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To study the acaricide resistance status and possible mechanisms of action in conferring resistance to commonly used acaricides (deltamethrin and coumaphos), Hyalomma anatolicum ticks were collected from 6 dairy farms of Hisar and Charkhi Dadri districts of Haryana. By using standard larval packet test, H. anatolicum tick larvae of Charkhi Dadri isolates were found to be susceptible (100% mortality) to both the acaricides. Level-I resistance against coumaphos was recorded from four isolates, whereas, level-II was observed in only one isolate, collected from Hisar. One isolates (Kaimri) from Hisar also showed level-I resistance against deltamethrin. Biochemically, the ticks having higher values of resistance factor (RF) against coumaphos were found to possess increased enzymatic activity of α-esterase, β-esterase, glutathione-S-transferase (GST) and mono-oxygenase enzymes, whereas, the monoamine oxidase did not show any constant trend. However, the RF showed a statistical significant correlation with GST only. Native PAGE analysis of H. anatolicum ticks revealed the presence of nine types of esterases (EST-1 h to EST-9 h) by using napthyl acetate as substrate. In the inhibitory assay, esterases were found to be inhibited by PMSF, indicating the presence of serine residue at catalytic triad. The partial cds of carboxylesterase and domain II of sodium channel genes were sequenced to determine any proposed mutations in resistant isolates of H. anatolicum ticks, however, no mutations were observed in either gene, indicating that increased expression of detoxification enzymes as a possible mechanism for resistance development, in the current study. [ABSTRACT FROM AUTHOR]

The effects of acute sublethal doses of coumaphos, an acaricide used against Varroa destructor infestation in beekeeping, on the locomotor activities of four native honeybee subspecies of Türkiye including two ecotypes (Carniolan honeybee -A. m. carnica, Syrian honeybee -A. m. syriaca, Caucasian honeybee- A. m. caucasica, and Muğla and Yığılca ecotypes of Anatolian honeybee A. m. anatoliaca) were investigated using an individual locomotor activity monitoring system. Analysis of locomotor activity data in the first 12-h, last 12-h, and 24-h time periods showed that bees from caucasica and carnica subspecies were not affected by coumaphos at all three acute doses (1, 2, and 5 μg coumaphos in 10 μl sucrose syrup for each bee). In contrast, bees from A. m. syriaca subspecies showed significantly elevated locomotor activity levels at 2 and 5 μg coumaphos doses within the first 12 h. Bees from both Muğla and Yığılca ecotypes of anatoliaca subspecies also showed elevated locomotor activity levels at 5 μg coumaphos dose but the magnitude of increase was lower in these ecotypes compared to that seen in syriaca subspecies in the first 12-h period. In general, increasing doses of coumaphos resulted in increased locomotor activity (locomotor activity), with differences in sensitivity across honeybee populations. Possible mechanisms underlying this variance and suggestions for further studies are discussed. [ABSTRACT FROM AUTHOR]

For a half-century, the commercial wild silkworm, Antheraea pernyi, has been protected by coumaphos, which is an internal organophosphorus insecticide used to kill the potential parasitic fly larvae inside. Knowledge about the detoxification genes of A. pernyi as well as the detoxification mechanism for this species remains severely limited. In this study, we identified 281 detoxification genes (32 GSTs, 48 ABCs, 104 CYPs, and 97 COEs) in the genome of this insect, which are unevenly distributed over 46 chromosomes. When compared to the domesticated silkworm, Bombyx mori, a lepidopteran model species, A. pernyi has a similar number of ABCs, but a greater number of GSTs, CYPs, and COEs. By transcriptome-based expression analysis, we found that coumaphos at a safe concentration level significantly changed the pathways related to ATPase complex function and the transporter complex in A. pernyi. KEGG functional enrichment analysis indicated that protein processing in the endoplasmic reticulum was the most affected pathway after coumaphos treatment. Finally, we identified four significantly up-regulated detoxification genes (ABCB1, ABCB3, ABCG11, and ae43) and one significantly down-regulated detoxification gene (CYP6AE9) in response to coumaphos treatment, suggesting that these five genes may contribute to detoxification of coumaphos in A. pernyi. Our study provides the first set of detoxification genes for wild silkworms from Saturniidae and highlights the importance of detoxification gene repertoire in insect pesticide tolerance. [ABSTRACT FROM AUTHOR]

