Progress 06/15/21 to 06/14/24
Outputs
Target Audience:The initial target audience listed for this research was other entomologists, academic researchers, beekeepers, and related stakeholders. In this reporting period this research has been presented in a professional context as a seminar at academic conferences (Pollinator Health Conference, Penn State 2023) and at the joint USDA/US-EPA pollinator state of the science webinar (2023). At each of these presentations' undergraduates, graduate students, post-doctoral researchers, faculty/staff, and industry representative of pollinator health research were present. Through my new position in the industry realm, this research has also been presented to industry groups and to the Pollinator Research Task Force, which is an industry sponsored task focused on research with pollinators to enhance the safety of pollinator testing in risk assessment. In addition to presentations, I also reached undergraduate students at University of Illinois through the practice of science based informal hands-on application of methods used throughout this study. Students helped to gather similar data using methods from this research and based on initial results of this study were able to develop their own research questions and design independent studies for continued research in the lab. Results from this research were presented at an informal workshop held between University of Illinois and Iowa State University discussing topics of bee health and nutrition in agricultural landscapes. Changes/Problems:No major changes have been needed, and thus the goals of the project remain unchanged. However, I have made some minor changes to the experimental approach based upon new data from other studies and preliminary experiments performed in this project. The original proposal called for an assessment of multiple pesticides each done individually. Rather than assess multiple insecticides we chose to look at a mix of one insecticide and several fungicides as this was a more field relevant exposure scenario. Firstly, the chemicals we chose (chlorpyrifos, azoxystrobin, and pyraclostrobin) were all based on residue assessments of pollen collected from bees in a midwestern corn and soybean system therefore the choice to use them and the doses used were based on real residue data. This was more biologically accurate than the proposed analysis which would have required preliminary dose response testing. Secondly, bees flying through fields are likely to encounter both insecticides and fungicides simultaneously because farmers often apply these chemicals in a "tank mix" at the same time. Therefore, I felt that an assessment of pesticides that were a most likely scenario to be encountered in the field would be a more accurate representation of the potential sublethal effects on queen health. We also proposed using pure rockrose and chestnut pollen as our high- and low-quality pollen sources as these diets have already been demonstrated to elicit different nutritional responses in bees. However, by the time this project was funded this pollen was no longer available from the source provider. I investigated alternative options for purchasing these pollens for scientific use and was not able to find a good source. However, the Arizona high desert pollen we used alternatively as a high-quality diet has also been previously published on for bee research, is a nutritious pollen, and importantly, has a published record of insecticide residues which are nearly zero. This was an important factor for this study. What opportunities for training and professional development has the project provided?Through this project I have been able to gain extensive experience running laboratory trials using this cage system, dosing pesticides in various diets, and running physiological assessments of both workers and queens. Specifically, I have been trained in HPG dissections and assessments of embryo viability. Although we have had issues getting reliable statistical data due to some struggle with control genes, I have gained training in RNA extraction using trizol methods, processing RT qPCR plates, and statistical analysis of the data using the Δ ΔCT method. All these opportunities were goals of my professional development training in my workforce development grant. As part of my development as a scientific mentor to junior researchers, I have had numerous undergraduate students develop summer research projects as an offshoot of research conducted under this grant. One student performed a project investigating how queens are exposed to the pesticide profiles in the QMC cages (i.e., do queens get fed the contaminated food directly or not?). Another student collected queens from the second trial of this experiment (on individual pesticide exposure) and to assess ovary health. Another student worked to understand if the results we have seen cause increased effects with increasing doses of contamination and at what timescale. I have also had the chance through this research to engage with multiple industry, government, and stakeholder representatives by both presenting my work and acting as a consultant for these members to utilize the same or similar testing system to conduct similar research. How have the results been disseminated to communities of interest?I have presented the results of this work at seminars as several universities. I have presented the results of this work at professional conferences, specifically the Entomological Society of America and the International Pollinator Health Conference. I have presented this work to local beekeeping societies such as the Illinois State Beekeeping Society and the Three Rivers Beekeeping Society of St. Louis. I have presented this research to several industry representatives (i.e., Bayer, Corteva, USDA, US-EPA) Parts of this work are published in Frontiers Food and Sustainable Systems journal and two more publications are in prep to be submitted in 2024 and 2025. