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Estelle Rathahao - One of the best experts on this subject based on the ideXlab platform.
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distribution of 14c Imidacloprid in sunflowers helianthus annuus l following seed treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the Imidacloprid seed treatment and the observed bee syndrome. This work studies the distribution of [(14)C-imidazolidin]Imidacloprid (1 mg/seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [(14)C]Imidacloprid spiked on seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, Imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-Imidacloprid have toxicities equivalent to that of Imidacloprid. In pollen, concentrations of Imidacloprid were 13 ng x g(-1). Thus, Imidacloprid residues from Gaucho seed treatment contaminated sunflower pollen, involving the translocation of Imidacloprid within the plant.
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distribution of 14c Imidacloprid in sunflowers helianthus annuus l following seed treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the Imidacloprid seed treatment and the observed bee syndrome. This work studies the distribution of [14C-imidazolidin]Imidacloprid (1 mg/seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [14C]Imidacloprid spiked on seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, Imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-Imidacloprid have toxicities equivalent to that of Imidacloprid. In pollen, concentrations of Imidacloprid were 13 ng·g-1. Thus, Imidacloprid re...
Francois Laurent - One of the best experts on this subject based on the ideXlab platform.
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distribution of 14c Imidacloprid in sunflowers helianthus annuus l following seed treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the Imidacloprid seed treatment and the observed bee syndrome. This work studies the distribution of [(14)C-imidazolidin]Imidacloprid (1 mg/seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [(14)C]Imidacloprid spiked on seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, Imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-Imidacloprid have toxicities equivalent to that of Imidacloprid. In pollen, concentrations of Imidacloprid were 13 ng x g(-1). Thus, Imidacloprid residues from Gaucho seed treatment contaminated sunflower pollen, involving the translocation of Imidacloprid within the plant.
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distribution of 14c Imidacloprid in sunflowers helianthus annuus l following seed treatment
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Francois Laurent, Estelle RathahaoAbstract:Imidacloprid, a neonicotinic insecticide, has been used as a seed dressing (Gaucho) to protect crops against soil and aerial insects. However, French beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the Imidacloprid seed treatment and the observed bee syndrome. This work studies the distribution of [14C-imidazolidin]Imidacloprid (1 mg/seed) in three stages of Gaucho-treated sunflowers grown in an outdoor lysimeter. Plants absorbed <10% of [14C]Imidacloprid spiked on seeds, and 75% of that absorbed radioactivity was found in cotyledons. Concentrations in the upper leaves were 20 times lower than in the first leaves. From the extracted radioactivity, Imidacloprid accounted for 50% and metabolites for the other 50%. Four major metabolites can be detected, in variable concentrations, among which the hydroxy- and olefin-Imidacloprid have toxicities equivalent to that of Imidacloprid. In pollen, concentrations of Imidacloprid were 13 ng·g-1. Thus, Imidacloprid re...
R. J. Nichols - One of the best experts on this subject based on the ideXlab platform.
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consequences of Imidacloprid treatments for hemlock woolly adelgid on stream water quality in the southern appalachians
Forest Ecology and Management, 2016Co-Authors: E. P. Benton, Jerome F. Grant, Thomas C Mueller, R J Webster, R. J. NicholsAbstract:Imidacloprid, a neonicotinoid pesticide, is commonly used in hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae), pest management programs to preserve hemlock resources. Great Smoky Mountains National Park (GRSM) has an extensive HWA integrated pest management program, with more than 200,000 individual hemlocks in the Park having received Imidacloprid soil treatments. A retrospective study was conducted in cooperation with GRSM to assess Imidacloprid and two of its insecticidal metabolites (5-hydroxy and olefin) are present in surface waters (i.e., streams) associated with HWA Imidacloprid treatment areas. Thirty stream locations were sampled in GRSM to assess the presence and concentration of Imidacloprid, 5-hydroxy, and olefin. Water samples were collected from 10 streams downstream from riparian areas where hemlocks received Imidacloprid soil treatments and immediately upstream from hemlock treatment areas in each of the selected 10 streams. In addition, water samples were collected from 10 control streams each in close proximity to one of the 10 streams flowing through treatment areas. The concentrations of Imidacloprid, 5-hydroxy, and olefin in parts per trillion (ppt) were determined by liquid chromatography mass spectroscopy (LC/MS). Data analysis included historical treatment data from GRSM. Data were analyzed using a Kruskal–Wallis test (P < 0.05), least significant difference (LSD), and a multiple regression (P < 0.05). Imidacloprid, in concentrations ranging from 28.5 to 379 ng L−1, was detected in 7 of the 10 downstream sampling locations. Upstream or adjacent stream locations did not have detectable concentrations of Imidacloprid. Five-hydroxy and olefin were not detected in any streams. A positive relationship between the total amount of Imidacloprid applied to a hemlock treatment area and the concentration of detectable Imidacloprid in the associated stream was observed. However, while Imidacloprid was detected in streams associated with hemlock treatment areas, the concentrations are below USEPA chronic and acute aquatic life benchmarks for fish (1200 and 41,500 μg L−1, respectively) and aquatic macroinvertebrates (1.05 and 34.5 μg L−1, respectively). Since the amount of Imidacloprid applied in a treatment area has an influence on the concentration of Imidacloprid in streams, resource managers must carefully consider the frequency and extent of Imidacloprid applications to meet management goals while providing minimal environmental impact.