Here, a molecular imprinting technique was employed to create an SPR-based nanosensor for the selective and sensitive detection of organophosphate-based coumaphos, a toxic insecticide/veterinary drug often used. To achieve this, UV polymerization was used to create polymeric nanofilms using N-methacryloyl-l-cysteine methyl ester, ethylene glycol dimethacrylate, and 2-hydroxyethyl methacrylate, which are functional monomers, cross-linkers, and hydrophilicity enabling agents, respectively. Several methods, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) analyses, were used to characterize the nanofilms. Using coumaphos-imprinted SPR (CIP-SPR) and non-imprinted SPR (NIP-SPR) nanosensor chips, the kinetic evaluations of coumaphos sensing were investigated. The created CIP-SPR nanosensor demonstrated high selectivity to the coumaphos molecule compared to similar competitor molecules, including diazinon, pirimiphos-methyl, pyridaphenthion, phosalone, N-2,4(dimethylphenyl) formamide, 2,4-dimethylaniline, dimethoate, and phosmet. Additionally, there is a magnificent linear relationship for the concentration range of 0.1–250 ppb, with a low limit of detection (LOD) and limit of quantification (LOQ) of 0.001 and 0.003 ppb, respectively, and a high imprinting factor (I.F.4.4) for coumaphos. The Langmuir adsorption model is the best appropriate thermodynamic approach for the nanosensor. Intraday trials were performed three times with five repetitions to statistically evaluate the CIP-SPR nanosensor's reusability. Reusability investigations for the two weeks of interday analyses also indicated the three-dimensional stability of the CIP-SPR nanosensor. The remarkable reusability and reproducibility of the procedure are indicated by an RSD% result of less than 1.5. Therefore, it has been determined that the generated CIP-SPR nanosensors are highly selective, rapidly responsive, simple to use, reusable, and sensitive for coumaphos detection in an aqueous solution. An amino acid, which was used to detect coumaphos, included a CIP-SPR nanosensor manufactured without complicated coupling methods and labelling processes. Liquid chromatography with tandem mass spectrometry (LC/MS-MS) studies was performed for the validation studies of the SPR. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) naturally inhabiting the digestive tract of honeybees are known for their ability to detoxify xenobiotics. The effect of chlorpyrifos, coumaphos, and imidacloprid on the growth of LAB strains was tested. All strains showed high resistance to these insecticides. Subsequently, the insecticide binding ability of LAB was investigated. Coumaphos and chlorpyrifos were bound to the greatest extent (up to approx. 64%), and imidacloprid to a much weaker extent (up to approx. 36%). The insecticides were detected in extra- and intracellular extracts of the bacterial cell wall. The ability of selected LAB to reduce the cyto- and genotoxicity of insecticides was tested on two normal (ovarian insect Sf-9 and rat intestinal IEC-6) cell lines and one cancer (human intestinal Caco-2) cell line. All strains exhibited various levels of reduction in the cyto- and genotoxicity of tested insecticides. It seems that coumaphos was detoxified most potently. The detoxification abilities depended on the insecticide, LAB strain, and cell line. The detoxification of insecticides in the organisms of honeybees may reduce the likelihood of the penetration of these toxins into honeybee products consumed by humans and may contribute to the improvement of the condition in apiaries and honeybee health. [ABSTRACT FROM AUTHOR]

Rhipicephalus microplus tick is the ectoparasite causing the greatest economic losses in the livestock industry. Multi-resistance in ticks is increasing, generating the inefficiency of traditional ixodicides, for which biological control has been proposed as an alternative. In this work, we analyze the histomorphological damage caused by the bacterial strain EC-35 on Rhipicephalus microplus. The ixodicidal effect of EC-35 total protein was evaluated on larval or adult ticks comparing with the commercial ixodicide coumaphos 0.02% as a control. Female ticks were processed using the paraffin-embedding technique and stained with hematoxylin–eosin. Also, the pathogenicity of EC-35 was evaluated by capillary feeding and coelom inoculation tests. The identification of the bacterium was performed using the molecular markers 16S RNA and rpoB, by PCR and sequencing technique, and the evolutionary distance was analyzed by Bayesian phylogenetic inference. No differences were observed in the perimeter and area of larvae treated with EC-35 or Coumaphos. The thickness of the integument decreased a 65% with the EC-35 treatment (6.01 ± 0.6 µm) and of 30% in coumaphos (12.04 ± 1.2 µm) in larvae compared with the control group (18.41 ± 2 µm), while no difference was found in adult ticks. The capillary feeding test and coelom inoculation with EC-35 showed an inhibition of reproductive potential of 99.8 ± 7 and an oviposition Inhibition 97 ± 3.02%. The EC-35 strain was genetically related to Serratia marcescens, concluding that these bacteria caused high mortality, oviposition Inhibition, and integument thinning and drastic loss of histoarchitecture in R. microplus tick larvae. [ABSTRACT FROM AUTHOR]

Beekeepers need new registered products to control the small hive beetle (SHB), Aethina tumida, a significant pest of western honey bee (Apis mellifera) colonies. Few approved chemical controls exist, and there is no standardized system for screening compounds against SHBs. We outline a detailed method for an acute toxicity bioassay that delivers compounds via pollen. We provide a detailed method for a field trial that delivers treated pollen in traps made from modified compact disc cases. We applied both methods in proof-of-concept experiments to assess acetamiprid as a SHB control agent. Using the laboratory bioassay, we found acetamiprid ( LC 50 = 20.5 µg/g) to be more toxic to SHBs than coumaphos was ( LC 50 = 1250 µg/g), yet less toxic to SHBs than fipronil was ( LC 50 = 1.78 µg/g). In our field trial, colonies treated with acetamiprid and fipronil significantly reduced (p < 0.001) live SHB populations over those of control colonies. Traps containing acetamiprid retained significantly higher (p < 0.001) numbers of dead SHBs than did traps containing fipronil. We outline the first detailed methods to assess the toxicity of compounds delivered in pollen for adult SHB control. Our proof-of-concept experiments showed acetamiprid to be a promising control agent for SHBs. [ABSTRACT FROM AUTHOR]