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Goals 1 and 2 were accomplished. For goal 1, I used the Queen Monitoring Cages (QMCs) to assess two nutritional diet profiles. Specifically, a high-quality polyfloral pesticide free pollen mix collected in the high desert Arizona landscape was compared to a low-quality diet that was made of the pesticide free pollen substitute MegaBee. The effects of each of these diets on queen egg laying was tested alone as a control. We also compared the interactive effects of these diets with a field relevant pesticide mix consisting of the insecticide (chlorpyrifos) and two fungicides (azoxystrobin and pyraclostrobin). These field relevant doses were based on previous exploration of honey bee collected pollen in a midwestern cropping landscape (Ames, IA) and were 24ppb for chlorpyrifos, 130ppb for azoxystrobin, and 20ppb for pyraclostrobin. Experiments showed that diet nutritional quality did not influence queen egg laying overall or on any specific trial day, however, there was a highly significant effect of the pesticide mix on queen egg laying with reduced egg laying from days 5-9 of the 12-day trial. We then ran the trial again separating the pesticides into individual components at the same concentrations and diet combinations and found that the largest contributor to the reduction in queen egg laying was likely due to an interaction of fungicides with the insecticide causing and additive effect. For goal 2, we assessed the lipid content of worker bees in the mixed pesticide trial and found no difference in lipids therefore we did not pursue that for the individual pesticide trials. We assessed viability of eggs laid by queens on trial day 5 and 9 by keeping the egg laying plates from the cages in an incubator for 72 hours and then assessing the hatch success rate. Supporting the additive effect hypothesis, we saw that eggs laid by queens which were fed the pesticide mix had significantly reduced viability, while no single pesticide treatment (azoxystrobin, pyraclostrobin, or chlorpyrifos alone) differed from the control. For worker bees, we assessed the quality of the hypopharyngeal glands, the glands responsible for producing the queen diet royal jelly. We found that there was a significant effect of pesticide on the physical quality of the glands (they were significantly more shriveled) and there was an interaction between diet and pesticide with the low-quality diet and pesticide exposed bees having the most reduced HPG size. For queens, once trials had concluded, we dissected and measured wet weight of ovaries as an indicator of reproductive health. We observed the ovaries of queens in the pesticide mix diet scenario to be significantly reduced compared to controls, while the individual pesticide treatments did not differ from the mix or controls. As part of goal 2 we aimed to run tangential assays where we would assess the retinue response of workers to experimental queens and to a standard queen signal. This work was accomplished in 2022. To compare honey bee worker retinue response to control and experimental queens, we set up QMCs with each respective diet combination. We also set up an additional set of "naive" worker cages fed only a control diet. At four days, when workers develop into nurse bees, we transferred control and experimental queens into the naive cages. We allowed the cages 1 hour to acclimate and then quantified retinue response in each cage for 5 minutes. We observed naïve bees to retinue (measured as feeding and touching) a queen which had been previously exposed to the pesticide mix environment significantly less compared to control queens. To compare control and pesticide exposed workers to a standard queen signal, we set up QMC cages as before except for no queen being present. We then, on day 4, placed a slide with one queen equivalent of queen pheromone (9-ODA) into each cage. We allowed cages to acclimate for 10 minutes and then observed number of interactions with the slide over 5 minutes. We found worker bees in the mixed pesticide diet treatment to interact with the synthetic queen pheromone significantly less compared to controls. These results support that not only do workers not want to interact with queens which may have been previously exposed to pesticides but workers with prior exposure are also less likely to interact with a queen, which could create negative feedback loop leading to decreased colony health.
Publications
- Type:
Peer Reviewed Journal Articles
Status:
Accepted
Year Published:
2022
Citation:
St. Clair, A.L., Suresh, S. and Dolezal, A.G. (2022) Access to prairie pollen affects honey bee queen fecundity in the field and lab. Front. Sustain. Food Syst. Vol 6. DOI: https://doi.org/10.3389/fsufs.2022.908667
- Type:
Other
Status:
Awaiting Publication
Year Published:
2024
Citation:
St. Clair, A.L., Dwyer, B., Shapiro, M., Dolezal, A.G. Adult honey bee queens consume pollen and nectar. PNAS Brief Reports. In Prep
- Type:
Other
Status:
Awaiting Publication
Year Published:
2025
Citation:
St. Clair, A.L., Shapiro, M., Fine, J., Dolezal, A.G. Effects of field relevant mixed and individual agrochemical profiles on honey bee queen reproductive biology. In Prep
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
St. Clair, A.L. and Dolezal, A.G. (2023) Teasing apart stressor interactions in honey bee workers and queens. USDA/US-EPA State of the Science Workshop.