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Assessing relationships between tree diameter and long-term persistence of Imidacloprid and olefin to optimize Imidacloprid treatments on eastern hemlock
Forest Ecology and Management, 2016Co-Authors: E. P. Benton, Jerome F. Grant, Richard S. Cowles, J. Webster, R. J. Nichols, Anthony F. Lagalante, Carla CootsAbstract:Abstract Hemlock woolly adelgid (HWA), Adelges tsugae (Annand), has caused widespread eastern hemlock mortality in the eastern U.S. HWA was first documented in Great Smoky Mountains National Park (GRSM) in 2002. Once documented, GRSM implemented an aggressive integrated pest management (IPM) program. As a part of this IPM strategy, systemic Imidacloprid treatments have been widely used to preserve the Park’s hemlock resources. A retrospective study was conducted in cooperation with GRSM to examine the long-term effectiveness of Imidacloprid treatments on different size hemlock trees. Of particular interest is olefin, a metabolite of Imidacloprid, which is greater than 15 times more toxic to HWA than Imidacloprid. The concentrations of Imidacloprid and olefin were assessed in hemlock branchlets four to seven years post-Imidacloprid treatment. Samples were collected from three strata of the canopy from each of four size classes (30, 45, 61, and 76 cm DBH). Imidacloprid and olefin were present in all size classes four to seven years after a single Imidacloprid treatment. Hemlocks from the 61 and 76 cm size classes exhibited higher Imidacloprid and olefin concentrations than the 45 cm hemlocks when larger hemlocks were given high-dose treatments. When all hemlocks were given low-dose treatments, 61 cm hemlocks had lower concentrations of olefin, but no significant differences in Imidacloprid concentrations among size classes were detected. Olefin concentrations were higher in high-dose compared to low-dose treatments in 76 cm hemlocks. A significant linear relationship exists between the concentration of Imidacloprid and olefin in individual branchlets. A model was developed to optimize the dose of Imidacloprid based on the diameter of hemlock trees. Use of this model will result in smaller ( 63 cm) hemlocks receiving lower doses of Imidacloprid with expected HWA suppression numerous years after treatment. Information obtained from this study can assist resource managers in developing and modifying HWA suppression programs to maintain low HWA populations while reducing the amount of Imidacloprid applied to individual hemlocks. Optimal pesticide applications based on specific hemlock diameters may result in more environmentally and economically sustainable hemlock management programs.
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assessment of Imidacloprid and its metabolites in foliage of eastern hemlock multiple years following treatment for hemlock woolly adelgid adelges tsugae hemiptera adelgidae in forested conditions
Journal of Economic Entomology, 2015Co-Authors: E. P. Benton, Jerome F. Grant, Richard S. Cowles, R. J. Nichols, Anthony F. Lagalante, R J Webster, Carla CootsAbstract:Widespread decline and mortality of eastern hemlock, Tsuga canadensis (L.) Carriere, have been caused by hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae). The current study is a retrospective analysis conducted in collaboration with Great Smoky Mountains National Park (GRSM) to determine longevity of Imidacloprid and its insecticidal metabolites (Imidacloprid olefin, 5-hydroxy, and dihydroxy) in GRSM's HWA integrated pest management (IPM) program. Foliage samples were collected from three canopy strata of hemlocks that were given Imidacloprid basal drench treatments 4-7 yr prior to sampling. Foliage was analyzed to assess concentrations in parts per billion (ppb) of Imidacloprid and its metabolites. Imidacloprid and its olefin metabolite were present in most, 95 and 65%, respectively, branchlets 4-7 yr post-treatment, but the 5-hydroxy and dihydroxy metabolites were present in only 1.3 and 11.7%, respectively, of the branchlets. Imidacloprid and olefin concentrations significantly decreased between 4 and 7 yr post-treatment. Concentrations of both Imidacloprid and olefin were below the LC50 for HWA 5-7 yr post-treatment. Knowledge of the longevity of Imidacloprid treatments and its metabolite olefin can help maximize the use of Imidacloprid in HWA IPM programs.