For a half-century, the commercial wild silkworm, Antheraea pernyi, has been protected by coumaphos, which is an internal organophosphorus insecticide used to kill the potential parasitic fly larvae inside. Knowledge about the detoxification genes of A. pernyi as well as the detoxification mechanism for this species remains severely limited. In this study, we identified 281 detoxification genes (32 GSTs, 48 ABCs, 104 CYPs, and 97 COEs) in the genome of this insect, which are unevenly distributed over 46 chromosomes. When compared to the domesticated silkworm, Bombyx mori, a lepidopteran model species, A. pernyi has a similar number of ABCs, but a greater number of GSTs, CYPs, and COEs. By transcriptome-based expression analysis, we found that coumaphos at a safe concentration level significantly changed the pathways related to ATPase complex function and the transporter complex in A. pernyi. KEGG functional enrichment analysis indicated that protein processing in the endoplasmic reticulum was the most affected pathway after coumaphos treatment. Finally, we identified four significantly up-regulated detoxification genes (ABCB1, ABCB3, ABCG11, and ae43) and one significantly down-regulated detoxification gene (CYP6AE9) in response to coumaphos treatment, suggesting that these five genes may contribute to detoxification of coumaphos in A. pernyi. Our study provides the first set of detoxification genes for wild silkworms from Saturniidae and highlights the importance of detoxification gene repertoire in insect pesticide tolerance.

To break through the bottleneck in preparation of nanobody (Nb) for chemical contaminants induced by the difficulties in the synthesis of immunogen, complexity and unexpectable efficiency of immunization, a novel strategy to generate Nbs based on the designed synthetic Nb libraries with final size up to 109 cfu/mL was adopted and succeeded in selection of anti-coumaphos Nb A4. Furthermore, an affinity-matured mutant Nb 3G was obtained from the secondary library. Finally, an ic-ELISA was established with the limit of detection for coumaphos low to 1.90 ng/mL, 6.4-fold improved than the parent Nb A4, and the detection range from 3.06 to 15.77 ng/mL. Meanwhile, the recovery rate of vegetable samples was from 89.9% to 98.5%. Finally, the accuracy was testified by the standard UPLC-MS/MS method with R2 up to 0.99. Overall, fully synthetic Nb libraries constructed in this work provided an alternative possibility to generate the specific Nbs for chemical contaminants. [Display omitted] • A new strategy to generate nanobodies for the chemical contaminants was constructed based on a designed synthetic Nb library. • A specific Nb 3G was selected from the coumaphos-targeted secondary Nb library. • Based on the Nb 3G, an ic-ELISA method showed satisfied sensitivity, accuracy and practicality for detecting coumaphos. [ABSTRACT FROM AUTHOR]

Here, a molecular imprinting technique was employed to create an SPR-based nanosensor for the selective and sensitive detection of organophosphate-based coumaphos, a toxic insecticide/veterinary drug often used. To achieve this, UV polymerization was used to create polymeric nanofilms using N-methacryloyl-l-cysteine methyl ester, ethylene glycol dimethacrylate, and 2-hydroxyethyl methacrylate, which are functional monomers, cross-linkers, and hydrophilicity enabling agents, respectively. Several methods, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) analyses, were used to characterize the nanofilms. Using coumaphos-imprinted SPR (CIP-SPR) and non-imprinted SPR (NIP-SPR) nanosensor chips, the kinetic evaluations of coumaphos sensing were investigated. The created CIP-SPR nanosensor demonstrated high selectivity to the coumaphos molecule compared to similar competitor molecules, including diazinon, pirimiphos-methyl, pyridaphenthion, phosalone, N-2,4(dimethylphenyl) formamide, 2,4-dimethylaniline, dimethoate, and phosmet. Additionally, there is a magnificent linear relationship for the concentration range of 0.1–250 ppb, with a low limit of detection (LOD) and limit of quantification (LOQ) of 0.001 and 0.003 ppb, respectively, and a high imprinting factor (I.F.4.4) for coumaphos. The Langmuir adsorption model is the best appropriate thermodynamic approach for the nanosensor. Intraday trials were performed three times with five repetitions to statistically evaluate the CIP-SPR nanosensor’s reusability. Reusability investigations for the two weeks of interday analyses also indicated the three-dimensional stability of the CIP-SPR nanosensor. The remarkable reusability and reproducibility of the procedure are indicated by an RSD% result of less than 1.5. Therefore, it has been determined that the generated CIP-SPR nanosensors are highly selective, rapidly responsive, simple to use, reusable, and sensitive for coumaphos detection in an aqueous solution. An amino acid, which was used to detect coumaphos, included a CIP-SPR nanosensor manufactured without complicated coupling methods and labelling processes. Liquid chromatography with tandem mass spectrometry (LC/MS-MS) studies was performed for the validation studies of the SPR.