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Progress 06/15/22 to 06/14/23
Outputs
Target Audience: The initial target audience listed for this research was other entomologists, academic researchers, beekeepers, and related stakeholders. In this reporting period this research has been presented in a professional context as a seminar at academic conferences (Pollinator Health Conference, Penn State 2023) and at the joint USDA/US-EPA pollinator state of the science webinar (2023). At each of these presentations' undergraduates, graduate students, post-doctoral researchers, faculty/staff, and industry representative of pollinator health research were present. Through my new position in the industry realm, this research has also been presented to industry groups and to the Pollinator Research Task Force, which is an industry sponsored task focused on research with pollinators to enhance the safety of pollinator testing in risk assessment. In addition to presentations, I also reached undergraduate students at University of Illinois through the practice of science based informal hands-on application of methods used throughout this study. Students helped to gather similar data using methods from this research and based on initial results of this study were able to develop their own research questions and design independent studies for continued research in the lab. Results from this research were presented at an informal workshop held between University of Illinois and Iowa State University discussing topics of bee health and nutrition in agricultural landscapes. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Through this project I have been able to gain extensive experience running laboratory trials using this cage system, dosing pesticides in various diets, and running physiological assessments of both workers and queens. Specifically, I have been trained in HPG dissections and assessments of embryo viability. Although we have had issues getting reliable statistical data due to some struggle with control genes, I have gained training in RNA extraction using trizol methods, processing RT qPCR plates, and statistical analysis of the data using the Δ ΔCT method. All these opportunities were goals of my professional development training in my workforce development grant. As part of my development as a scientific mentor to junior researchers, I have had numerous undergraduate students develop summer research projects as an offshoot of research conducted under this grant. One student performed a project investigating how queens are exposed to the pesticide profiles in the QMC cages (i.e., do queens get fed the contaminated food directly or not?). Another student collected queens from the second trial of this experiment (on individual pesticide exposure) and to assess ovary health. Another student worked to understand if the results we have seen cause increased effects with increasing doses of contamination and at what timescale. I have also had the chance through this research to engage with multiple industry, government, and stakeholder representatives by both presenting my work and acting as a consultant for these members to utilize the same or similar testing system to conduct similar research. How have the results been disseminated to communities of interest?I have presented the results of this work at seminars as several universities. I have presented the results of this work at professional conferences, specifically the Entomological Society of America and the International Pollinator Health Conference. I have presented this work to local beekeeping societies such as the Illinois State Beekeeping Society and the Three Rivers Beekeeping Society of St. Louis. I have presented this research to several industry representatives (i.e., Bayer, Corteva, USDA, US-EPA) Parts of this work are published in Frontiers Food and Sustainable Systems journal and two more publications are in prep to be submitted in 2024 and 2025. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Goals 1 and 2 were accomplished. For goal 1, I used the Queen Monitoring Cages (QMCs) to assess two nutritional diet profiles. Specifically, a high-quality polyfloral pesticide free pollen mix collected in the high desert Arizona landscape was compared to a low-quality diet that was made of the pesticide free pollen substitute MegaBee. The effects of each of these diets on queen egg laying was tested alone as a control. We also compared the interactive effects of these diets with a field relevant pesticide mix consisting of the insecticide (chlorpyrifos) and two fungicides (azoxystrobin and pyraclostrobin). These field relevant doses were based on previous exploration of honey bee collected pollen in a midwestern cropping landscape (Ames, IA) and were 24ppb for chlorpyrifos, 130ppb for azoxystrobin, and 20ppb for pyraclostrobin. Experiments showed that diet nutritional quality did not influence queen egg laying overall or on any specific trial day, however, there was a highly significant effect of the pesticide mix on queen egg laying with reduced egg laying from days 5-9 of the 12-day trial. We then ran the trial again separating the pesticides into individual components at the same concentrations and diet combinations and found that the largest contributor to the reduction in queen egg laying was likely due to an interaction of fungicides with the insecticide causing and additive effect. For goal 2, we assessed the lipid content of worker bees in the mixed pesticide trial and found no difference in lipids therefore we did not pursue that for the individual pesticide trials. We assessed viability of eggs laid by queens on trial day 5 and 9 by keeping the egg laying plates