Progress 01/01/22 to 12/31/24
Outputs
Target Audience:The target audience for this research are scientists focused on apidology, entomologists, visual ecologists, insect virologists, USDA scientists, and any constituents interested in honey bee health, including the general pubic. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This award funded 1 full PhD student for 2 years (CJ Fellows) who has now obtained his doctorate degree and is a study director for pollinator health at Eurofins. In addition to this PhD student, this award funded 12 months of a postdoctoral fellow (Sanghyeon Kim) at the Univesrity of Florida where he focused on the semi-field studies and assessment of visual sensitivity through ERG recordings. Sanghyeon is applying to faculty positions currently. Without this award, these training opportunities would not have been possible. How have the results been disseminated to communities of interest?The results from this study have been disseminated by 1 graduate student, 1 postdoctoral fellow, and myself through invited and contributed presentations at national and international symposia, through trade journals and extension/outreach journals, and to stakeholders during the bee research day held at the USDA-ARS in baton Rouge LA. In addition we are preparing two peer-reviewed manuscripts that will disseminate these fundamental data sets to the scientific community. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Obj 1: We worked closely with the USDA honey bee lab in Baton Rouge (coPD: Mike Finstrom) to complete this objective. Colony parasitism by Varroamites, positively correlated with both forager and colony DWV-B levels, was negatively associated with nectar weight. Further, colony DWV-B levels were negatively associated with individually foraged pollen protein: lipid ratios but positively correlated with nectar weight and sugar content. This study shows that both colony and forager health can simultaneously mediate individual foraging decisions and that the importance of viral infections and parasite levels varies with foraging metrics. Obj 2: We identified that DWV-A and DWV-B infected the honey bee eyes at very high concentrations that were quantified up to 10e8 genome equivalents, which justified analysis of the influence of virus infection to visual sensitivity. To do this, we performed electroretinogram (ERG) recordings to assess DWV influence to eye physiology and data suggest reduced photoreceptor sensitivity at shorter (SW) wavelengths. Bees were dark adapted for 30 min and subsequently tested with increasing intensities of light at 540 nm, the approximate sensitivity of the photoreceptor. The intensity athalf the maximum response was chosen for spectral tests and the wavelength range studied was 315 to 550 nm in 5 nm inrements. Individual and averaged data suggest DWV-infected bees have reduced photoreceptor sensitivity when compared to control. Interestingly, long wavelengths were dramatically different in DWV-A and DWV-B infected bees when compared to control and UV sensitivity was reduced by 30%. These data are the first to show virus infection of bee eyes alters visual sensitivity and receptiveness to colors in a wavelength specific manner that has large implications for visual signal processing Obj 3: We investigated changes to transcriptomes of the Light Interacting Toolkit (LIT), which comprises the major visual gene families identified from the A. mellifera gene set, to assess the impact of DWV infection to the gene regulation of these visual specific genes.Bees infected with increasing of DWV and IAPV are likely experiencing localized accumulations of virus in visual tissues, impairing the expression of genes in the rhabdomeric phototransduction across the entirety of the eye. As the retinal mosaic of honeybee eyes are not uniform in nature (e.g., long-wavelength-sensitive and UV-sensitive opsin distributions across the ommatidia), a mechanical filtering of available opsins for expression are causing shifts in sensitivities due to overall fluxes in phototransduction expression profiles. Semi-field:In year 3 of this award, which was the NCE year, we focused on performing semi field experiments with state-of-the-art flight tunnels that were recently constructed at the University of Florida. We placed colonies at the edge of a flight tunnel that were either infected with DWV-A or uninfected and quantified shifts in foraging behavior with plants that were placed at the opposite end of the tunnel. Data from this semi-field study mirror data generated in Obj 1 that showed changes to foraging behavior. Our previously funded USDA NIFA award identified that activation of potassium ion channels reduced DWV replication and thus, we tested if exposure to these chemicals would restore foraging behavior in DWV infected colonies. Indeed, preliminary assessments suggest that, while not complete restoration, exposure to a potassium channel activator to DWV infected colonies via drizzle techniques shifted pollen/nectar ratios toward the ratios observed in uninfected colonies in a statistically significant manner (P<0.05).