Hyalomma dromedarii ticks collected from a camel herd of Hanumangarh district in the Rajasthan State of India were subjected to FAO recommended adult immersion test with discriminating dose (AIT-DD) against amitraz (formamidines), deltamethrin (synthetic pyrethroids) and coumaphos (organophosphate). The country-specific data generated using the IVRI-I line (deltamethrin (59.2 ppm), coumaphos (262 ppm) and amitraz (975.40 ppm)) was taken as discriminating dose for concerned acaricide since the reference susceptible H. dromedarii ticks line is not maintained anywhere in world. Standard FAO protocol for the rapid detection of acaricide resistance was followed. The percent resistance against deltamethrin, coumaphos and amitraz were found to be 26.67%, 46.67% and 0% respectively. Results revealed a high susceptibility of these ticks against amitraz, resulting in 100% mortality at discriminating concentration. Esterase characterization using Native PAGE of Hyalomma dromedarii homogenate reveals a total of 7 esterase bands, viz. Est-1 h-5 h, Est-7 h and Est-8 h in larva and only 5 esterase bands viz. Est-1 h, Est-3 h-4 h, Est-6 h and Est-7 h in adult. Inhibition assay using inhibitors (copper sulphate, p-chloromercuribenzoate, eserine sulphate, phenylmethylsulfonylfluoride) against esterase of H. dromedarii ticks confirms the presence of serine residues in their active site and provide evidence for the presence of Est-7 and Est-8 in larvae as acetylcholinesterases (AChEs) in larvae. It is the first attempt of biochemical characterization of esterases present in H. dromedarii ticks and could be in future related with development of resistance against organophosphates and synthetic pyrethroids compounds. The high susceptibility status to formamidines drugs may be attributed to low selection pressure as they are still preferred next to synthetic pyrethroids in veterinary practices. It also indicates an alternative tick control measure needs to be adopted in camels to extenuate the development of acaricide resistance. [ABSTRACT FROM AUTHOR]

Survival of European honey bee (Apis mellifera) colonies has been threatened over the past few decades as Varroa destructor has become a growing concern on a near-global scale. Prominent treatment methods have included the synthetic acaricides amitraz, coumaphos, and tau-fluvalinate. Since widespread resistance to these compounds has been noted, this study sought to investigate V. destructor resistance in Virginia. V. destructor infestation levels in apiaries located in three geographic regions of Virginia were monitored throughout the 2018 field season. By autumn, all apiaries had mite populations above the recommended treatment threshold. The results of resistance screening with glass surface contact bioassays indicated no resistance to amitraz, coumaphos, or tau-fluvalinate. These results have implications in future control strategies and responsible use of these acaricides may offer an additional option to those battling these aggressive ectoparasites. [ABSTRACT FROM AUTHOR]

Apart from the efficiency of coumaphos against Varroa mites, its impact on the oxidative status and survival of the honey bee (Apis mellifera) was assessed. The research was conducted on hives from the same apiary, equalised regarding the number of bees, brood area and food storage. Based on Varroa infestation the hives were allotted to two groups: non-infested (N) and infested (I). Both groups were either treated (T) – NT and IT, or untreated (U) – NU and IU. The treatment of infested bees was controlled with a follow-up treatment with amitraz. The efficiency of coumaphos was 96-97%. This organophosphate had a negligible effect on bee survival, but it significantly affected their oxidative status: superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities, and the concentrations of malonyl dialdehyde (MDA). Coumaphos significantly (p˂0.0001) decreased SOD activity in non-infested bees, but increased it in those infested. By contrast, both CAT and GST activities, as well as MDA concentrations significantly increased (from p˂0.05 to p˂0.0001) after treatment in all groups, with the exception of IT, where it declined. Coumaphos in non-infested hives caused oxidative stress per se, not unlike varroa in infested colonies. However, in infested colonies it decreased oxidative stress, owing to its efficacy against Varroa mites and contributed to the recovery of bee colonies. In spite of its certain downsides, coumaphos remains an effective anti-varroa substance, but should be used with precaution, not to add to the effects of environmental factors which may cause red-ox misbalance.

Managed bees commonly suffer from cross-contamination with acaricides and neonicotinoids, posing robust threats to bee population health. However, their residual characteristics and spatial distribution in beehives and surrounding environments are poorly understood. This study detected two common acaricides and five neonicotinoids in 240 beehive samples and 44 surrounding environmental samples collected from 25 Chinese provinces. The results showed that 40.0% of the honey samples contained acaricides and 83.1% contained neonicotinoids. Neonicotinoid concentrations in honey were geographically distinguished by the "Hu Huanyong line", and concentrations of neonicotinoids in honey from eastern areas were 2.65-fold higher than those in honey from western areas. Compared to the approved acaricide amitraz, the banned acaricide coumaphos was detected more frequently in honey and was positively correlated with that quantified in the paired pollen samples. Although coumaphos was identified in only three soil samples, lower coumaphos residues in honey might be associated with persistent pollution in the surrounding environment. Conversely, neonicotinoids were detected at higher levels in honey than in the pollen and soil, demonstrating that the neonicotinoid residues in honey have a cumulative effect. This study contributes to a better understanding of the pesticide contamination scenarios that underlie the exposure risks of bees., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Beekeepers need new registered products to control the small hive beetle (SHB), Aethina tumida, a significant pest of western honey bee (Apis mellifera) colonies. Few approved chemical controls exist, and there is no standardized system for screening compounds against SHBs. We outline a detailed method for an acute toxicity bioassay that delivers compounds via pollen. We provide a detailed method for a field trial that delivers treated pollen in traps made from modified compact disc cases. We applied both methods in proof-of-concept experiments to assess acetamiprid as a SHB control agent. Using the laboratory bioassay, we found acetamiprid (LC50 = 20.5 µg/g) to be more toxic to SHBs than coumaphos was (LC50 = 1250 µg/g), yet less toxic to SHBs than fipronil was (LC50 = 1.78 µg/g). In our field trial, colonies treated with acetamiprid and fipronil significantly reduced (p < 0.001) live SHB populations over those of control colonies. Traps containing acetamiprid retained significantly higher (p < 0.001) numbers of dead SHBs than did traps containing fipronil. We outline the first detailed methods to assess the toxicity of compounds delivered in pollen for adult SHB control. Our proof-of-concept experiments showed acetamiprid to be a promising control agent for SHBs.

