Progress 12/15/20 to 06/14/22
Outputs
Target Audience:Specialty crop growers who depend on pollination services for maximizing crop yield are the main target audience for this project. Extension educators and researchers who work to improve and understand services provided by beneficial insects on farms are also a target audience. Installation of wildflower plantings adjacent to specialty crops has been increasing due to the expected benefits of increased pollination and natural enemy activity, and the availability of targeted funding to support this practice. Specialty crops are therefore an important system in which to study the risk of pesticides to bees in wildflower plantings. The need for assessments of wildflower plantings on agricultural lands are also imperative for the ongoing success of programs which provide support for growers implementing pollinator conservation management on their farms. This includes the USDA's Natural Resource Conservation Service (NRCS) and the Farm Service Agency (FSA). Providing additional guidelines to growers for how to mitigate risk from pesticides in wildflower plantings will help ensure the success of these investments over the long term. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?I have trained twopost graduate researchers in morphological pollen identification, and field collections of samples (bee pollen provisions and soil samples).This project has allowed me to expand on my knowledge of chemical control of pests in specialty crops, as well as their risks to bees. I've also been able to further develop my collaboration with the McArt lab at Cornell, which runs the Cornell Chemical Ecology Core Facility. I have also continued to build on my experiences in extension by presenting at the Great Lakes Expo, at the Alfalfa Growers Field Day, and the Western Alfalfa Seed Growers Association meetings. This project has also allowed me to continue growing my mentoring abilities, as I have mentored fourundergraduates and fourpost-grad technicians that have worked on this project. How have the results been disseminated to communities of interest?Results from this project have been disseminated to specialty crop growers through presentations (Great Lakes Expo, talk at the University of Illinois), one on one meetings, and through a handout at the Great Lakes Expo. They have also been disseminated to alfalfa seed growers at the Alfalfa Growers Field Day, and the Western Alfalfa Seed Growers Association meetings. I have also presented these data atthe American Chemical Society Fall 2022 meeting. Project results will also be disseminated to researchers and state/federal agencies through publication of peer-reviewed articles. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 1: Bumble bee pollen, soil samples, and flower samples collected in Summer 2019 on eight conventionally managed blueberry farms with and without wildflower plantings, and at four unsprayed blueberry farms (no pesticide applications). Flower and soil samples were collected both from within blueberry row middles and from the field margins (either within wildflower plantings or open areas adjacent to the blueberry rows. Samples were analyzed at the Cornell Chemical Ecology Core Facility (CCECF) for 261 pesticide residues via a modified QuECheRS extraction protocol. Exposure from bumble bee collected pollen samples - On average there were 17.1 ± 1.2 S.E. active ingredients (AIs) present in pollen samples. The average sample concentration was 1859.4ppb ± 577.7 S.E. Even though the pollen samples collected from the unsprayed farms had average concentrations of pesticides (644.1ppb ± 277.2) that were much lower than the conventional field types (With Planting: 2457.3ppb ± 1521.7; No Planting: 2476.6ppb ± 735.0), there was no significant difference between the field management types (p=0.30). The insecticide phosmet was found at high concentrations and frequency across pollen samples, though represented the greatest amount of exposure at conventional sites with no wildflower plantings (93.0%) and at unsprayed farms (83.8%). Phosmet was also highly represented in pollen from conventional farms with wildflower plantings (50.6%), though the insecticide methoxyfenozide was more common (50.6%). Exposure from flowers - On average there were 9.8 ± 0.5 active ingredients present in flower samples. The average sample concentration was 6054.5ppb ± 3182.5. There was no significant effect of field location (field margin or blueberry row middle) on sample concentration (p=0.21) or average number of active ingredients (p=0.33). There was no significant difference in average concentration or number of AIs in flower samples between conventionally managed sites with wildflower plantings (concentration: 8614.2ppb ± 7028.0; AIs: 11.0 ± 0.7) and conventionally managed sites without wildflower plantings (9070.9ppb ± 6004.4; 11.0 ± 0.9) (p>0.05). However, flowers from unsprayed farms had significantly lower average pesticide concentrations (13.5ppb ± 3.6) and lower average number of sample AIs (7.1 ± 0.6) compared to both conventional farm types (p<0.01). The insecticide phosmet was again found at high concentrations and frequency across flower samples, both