Methomyl Residues Research Articles

Dissipation pattern and dietary risk assessment of chlorfenapyr and methomyl in corn under Egyptian field conditions.

Corn is the second most widely farmed grain for human consumption. Low corn productivity due to damage caused by pests has led to using pesticides to control pest infestations. However, the uncontrolled application of pesticides on corn harms both environmental and human health. Accordingly, field experiments followed good agricultural practices to investigate the dissipation pattern and terminal residues of chlorfenapyr and methomyl in corn and compare the values with established safety limits. Gas chromatography-tandem mass spectrometer coupled with the quick, easy, cheap, effective, rugged, and safe technique was used to analyze residues of chlorfenapyr and methomyl in corn. The average recoveries varied from 94% to 105%, with relative standard deviations (RSDs) of 8%-13% for chlorfenapyr and from 99% to 111%, with RSDs of 10-16% for methomyl. Chlorfenapyr and methomyl residues degraded in corn following a first-order kinetic model, with an estimated half-life (t1/2) of 3.9 and 2.8days, respectively, and significant degradation (91.4%-98.1.5%, respectively) after 14 days. Although the maximum residue limits of chlorfenapyr and methomyl for corn are yet to be formulated in Egypt, the long-term dietary risk for those pesticides was acceptable, with arisk quotient < 100%, according to the national assessments. These findings are required to guide the correct and safe application of these insecticides in Egypt.

Pathological and biochemical investigation of the effects of Silybum marianum against Methomyl damage in broiler liver

This study was aimed to investigate the protective/preventive and/or curative effects of Silybum marianum seed powder against Methomyl toxication by examining some biochemical parameters and pathological changes hepatic in broiler chicks fed with feeds supplemented with Methomyl and S. marianum seed powder. For this purpose, 4 different groups, each containing 32 animals, were used; Control group (CONT), Methomyl group (MET), S. marianum seed powder group (SMT) and Methomyl + S. marianum seed powder group (MET+SMT). In the study, Methomyl was added to the feeds as 20 ppm and S. marianum seed powder as 10 g·kg-1. The trial period was planned as 28 days, and necropsies of animals from each group were performed daily, and samples were taken for histopathology and biochemistry. In the study, liver enzyme activities and liver tissue oxidative stress markers GPx, MDA and SOD values were found to be similar in the CONT and SMT groups, but statistically higher in the MET group. In the MET+SMT group, the increased parameters were lower than the MET group. The histopathological examinations of liver sections, hyperemia, hemorrhage, hydropic degeneration and fatty changes of hepatocytes, focal necrosis, dissociation of remark cords, mononuclear cell infiltration in the portal area and bile ducts hyperplasia were detected. It has been observed that S. marianum given for preventive/healing purposes reduces histopathological damage and contributes positively in all groups. It has been concluded that S. marianum can be added to poultry diets against Methomyl residues or contamınatıons according to thıs study.

Removal of Pesticide Residues in Aqueous Solution by Adsorption Using Pineapple Peel Activated Carbon

The use of synthetic pesticides in crop protection generates dilute pesticide solution resulting from the cleaning of pesticide application equipment, also known as pesticide rinsate. If not disposed or treated properly, this may result to the contamination of surface water or groundwater. One of the possible management practices for pesticide rinsate is the use of activated carbon as an adsorbent. Activated carbon was prepared from pineapple peel using phosphoric acid through chemical activation. Characterization of the surface morphology through Scanning Electron Microscopy (SEM) confirmed the successful activation of the carbon. The resulting Pineapple Peel Activated Carbon (PPAC) was utilized as adsorbent in the removal of the carbamate methomyl in the pesticide rinsate. Analysis of the cleaned rinsate using a High-Performance Liquid Chromatograph confirmed the removal of 96.0-98.4% of methomyl residues in a 7.5 mg L-1 methomyl pesticide rinsate using a 0.5-1.0% w/v PPAC:rinsate ratio. This study showed that activated carbon could be successfully prepared from pineapple peel and used as an effective adsorbent for the remediation of pesticide rinsate to prevent the pollution of surface water or groundwater.

Dissipation of methomyl residues in tomato fruits, soil and water using LC-MS/MS

Dissipation of methomyl residues in tomato fruits, soil and water using LC-MS/MS

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions.

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions.