BACKGROUND A national survey on pesticides in recycled beeswax originating from beekeeping has been conducted in Switzerland for almost three decades. It allowed obtaining a good overview of the lipophilic products used for beekeeping within the last 30 years. RESULTS: The use of the veterinary drugs containing bromopropylate or tau‐fluvalinate two decades ago led to substantial residues in commercial beeswax. These contaminants are still detectable although in Switzerland the corresponding products have been out of use for many years. The level of coumaphos substantially increased in 2015 up to an annual value of 3.25 mg·kg−1, suggesting that at least a few beekeepers used coumaphos‐containing products. Consequently, an information campaign was launched, and the annual value decreased again. Maximal levels of thymol up to an annual value of 87.5 mg·kg−1 were measured in 2009. Since that time, a steady decrease of thymol residues suggests that beekeepers less frequently use thymol‐containing products. Twenty‐five years ago, 1,4‐dichlorobenzene (PDCB) was widely used for the control of the wax moth, resulting in residues in beeswax up to an annual value of 10.9 mg·kg−1 whereas nowadays, PDCB residues are rarely detected in Swiss beeswax. CONCLUSIONS: Our survey illustrates that several beekeeping‐associated pesticides persist in recycled beeswax for many years. Most recent analyses show lower residue levels in Swiss beeswax as compared to previous years. Nowadays Swiss beekeepers mostly use hydrophilic substances for treatment against the Varroa destructor that do not accumulate in beeswax, thus reducing exposure of the honey bees to lipophilic contaminants. [ABSTRACT FROM AUTHOR]

Honey bee populations are declining as occurs with other pollinators. One suggested cause of this decline is the impact of pesticides. To improve bees’ health, pesticides and food sources may be monitored using sentinel hives, given that bees forage in a 2.5 km radius around the hive. We extracted 20 (twenty) bees, as well as samples of wax, honey and pollen from a sentinel hive. Six pesticides were detected in the samples, except for the honey. All detected pesticides in the sentinel hive are pro- hibited in Argentina. Eight different plant families and genera were detected in the honey and pollen samples. Our work suggests that monitoring pesticides with sentinel beehives will be useful to improve agricultural practices in the region.

A survey on concentrations of veterinary drug residues amitraz, coumaphos and thymol in honey, produced in year 2020 by Slovenian beekeepers, was conducted. 100 samples were analysed: 22 from organic and 78 from conventional production, with two analytical methods. In method for determination of coumaphos and thymol samples were extracted with acetone, petroleumether and dichlorometane. In method for determination of amitraz and its degradation products, samples were hydrolisated with HCl and NaOH, extractied with n-hexane and derivatisated with heptafluorobutyric anhydride. Determination in both methods was performed with gas chromatograph coupled with mass spectrometer. Measured concentrations of amitraz, coumaphos and thymol were in the range of 0.01-0.12 mg kg-1, 0.02-0.06 mg kg-1 and 0.08-0.17 mg kg-1, respectively. In 61 % of samples analysed no residues of amitraz, thymol and coumaphos were found. Data obtained were compared with the data from literature. Chronic and acute exposure were calculated for consumers. Maximum chronic exposure for amitraz and thymol was 0.1 % and 0.05 % of acceptable daily intake, respectively. Maximum acute exposure for amitraz and thymol was 4 % and 0.8 % of acute reference dose, respectively

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Evidence suggests that acaricide residues, such as tau-fluvalinate and coumaphos, are very prevalent in honey bee colonies worldwide. However, the endpoints and effects of chronic oral exposure to these compounds remain poorly understood. In this study, we calculated LC 50 and LDD 50 endpoints for coumaphos and tau-fluvalinate, and then evaluated in vivo and in vitro effects on honey bees using different biomarkers. The LDD 50 values for coumaphos were 0.539, and for tau-fluvalinate, they were 12.742 in the spring trial and 8.844 in the autumn trial. Chronic exposure to tau-fluvalinate and coumaphos resulted in significant changes in key biomarkers, indicating potential neurotoxicity, xenobiotic biotransformation, and oxidative stress. The Integrated Biomarker Response was stronger for coumaphos than for tau-fluvalinate, supporting their relative lethality. This study highlights the chronic toxicity of these acaricides and presents the first LDD 50 values for tau-fluvalinate and coumaphos in honey bees, providing insights into the risks faced by colonies. [Display omitted] • Chronic exposure risks to widely detected acaricide residues. • First-time LDD 50 quantification for tau-fluvalinate and coumaphos in honey bees. • Chronic exposure alters neurotoxic, biotransformation and oxidative stress biomarkers. • IBR index indicates higher toxicity for coumaphos compared to tau-fluvalinate. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Apart from the efficiency of coumaphos against Varroa mites, its impact on the oxidative status and survival of the honey bee (Apis mellifera) was assessed. The research was conducted on hives from the same apiary, equalised regarding the number of bees, brood area and food storage. Based on Varroa infestation the hives were allotted to two groups: non-infested (N) and infested (I). Both groups were either treated (T) - NT and IT, or untreated (U) - NU and IU. The treatment of infested bees was controlled with a follow-up treatment with amitraz. The efficiency of coumaphos was 96-97%. This organophosphate had a negligible effect on bee survival, but it significantly affected their oxidative status: superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities, and the concentrations of malonyl dialdehyde (MDA). Coumaphos significantly (p˂0.0001) decreased SOD activity in non-infested bees, but increased it in those infested. By contrast, both CAT and GST activities, as well as MDA concentrations significantly increased (from p˂0.05 to p˂0.0001) after treatment in all groups, with the exception of IT, where it declined. Coumaphos in non-infested hives caused oxidative stress per se, not unlike varroa in infested colonies. However, in infested colonies it decreased oxidative stress, owing to its efficacy against Varroa mites and contributed to the recovery of bee colonies. In spite of its certain downsides, coumaphos remains an effective anti-varroa substance, but should be used with precaution, not to add to the effects of environmental factors which may cause red-ox misbalance. [ABSTRACT FROM AUTHOR]

