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Irrigation runoff and soil samples were collected from a lettuce field located at the USDA-ARS Spence Research farm in the Salinas Valley, California to measure neonicotinoid insecticides (clothianidin and imidacloprid) and a fungicide (azoxystrobin) applied via coated seed and drench treatments. The field trial was designed to evaluate four treatments with replication: 1) control, untreated seed, 2) imidacloprid treated seed, 3) clothianidin treated seed, and 4) azoxystrobin treated seed with an imidacloprid drench. Samples were collected from each treatment over two lettuce growing seasons: August to October 2019 and September to October 2020. Runoff samples were collected over both growing seasons during 6 irrigation...
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Hybrid sunflower production occurs near Sacramento in Northern California where seed treatments are commonly used. In this study, four locations were sampled in 2016 as matched pairs; half of each field was sown with thiamethoxam treated seed and half without. In addition to the thiamethoxam seed treatment, all seeds were coated with two fungicides, fludioxonil and mefenoxam/metalaxyl. Both wild bee and honey bee pesticide exposure was assessed by analyzing field soil, sunflower pollen and nectar, honey bees (pollen and nectar foraging) and a sunflower specialist wild bee, Melissodes agilis. Samples were extracted via pressurized liquid extraction (except nectar which underwent a room temperature solvent extraction)...
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Surface water samples were collected from four stream/agricultural drain sites in the Sacramento Valley of California to measure pesticides commonly applied to rice. Samples were collected weekly from May through August 2010 to capture the rice pesticide application season. Water samples were filtered (0.7 µm) and extracted via solid-phase extraction. Additionally, the filter paper was solvent extracted to measure suspended sediment-associated pesticides. Both fractions were analyzed via gas chromatography-mass spectrometry. A total of 89 pesticides and pesticide degradates were measured in the dissolved water phase, while 14 pyrethroid insecticides were measured in the suspended sediment-associated fraction (pyrethroids...
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To better understand the exposure of wild bees to pesticides in an agricultural landscape, samples were collected from fields in northern California. Hedgerows are known to provide habitat for wild bees, but these bees may also be exposed to pesticides from nearby agricultural fields. The study included eight hedgerow sites located in an intensively managed agricultural landscape that includes almonds, (wine) grapes, rice, tomatoes, and walnuts. In addition to collecting both wild bees and honey bees, soil, flowers, and silicone passive sampling devices (PSD; staked near the hedgerows to sample the air) were also included. Sampling was conducted from April to June 2016, to coincide with peak bloom and bee activity...
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Japanese quail (Coturnix japonica) were orally dosed with pesticide-treated or control-untreated wheat seeds. Pesticide treated wheat seeds were analytically verified for active ingredients of imidacloprid, metalaxyl, tebuconazole, and fludioxonil. Pesticide and metabolite residues were measured in plasma, liver, brain, kidney, muscle, and excreta of exposed and control birds. Samples were extracted via solid phase extraction, pressurized liquid extraction, or sonication. Clean-up steps included protein precipitation followed by solid phase extraction. All samples were analyzed by liquid chromatography tandem mass spectrometry.
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Lab-reared colonies of Bombus huntii (Hunt bumble bee) were deployed in a commercial cherry orchard in the spring of 2016. A fungicide formulation containing boscalid (25.2%) and pyraclostrobin (12.8%) was applied one time at the recommended label rate. Nectar and pollen were collected daily, beginning two days before spray application and continuing for ten days following. Nectar samples were extracted with acetonitrile and cleaned up using dispersive solid-phase extraction with primary-secondary amine, C18, and magnesium sulfate. Pollen samples were extracted with ethyl acetate. Both types of samples were analyzed by GC-MS/MS for boscalid and pyraclostrobin. Fungicide concentrations in nectar varied spatially...
    map background search result map search result map Fungicides in nectar and pollen collected by bumble bees in a cherry orchard Concentrations of pesticides in multiple matrices to measure exposure of wild bees visiting pollinator hedgerows in northern California Pesticide concentrations in surface waters of the Sacramento Valley rice-growing region, 2010 Pesticide concentrations in bees and other matrices collected from sunflower fields (with and without a neonicotinoid seed treatment) near Sacramento, California Insecticide and fungicide concentrations in irrigation runoff and soils from a lettuce field in the Salinas Valley, California, 2019 and 2020 Insecticide and fungicide concentrations in irrigation runoff and soils from a lettuce field in the Salinas Valley, California, 2019 and 2020 Pesticide concentrations in bees and other matrices collected from sunflower fields (with and without a neonicotinoid seed treatment) near Sacramento, California Concentrations of pesticides in multiple matrices to measure exposure of wild bees visiting pollinator hedgerows in northern California Pesticide concentrations in surface waters of the Sacramento Valley rice-growing region, 2010 Fungicides in nectar and pollen collected by bumble bees in a cherry orchard