from the cages in an incubator for 72 hours and then assessing the hatch success rate. Supporting the additive effect hypothesis, we saw that eggs laid by queens which were fed the pesticide mix had significantly reduced viability, while no single pesticide treatment (azoxystrobin, pyraclostrobin, or chlorpyrifos alone) differed from the control. For worker bees, we assessed the quality of the hypopharyngeal glands, the glands responsible for producing the queen diet royal jelly. We found that there was a significant effect of pesticide on the physical quality of the glands (they were significantly more shriveled) and there was an interaction between diet and pesticide with the low-quality diet and pesticide exposed bees having the most reduced HPG size. For queens, once trials had concluded, we dissected and measured wet weight of ovaries as an indicator of reproductive health. We observed the ovaries of queens in the pesticide mix diet scenario to be significantly reduced compared to controls, while the individual pesticide treatments did not differ from the mix or controls. As part of goal 2 we aimed to run tangential assays where we would assess the retinue response of workers to experimental queens and to a standard queen signal. This work was accomplished in 2022. To compare honey bee worker retinue response to control and experimental queens, we set up QMCs with each respective diet combination. We also set up an additional set of "naive" worker cages fed only a control diet. At four days, when workers develop into nurse bees, we transferred control and experimental queens into the naive cages. We allowed the cages 1 hour to acclimate and then quantified retinue response in each cage for 5 minutes. We observed naïve bees to retinue (measured as feeding and touching) a queen which had been previously exposed to the pesticide mix environment significantly less compared to control queens. To compare control and pesticide exposed workers to a standard queen signal, we set up QMC cages as before except for no queen being present. We then, on day 4, placed a slide with one queen equivalent of queen pheromone (9-ODA) into each cage. We allowed cages to acclimate for 10 minutes and then observed number of interactions with the slide over 5 minutes. We found worker bees in the mixed pesticide diet treatment to interact with the synthetic queen pheromone significantly less compared to controls. These results support that not only do workers not want to interact with queens which may have been previously exposed to pesticides but workers with prior exposure are also less likely to interact with a queen, which could create negative feedback loop leading to decreased colony health.
Publications
|
Progress 06/15/21 to 06/14/22
Outputs
Target Audience:The initial target audience listed for this research was other entomologists, academic researchers, beekeepers, and related stakeholders. In this reporting period this research has been presented in a professional context as a seminar at three universities: the University of Illinois at Urbana-Champaign, Iowa State University in Ames Iowa, and Murray State University in Murray Kentucky. At each of these presentationsundergraduates, graduate students, post-doctoral researchers, and faculty/staff were welcome to attend from entomology and other biological disciplines. In addition to presentations, I also reached undergraduate students at the University of Illinois through the practice of science based informal hands-on application of methods used throughout this study. Students helped to gather similar data using methods from this research and based on initial results of this study were able to develop their own research questions and design independent studies for continued research in the lab. Results from this research were presented at an informal workshop held between the University of Illinois and Iowa State University discussing topics of bee health and nutrition in agricultural landscapes. Changes/Problems:No major changes have been needed, and thus the goals of the project remain unchanged. However, I have made some minor changes to the experimental approach based upon new data from other studies and preliminary experiments performed in this project. The original proposal called for an assessment of multiple pesticides each done individually. Rather than assess multiple insecticides we chose to look at a mix of one insecticide and several fungicides as this was a more field relevant exposure scenario. Firstly, the chemicals we chose (chlorpyrifos, azoxystrobin, and pyraclostrobin) were all based on residue assessments of pollen collected from bees in a midwestern corn and soybean system therefore the choice to use them and the doses used were based on real residue data. This was more biologically accurate than the proposed analysis which would have required preliminary dose response testing. Secondly, bees flying through fields are likely to encounter both insecticides and fungicides simultaneously because farmers often apply these chemicals in a "tank mix" at the same time. Therefore, I felt that an assessment of pesticides that were a most likely scenario to be encountered in the field would be a more accurate representation of the potential sublethal effects on queen health. We also proposed using pure rockrose and chestnut pollen as our high- and low-quality pollen sources as these diets have already been demonstrated to elicit different nutritional responses in bees. However, by the time this project was funded this pollen was no longer available from the source provider. I investigated alternative options for purchasing these pollens for scientific use and was not able to find a good