In this study, the photodegradation of organophosphorus (OPs) pesticides in the honey medium was evaluated under sunlight irradiation. Some of the 22 samples collected at different sites contained OPs pesticides (Methyl parathion, Coumaphos and Fenitrothion) with an average of 8 ng/g. Moreover, three samples were found with pesticide residue levels exceeding the maximum residue limits (MRL ≥ 50 ng/g) imposed by the standard water (WHO). Gas chromatography (GC) combined with a tritium electron capture detector system was used for the analysis of OPs pesticides in honey. Total degradation of the Methyl parathion was obtained in less than 60 min of irradiation. Moreover, the elimination of the other OPs found in the samples was also effective with a rate of 85% for Coumaphos and Fenitrothion after 50 min of sunlight irradiation. The kinetics of the photodegradation reaction of all OPs pesticides studied followed a pseudo-first order model. [ABSTRACT FROM AUTHOR]

We studied the distribution of coumaphos in beeswax after a single application of CheckMite® to 15 bee colonies in the fall according to the manufacturer's instruction. Immediately after the treatment, residue levels were especially elevated in the wax that came into contact with the CheckMite® strips. During the following spring season, coumaphos levels ranged from 36 to 159 mg/kg in the wax of the brood frames next to the CheckMite® strips, and residue levels were about 10 times lower in the wax of frames that did not come into contact with the strips. Beeswax that was newly constructed 5 months after removing the treatment strips contained up to 7.3 mg/kg of coumaphos, and up to 0.5 and 2.3 mg/kg was detected in the honeycomb and capping wax, respectively. These results suggest that beeswax exposed to CheckMite® should not be recycled in order to prevent elevated concentrations of coumaphos in new foundations and hence to prevent honeybee larvae from being exposed to detrimental residue levels. [ABSTRACT FROM AUTHOR]

Chemical control of tick infestation on dairy farms in India strongly relies upon the use of synthetic pyrethroids (deltamethrin) and organophosphate (coumaphos) drugs. Therefore, the present manuscript aims to investigate the resistance status of Rhipicephalus microplus ticks against these acaricides. Fully engorged adult R. microplus ticks were randomly collected from 8 dairy farms in North India and evaluated for acaricide resistance by using the Larval Packet Test (LPT). Of these, ticks collected from one and three farms showed the emergence of Level I acaricide resistance against deltamethrin and coumaphos, respectively. Significant positive correlations were found in the enzymatic activity (α-esterase, β-esterase, glutathione-S-transferase, and mono‐oxygenase) of R. microplus tick resistant against coumaphos. Native electrophoretogram analysis showed six different types of esterase activity in R. microplus (EST-1b to EST-6b), and EST-5b activity was more predominantly expressed in resistant ticks. Further, inhibitor studies using various esterase inhibitors suggested that EST-5b is a putative acetylcholine-esterase (AchE), and increased expression of one of the AchE might be responsible for the emergence of acaricide resistance. Further, no mutations were detected in the carboxylesterase (G1120A) and domain II S4‐5 linker region (C190A) of the sodium channel genes of resistant R. microplus ticks, indicating that increased expression of detoxification enzymes was the probable mechanism for the development of acaricide resistance in the resistant ticks. [Display omitted] • R. microplus ticks collected from dairy farms showed resistance against deltamethrin and coumaphos. • Significant correlations were found in the enzymatic activity and resistance factor of the ticks, resistant to coumaphos. • Native PAGE analysis showed an acetylcholinesterase to be more predominantly expressed in coumaphos resistant ticks. • Widely proposed genetic mutations were not recorded in carboxylesterase and sodium channel genes of resistant ticks. • Increased expression of detoxification enzymes was concluded as the probable mechanism for acaricide resistance. [ABSTRACT FROM AUTHOR]

There is an issue concerning the migration of pesticides from stamped beeswax to other bee products, mainly, honey. This implies that honey and other beehive-based products could be contaminated, which would represent a potential risk to consumers and food safety. To determine the degree to which acaricides can be transferred from the stamped beeswax to the honey, a pilot experiment was designed consisting of placing beeswax that contained acaricides (endogenous content, τ-fluvalinate, chlorfenvinphos, and coumaphos; spiked samples, coumaphos) in contact with multifloral honey in an incubator. Temperature and shaking conditions were settled simulating beehive conditions. The isolation of the analytes from beeswax involved the use of a QuEChERS (quick, easy, cheap, effective, rugged & safe) method, and honey was analyzed through a solvent extraction procedure. Acaricides were determined in the resulting extracts by gas chromatography with mass spectrometry detection. Coumaphos was the only acaricide transferred into honey in beeswaxes with endogenous acaricide content; meanwhile, results of the experiments with spiked beeswax samples showed that the initial concentration present in the contaminated beeswax significantly influences the transfer to honey, as it was observed that in the spiked beeswax sheets with high levels of coumaphos, the migration from beeswax to honey arose. [Display omitted] • Beeswax and honey were analyzed using previously validated GC-MS methods. • It has been demonstrated that acaricide residues migrated from beeswax to honey. • Coumaphos was the only acaricide of three migrated to honey from contaminated beeswax. • Initial acaricide concentration in spiked beeswax influences the transfer to the honey. [ABSTRACT FROM AUTHOR]

