A recent reconnaissance study by the U.S. Geological Survey (USGS) demonstrates the first observed occurrence of pesticides, including neonicotinoid insecticides, in wild-caught native bees. The results indicate that native bees collected in an agricultural landscape are exposed to multiple pesticides including insecticides, fungicides, and herbicides. This reconnaissance study is the first step in understanding the exposure of native bee populations to pesticides in relation to the surrounding landscape.
Native bees foraging in grasslands and agricultural fields provide ecosystem services through pollination and may play a greater role in the future as honey bee populations decline worldwide. It is unclear how the widespread use of pesticides may affect native bees as they move across the broader agricultural landscape.
USGS scientists initiated a field-based reconnaissance study to determine the exposure of native bees to pesticides. A total of 54 composite samples of native bees were collected over two field seasons from traps in northeastern Colorado in both grasslands and wheat fields. The samples were then tested for 122 different pesticides and 14 pesticide breakdown products.
Nineteen pesticides and breakdown products were detected in native bees from all sites sampled in 2013 and 2014. The neonicotinoid insecticide, thiamethoxam, was the most frequently detected pesticide (present in 46 percent of the samples). Native bees in the non-agricultural grasslands were determined to have at least one of the pesticides measured, which indicates they were potentially exposed to pesticides applied to nearby agricultural areas. Pesticide concentrations and detections were generally less in bees collected in grasslands with a smaller percentage of active agriculture within 1 kilometer, which is the maximum foraging distance for native bees. As a result, it seems that the land cover surrounding the agricultural fields could be an important factor for consideration in conservation planning.
Although overall toxicity of these pesticides to native bees is unknown, the chemicals do not have to kill the bees to have an effect. For example, neonicotinoids can cause a reduction in population densities and reproductive success, and impairing the bees' ability to forage. Insecticides and fungicides can also increase a bee's susceptibility to disease and parasites.
The pesticide residues documented in native bees in this preliminary field-based reconnaissance study provides critical information necessary to design more focused research on exposure, uptake, and accumulation of pesticides relative to land use, agricultural practices, and pollinator conservation efforts on the landscape.
This research was funded by the USGS Ecosystems Mission Area’s Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology), USGS Wildlife: Terrestrial and Endangered Resources program and the U.S. Department of Agriculture Farm Service Agency.
Below are other science projects associated with this project.
Food Resources Lifecycle Integrated Science Team
Organic Chemistry Research — Sacramento, California
Pesticide Fate Research Group (PFRG)
Scientists Start at the Base of the Food Chain to Understand Contaminant Affects on Energy Cycling in Streams
New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams
Pesticide Contamination and Environmental Exposure
First National-Scale Reconnaissance of Neonicotinoid Insecticides in United States Streams
Neonicotinoid Insecticides Documented in Midwestern U.S. Streams
Common Weed Killer is Widespread in the Environment
Pesticides Common in California Estuary
Pesticides Found in Amphibians from Remote Areas in California
Mixtures of Pesticides Detected in Crab Embryos
Understudied Fungicides Common in U.S. Streams Draining Agricultural Land
- Overview
A recent reconnaissance study by the U.S. Geological Survey (USGS) demonstrates the first observed occurrence of pesticides, including neonicotinoid insecticides, in wild-caught native bees. The results indicate that native bees collected in an agricultural landscape are exposed to multiple pesticides including insecticides, fungicides, and herbicides. This reconnaissance study is the first step in understanding the exposure of native bee populations to pesticides in relation to the surrounding landscape.
Sources/Usage: Public Domain.Native bee foraging on a native flower in Logan County, Colorado. Photo Credit: Mark Vandever, USGS. Native bees foraging in grasslands and agricultural fields provide ecosystem services through pollination and may play a greater role in the future as honey bee populations decline worldwide. It is unclear how the widespread use of pesticides may affect native bees as they move across the broader agricultural landscape.
USGS scientists initiated a field-based reconnaissance study to determine the exposure of native bees to pesticides. A total of 54 composite samples of native bees were collected over two field seasons from traps in northeastern Colorado in both grasslands and wheat fields. The samples were then tested for 122 different pesticides and 14 pesticide breakdown products.
Nineteen pesticides and breakdown products were detected in native bees from all sites sampled in 2013 and 2014. The neonicotinoid insecticide, thiamethoxam, was the most frequently detected pesticide (present in 46 percent of the samples). Native bees in the non-agricultural grasslands were determined to have at least one of the pesticides measured, which indicates they were potentially exposed to pesticides applied to nearby agricultural areas. Pesticide concentrations and detections were generally less in bees collected in grasslands with a smaller percentage of active agriculture within 1 kilometer, which is the maximum foraging distance for native bees. As a result, it seems that the land cover surrounding the agricultural fields could be an important factor for consideration in conservation planning.
Although overall toxicity of these pesticides to native bees is unknown, the chemicals do not have to kill the bees to have an effect. For example, neonicotinoids can cause a reduction in population densities and reproductive success, and impairing the bees' ability to forage. Insecticides and fungicides can also increase a bee's susceptibility to disease and parasites.