at the different farm management types and comparing between flowers sampled from blueberry row middles and the field margins. Exposure from soil - On average there were 6.6 ± 0.5 active ingredients present in soil samples. The average sample concentration was 55.4ppb ± 9.7. There was a significant effect of field location (field margin or blueberry row middle) on sample concentration (p<0.01) and average number of active ingredients (p<0.01), with higher concentrations and greater number of active ingredients found in blueberry row middles. There was no significant difference in average concentration or number of AIs in soil samples between conventionally managed sites with wildflower plantings (concentration: 71.1ppb ± 15.5; AIs: 8.3 ± 1.0) and conventionally managed sites without wildflower plantings (85.2ppb ± 20.6; 7.7 ± 0.7) (p > 0.05). However, soil from unsprayed farms had significantly lower average pesticide concentrations (7.2ppb ± 3.0) and lower average number of sample AIs (3.7 ± 0.5) compared to both conventional farm types (p<0.01). The composition of pesticides found in the soil samples was very different from both the pollen and flower samples. Pesticides commonly applied on blueberry farms during bloom were much more abundant, including the insecticide methoxyfenozide, and the fungicides azoxystrobin and boscalid. Summary - Overall, pesticide exposure did not differ greatly between conventional farms with or without wildflower plantings. Though exposure was generally lower at unsprayed farms. The insecticide phosmet was the most commonly detected pesticide and at the highest concentrations. Phosmet is an organophosphate insecticide that is registered for use on blueberries for control of spotted wing drosophila, the most economically damaging pest of blueberries. It is considered high risk for bees. Exposure through soil was much different from pollen and flowers, with insecticides and fungicides commonly applied during blueberry bloom being the most commonly detected and at the highest concentrations. These pesticides are considered low (e.g. methoxyfenozide) to moderate (e.g. fenbuconazole) risk to bees. Additional work added in 2021 - Quantify pesticide exposure for alkali bees adjacent to alfalfa seed production. I similarly tested pesticide exposure within field margins in another important bee-pollinated crop, alfalfa seed production. Alkali bees, Nomia melanderi, are native solitary soil nesting bees that growers in the Touchet valley of Washington State have been managing for at least fifty years. In June 2021, I sampled soil from eight alkali bee nesting beds near Touchet, WA. To screen for pesticides in bee provisioned pollen, we dug up completed nests at eight productive bee beds. Each pollen provision was removed, and divided into two parts, one for pesticide residue analysis, and the other for pollen identification. We also identified pollen sources using morphological features to identify where bees were foraging. Alkali bee pesticide exposure - Across all eight beds, alfalfa pollen was the most abundant in provisions, making up 87.3% (mean ±1.0) of the pollen in provisions. The next most common pollen was bindweed (Convolvulus sp.), a common weed of agricultural fields in the area, and a species that Nomia are historically known to collect from (Bohart, 1950). We detected 13 AIs in the soil, and 13 in the pollen provisions, with 5 AIs shared across both substrates. In soil samples, the herbicide diuron was the most dominant for exposure. For pollen provisions, the insecticide flonicamid was the most dominant. Diuron is a pre-emergence herbicide for control of weeds that is used in alfalfa fields, and flonicamid is an insecticide used for the control of lygus bugs, especially during alfalfa bloom. Both are considered low risk to bees. Objective 2: Minimizing drift in field margins. We used silicone bands to passively sample drift at 15 farms. We placed silicone bands in two transects perpendicular to the crop field, at varying distances (0m, 2m, 4m, 8m, 16m, 24m, and 32m). Bands were left out for 1-2 weeks, allowing for at least one pesticide application in the focal field. Bands are currently being stored in the dark in a -30°C freezer at the Cornell Chemical Ecology Core Facility (CCECF). The CCECF staff are currently working to optimize extraction methods for these bands, so I am still awaiting the results. Objective 3: Pesticide risk mitigation - In conjunction with Objective 1, I have gathered spray records, information on spray methods (e.g., equipment used), measured the distance from crop to pollinator planting, and the distance from crop to the bumble bee Quad. I'm currently using multivariate statistics to determine whether these measured factors affect pesticide concentrations in bee collected pollen. I will use these results and results from measuring drift in Obj. 2 to formulate recommendations for minimizing risks to wild bees during the post-bloom period. Recommendations will then be shared with collaborating growers in reports and through ZOOM meetings, and to the community during extension meetings led by collaborating MSU Extension Educators and Specialists (Drs. Garcia-Salazar and Isaacs).
