the potential effects of pesticides on aquatic organisms inhabiting a realistic environment, we explored the characteristics and mechanisms of chemical...
To determine the potential effects of pesticides on aquatic organisms inhabiting a realistic environment, we explored the characteristics and mechanisms of chemical tolerance in Scapholeberis kingi(Cladocera). We established a chemical-tolerant population via continuous exposure to pirimicarb, an acetylcholinesterase (AChE) inhibitor, and examined the effects of pirimicarb concentration on the intrinsic growth rates (r) of tolerant cladocerans. We also explored the association between r and feeding rate and tested the involvement of antioxidant enzymes [peroxidase (PO) and superoxide dismutase] and AChE in pirimicarb sensitivity. S. kingi was continuously exposed to lethal and sublethal pirimicarb concentrations (0, 2.5, 5, and 10 µg/L) for 15 generations, and changes (half maximal effective concentration at 48 h, 48 h-EC) in chemical sensitivity were investigated. In the F14 generation, the sensitivity of the 10 µg/L group was three times lower than that of the control group, suggesting the acquisition of chemical tolerance. Moreover, r was significantly and negatively correlated with 48 h-EC, suggesting a fitness cost for tolerance. Surprisingly, there was no significant correlation between r and feeding rate. There was a weak but significant positive correlation between each enzyme activity and the 48 h-EC value (p < 0.05). Thus, oxidative stress regulation and enhanced AChE may be involved in the acquisition of chemical tolerance in cladocerans. These findings will help elucidate the characteristics and mechanisms of chemical tolerance in aquatic organisms.
Topics: Acetylcholinesterase; Animals; Cholinesterase Inhibitors; Cladocera; Pesticides; Water Pollutants, Chemical
PubMed: 34705208
DOI: 10.1007/s11356-021-17071-8 -
Food Chemistry Feb 2022A novel deep eutectic solvent-based extraction and sulfur-doped carbon quantum dots (S-CQDs) serving as fluorescence probes to detect pirimicarb in cereals were...
A novel deep eutectic solvent-based extraction and sulfur-doped carbon quantum dots (S-CQDs) serving as fluorescence probes to detect pirimicarb in cereals were established. The deep eutectic solvent was synthesized using choline chloride and butanediol, achieving direct and efficient extraction of pirimicarb residue in the cereals. The fluorescence quenching of S-CQDs was caused by the electrostatic interaction between the negatively charged S-CQDs and positively charged thiocholine, which was the hydrolysate of acetylthiocholine. The fluorescence of S-CQDs was enhanced as the activity of acetylcholinesterase (AChE) was inhibited by pirimicarb, achieving the detection of pirimicarb in the cereal samples. The limit of detection (LOD) was 0.006 μg mL. The recovery ranged from 96.6% to 108.2%. This extraction and detection method of pirimicarb based on an environmentally friendly DES and S-CQD fluorescent sensor maintains good stability and convenience, offering a promising strategy for extracting and testing harmful substances in food samples.
Topics: Acetylcholinesterase; Carbamates; Edible Grain; Pyrimidines; Quantum Dots; Solvents
PubMed: 34662796
DOI: 10.1016/j.foodchem.2021.131360 -
Journal of Environmental Science and... 2020We evaluated the real effects of pollutants through a multi-generation study. We tested whether short-term exposure (48 h) of successive (first and second) generations...
We evaluated the real effects of pollutants through a multi-generation study. We tested whether short-term exposure (48 h) of successive (first and second) generations of neonates (<24-h-old) to two acetylcholinesterase inhibitor insecticides, pyraclofos, and pirimicarb, would change insecticide sensitivity and life-cycle parameters over four generations. Additionally, we tested whether acetylcholinesterase (AChE) activity levels would be associated with this sensitivity change. Sensitivities (48 h EC value, using immobility as the endpoint) in chironomids (<24-h-old) and insect life-cycle parameters (the number of larvae per egg mass and adult size) were investigated. Parental chironomids produced larvae that were less sensitive than those in the control group following the two 48 h pirimicarb exposure events, whereas exposure to pyraclofos did not affect sensitivity. The AChE activity in larvae with low sensitivity to pirimicarb was significantly higher than that in the control. Thus, increased AChE activity might be associated with low sensitivity. The life-cycle parameters in chironomids recovered from the effects of pyraclofos and pirimicarb suggested they could adapt to the insecticides by changing biomass allocation. Our study suggested potential chemical risks of insecticide stress and how aquatic organisms adapt to it.