The pesticide residues documented in native bees in this preliminary field-based reconnaissance study provides critical information necessary to design more focused research on exposure, uptake, and accumulation of pesticides relative to land use, agricultural practices, and pollinator conservation efforts on the landscape.
This research was funded by the USGS Ecosystems Mission Area’s Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology), USGS Wildlife: Terrestrial and Endangered Resources program and the U.S. Department of Agriculture Farm Service Agency.
- Science
Below are other science projects associated with this project.
Food Resources Lifecycle Integrated Science Team
The team studies the movement of toxicants and pathogens that could originate from the growing, raising, and processing/manufacturing of plant and animal products through the environment where exposure can occur. This information is used to understand if there are adverse effects upon exposure and to develop decision tools to protect health.Filter Total Items: 13Organic Chemistry Research — Sacramento, California
About the ResearchThe Environmental Health Program collaborates with chemists and hydrologists at the Organic Chemistry Research Laboratory (OCRL) to develop targeted analytical methods for the quantitation of chemicals that can impact the health of organisms and humans. The scientists have developed methods in a wide variety of environmental media; in addition to water and sediment, they also...Pesticide Fate Research Group (PFRG)
Pesticides are applied in agricultural and urban areas to control weeds, insects, fungus, and other pests. Applied pesticides and their degradates can be transported off-site through a variety of mechanisms; these pesticides can then be found in non-target areas. Pesticide transport can occur through the atmosphere, in the aqueous phase (surface and groundwater) and associated with soil/sediment...Scientists Start at the Base of the Food Chain to Understand Contaminant Affects on Energy Cycling in Streams
Study examines the potential adverse effects of fungicides on leaf decomposition by microbes and aquatic invertebrates.New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams
First-ever reconnaissance study documents the off-field transport of nitrapyrin — a nitrification inhibitor applied with fertilizers as a bactericide to kill natural soil bacteria for the purpose of increasing crop yields — to adjacent streams. This study is the first step in understanding the transport, occurrence, and potential effects of nitrapyrin or similar compounds on nitrogen processing in...Pesticide Contamination and Environmental Exposure
The USGS is developing methods to measure new pesticides and their byproducts in environmental media, conducting studies on the fate of these chemicals, and assessing exposure and potential effects on fish, wildlife, and human health.First National-Scale Reconnaissance of Neonicotinoid Insecticides in United States Streams
Neonicotinoid insecticides (neonicotinoids) were present in a little more than half of the streams sampled across the United States and Puerto Rico, according to a new U.S. Geological Survey (USGS) study. This is the first national-scale study of the presence of neonicotinoids in urban and agricultural land use settings across the Nation and was completed as part of ongoing USGS investigations of...Neonicotinoid Insecticides Documented in Midwestern U.S. Streams
Three neonicotinoid insecticides (clothianidin, thiamethoxam and imidacloprid) were detected commonly throughout the growing season in water samples collected from nine Midwestern stream sites during the 2013 growing season according to a team of U.S. Geological Survey (USGS) scientists. Clothianidin was detected most frequently (75 percent) and at the highest maximum concentration (257 nanograms...Common Weed Killer is Widespread in the Environment
U.S. Geological Survey (USGS) scientists report that glyphosate, known commercially by many trade names, and its degradation product AMPA (aminomethylphosphonic acid) are transported off-site from agricultural and urban sources and occur widely in the environment. This study is the largest and most comprehensive assessment of the environmental occurrence of glyphosate and AMPA in the United States...Pesticides Common in California Estuary
Pesticides were observed frequently in water, sediment, and the tissue of resident aquatic organisms from an agriculturally dominated estuary along the central California coast according to a collaborative study by U.S. Geological Survey (USGS) and University of California, Davis scientists published in Marine Pollution Bulletin.Pesticides Found in Amphibians from Remote Areas in California
Amphibians from remote locations in California have accumulated several current-use pesticides, including fungicides, in their bodies. A team of U.S. Geological Survey (USGS) scientists recently reported on field results in the journal Environmental Toxicology and Chemistry. Two fungicides, pyraclostrobin and tebuconazole, and the herbicide simazine were detected frequently in amphibians from all...Mixtures of Pesticides Detected in Crab Embryos
Crab embryos from two Northern California salt marshes accumulate mixtures of currently used as well as discontinued pesticides, according to a study published by U.S. Geological Survey (USGS) and University of California scientists in the journal Environmental Toxicology and Chemistry.Understudied Fungicides Common in U.S. Streams Draining Agricultural Land
U.S. Geological Survey (USGS) scientists have detected one or more fungicides in 20 of 29 streams across the United States that were sampled during 2005 and 2006 in areas where soybeans are grown. The number of fungicides used has increased significantly since 2002, and very little is known about their occurrence in the environment. For some of the fungicides this is the first data documenting... - Publications
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