Yong-lak Park - One of the best experts on this subject based on the ideXlab platform.
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Bioaccumulation of the pesticide Imidacloprid in stream organisms and sublethal effects on salamanders
Global Ecology and Conservation, 2020Co-Authors: Sara M. Crayton, Petra Bohall Wood, Donald J. Brown, Alice R. Millikin, Terence J. Mcmanus, Tyler J. Simpson, Yong-lak ParkAbstract:Abstract Neonicotinoids are one of the most widely used classes of insecticides in the world. The neonicotinoid Imidacloprid is commonly applied to hemlock (Tsuga spp.) stands in eastern North America to reduce tree mortality from infestations of the invasive hemlock woolly adelgid (HWA; Adelges tsugae). While laboratory and mesocosm studies have determined that Imidacloprid can bioaccumulate in anurans and cause sublethal effects, no field studies have investigated whether salamanders or insects in streams adjacent to HWA treatments bioaccumulate Imidacloprid or if sublethal effects are detectable in wild salamanders. We assessed relationships between Imidacloprid exposure and stream salamander health in West Virginia, USA, using concentration of the stress hormone corticosterone and body condition indices (BCI) as response variables. Of 107 Desmognathus salamanders from 11 sites tested for bioaccumulation, we detected Imidacloprid in 47 salamanders. Of 15 benthic macroinvertebrate samples tested, we detected Imidacloprid, Imidacloprid-urea, and Imidacloprid-olefin in 15, 13, and 1 sample, respectively. Based on 115 Desmognathus salamanders sampled at 11 sites for stress hormone responses, corticosterone concentration increased with Imidacloprid concentration in stream water. For 802 salamanders sampled at 48 sites, BCI decreased as concentration of Imidacloprid in stream water increased, but explanatory power was low. Our study suggests that chronic leaching of Imidacloprid from treated hemlock stands into adjacent streams has the potential to negatively affect aquatic organisms and may provide a route of exposure to higher trophic levels.
E. P. Benton - One of the best experts on this subject based on the ideXlab platform.
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consequences of Imidacloprid treatments for hemlock woolly adelgid on stream water quality in the southern appalachians
Forest Ecology and Management, 2016Co-Authors: E. P. Benton, Jerome F. Grant, Thomas C Mueller, R J Webster, R. J. NicholsAbstract:Imidacloprid, a neonicotinoid pesticide, is commonly used in hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae), pest management programs to preserve hemlock resources. Great Smoky Mountains National Park (GRSM) has an extensive HWA integrated pest management program, with more than 200,000 individual hemlocks in the Park having received Imidacloprid soil treatments. A retrospective study was conducted in cooperation with GRSM to assess Imidacloprid and two of its insecticidal metabolites (5-hydroxy and olefin) are present in surface waters (i.e., streams) associated with HWA Imidacloprid treatment areas. Thirty stream locations were sampled in GRSM to assess the presence and concentration of Imidacloprid, 5-hydroxy, and olefin. Water samples were collected from 10 streams downstream from riparian areas where hemlocks received Imidacloprid soil treatments and immediately upstream from hemlock treatment areas in each of the selected 10 streams. In addition, water samples were collected from 10 control streams each in close proximity to one of the 10 streams flowing through treatment areas. The concentrations of Imidacloprid, 5-hydroxy, and olefin in parts per trillion (ppt) were determined by liquid chromatography mass spectroscopy (LC/MS). Data analysis included historical treatment data from GRSM. Data were analyzed using a Kruskal–Wallis test (P < 0.05), least significant difference (LSD), and a multiple regression (P < 0.05). Imidacloprid, in concentrations ranging from 28.5 to 379 ng L−1, was detected in 7 of the 10 downstream sampling locations. Upstream or adjacent stream locations did not have detectable concentrations of Imidacloprid. Five-hydroxy and olefin were not detected in any streams. A positive relationship between the total amount of Imidacloprid applied to a hemlock treatment area and the concentration of detectable Imidacloprid in the associated stream was observed. However, while Imidacloprid was detected in streams associated with hemlock treatment areas, the concentrations are below USEPA chronic and acute aquatic life benchmarks for fish (1200 and 41,500 μg L−1, respectively) and aquatic macroinvertebrates (1.05 and 34.5 μg L−1, respectively). Since the amount of Imidacloprid applied in a treatment area has an influence on the concentration of Imidacloprid in streams, resource managers must carefully consider the frequency and extent of Imidacloprid applications to meet management goals while providing minimal environmental impact.