One of the most economical approaches for removal of toxic compounds is bioremediation. In the long term, bioremediation is economic and feasible compared to other methods, such as physical or chemical methods. A bacterium that can efficiently reduce molybdenum blue was isolated from polluted soil. Biochemical analysis revealed the identity of the bacterium as Enterobacter sp. strain Saw-1. The growth parameters for optimal reduction of molybdenum to Mo-blue or molybdenum blue, a less toxic product, were determined around pH 6.0 to 6.5 and in the range of 30 to 37 ℃, respectively. Glucose was selected as preferred carbon source, followed by sucrose, maltose, l-rhamnose, cellobiose, melibiose, raffinose, d-mannose, lactose, glycerol, d-adonitol, d-mannitol, l-arabinose and mucate. Phosphate and molybdate were critically required at 5.0 mM and 10 mM, respectively. The scanning absorption spectrum acquired to detect the development of complex Mo-blue showed similarity to previously isolated Mo-reducing bacteria. In addition, the spectrum closely resembled the molybdenum blue from the phosphate determination method. Heavy metals, including mercury, copper (II) and silver (I), inhibited reduction. Moreover, the bacterium also showed capability of exploiting the pesticide coumaphos as an alternative carbon source for growth. As the bacterium proved its ability to detoxify organic and inorganic xenobiotics, the usefulness of this microorganism for bioremediation is highlighted.

Western honey bees are very sensitive bioindicators for studying environmental conditions, hence frequently included in many investigations. However, it is very common in both research studies and health surveillance programs to sample different components of the colony, including adult bees, brood and their food reserves. These practices are undoubtedly aggressive for the colony as a whole, and may affect its normal functioning and even compromise its viability. APIStrip-based passive sampling allows long-term monitoring of residues without affecting the colony in any way. In this study, we compared the effectiveness in the control of acaricide residues by using passive and conventional sampling, where the residue levels of the acaricides coumaphos, tau-fluvalinate and amitraz were evaluated. Conventional and APIStrip-based sampling differ in methods for evaluating bee exposure to residues. APIStrip is less invasive than conventional sampling, offers more efficient measurement of environmental contaminants, and can be stored at room temperature, saving costs and minimizing operator error., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Rhipicephalus sanguineus s.l. is an intra- and peridomiciliary tick of medical and veterinary importance, whose control is carried out through the application of various ixodicides, to which it can develop resistance. The objective of this work was to determine the discriminant doses (d.d.) to identify resistance against three ixodicides - fipronil, flumethrin and coumaphos - in R. sanguineus s.l. larvae originating from Mexico. Engorged ticks were collected from naturally infested dogs residing in rural communities in five Mexican states; the dogs had no history of recent treatment with ixodicides. All ticks were identified as R. sanguineus s.l. They were incubated for 25 days and their progeny was used in the larval package test (LPT) to be exposed to d.d. as determined in Rhipicephalus microplus, and those that were susceptible were analyzed using the LPT with six concentrations, for fipronil from 0.1 to 0.003125%, for flumethrin from 0.02 to 0.000625% and for coumaphos from 0.4 to 0.0125%. Mortality was analyzed with Probit methodology, to calculate the 50 and 99% lethal concentrations (LC50 and LC99). The d.d. was determined as a consensus value by multiplying the LC99 value × 2. Nine double susceptible samples (fipronil + flumethrin) and one triple susceptible sample (fipronil + flumethrin + coumaphos) were found; the d.d. determined were fipronil 0.05%, flumethrin 0.01% and coumaphos 0.43%. These doses can be used to rapidly and inexpensively identify resistant populations in samples collected in the field., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The present experiment was conducted to evaluate and compare the impact of Ageratum conyzoides plant extract (ACE) with routinely used synthetic acaricides i.e., amitraz and coumaphos on the oogenesis of engorged adult females of Rhipicephalus microplus tick. On the day of dropping from the host, panoistic ovary of R. microplus appeared white in colour, horseshoe shaped, hollow tubular organ with immature oocytes predominantly in dorsal groove. Different developmental stages of oocytes (I–V) proceed simultaneously and asynchronously. Oocytes showed gradual increase in size, deep brown colored with accumulation of eggs in oviduct during 24–72 hours of development.At LC 90 concentration a highly significant (p < 0.001) cessation of egg laying after exposure to amitraz and ACE while significant reduction (p < 0.01) of egg laying in coumaphos treated ticks was observed. Upon dissection of treated ticks, uterus and oviduct packed with eggs, which failed to pass out was observed. The histo-architectural alterations including presence of extensive vacuolation, alteration of oocyte morphology, deformation of chorion and disorganization of yolk granules were observed in the treated ovaries. Histochemically, low level of storage or synthesis of essential elements viz., proteins, polysaccharides and lipids in treated oocytes responsible for reduction of fertility and inhibition of progress of vitellogenesis was observed. [ABSTRACT FROM AUTHOR]