Publications
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Progress 01/01/23 to 12/31/23
Outputs
Target Audience:The target audience for this research are scientists focused on apidology, entomologists, visual ecologists, insect virologists, USDA scientists, and any constituents interested in honey bee health, including the general pubic. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This award funded 1 full PhD student for 2 years (CJ Fellows) who has now obtained his doctorate degree and is a study director for pollinator health at Eurofins. In addition to this PhD student, this award funded 12 months of a postdoctoral fellow (Sanghyeon Kim) at the Univesrity of Florida where he focused on the semi-field studies and assessment of visual sensitivity through ERG recordings. Sanghyeon is applying to faculty positions currently. Without this award, these training opportunities would not have been possible. How have the results been disseminated to communities of interest?The results from this study have been disseminated by 1 graduate student, 1 postdoctoral fellow, and myself through invited and contributed presentations at national and international symposia, through trade journals and extension/outreach journals, and to stakeholders during the bee research day held at the USDA-ARS in baton Rouge LA. In addition we are preparing two peer-reviewed manuscripts that will disseminate these fundamental data sets to the scientific community. What do you plan to do during the next reporting period to accomplish the goals??Final report will be ready in 30 days.
Impacts
What was accomplished under these goals?
Obj 1: We worked closely with the USDA honey bee lab in Baton Rouge (coPD: Mike Finstrom) to complete this objective. Colony parasitism by Varroamites, positively correlated with both forager and colony DWV-B levels, was negatively associated with nectar weight. Further, colony DWV-B levels were negatively associated with individually foraged pollen protein: lipid ratios but positively correlated with nectar weight and sugar content. This study shows that both colony and forager health can simultaneously mediate individual foraging decisions and that the importance of viral infections and parasite levels varies with foraging metrics. Obj 2: We identified that DWV-A and DWV-B infected the honey bee eyes at very high concentrations that were quantified up to 10e8 genome equivalents, which justified analysis of the influence of virus infection to visual sensitivity. To do this, we performed electroretinogram (ERG) recordings to assess DWV influence to eye physiology and data suggest reduced photoreceptor sensitivity at shorter (SW) wavelengths. Bees were dark adapted for 30 min and subsequently tested with increasing intensities of light at 540 nm, the approximate sensitivity of the photoreceptor. The intensity athalf the maximum response was chosen for spectral tests and the wavelength range studied was 315 to 550 nm in 5 nm inrements. Individual and averaged data suggest DWV-infected bees have reduced photoreceptor sensitivity when compared to control. Interestingly, long wavelengths were dramatically different in DWV-A and DWV-B infected bees when compared to control and UV sensitivity was reduced by 30%. These data are the first to show virus infection of bee eyes alters visual sensitivity and receptiveness to colors in a wavelength specific manner that has large implications for visual signal processing Obj 3: We investigated changes to transcriptomes of the Light Interacting Toolkit (LIT), which comprises the major visual gene families identified from the A. mellifera gene set, to assess the impact of DWV infection to the gene regulation of these visual specific genes. We inoculated bees at a low and high DWV titer that resulted in no symptomology and select symptomology, respectively to ascertain the impact of sub-lethal and lethal infection titers to gene regulation. We compared this to uninfected individuals that were tested by qPCR to have no detectable DWV infection. Preliminary assessment of data indicate significant reduction of opsin genes, which correlates closely to the data generated in Obj 2 because opsins are responsible for controlling spectral sensitivity of the visual system. These data are the first to provide mechanistic insight into the effect of virus infection to visual genes and how this physiological change manifests itself into behavioral changes. Semi-field:In year 3 of this award, which was the NCE year, we focused on performing semi field experiments with state-of-the-art flight tunnels that were recently constructed at the University of Florida. We placed colonies at the edge of a flight tunnel that were either infected with DWV-A or uninfected and quantified shifts in foraging behavior with plants that were placed at the opposite end of the tunnel. Data from this semi-field study mirror data generated in Obj 1 that showed changes to foraging behavior. Our previously funded USDA NIFA award identified that activation of potassium ion channels reduced DWV replication and thus, we tested if exposure to these chemicals would restore foraging behavior in DWV infected colonies. Indeed, preliminary assessments suggest that, while not complete restoration, exposure to a potassium channel activator to DWV infected colonies via drizzle techniques shifted pollen/nectar ratios toward the ratios observed in uninfected colonies in a statistically significant manner (P<0.05).