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Assessing relationships between tree diameter and long-term persistence of Imidacloprid and olefin to optimize Imidacloprid treatments on eastern hemlock
Forest Ecology and Management, 2016Co-Authors: E. P. Benton, Jerome F. Grant, Richard S. Cowles, J. Webster, R. J. Nichols, Anthony F. Lagalante, Carla CootsAbstract:Abstract Hemlock woolly adelgid (HWA), Adelges tsugae (Annand), has caused widespread eastern hemlock mortality in the eastern U.S. HWA was first documented in Great Smoky Mountains National Park (GRSM) in 2002. Once documented, GRSM implemented an aggressive integrated pest management (IPM) program. As a part of this IPM strategy, systemic Imidacloprid treatments have been widely used to preserve the Park’s hemlock resources. A retrospective study was conducted in cooperation with GRSM to examine the long-term effectiveness of Imidacloprid treatments on different size hemlock trees. Of particular interest is olefin, a metabolite of Imidacloprid, which is greater than 15 times more toxic to HWA than Imidacloprid. The concentrations of Imidacloprid and olefin were assessed in hemlock branchlets four to seven years post-Imidacloprid treatment. Samples were collected from three strata of the canopy from each of four size classes (30, 45, 61, and 76 cm DBH). Imidacloprid and olefin were present in all size classes four to seven years after a single Imidacloprid treatment. Hemlocks from the 61 and 76 cm size classes exhibited higher Imidacloprid and olefin concentrations than the 45 cm hemlocks when larger hemlocks were given high-dose treatments. When all hemlocks were given low-dose treatments, 61 cm hemlocks had lower concentrations of olefin, but no significant differences in Imidacloprid concentrations among size classes were detected. Olefin concentrations were higher in high-dose compared to low-dose treatments in 76 cm hemlocks. A significant linear relationship exists between the concentration of Imidacloprid and olefin in individual branchlets. A model was developed to optimize the dose of Imidacloprid based on the diameter of hemlock trees. Use of this model will result in smaller ( 63 cm) hemlocks receiving lower doses of Imidacloprid with expected HWA suppression numerous years after treatment. Information obtained from this study can assist resource managers in developing and modifying HWA suppression programs to maintain low HWA populations while reducing the amount of Imidacloprid applied to individual hemlocks. Optimal pesticide applications based on specific hemlock diameters may result in more environmentally and economically sustainable hemlock management programs.
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assessment of Imidacloprid and its metabolites in foliage of eastern hemlock multiple years following treatment for hemlock woolly adelgid adelges tsugae hemiptera adelgidae in forested conditions
Journal of Economic Entomology, 2015Co-Authors: E. P. Benton, Jerome F. Grant, Richard S. Cowles, R. J. Nichols, Anthony F. Lagalante, R J Webster, Carla CootsAbstract:Widespread decline and mortality of eastern hemlock, Tsuga canadensis (L.) Carriere, have been caused by hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae). The current study is a retrospective analysis conducted in collaboration with Great Smoky Mountains National Park (GRSM) to determine longevity of Imidacloprid and its insecticidal metabolites (Imidacloprid olefin, 5-hydroxy, and dihydroxy) in GRSM's HWA integrated pest management (IPM) program. Foliage samples were collected from three canopy strata of hemlocks that were given Imidacloprid basal drench treatments 4-7 yr prior to sampling. Foliage was analyzed to assess concentrations in parts per billion (ppb) of Imidacloprid and its metabolites. Imidacloprid and its olefin metabolite were present in most, 95 and 65%, respectively, branchlets 4-7 yr post-treatment, but the 5-hydroxy and dihydroxy metabolites were present in only 1.3 and 11.7%, respectively, of the branchlets. Imidacloprid and olefin concentrations significantly decreased between 4 and 7 yr post-treatment. Concentrations of both Imidacloprid and olefin were below the LC50 for HWA 5-7 yr post-treatment. Knowledge of the longevity of Imidacloprid treatments and its metabolite olefin can help maximize the use of Imidacloprid in HWA IPM programs.
