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Parasitology Research Mar 2024Musca domestica Linnaeus is a devastating insect pest of medical and veterinary importance with reports of resistance development to commonly used insecticides...
Musca domestica Linnaeus is a devastating insect pest of medical and veterinary importance with reports of resistance development to commonly used insecticides worldwide. Rearing substrates usually play a crucial role in determining susceptibility to insecticides and control of insect pests. The aim of the present study was to investigate the effect of five rearing substrates of M. domestica on its susceptibility to different insecticides and activities of metabolic enzymes. After 30 generations of rearing, susceptibility of M. domestica to tested insecticides, viz., malathion, pirimiphos-methyl, alpha-cypermethrin, deltamethrin, methomyl, propoxur, spinetoram, and chlorfenapyr had evident differences. Musca domestica reared on hen liver exhibited reduced susceptibility to all insecticides followed by the strain reared on poultry manure. However, M. domestica reared on milk-based diet showed the highest susceptibility to tested insecticides followed by the strain reared on manures of buffalo and horse. In addition, M. domestica reared on different substrates exhibited significant differences (p < 0.01) in the activities of glutathione S-transferase (GST), cytochrome P450-dependent monooxygenase, and carboxylesterase (CarE). Overall, hen liver and poultry manure strains exhibited higher activities of metabolic enzymes than those of the milk-based diet, buffalo, and horse manure strains. In conclusion, the data of the present study exhibited a significant effect of rearing substrates on the susceptibility to insecticides and activities of metabolic enzymes in M. domestica. These results could be helpful for the sustainable management of M. domestica on different hosts by selecting appropriate insecticides.
Topics: Animals; Female; Horses; Insecticides; Houseflies; Manure; Buffaloes; Chickens; Insecticide Resistance
PubMed: 38459281
DOI: 10.1007/s00436-024-08180-7 -
Ecotoxicology (London, England) Mar 2024The use of insecticides in agricultural settings often exerts negative effects on nontarget species. Methomyl, a broad-spectrum carbamate insecticide, is recommended to...
The use of insecticides in agricultural settings often exerts negative effects on nontarget species. Methomyl, a broad-spectrum carbamate insecticide, is recommended to manage a number of insect pests of the cotton crop. Recently, Musca domestica, which is a nontarget insect species in cotton fields, has shown resistance to methomyl in Pakistan. The present study tried to assess resistance-risk assessment, rapidity of resistance development to methomyl, cross-resistance potential to other insecticides, resistance heritability and to forecast the projected rate of resistance development under field conditions. For this purpose, a field strain of M. domestica with 186 fold resistance to methomyl was re-selected in the laboratory for eight consecutive generations. Consequently, LD values increased rapidly (126.64 ng/fly to 3112.79 ng/fly) compared to those before selection experiments. Similarly, RR values increased from 186 to 3113 fold as a result of the selection process. However, resistance to methomyl did not remain stable when the selected strain (Meth-SEL) reared for the next five generations in a pesticide free environment. The Meth-SEL strain also developed cross-resistance to permethrin. The realized heritability (h) value for the Meth-SEL strain was 0.39 with 27% average mortality of M. domestica. Assuming the standard deviation (σp) value 0.27 and the h value 0.39 for eight generations of continuous exposure to methomyl, then five, seven, eight, ten and twelve generations at 90, 80, 70, 60 and 50% selection intensity, respectively, would be required for a tenfold increase in the LD value of methomyl. In conclusion, the Meth-SEL strain of M. domestica exhibited a high risk of resistance development to methomyl under continuous selection pressure. Resistance increased rapidly during selection experiments that reflect the probability of resistance development under field conditions if M. domestica receive exposures to methomyl during its applications for the management of target pest species.
Topics: Animals; Houseflies; Insecticides; Methomyl; Permethrin; Risk Assessment; Insecticide Resistance
PubMed: 38424316
DOI: 10.1007/s10646-024-02742-2 -
The Science of the Total Environment Apr 2024Pesticide active ingredients (PAIs) are one of the main contributors affecting water quality in the Great Barrier Reef Catchment Area (GBRCA). While an extensive list of...
