The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Martín Javier Eguaras - One of the best experts on this subject based on the ideXlab platform.
-
Heat shock proteins in Varroa destructor exposed to heat stress and in-hive Acaricides
Experimental and Applied Acarology, 2018Co-Authors: P. M. Garrido, Sergio Roberto Ruffinengo, Martín Pablo Porrini, Giselle María Astrid Martínez-noël, N. Damiani, G. Salerno, Martín Javier EguarasAbstract:Varroa destructor is one of the major pests that affect honeybees around the world. Chemical treatments are common to control varroosis, but mites possess biochemical adaptive mechanisms to resist these treatments, enabling them to survive. So far, no information is available regarding whether these pesticides can induce the expression of heat shock protein (Hsp) as a common protective mechanism against tissue damage. The aims of this study were to determine differences in heat shock tolerance between mites collected from brood combs and phoretic ones, and to examine patterns of protein expression of Hsp70 that occur in various populations of V. destructor after exposure to Acaricides commonly employed in beekeeping, such as flumethrin, tau -fluvalinate and coumaphos. Curiously, mites obtained from brood cells were alive at 40 °C, unlike phoretic mites that reached 100% mortality, demonstrating differential thermo-tolerance. Heat treatment induced Hsp70 in mites 4 × more than in control mites and no differences in response were observed in phoretic versus cell-brood-obtained mites. Dose–response assays were carried out at increasing Acaricide concentrations. Each population showed a different stress response to Acaricides despite belonging to the same geographic region. In one of them, coumaphos acted as a hormetic stressor. Pyrethroids also induced Hsp70, but mite population seemed sensitive to this treatment. We concluded that Hsp70 could represent a robust biomarker for measuring exposure of V. destructor to thermal and chemical stress, depending on the Acaricide class and interpopulation variability. This is relevant because it is the first time that stress response is analyzed in this biological model, providing new insight in host-parasite-xenobiotic interaction.
-
Sublethal effects of Acaricides and Nosema ceranae infection on immune related gene expression in honeybees
Veterinary Research, 2016Co-Authors: Paula Melisa Garrido, Martín Javier Eguaras, Martín Pablo Porrini, Karina Antúnez, Belén Branchiccela, Giselle María Astrid Martínez-noël, Pablo Zunino, Graciela Salerno, Elena IenoAbstract:AbstractNosema ceranae is an obligate intracellular parasite and the etiologic agent of Nosemosis that affects honeybees. Beside the stress caused by this pathogen, honeybee colonies are exposed to pesticides under beekeeper intervention, such as Acaricides to control Varroa mites. These compounds can accumulate at high concentrations in apicultural matrices. In this work, the effects of parasitosis/Acaricide on genes involved in honeybee immunity and survival were evaluated. Nurse bees were infected with N. ceranae and/or were chronically treated with sublethal doses of coumaphos or tau-fluvalinate, the two most abundant pesticides recorded in productive hives. Our results demonstrate the following: (1) honeybee survival was not affected by any of the treatments; (2) parasite development was not altered by Acaricide treatments; (3) coumaphos exposure decreased lysozyme expression; (4) N. ceranae reduced levels of vitellogenin transcripts independently of the presence of Acaricides. However, combined effects among stressors on imagoes were not recorded. Sublethal doses of Acaricides and their interaction with other ubiquitous parasites in colonies, extending the experimental time, are of particular interest in further research work.
-
susceptibility of varroa destructor acari varroidae to synthetic Acaricides in uruguay varroa mites potential to develop Acaricide resistance
Parasitology Research, 2011Co-Authors: Matias Maggi, Sergio Roberto Ruffinengo, Yamandu Mendoza, Pilar Ojeda, Gustavo Ramallo, Iganazio Floris, Martín Javier EguarasAbstract:The purpose of this study was to estimate the Acaricide susceptibility of Varroa destructor populations from Uruguay, which had never been exposed to synthetic Acaricides. It was also to determine whether Acaricide resistance to coumaphos occurred in apiaries in which Acaricide rotation had been applied. Bioassays with Acaricides against mite populations that had never been exposed to synthetic Acaricides were performed, also against mite populations in which control failures with coumaphos had been reported. Additionally, coumaphos’ effectiveness in honeybee colonies was experimentally tested. The lethal concentration that kills 50% of the exposed animals (LC50) for susceptible mite populations amounted to 0.15 μg/Petri dish for coumaphos and to less than 0.3 μg/Petri dish for the other Acaricides. Coumaphos LC50 was above 40 μg/Petri dish for resistant mites. The effectiveness of coumaphos in honeybee colonies parasitized by V. destructor ranged from 17.6% to 93.9%. LC50 for mite populations susceptible to the most commonly applied miticides was determined, and the first case of coumaphos resistance recorded in Uruguay was established.