source. However, the Arizona high desert pollen we used alternatively as a high-quality diet has also been previously published on for bee research, is a nutritious pollen, and importantly, has a published record of insecticide residues. What opportunities for training and professional development has the project provided?Through this project I have been able to gain extensive experience running laboratory trials using this cage system, dosing pesticides in various diets, and running physiological assessments of workers. Specifically, I have been trained in HPG dissections and assessments of embryo viability. Although we have had issues getting reliable statistical data due to some struggle with control genes, I have gained training in RNA extraction using trizol methods, processing RT qPCR plates, and statistical analysis of the data using the Δ ΔCT method. All these opportunities were goals of my professional development training in my workforce development grant. As part of my development as a scientific mentor to junior researchers, I have had two undergraduate students develop summer research projects as an offshoot of research conducted under this grant. One student performed a project last summer (2021) investigating how queens are exposed to the pesticide profiles in the QMC cages (i.e., do queens get fed the contaminated food directly or not?). Another student collected queens from the second trial of this experiment (on individual pesticide exposure) and she plans to assess ovary health this summer (2022). How have the results been disseminated to communities of interest?I have presented the results of this work at seminars as several universities. I will present the results of this work at professional conferences, specifically the Entomological Society of America. This work has not yet been published in a peer reviewed journal but is presently being formulated into a manuscript for submission. What do you plan to do during the next reporting period to accomplish the goals?The next reporting period will be used to conduct retinue assays regarding Goal 2. These assays will help tease apart whether changes in queen egg laying from pesticide exposure are a result of worker physiological shifts altering the way the care for the queen or if shifts in the queen's physiology because of exposure change the way workers respond to her. I will also work this reporting period to prepare this research for publication into a peer reviewed journal. If there is time, I would like to do some additional research that will validate the findings of the cage assays in field colonies.
Impacts
What was accomplished under these goals?
Components of Goals 1 and 2 were accomplished. For Goal 1, I used the Queen Monitoring Cages (QMCs) to assess two nutritional diet profiles. Specifically, a high-quality polyfloral pesticide free pollen mix collected in the high desert Arizona landscape was compared to a low-quality diet that was made of the pesticide free pollen substitute MegaBee. The effects of each of these diets on queen egg laying was tested alone as a control. We also compared the interactive effects of these diets with a field relevant pesticide mix consisting of the insecticide (chlorpyrifos) and two fungicides (azoxystrobin and pyraclostrobin). These field relevant doses were based on previous exploration of honey bee collected pollen in a midwestern cropping landscape (Ames, Iowa) and were 24ppb for chlorpyrifos, 130ppb for azoxystrobin, and 20ppb for pyraclostrobin. Those pesticide residuals were detected by Dr. Maura Hall who was a graduate student at Iowa State University. Experiments showed that diet nutritional quality did not influence queen egg laying overall or on any specific trial day, however, there was a highly significant effect of the pesticide mix on queen egg laying with reduced egg laying from days five through nine of the twelve-day trial. We then ran the trial again separating the pesticides into individual components at the same concentrations mixed only with MegaBee and found that the largest contributor to the reduction in queen egg laying was likely due to the fungicide azoxystrobin. For Goal 2, we assessed the lipid content of worker bees in the mixed pesticide trial and found no difference in lipids therefore we did not pursue that for the individual pesticide trials. We assessed viability of eggs laid by queens on trial day fiveand nineby keeping the egg laying plates from the cages in an incubator for 72 hours and then assessing the hatch success rate. We did not see a difference in the proportion hatch success by nutritional or pesticide treatment, therefore, we did not pursue this in the individual pesticide trials either. For worker bees, we assessed the quality of the hypopharyngeal glands, the glands responsible for producing the queen diet royal jelly. We found that there was a significant effect of pesticide on the physical quality of the glands (they were significantly more shriveled) and there was an interaction between diet and pesticide with the low-quality diet and pesticide exposed bees having the most reduced HPG size. We are currently processing the HPGs of bees from the individual pesticide trial. As part of Goal 2 we aimed to run tangential assays where we would assess the retinue response of workers to experimental queens and to a standard queen signal. We will run these assays summer 2022.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2022
Citation:
St. Clair, A.L., Suresh, S. and Dolezal, A.G. 2022. Polyfloral prairie pollen boosts honey bee queen fecundity during late season agricultural forage dearth. Frontiers. 10.3389/fsufs.2022.908667.
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