Derivation of species sensitivity distributions and ecotoxicity threshold values for 66 pesticide active ingredients and the hazard and risk they pose to freshwater waterways that discharge to the Great Barrier Reef, Australia.
Pesticide active ingredients (PAIs) are one of the main contributors affecting water quality in the Great Barrier Reef Catchment Area (GBRCA). While an extensive list of pesticides is monitored in the GBRCA, only a limited number have water quality guideline values (WQGs), meaning it is not possible to know whether these PAIs are present at concentrations that may pose a hazard to the aquatic environment. In the current study, we derived 66 ecotoxicity threshold values (ETVs) for PAIs, the equivalent of WQGs, with a focus on PAIs applied to sugar cane. The hazard posed by PAIs monitored as part of the Great Barrier Reef Catchment Loads Monitoring Program (GBRCLMP) was assessed by comparing the derived ETVs with monitoring data from 2016/2017 to 2021/2022. The derived ETVs included herbicides, insecticides and fungicides, with the values that should protect 99 or 95 % of aquatic species (PC99 or PC95) spanning nine orders of magnitude. The concentrations of 10 PAIs exceeded their respective ETVs, giving a hazard quotient (HQ) >1. Of particular concern were insecticides chlorpyrifos, diazinon and methomyl, which have maximum HQ values >10. However, joint probability plots indicated that the PAIs generally pose a low risk to the aquatic environment, with most samples below the limit of reporting. As PAIs are predominantly found in mixtures in the GBRCA, the hazard posed by PAI mixtures was assessed by summing all individual HQ values in a sample for all PAIs with an ETV or WQG. On average, the insecticide active ingredient imidacloprid and herbicide active ingredients metolachlor, metsulfuron methyl, diuron and imazepic were the drivers of combined mixture hazard. Methomyl was an important contributor at some sites, suggesting that this pesticide should be considered for inclusion in any future PAI mixture hazard and/or risk assessment of the GBRCA.
Topics: Pesticides; Insecticides; Methomyl; Water Pollutants, Chemical; Environmental Monitoring; Herbicides; Fresh Water; Australia
PubMed: 38365043
DOI: 10.1016/j.scitotenv.2024.170988 -
Pest Management Science Apr 2024The stingless bee, Trigona spinipes, is an important pollinator of numerous native and cultivated plants. Trigona spinipes populations can be negatively impacted by...
BACKGROUND
The stingless bee, Trigona spinipes, is an important pollinator of numerous native and cultivated plants. Trigona spinipes populations can be negatively impacted by insecticides commonly used for pest control in crops. However, this species has been neglected in toxicological studies. Here we observed the effects of seven insecticides on the survival of bees that had fed directly on insecticide-contaminated food sources or received insecticides via trophallactic exchanges between nestmates. The effects of insecticides on flight behavior were also determined for the compounds considered to be of low toxicity.
RESULTS
Imidacloprid, spinosad and malathion were categorized as highly toxic to T. spinipes, whereas lambda-cyhalothrin, methomyl and chlorfenapyr were of medium to low toxicity and interfered with two aspects of flight behavior evaluated here. Chlorantraniliprole was the only insecticide tested here that had no significant effect on T. spinipes survival, although it did interfere with one aspect of flight capacity. A single bee that had ingested malathion, spinosad or imidacloprid, could contaminate three, four and nineteen other bees, respectively via trophallaxis, resulting in the death of the recipients.
CONCLUSION
This is the first study to evaluate the ecotoxicology of a range of insecticides that not only negatively affected T. spinipes survival, but also interfered with flight capacity, a very important aspect of pollination behavior. The toxicity of the insecticides was observed following direct ingestion and also via trophallactic exchanges between nestmates, highlighting the possibility of lethal effects of these insecticides spreading throughout the colony, reducing the survival of non-foraging individuals. © 2023 Society of Chemical Industry.