Immunochromatographic assay for the analysis of methomyl in cabbage and tomato

In this study, a hapten of methomyl was designed and used to produce monoclonal antibodies (mAbs) against methomyl. Based on these mAbs, we developed an enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay (ICA) strip for the determination of methomyl residues. Results from the ELISA showed that mAb 1D10 exhibited higher affinity with an affinity constant of 2.76 × 1010 L/mol and higher sensitivity with a limit of detection (LOD) was 8.12 ng/mL. After optimizing the ICA, a visible limit of detection (vLOD) was found to be 100 ng/g and the cut-off value was 500 ng/g for methomyl in cabbage and tomato. The calculated LODs were 3.2 ng/g and 5.4 ng/g in cabbage and tomato, respectively. Moreover, results from the ICA were consistent with those of the ELISA in our recovery assay using spiked samples. Hence, the ICA method has a bright future and great prospects for the detection of methomyl in food samples.

Monitoring of Pesticide Residues in Lebanese Vegetables and Agricultural Soils and Their Impact on Soil Microbiological Properties

The practice of pesticide application in agriculture done in Lebanon deviate from standard agricultural disciplines, raising awareness of their contamination of soil and vegetables as well as their repercussions on microbial communities. To this end, soil and vegetable samples from different pesticide-treated sites were quantified for chlorpyrifos (C) and methomyl (M) residues using Gas Chromatography-Mass Spectrometry. Moreover, clear soil specimens were treated with different concentrations of C, M, and CM assortment to assess their repercussion on the microbial population. High pesticide concentrations were recovered ranging between 31.13 and 53.74 mg/kg in eight agricultural fields, which abate gradually with time. After 20 days of pesticide implementation, their residues were above the maximum residual levels for lettuce, cabbage, tomato, and corn. Soil altered with pesticides showed fluctuation in its microbial community by suppressing some groups while favouring the propagation of tolerant species. Our data indicate the need for the requirement of strict laws to minimise pesticide usage and reduce their impact on soil quality, human health, and non-target organisms.

Engineering ZIF-8 Hybridization by Extracted Lignin with Antibacterial Property for Uptake of Methomyl Residues from Wastewater

ABSTRACT The hybridization between lignin and ZIF-8 and the removal of methomyl insecticides from wastewater was studied. Fourier-Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) were used to confirm the compounds. The effect of variables such as adsorbent dosage and contact time on the methomyl removal efficiency was investigated. The optimized condition dosage was 1 g L−1 at speed = 300 rpm, 300 min, and the pesticide concentration was 200 mg L−1 at room temperature (25°C) and pH = 7. The SEM and FTIR were used to thoroughly examine the reaction mechanism. Kinetic and isotherm parameters were precisely matched to the Langmuir and pseudo-second order models. The adsorption capacity in 60% ZIF-8@Lignin approached 324.6 mg g−1 which was significantly higher than that of lignin alone. Compared to other studies, the current study demonstrated superior adsorption capacity and cost-effectiveness. Antimicrobial testing confirmed that adding ZIF-8 to lignin enhanced the microbial activity and the minimum inhibitory concentration (MIC) value. The lowest values against all tested microbial strains were 19 mg mL−1.

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions.

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions.

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions.

Estimation of effectiveness and residues of pyridalyl, methomyl, emamectin-benzoate and lufenuron against (Spodotera Littoralis) on tomato fruits under field conditions.

Ambient moisture causes methomyl residues on corn plants to rapidly lose toxicity to the pest slug, Arion subfuscus, Müller (Gastropoda, Stylommatophora)

The carbamate insecticide methomyl is sometimes used to control slugs in field corn and soybean by foliar applications, but control outcomes in research trials and commercial operations have been mixed. In this study, laboratory bioassays were conducted on dusky slug, Arion subfuscus Müller, a common pest of corn and soybean in the Mid-Atlantic United States, to evaluate residual toxicity of Lannate LV (methomyl) at low and high concentrations corresponding to label recommended field rates, and if toxicity may be affected by ambient moisture or repellency to treated plants. Without wetting events, methomyl residues on corn plants caused 90–100% mortality of A. subfuscus for two days and 70–90% mortality for six days. When corn plants were briefly misted with ca. 0.3 cm of water 6 h after methomyl application, mortality was 36% 12 h after treatment, and 0 to 5% 24 h after treatment for both low and high rates. Repellency of A. subfuscus to corn plants treated with the high rate of methomyl was narrowly significant (P = 0.04) and low rate was not significant. These results suggest that high ambient moisture needed to elicit slug activity in the field also abates toxicity of methomyl residues, explaining why field control is usually poor despite high mortality in the lab.