-
resistance phenomena to amitraz from populations of the ectoparasitic mite varroa destructor of argentina
Parasitology Research, 2010Co-Authors: Matias Maggi, Pedro Negri, Sergio Roberto Ruffinengo, Martín Javier EguarasAbstract:In Argentina, Varroa destructor resistance to coumaphos has been previously reported. However, the status of mite susceptibility to other hard Acaricides is still unknown. At present, high infestation levels of V. destructor are being detected in colonies of Apis mellifera after treatment with amitraz. The aim of the present study was to determine the LC50 of amitraz in V. destructor from three apiaries with high mite density after treatment with the Acaricide. The LC50 values were 3.9, 3.5, and 3.7 μg/Petri dish for mites from three different apiaries. Significant LC50 differences were detected between resistant and susceptible mites. LC50 increased 35–39-fold when compared to the corresponding baseline, suggesting the development of resistance. These results are the first report of resistance to amitraz in V. destructor in Argentina and extend the knowledge according to the status of Acaricides resistance in the country.
-
lc50 baseline levels of amitraz coumaphos fluvalinate and flumethrin in populations of varroa destructor from buenos aires province argentina
Journal of Apicultural Research, 2008Co-Authors: Matias Maggi, Martín Javier Eguaras, Sergio Roberto Ruffinengo, Liesel B. Gende, Norma H SardellaAbstract:SummaryThis study estimates the LC50 baseline levels for amitraz, coumaphos, fluvalinate, and flumethrin in susceptible Varroa destructor populations in Argentina. Concentration response bioassays were conducted with each Acaricide. Laboratory results of lethal concentrations (LC50) were: 0.1 μg/dish for amitraz; 0.29 μg/dish for fluvalinate; 0.34 μg/dish for flumethrin; and 0.57 μg/dish for coumaphos, respectively. All tests guaranteed 100 % bee survival. LC50 references for mite populations susceptible to the most commonly used Acaricides were thus established for Argentina, which will aid the establishment of integrated pest management programmes for V. destructor.
Gary Lukacik - One of the best experts on this subject based on the ideXlab platform.
-
Effectiveness of Residential Acaricides to Prevent Lyme and Other Tick-borne Diseases in Humans
The Journal of infectious diseases, 2016Co-Authors: Alison F. Hinckley, James I. Meek, Julie A. E. Ray, Sara A. Niesobecki, Neeta P. Connally, Katherine A. Feldman, Erin H. Jones, P. Bryon Backenson, Jennifer L. White, Gary LukacikAbstract:Background In the northeastern United States, tick-borne diseases are a major public health concern. In controlled studies, a single springtime application of Acaricide has been shown to kill 68%-100% of ticks. Although public health authorities recommend use of Acaricides to control tick populations in yards, the effectiveness of these pesticides to prevent tick bites or human tick-borne diseases is unknown. Methods We conducted a 2-year, randomized, double-blinded, placebo-controlled trial among 2727 households in 3 northeastern states. Households received a single springtime barrier application of bifenthrin or water according to recommended practices. Tick drags were conducted 3-4 weeks after treatment on 10% of properties. Information on human-tick encounters and tick-borne diseases was collected through monthly surveys; reports of illness were validated by medical record review. Results Although the abundance of questing ticks was significantly lower (63%) on Acaricide-treated properties, there was no difference between treatment groups in human-tick encounters, self-reported tick-borne diseases, or medical-record-validated tick-borne diseases. Conclusions Used as recommended, Acaricide barrier sprays do not significantly reduce the household risk of tick exposure or incidence of tick-borne disease. Measures for preventing tick-borne diseases should be evaluated against human outcomes to confirm effectiveness.
Ronald Davey - One of the best experts on this subject based on the ideXlab platform.
-
chemical control of ticks on cattle and the resistance of these parasites to Acaricides
Parasitology, 2004Co-Authors: Joh E George, J M Pound, Ronald DaveyAbstract:Toward the end of the nineteenth century a complex of problems related to ticks and tick-borne diseases of cattle created a demand for methods to control ticks and reduce losses of cattle. The discovery and use of arsenical solutions in dipping vats for treating cattle to protect them against ticks revolutionized tick and tick-borne disease control programmes. Arsenic dips for cattle were used for about 40 years before the evolution of resistance of ticks to the chemical, and the development and marketing of synthetic organic Acaricides after World War II provided superior alternative products. Most of the major groups of organic pesticides are represented on the list of chemicals used to control ticks on cattle. Unfortunately, the successive evolution of resistance of ticks to Acaricides in each chemical group with the concomitant reduction in the usefulness of a group of Acaricides is a major reason for the diversity of Acaricides. Whether a producer chooses a traditional method for treating cattle with an Acaricide or uses a new method, he must recognize the benefits, limitations and potential problems with each application method and product. Simulation models and research were the basis of recommendations for tick control strategies advocating approaches that reduced reliance on Acaricides. These recommendations for controlling ticks on cattle are in harmony with recommendations for reducing the rate of selection for Acaricide resistance. There is a need to transfer knowledge about tick control and resistance mitigation strategies to cattle producers.
Matias Maggi - One of the best experts on this subject based on the ideXlab platform.