Publications
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Progress 12/15/20 to 12/14/21
Outputs
Target Audience:Specialty crop growers who depend on pollination services for maximizing crop yield are the main target audience for this project. Extension educators and researchers who work to improve and understand services provided by beneficial insects on farms are also a target audience. Installation of wildflower plantings adjacent to specialty crops has been increasing due to the expected benefits of increased pollination and natural enemy activity, and the availability of targeted funding to support this practice. Specialty crops are therefore an important system in which to study the risk of pesticides to bees in wildflower plantings. The need for assessments of wildflower plantings on agricultural lands are also imperative for the ongoing success of programs which provide support for growers implementing pollinator conservation management on their farms. This includes the USDA's Natural Resource Conservation Service (NRCS) and the Farm Service Agency (FSA). Providing additional guidelines to growers for how to mitigate risk from pesticides in wildflower plantings will help ensure the success of these investments over the long term. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?I have trained one post graduate researcher in morphological pollen identification, and field collections of samples (bee pollen provisions and soil samples). How have the results been disseminated to communities of interest?Results on pollen identification from alkali bee nests have been distributed to alfalfa seed growers in WA through a written report and a presentation at the 2022 Western Alfalfa Seed Growers meeting (January). What do you plan to do during the next reporting period to accomplish the goals?For data that I have, I'm actively working to wrap up data analysis and include these in manuscripts before the end of the project (June 2022).For the pesticide residue analysis on silicone bands, and the alkali bee samples, I am still waiting results and will work on data analysis as soon as these are in hand. I will set up meetings with MSU extension educators in summer 2022 to distribute results to Michigan blueberry growers. Results on alkali bees will be distributed to alfalfa seed growersat one-on-one meetings this June (I will providehandouts specific to each grower cooperator).
Impacts
What was accomplished under these goals?
Objective 1:Objective 1a: Identification and quantification of pesticides on farms. Bumble bee pollen, soil samples, and flower samples collected in Summer 2019 on blueberry farms with and without wildflower plantings. Samples were analyzed at the Cornell Chemical Ecology Core Facility (CCECF) for 261 pesticide residues via a modified QuECheRS extraction protocol and analyzed on an LC-MS/MS system. While campus access restrictions due to COVID-19 delayed the processing of these samples, I received the reports in Dec. 2020 and data is currently being analyzed. Objective 1b: Identify the bee community utilizing the floral resources on blueberry farms post bloom. I sampled the bee community at each site using an aerial net for 30 minutes. Bees have been identified to the lowest taxonomic level by an expert taxonomist (Dr. Jason Gibbs, University of Manitoba) who specializes in the hard to identify Dialictus group, which is common in this system. Data are currently being analyzed. Additional work added- Quantify pesticide exposure for alkali bees adjacent to alfalfa seed production. I similarly tested pesticide exposure within field margins in another important bee-pollinated crop, alfalfa seed production.In June 2021, I sampled soil from eight alkali bee beds near Touchet, WA, they ranged from very productive beds, to unproductive beds. At each bed, we used a 14 inch stainless steel soil sampler to sample at five locations in the bed. Each sample was then separated into top soil (upper 7" of the soil sample) and lower soil (lower 7"). The five upper soil samples at a bed were then combined into a single conglomerate sample, as were the five lower soil samples. Conglomerate samples were mixed in the bag, and then 5 grams (+/- 0.1g) were subsampled and sent to the Cornell Chemical Ecology Core Facility (CCECF) for residue analysis. At the CCECF, pesticide residues have been extracted, and are currently being identified and quantified using liquid chromatography mass spectrometry (LC-MS/MS). The CCECF will be screening for 95 pesticides in use across various crops. To screen for pesticides in bee provisioned pollen, we dug up completed nests at eight productive bee beds. At each bed, we used a shovel to remove roughly 0.5ft3 of soil at two sites with a lot of bee activity. Each sample was then placed in a shallow bin, and we carefully sorted through the samples to locate pollen provisions. Each pollen provision was removed, and divided into two parts, with each part going into its own sample tube, one for pesticide residue analysis, and the other for pollen identification. All pollen bound for residue analysis was combined at each bed, creating one conglomerate sample for each of the eight bee beds. Pollen samples were then shipped to the CCECF, where residues have been extracted and we are waiting on identification and quantification of samples, as above. I am still awaiting the results of the residue analysis. We collected bee provisioned pollen as above, and split each provision for pesticide analysis or pollen identification. We then identified pollen samples via morphology using a microscope. 