Objective: To describe 2 cases of organophosphate intoxication through a previously unreported method of exposure. Case series: A 2‐year‐old intact male Australian Cattle Dog (case 1) presented with progressive muscarinic and nicotinic clinical signs, and a 3‐year‐old neutered male mixed breed dog (case 2) presented after known ingestion of cattle ear tags. The dog in case 1 was discovered to have ingested cattle ear tags after abdominal radiographs. Organophosphate testing of gastric contents confirmed diazinon toxicosis. The dog in case 2 was found to be eating ear tags by the owner. The tags in case 2 contained diazinon and coumaphos. The dog in case 1 was treated with gastric lavage, gastroprotectants, prokinetics, antiemetics, pralidoxime chloride, and atropine. The dog in case 2 was treated with pralidoxime chloride. Both patients received standard supportive and nursing care and recovered completely with no further concerns. New or unique information provided: This is a novel exposure to organophosphates that has not been reported in small animals. In dogs with relevant clinical signs and potential environmental exposure, cattle ear tag ingestion is an important differential diagnosis to consider. [ABSTRACT FROM AUTHOR]

Due to the presence of pollutants in aquatic systems, this research aims to analyze toxicity levels of Faena Clásico®, Asuntol®, sodium hypochlorite and diesel on Macrobrachium tenellum juveniles. For the purpose of this study, specimens from 2 to 4 cm in length were used. For glyphosate, hypochlorite and coumaphos bio-assays, a total of 8 individuals were placed per experimental unit, however, only 5 individuals were placed for diesel. Dead individuals were counted at the end of 24 h of exposure. All bioassays were performed in quintuplicate plus a negative control. The mean lethal concentration (LC50) was calculated by a Probit analysis and standard error. The mean lethal concentrations obtained are given at 6 h of exposure for 16 mL L-1 of diesel aqueous extract; and 24 h of exposure, solutions of Asuntol® 6 mg L-1, Classic Faena® 32 mg L-1 and sodium hypochlorite 59 mg L-1. Results show that the different chemicals assessed generate harmful damage to M. tenellum, since agrochemical compounds can cause alterations in the composition of ecosystems, reducing biodiversity in a temporarily or permanently manner. [ABSTRACT FROM AUTHOR]

The present study compares the in vitro efficacy of four chemical acaricides, viz. amitraz, coumaphos, deltamethrin and lindane, against Rhipicephalus (Boophilus) annulatus and Haemaphysalis bispinosa ticks based on adult immersion tests. Amitraz, at 350 ppm, elicited 29.2 ± 4.17% mortality against R. (B.) annulatus, 100% inhibition of fecundity and absence of hatching of eggs laid by treated ticks. The same compound at 300 ppm caused 62.5 ± 12.5% mortality against H. bispinosa, 96.7% inhibition of fecundity and complete blocking of eclosion. The LC50 value of amitraz against susceptible H. bispinosa was 181 ppm. Deltamethrin at 400 ppm, elicited 25.0 ± 4.81% adult R. (B.) annulatus mortality, 97.5% inhibition of fecundity and absence of egg hatching. Complete blocking of egg hatching was observed even at 30 ppm. However, deltamethrin (at 50 ppm) elicited 75.0 ± 10.76% mortality against H. bispinosa, 65.8% inhibition of fecundity and very low egg hatching (10%). The LC50 for deltamethrin against susceptible H. bispinosa was 33.8 ppm. Coumaphos at 50 ppm, caused mortality of 70.8 ± 4.17% with R. (B.) annulatus whereas 100% mortality was observed against H. bispinosa. The LC50 values of coumaphos against R. (B.) annulatus and H. bispinosa were 9 and 8.75 ppm, respectively. Complete inhibition (100%) of fecundity was observed even at 30 ppm against both parasites. Complete blocking of egg hatching was also observed even at 10 ppm of coumaphos. Lindane at 1000 ppm caused mortality of 87.5 ± 7.98% against R. (B.) annulatus and 83.3% mortality against H. bispinosa at 100 ppm. The LC50 values of lindane against R. (B.) annulatus and H. bispinosa were 157 and 8.61 ppm, respectively. Complete inhibition of fecundity was observed with R. (B.) annulatus treated with lindane above 200 ppm and with H. bispinosa at a concentration above 50 ppm. Complete blocking of egg hatching was observed in R. (B.) annulatus, even at 100 ppm. Lindane caused 100% blocking of egg hatching at 1 ppm in the case of H. bispinosa. [ABSTRACT FROM AUTHOR]

Bees are natural pollinators, which are able to pollinate most flowers in the world. The serious problem of bee population is an external parasite mite Varroa destructor that causes many viral and bacterial diseases of bees like American foulbrood, European foulbrood or black queen cell virus. It is very important to find a safe and effective treatment against Varroa destructor. There are several methods to fight the parasite, one often used is to remove capped drone brood. Another method is to use various chemical compounds. The aim of this study was to evaluate the effectiveness of five commonly applied commercial products: flumethrin, coumaphos, amitraz, formic acid and thymol. According to the obtained results, the effectiveness of these compounds was about 90%, 82%, 91%, 57% and 56%, respectively. Fumigation with amitraz turned out to be the quickest and the most effective method to fight against Varroa. All treatment were carried out in private apiaries located in north-eastern Poland, in Podlaskie Voivodeship. Every chemical compound was tested on six bee colonies. [ABSTRACT FROM AUTHOR]