Microbial Detoxification of Dimethoate and Methomyl Residues in Aqueous Media

The extensive and random application of major organic pollutants, mainly pesticides, threatens ecosystems and human health. The present study was conducted to isolate and identify microorganisms from some water resources contaminated with pesticides. We investigated the ability of the identified microbes to grow in water spiked with dimethoate and methomyl. We also evaluated the potential effect of the identified microbial isolates on dimethoate and methomyl biodegradation in water. In addition, the total detoxification of dimethoate and methomyl residues in water after treatment with the most effective microbial isolates was confirmed using toxicity tests and analyzing biochemical parameters and histopathological changes in the kidney and liver of treated rats. The microbial isolates were identified as Xanthomonas campestris pv. Translucens and Aspergillus fumigates. Results showed that X. campestris pv. Translucens and A. fumigatus grow in media supplemented with dimethoate and methomyl faster than in other media without both pesticides. About 97.8% and 91.2% of dimethoate and 95% and 87.8% of methomyl (initial concentration of both 5 mg L−1) were biodegraded within 32 days of incubation with X. campestris pv. Translucens and A. fumigatus, respectively. There was no remaining toxicity in rats treated with dimethoate- and methomyl-contaminated water with respect to biochemical parameters and histopathological changes. Collectively, the identified bacterial isolate showed high potential for the complete degradation of dimethoate and methomyl residues in water.

Determination of Methomyl Residues in Bohe by Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS).

The aim of this work is to investigate the presence of methomyl pesticide residue and the rate of disappearance in mint cultivated in the aquaponics system based on the application of UPLC-MS to establish a safety time interval before crop harvesting. Results showed that an effective and sensitive method based on UPLC-MS has been used for the determination of methomyl pesticide residues in mint. The initial residue level was much higher in roots (79.52 μg/kg), and it can be decreased to 16.73 (after 15 days) μg/kg and 3.31 (20 days) μg/kg, while the least was detected on the mix leaves and stems (44.54 μg/kg), and it can be decreased to 15.35 (after 20 days). In our case, we suggest that a safety interval in the range of 15–20 days should be allowed after the detection of methomyl in water, and the concentration of methomyl was lower than the acceptable daily intake (ADI) of the China Food and Drug Administration (CFDA) (20 μg/kg).

Reduction of methomyl and acetamiprid residues from tomatoes after various household washing solutions

ABSTRACTThe removal of pesticide residues is essential in order to control and reduce the harmful effects of pesticides commonly used in agriculture. The aim of this study was to investigate the effectiveness of 18 different household washing solutions for the reduction of methomyl and acetamiprid residues from tomatoes. These basic household solutions were used to prepare washing solution to remove pesticides. During this study, tomatoes were divided into two groups: in the first group, tomatoes were treated with the pesticides and the second group was washed with household solutions (distilled water, acetic acid, sodium chloride, ethanol, sodium bicarbonate, hydrogen peroxide, sodium hypochlorite, and liquid soap, lemon juice, mineral water, zam-zam water, whey, milk, and their combinations) after treating with pesticides. The pesticides residues in all samples were extracted by the QuEChERS technique, analyzed by LC-MS/MS. The results showed significant reduction in residues of all washed groups compared with the control (p < 0.01). Acetic acid, sodium chloride+sodium bicarbonate, zam-zam water, acetic acid+sodium chloride, sodium hypochlorite, milk, acetic acid+sodium chloride+sodium bicarbonate, liquid whey, liquid soap, lemon juice, ethanol, and sodium bicarbonate were found to remove more than 50% of both pesticide residues. The effectiveness of washing solutions was different for every type of pesticide. In the same way, blend of washing solutions has shown a synergetic effect on the removal of pesticides and was more effective compared to one solution. This research has raised the potential use of household solutions easily found at home that could be used to remove pesticide residues.

The consequences of sublethal exposure to insecticide on the survivorship and mobility of Halyomorpha halys (Hemiptera: Pentatomidae).