Publications
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Progress 01/01/22 to 12/31/22
Outputs
Target Audience:The target audience for this research are scientists focused on apidology, entomologists, visual ecologists, insect virologists, USDA scientists, and any constituents interested in honey bee health, including the general pubic. Changes/Problems:As mentioned, the transition of the previous PD (Daniel Swale) from LSU to the Univ. of Florida has necessitated re-assigning the PD of the grant to Lord (LSU) and re-budgeting. We also encountered difficulties with the pre-existing bioinformatics pipeline, necessitating a rebuild on our home supercomputing cluster. Both of these issues have been resolved. What opportunities for training and professional development has the project provided?CJ Fellows was a PhD student under DR Swale (former PD) and was funded from this award. He has since graduated with his PhD and obtained a permanent position with Eurofins. This award resulted in 4 presentations at National conferences given by Fellows that assisted in his professional development through an ability to disseminate information to scientists and industry stakeholders as well as networking, which ultimately assisted in obtaining a permanent position. How have the results been disseminated to communities of interest?Results from this award have been presented to the scientific community at the Entomological Society of American in the fall of 2022 as well as bee stakeholder meetings in Louisiana and Florida. Manuscripts are currently being prepared and we anticipate the first manuscript from this work submitted Summer 2023 and the second in winter 2023. What do you plan to do during the next reporting period to accomplish the goals?In Summer 2023 we will initiate the flight tunnel experiments that will finalize the experiments proposed in Objective 1 and be correlated to the nutrition data collected from returning foragers. This will complete objective 1. The move of Swale from LSU to UF has delayed the electrophysiological recordings proposed in Objective 2, but we anticipate finalizing these data before the end of 2023. Equipment is currently being set up in the Swale lab at UF, apiaries have been established, and personnel have been identified to complete these studies. The Lord Lab will begin morphological analyses of bee eyes in Summer 2023 with completion of these analyses anticipated to be March 2024. Data collection for Objective 3 have been completed and will be published in 2023.
Impacts
What was accomplished under these goals?
Significant progress has been made to completion of two of the three proposed objectives. Objective 1 aimed to define DWV-induced changes to foraging behavior and homing ability and we anticipate completion of this objective by Fall 2023. We have performed analysis of percent protein and percent lipids from returning foragers and analyzed these products in relation to the percent infection with DWV. Data show that DWV indeed alters infection with increased infection indices resulting in increased lipids returned whereas uninfected or low infection levels prioritized the return of proteins over lipids. This data will be published with the manuscript that includes the flight behavior assessed in wind tunnels. Wind tunnels were constructed during winter 2022-2023 and will be used to test the influence of DWV to homing and ability of pinacidil to restore flight behaviors. Objective 2 aimed to define shifts in spectral sensitivity to the bee eye through electrophysiological recordings that show physiological differences in eye responses to different wavelengths of light. We have started these assays and have identified spectral shifts in DWV infected eyes compared to uninfected bees. Although replicates are too low to draw any firm conclusions, data suggest that high DWV infection shifts the spectral sensitivity by approximately 2-fold, which is a highly significant (P<0.001) reduction of photoreceptor responses. We anticipate these data will be completed in winter 2023 and data will be prepared for publication with morphological data sets in spring 2024. Objective 3 aimed to test if DWV infection alters the transcriptional regulation of phototransduction genes, which has been partially completed. We have performed extensive transcriptome profiling of the phototransduction genes of honey bees at 4 different time points and at multiple infection titers and these transcriptomes are currently being annotated. We were met with slight barriers that prolonged this study because the global phylogenetically informed annotation database for visual genesof insects (PIA) is now no longer supported or hosted by UC Santa Barbara. This necessitatedus reconstructing the bioinformatics pipeline on the LSU supercomputing cluster and performing tests of appropriate functionality. However, we completed this and are currently in the process of annotating the transcriptomes. We anticipate annotation to be complete by the end of May 2023 and the manuscript will be submitted by the end of June 2023.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
Keynote talk at the Integrated Beekeeping Systems and Integrated Pest Management Workshop, Edmonton, Alberta. February 2022. From Genetics to Nutrition: Complex impacts of viruses on honey bee health, behavior and management (MSF)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2023
Citation:
Keynote speaker, Integrative approaches to improve honey bee resiliency through breeding and management" at the BeeConnected! Czech-Slovak Scientific Conference in Apidology. Oloumec, Czech Republic (April 2023) (MSF)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2023
Citation:
Annual meeting of the COLOSS Virus Task Force. February 2023. Genetic and context dependent variation in response to viral infection across generations and castes. (MSF)
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