10 pollen samples per bee bed were identified. To make pollen slides, we suspended pollen samples in 70% ethanol and pipetted a subsample onto a microscope slide. We then stained the pollen with fuchsin gel to better visualize morphological features. We estimated the percent volume of pollen types that were present in the prepared slides by examining them through a compound microscope (400x). Pollen types were identified to the lowest possible taxonomic rank and estimated as the percent of volume within the site. While in the field, we collected anthers of surrounding blooming species regardless if they were weeds growing on roadsides or planted for agriculture. Pollen from these anthers were then made into slides which served as our reference collection to aid in identification, in addition to published reference materials. Results: Across all eight beds, alfalfa pollen was the most abundant in provisions, making up 87.3% (mean ±1.0 S.E.) of the pollen in provisions. The next most common pollen was bindweed (Convolvulus sp.), a common weed of agricultural fields in the area, and a species that Nomia are historically known to collect from (Bohart, 1950). Bindweed pollen represented 8.0% (mean ±0.9 S.E.) of the pollen in provisions. Other pollen types identified were found at low occurrences. Objective 2: Minimizing drift in field margins. This objective was originally planned for summer 2020. Due to logistical complications from the ongoing COVID-19 pandemic, we decided against the proposed testing of drift reduction technologies on farms, as it would have required working in groups for extended periods of time. Instead, we decided to use silicone bands to passively sample drift at 15 farms. We placed silicone bands in two transects perpendicular to the crop field, at varying distances (0m, 2m, 4m, 8m, 16m, 24m, and 32m). Bands were left out for 1-2 weeks, allowing for at least one pesticide application in the focal field. Bands are currently being stored in the dark in a -30°C freezer at the Cornell Chemical Ecology Core Facility (CCECF). The CCECF staff are currently working to optimize extraction methods for these bands, so I am still awaiting the results. These data will be used to provide recommendations on locations for wildflower planting installation to mitigate pesticide exposure from drift (see Obj. 3). Additionally, in 2020, we dipped 42 bands in field application concentrations of five commonly applied insecticides: phosmet, acetamiprid, spinetoram, malathion, and imidacloprid. Bands were then attached to poles in an open field. Immediately after placement, six bands were randomly selected and collected for a 0-day replicate. Collected bands were wrapped in aluminum foil and stored at -20°C. These collection methods were continued at days: 1, 3, 7, 14, 21, and 28. These bands are currently being stored at the CCECF for quantification of residues, as above. We will use these data to write a methods paper for peer-review on use of silicone bands for measuring drift in the field and degradation rates of commonly used insecticides on the silicone bands. We hope these methods can be utilized by researchers across landscapes and disciplines. Objective 3: Pesticide risk mitigation - In conjunction with Objective 1, I have gathered spray records, information on spray methods (e.g., equipment used), measured the distance from crop to pollinator planting, and the distance from crop to the bumble bee Quad. I'm currently using multivariate statistics to determine whether these measured factors affect pesticide concentrations in bee collected pollen. I will use these results and results from measuring drift in Obj. 2 to formulate recommendations for minimizing risks to wild bees during the post-bloom period. Recommendations will then be shared with collaborating growers in reports and through ZOOM meetings, and to the community during extension meetings led by collaborating MSU Extension Educators and Specialists (Drs. Garcia-Salazar and Isaacs). Recommendations from this study will be relevant to blueberry growers and other specialty crop growers who benefit from a healthy wild bee community to maximize crop yields. I will therefore develop an extension document relevant to all specialty crop growers highlighting recommendations for minimizing risk to pollinators outside crop bloom, which will be made available through the MSU Extension bookstore.
Publications
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