Topics: Humans; Bees; Animals; Insecticides; Hymenoptera; Malathion; Neonicotinoids; Eating; Nitro Compounds
PubMed: 38158650
DOI: 10.1002/ps.7956 -
Journal of Experimental Zoology. Part... Apr 2024The present study aimed to unravel the possible adverse effects of methomyl on the developing adrenal gland of rat fetuses and pups. Additionally, this study explored...
The present study aimed to unravel the possible adverse effects of methomyl on the developing adrenal gland of rat fetuses and pups. Additionally, this study explored the potential improving effects of propolis against these possible hazards induced by methomyl exposure. To achieve that, pregnant rats were divided into four groups: control group, received 1 mL distilled water, propolis group, received 1 mL propolis at a dose of 300 mg/kg, methomyl group, received 1 mL methomyl at a dose of 2 mg/kg, and combined group, received 1 mL methomyl followed by 1 mL propolis, an hour later at the same previous doses. The results revealed that methomyl exposure, during pregnancy and lactation, induced many histological and ultrastructural changes, caused DNA damage and downregulated the expression of steroidogenic acute regulatory (StAR) and CYP11B2 genes in the adrenal glands of both rat fetuses and pups. Interestingly, propolis supplementation demonstrated a remarkable ability to mitigate these deleterious effects and restored the histology and ultrastructure architecture of the adrenal glands of both fetuses and pups, as well as decreased DNA damage and upregulated the expression of StAR and CYP11B2 genes in the adrenal gland of rat fetuses and pups. In conclusion, our study highlights the potential hazardous impact of methomyl exposure during pregnancy and lactation on the development of the adrenal gland in rat fetuses and pups, moreover, the study presents a new approach to alleviate these effects through propolis administration which could be used as a dietary supplement to mitigate the adverse effects of methomyl exposure.
Topics: Pregnancy; Female; Rats; Animals; Methomyl; Propolis; Cytochrome P-450 CYP11B2; Adrenal Glands; Fetus; Dietary Supplements
PubMed: 38155514
DOI: 10.1002/jez.2777 -
Environmental Science and Pollution... Jan 2024This study aimed to investigate the presence of pesticide residues in a variety of commonly consumed leafy vegetables, including Grape leaves, Lettuce, Arugula, Spinach,...
This study aimed to investigate the presence of pesticide residues in a variety of commonly consumed leafy vegetables, including Grape leaves, Lettuce, Arugula, Spinach, Purslane, Ocimum, Parsley, Jew's mallow, Celery, Coriander, and Mint. A total of 100 samples were collected from the Central Market of Jeddah, Kingdom of Saudi Arabia. Our methodology involved employing the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction method in combination with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) to analyze a comprehensive database of 237 distinct pesticides. The range for limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.0001 to 0.0014 mg. Kg and 0.0010 to 0.0064 mg. Kg for tested pesticides, respectively. The recoveries were in the range of 70-172.9%, with a relative standard deviation (RSD) of less than 19.0% for all tested pesticides. The results revealed that 60% of the analyzed samples were free from pesticide residues, while 40% exhibited contamination with 17 different pesticide residues. Notably, the most prevalent pesticide detected was Triallate in the Ocimum samples, followed by Metalaxyl in Grape leaves, Mint, and Spinach, and Methomyl in Celery. Approximately 45% of the samples contained pesticide residues that fell below or were equal to the European Union Maximum Residue Levels (EU MRLs), while the remaining 55% exceeded these MRLs. Remarkably, high pesticide concentrations were observed in all Ocimum samples (Triallate, Pyridaben, Hexythiazox, Imidacloprid), 67% of Grape leaves (Metalaxyl, Azoxystrobin, Difenoconazole Isomer), and 40% of Celery (Azoxystrobin, Methomyl). In conclusion, this study sheds light on the contamination levels of commonly consumed domestically produced and purchased leafy vegetables in the Central Market of Jeddah. To ensure food safety and the well-being of consumers, we strongly recommend enhanced scientific assessments and continued monitoring of pesticide usage in agricultural practices.