The direct lethal effects of conventional and organic insecticides have been investigated thoroughly for all life stages of Halyomorpha halys. However, the sublethal effects of insecticides on the behavior of H. halys have not been well documented. Our aims were to evaluate the impact of a brief 5 min exposure to residues of bifenthrin, dinotefuran, methomyl, thiamethoxam and thiamethoxam + λ-cyhalothrin on survivorship, horizontal and vertical movement, and flight capacity of adult H. halys under laboratory conditions. Over half of the insecticide-exposed adults were classified as affected, moribund or dead after the 5 min exposure, compared with only 6% of the adults in the water-only control. We found that the horizontal movement, vertical climbing and flight capacity of adults exposed to insecticides were decreased by 20-60% overall relative to the water-only control. The most lethal insecticide was bifenthrin. Many insecticide-exposed H. halys adults retained significant mobility and flight capacity, with flight most pronounced immediately after exposure. These results suggest that brief exposure periods to efficacious insecticides will result in high dispersal and low mortality. Therefore, management strategies that enhance the retention of H. halys on insecticide-coated surfaces should be considered to ensure that adults are exposed to a lethal dose of insecticide. © 2016 Society of Chemical Industry.

Degradation profile and safety evaluation of methomyl residues in tomato and soil

Summary A high performance liquid chromatography with the photodiode array detector (HPLCDAD) analytical method was developed to determine the residue levels and investigate the dissipation pattern and safety use of methomyl in tomato and soil. Methomyl residues were extracted from tomato and soil samples with ethyl acetate. The extract was cleaned up with the QuEChERS method. The results showed that the average recoveries were in the range of 87.1-94.5%, with RSD of 6.9-11.2%. Limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.007 mg/kg, respectively. The residue levels of methomyl were best described to first order rate kinetics and half-lives ranged from 1.34 to 1.8 days in tomato and soil, respectively. The theoretical maximum residue contributions for methomyl on tomato were found to be less than the maximum permissible intake values even on zero days, therefore consumer health risks are minimal at the recommended dose on tomato.

Pachycrepoideus vindemmiae(Hymenoptera: Pteromalidae) as a Potential Natural Enemy of Maize-Infesting Ulidiidae

Euxesta annonae Fabricius, E. eluta Loew, E. stigmatias Loew, and Chaetopsis massyla Walker (Diptera: Ulidiidae) are primary sweet corn pests in Florida. Few natural enemies of these flies are known. The pupal parasitoid Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) was discovered in a laboratory colony of E. eluta and E. stigmatias, and its potential as a biological control agent was studied. Development times in fresh, chilled, and frozen E. eluta pupae were recorded. Fly larvae were allowed to dig into soil to pupate, and pupae covered by 2.5 cm of soil were presented to wasps to determine if P. vindemmiae could locate them. Finally, to evaluate susceptibility to insecticides commercially used in ear-stage sweet corn, adult parasitoids were caged on maize leaves treated with chlorpyrifos, methomyl, or zeta cypermethrin for 24 h. Pachycrepoideus vindemmiae completed development in normal, chilled, and frozen fly pupae in 15–17 days. None of the fly pupae covered by soil were parasitized. Chlorpyrifos and methomyl residues killed >95% of P. vindemmiae within 24 h. Zeta cypermethrin was slower acting, but resulted in 50% mortality after 24 h. Therefore, P. vindemmiae does not appear to be well suited as an effective biological control agent of maize-infesting Ulidiidae in sweet corn fields. This is the first known account of this cosmopolitan parasitoid attacking maize-infesting ulidiids.

Insecticide residues in head lettuce, cabbage, Chinese cabbage, and broccoli grown in fields.

The residues of four insecticides belonging to different families were studied on head lettuce (Lactuca sativa L. var. capitata L.), cabbage (Brassica oleracea Linn. var. capitata DC.), Chinese cabbage (Brassica pekinensis Skeels), and broccoli (Brassica oleracea var. italica) after pesticide application. To reduce application variability, a tank mix of acetamiprid 20% SP, chlorpyrifos 22.5% EC, deltamethrin 2.4% SC, and methomyl 40% SP was applied at recommended and double doses. Initial deposits of all pesticides on head lettuce were higher than those of the other three crops. The residues of chlorpyrifos and deltamethrin were higher than the maximum residue limits (MRLs) at recommended preharvest intervals (PHIs) on head lettuce and Chinese broccoli treated with higher doses. The residues of methomyl on head lettuce also showed the same phenomenon.