Topics: Adaptation, Biological; Animals; Carbamates; Chironomidae; Cholinesterase Inhibitors; Ecotoxicology; Insecticides; Larva; Organothiophosphates; Pyrimidines; Water Pollutants, Chemical
PubMed: 32065017
DOI: 10.1080/03601234.2019.1708165 -
Journal of Molecular Recognition : JMR Sep 2019This study aimed to prepare a novel quartz crystal microbalance (QCM) sensor for the detection of pirimicarb. Pirimicarb-imprinted poly (ethylene glycol...
This study aimed to prepare a novel quartz crystal microbalance (QCM) sensor for the detection of pirimicarb. Pirimicarb-imprinted poly (ethylene glycol dimethacrylate-N-metacryloyl-(l)-tryptophan methyl ester) [p (EGDMA-MATrp)] nanofilm (MIP) on the gold surface of a QCM chip was synthesized using the molecular imprinting technique. A nonimprinted p (EGDMA-MATrp) nanofilm (NIP) was also synthesized using the same experimental technique. The MIP and NIP nanofilms were characterized via Fourier transform infrared spectroscopy attenuated total reflectance spectroscopy, contact angle, atomic force microscopy, and an ellipsometer. A competitive adsorption experiment on the sensor was performed to display the selectivity of the nanofilm. An analysis of the QCM sensor showed that the MIP nanofilm exhibited high sensitivity and selectivity for pirimicarb determination. A liquid chromatography-tandem mass spectrometry method was prepared and validated to determine the accuracy and precision of the QCM sensor. The accuracy and precision of both methods were determined by a comparison of six replicates at three different concentrations to tomato samples extracted by using a Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method. The limit of detection of the QCM sensor was found to be 0.028 nM. In conclusion, the QCM sensor showed good accuracy, with recovery percentages between 91 and 94%. Also, the pirimicarb-imprinted QCM sensor exhibited a fast response time, reusability, high selectivity and sensitivity, and a low limit of detection. Therefore, it offers a serious alternative to the traditional analytical methods for pesticide detection in both natural sources and aqueous solutions.
Topics: Carbamates; Limit of Detection; Solanum lycopersicum; Molecular Imprinting; Nanoparticles; Polymers; Pyrimidines; Quartz Crystal Microbalance Techniques; Reproducibility of Results
PubMed: 31033053
DOI: 10.1002/jmr.2785 -
Environmental Monitoring and Assessment Jan 2023Pesticides are the potent agrochemicals used to successfully manage, repel, or stop pests and weeds in agricultural production. This study analyzed 222 pesticide active...
Pesticides are the potent agrochemicals used to successfully manage, repel, or stop pests and weeds in agricultural production. This study analyzed 222 pesticide active substances in 90 samples of seven different vegetables and fruits acquired from producers through liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) technology. The validation parameters of each pesticide's active substances were determined. The LOD, LOQ values, and recovery studies of the 222 active substances were 3.00, 10.00 ng/g, and between 76.07 and 108.08%, respectively. The correlation coefficients and measurement uncertainty were determined to be between 0.990-0.999 and 8.91-31.46%, respectively. There were active substances of chlorpyrifos, acetamiprid, azoxystrobin, difenoconazole, malathion, dieldrin, boscalid, triticonazole, tebuconazole, triadimenol, trifloxystrobin, pirimicarb, and dodine among the vegetable and fruit samples used in the study. There were no active substances in 55 (61%) samples. Among the 35 samples (39%), 31 samples (34%) contained only one active substance, whereas four (5%) contained two active substances. However, the amount of active substances in six (7%) samples was above the maximum residue levels (MRL) limits. Various processes used in the study revealed that peeling was the most effective pesticide residue removal strategy. The washing procedure also proved that it reduced some pesticide residues but failed to eliminate all pesticides. The peeling process successfully reduced a significant amount of the active substances from the products, however, residues remained. Washing the fruits with hot water was also effective in removing residues. As a result, analyses of the peeled sections yielded higher pesticide residue concentrations than those of the entire product.
Topics: Pesticide Residues; Tandem Mass Spectrometry; Fruit; Vegetables; Chromatography, Liquid; Gas Chromatography-Mass Spectrometry; Environmental Monitoring; Pesticides; Food Contamination
PubMed: 36609771
DOI: 10.1007/s10661-022-10910-2