Topics: Pesticide Residues; Vegetables; Chromatography, Liquid; Saudi Arabia; Methomyl; Triallate; Tandem Mass Spectrometry; Food Contamination; Pesticides; Strobilurins; Pyrimidines
PubMed: 38147241
DOI: 10.1007/s11356-023-31694-z -
The Science of the Total Environment Feb 2024Our study assessed whether banning specific insecticides to reduce the PD burden in three Central California (CA) counties is cost-effective.
BACKGROUND
Our study assessed whether banning specific insecticides to reduce the PD burden in three Central California (CA) counties is cost-effective.
METHOD
We applied a cost-effectiveness analysis using a cohort-based Markov model to estimate the impact and costs of banning seven insecticides that were previously associated with PD in these counties as well as mixture exposures to some of these pesticides. We relied for our estimations on the cohort of 65- and 66-year-olds living in these counties who were unaffected by PD at baseline in 2020 and projected their incidence, costs, and reduction in quality-adjusted-life-years (QALY) loss due to developing PD over a 20-year period. We included a shiny app for modeling different scenarios (https://sherlockli.shinyapps.io/pesticide_pd_economics_part_2/).
RESULTS
According to our scenarios, banning insecticides to reduce the occurrence of PD in three Central CA counties was cost-effective relative to not banning insecticides. In the worst-case scenario of exposure to a single pesticide, methomyl, versus none would result in an estimated 205 (95 % CI: 75, 348) additional PD cases or 12 % (95 % CI: 4 %, 20 %) increase in PD cases over a 20-year period based on residential proximity to pesticide applications. The increase in PD cases due to methomyl would increase health-related costs by $72.0 million (95 % CI: $5.5 million, $187.4 million). Each additional PD patient due to methomyl exposure would incur $109,327 (95 % CI, $5554, $347,757) in costs per QALY loss due to PD. Exposure to methomyl based on workplace proximity to pesticide applications generated similar estimates. The highest PD burden and associated costs would be incurred from exposure to multiple pesticides simultaneously.
CONCLUSION
Our study provides an assessment of the cost-effectiveness of banning specific insecticides to reduce PD burden in terms of health-related QALYs and related costs. This information may help policymakers and stakeholders to make decisions concerning the regulation of pesticides.
Topics: Humans; Parkinson Disease; Insecticides; Cost-Effectiveness Analysis; Methomyl; Pesticides; California; Cost-Benefit Analysis
PubMed: 38042187
DOI: 10.1016/j.scitotenv.2023.168913 -
Gels (Basel, Switzerland) Oct 2023The attention of the research community is focused not only on waste elimination, but also on waste valorization. The natural marine biopolymer gel substance chitosan,...
The attention of the research community is focused not only on waste elimination, but also on waste valorization. The natural marine biopolymer gel substance chitosan, which can be derived from the waste substances of marine life, is a polymer-matrix-based nanocomposite. Chitosan attracts special attention due to its potential applications, especially in wastewater treatment. In this regard, magnetite-incorporated chitosan powders of nanometer scale were synthesized by a simple co-precipitation method to attain the dual functions of chitosan gel and magnetite. The synthesized magnetite-incorporated chitosan nanopowders were verified using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, a vibrating-sample magnetometer (VSM), a scanning electron microscope (SEM), and transmission electron microscopy (TEM) images, which showed that the synthesized magnetite-incorporated chitosan was nanosized. The superior application of such a material to offset the deterioration of the environment caused by insecticides is attained through a photocatalytic reaction. The experimental results verified the function of magnetite-incorporated chitosan, since it increased the composite-specific surface area, resulting in high methomyl molecule oxidation. Methomyl oxidation reached almost complete insecticide removal (99%) within only one hour of irradiance time. The optimal operational conditions were investigated, and the maximal removal rate occurred when the aqueous solution was at an acidic pH of 3.0. The reaction was affected by differing hydrogen peroxide and catalyst doses, and the optimized reagent was recorded at the levels of 40 and 400 mg/L of catalyst and hydrogen peroxide, respectively. Also, catalyst reusability was attained, confirming its sustainability, since it could be used for successive cycles. From the current investigation, it is proposed that magnetite-chitosan nanoparticles could serve as a promising photocatalyst for the elimination of insecticides from wastewater in a green manner.