-
susceptibility of varroa destructor acari varroidae to synthetic Acaricides in uruguay varroa mites potential to develop Acaricide resistance
Parasitology Research, 2011Co-Authors: Matias Maggi, Sergio Roberto Ruffinengo, Yamandu Mendoza, Pilar Ojeda, Gustavo Ramallo, Iganazio Floris, Martín Javier EguarasAbstract:The purpose of this study was to estimate the Acaricide susceptibility of Varroa destructor populations from Uruguay, which had never been exposed to synthetic Acaricides. It was also to determine whether Acaricide resistance to coumaphos occurred in apiaries in which Acaricide rotation had been applied. Bioassays with Acaricides against mite populations that had never been exposed to synthetic Acaricides were performed, also against mite populations in which control failures with coumaphos had been reported. Additionally, coumaphos’ effectiveness in honeybee colonies was experimentally tested. The lethal concentration that kills 50% of the exposed animals (LC50) for susceptible mite populations amounted to 0.15 μg/Petri dish for coumaphos and to less than 0.3 μg/Petri dish for the other Acaricides. Coumaphos LC50 was above 40 μg/Petri dish for resistant mites. The effectiveness of coumaphos in honeybee colonies parasitized by V. destructor ranged from 17.6% to 93.9%. LC50 for mite populations susceptible to the most commonly applied miticides was determined, and the first case of coumaphos resistance recorded in Uruguay was established.
-
resistance phenomena to amitraz from populations of the ectoparasitic mite varroa destructor of argentina
Parasitology Research, 2010Co-Authors: Matias Maggi, Pedro Negri, Sergio Roberto Ruffinengo, Martín Javier EguarasAbstract:In Argentina, Varroa destructor resistance to coumaphos has been previously reported. However, the status of mite susceptibility to other hard Acaricides is still unknown. At present, high infestation levels of V. destructor are being detected in colonies of Apis mellifera after treatment with amitraz. The aim of the present study was to determine the LC50 of amitraz in V. destructor from three apiaries with high mite density after treatment with the Acaricide. The LC50 values were 3.9, 3.5, and 3.7 μg/Petri dish for mites from three different apiaries. Significant LC50 differences were detected between resistant and susceptible mites. LC50 increased 35–39-fold when compared to the corresponding baseline, suggesting the development of resistance. These results are the first report of resistance to amitraz in V. destructor in Argentina and extend the knowledge according to the status of Acaricides resistance in the country.
-
lc50 baseline levels of amitraz coumaphos fluvalinate and flumethrin in populations of varroa destructor from buenos aires province argentina
Journal of Apicultural Research, 2008Co-Authors: Matias Maggi, Martín Javier Eguaras, Sergio Roberto Ruffinengo, Liesel B. Gende, Norma H SardellaAbstract:SummaryThis study estimates the LC50 baseline levels for amitraz, coumaphos, fluvalinate, and flumethrin in susceptible Varroa destructor populations in Argentina. Concentration response bioassays were conducted with each Acaricide. Laboratory results of lethal concentrations (LC50) were: 0.1 μg/dish for amitraz; 0.29 μg/dish for fluvalinate; 0.34 μg/dish for flumethrin; and 0.57 μg/dish for coumaphos, respectively. All tests guaranteed 100 % bee survival. LC50 references for mite populations susceptible to the most commonly used Acaricides were thus established for Argentina, which will aid the establishment of integrated pest management programmes for V. destructor.
Alison F. Hinckley - One of the best experts on this subject based on the ideXlab platform.
-
Effectiveness of Residential Acaricides to Prevent Lyme and Other Tick-borne Diseases in Humans
The Journal of infectious diseases, 2016Co-Authors: Alison F. Hinckley, James I. Meek, Julie A. E. Ray, Sara A. Niesobecki, Neeta P. Connally, Katherine A. Feldman, Erin H. Jones, P. Bryon Backenson, Jennifer L. White, Gary LukacikAbstract:Background In the northeastern United States, tick-borne diseases are a major public health concern. In controlled studies, a single springtime application of Acaricide has been shown to kill 68%-100% of ticks. Although public health authorities recommend use of Acaricides to control tick populations in yards, the effectiveness of these pesticides to prevent tick bites or human tick-borne diseases is unknown. Methods We conducted a 2-year, randomized, double-blinded, placebo-controlled trial among 2727 households in 3 northeastern states. Households received a single springtime barrier application of bifenthrin or water according to recommended practices. Tick drags were conducted 3-4 weeks after treatment on 10% of properties. Information on human-tick encounters and tick-borne diseases was collected through monthly surveys; reports of illness were validated by medical record review. Results Although the abundance of questing ticks was significantly lower (63%) on Acaricide-treated properties, there was no difference between treatment groups in human-tick encounters, self-reported tick-borne diseases, or medical-record-validated tick-borne diseases. Conclusions Used as recommended, Acaricide barrier sprays do not significantly reduce the household risk of tick exposure or incidence of tick-borne disease. Measures for preventing tick-borne diseases should be evaluated against human outcomes to confirm effectiveness.