PubMed: 37998954
DOI: 10.3390/gels9110864 -
Ecotoxicology and Environmental Safety Dec 2023The extensive use of carbamate pesticides has led to a range of environmental and health problems, such as surface and groundwater contamination, and endocrine disorders...
The extensive use of carbamate pesticides has led to a range of environmental and health problems, such as surface and groundwater contamination, and endocrine disorders in organisms. In this study, we focused on examining the effects of toxic exposure to the carbamate pesticide methomyl on the hatching, morphology, immunity and developmental gene expression levels in zebrafish embryos. Four concentrations of methomyl (0, 2, 20, and 200 μg/L) were administered to zebrafish embryos for a period of 96 h. The study found that exposure to methomyl accelerated the hatching process of zebrafish embryos, with the strongest effect recorded at the concentration of 2 μg/L. Methomyl exposure also trigged significantly reductions in heart rate and caused abnormalities in larvae morphology, and it also stimulated the synthesis and release of several inflammatory factors such as IL-1β, IL-6, TNF-α and INF-α, lowered the IgM contents, ultimately enhancing inflammatory response and interfering with immune function. All of these showed the significant effects on exposure time, concentration and their interaction (Time × Concentration). Furthermore, the body length of zebrafish exposed to methomyl for 96 h was significantly shorter, particularly at higher concentrations (200 μg/L). Methomyl also affected the expression levels of genes associated with development (down-regulated igf1, bmp2b, vasa, dazl and piwi genes), demonstrating strong developmental toxicity and disruption of the endocrine system, with the most observed at the concentration of 200 μg/L and 96 h exposure to methomyl. The results of this study provide valuable reference information on the potential damage of methomyl concentrations in the environment on fish embryo development, while also supplementing present research on the immunotoxicity of methomyl.
Topics: Animals; Zebrafish; Methomyl; Embryo, Nonmammalian; Endocrine System; Pesticides; Carbamates; Larva; Water Pollutants, Chemical
PubMed: 37976935
DOI: 10.1016/j.ecoenv.2023.115684 -
Plants (Basel, Switzerland) Oct 2023Several soil fungi significantly contribute to the enhancement of plant development by improving nutrient uptake and producing growth-promoting metabolites. In the...
Several soil fungi significantly contribute to the enhancement of plant development by improving nutrient uptake and producing growth-promoting metabolites. In the present study, three strains of phosphate-solubilizing fungi, namely, SDBR-CMUI4, SDBR-CMUI1, and SDBR-CMUO2, were examined for their plant-growth-promoting capabilities. The findings demonstrated that all fungi showed positive siderophore production, but only can produce indole-3-acetic acid. All fungi were able to solubilize insoluble phosphate minerals [Ca(PO) and FePO] by producing phosphatase enzymes and organic acids (oxalic, tartaric, and succinic acids). These three fungal species were grown at a water activity ranging from 0.837 to 0.998, pH values ranging from 4 to 9, temperatures between 4 and 40 °C, and 16-17% NaCl in order to evaluate their drought, pH, temperature, and salt tolerances, respectively. Moreover, the results indicated that and were able to tolerate commercial insecticides (methomyl and propargite) at the recommended dosages for field application. The viability of each fungal strain in the inoculum was higher than 50% at 4 and 20 °C after 3 months of storage. Subsequently, all fungi were characterized as plant-growth-promoting strains by improving the root inductions of cassava ( Crantz) and sugarcane ( L.) stem cuttings in greenhouse experiments. No symptoms of plant disease were observed with any of the treatments involving fungal inoculation and control. The cassava and sugarcane stem cuttings inoculated with fungal strains and supplemented with Ca(PO) exhibited significantly increased root lengths, shoot and root dry biomasses, chlorophyll concentrations, and cellular inorganic phosphate contents. Therefore, the application of these phosphate-solubilizing fungi is regarded as a new frontier in the induction of roots and the promotion of growth in plants.
PubMed: 37896093
DOI: 10.3390/plants12203630