Progress 05/01/17 to 04/30/23
Outputs
Target Audience:Our target audience is multi-fold. First, the scientific audience interested in bumble bee decline and the interactions among environmental stressors that have led to the decline of these pollinators over the last few decades. The audience includes those assessing pesticide effects on bumble bee physiology, including genomic expression patterns under different exposure regimes, others interesed in pathogens and bumble bee health, and those interested in the interactive effects between multiple stressors at the at the genome level.During 2022-2023our activities focused on final publications of research results.We have also presented our research results to audiences at national and international meetings and at invited siminars throughout the grant tenure. Other target audiences haveincluded Federal agencies, including the FWS and EPA, as well as citizen scientists, particularly within the agricultural Midwest,intersted in wild bees and their health. Throughout the tenure of the grant we have been involved in multiple activities to assist FWS in both listing threatened bumble bee species and assessing realistic practices to bring populations back to healthy levels in regions where they have been extirpated. These activities includescientific support to FWS in their Species Status Assessments of threatened species and work with the North American Pollinator Protection Campaign (NAPPC) Imperiled Bombus Conservation Task Force. We have provided specific locality data to the U.S. Forest Service and to the Vermont Agency of Natural Resources on Bombus terricola throughout the grant tenure, a species that has undergone population decline in the northeastern U.S. We have also engaged citizen scientists with programs we'vehelped to develop, including BeeSpotter and the National Pollinator Week BeeBlitz. BeeSpotter is anonline interactive webpage targeting pollinator range distributions in Illinois, Missouri, Indiana and Ohio; we help to identify hundreds of bees from photographs sent in to BeeSpotter by citizens interested in documenting bumble bees and honey bees in their areas.We also updated our bumble bee field guide to include species from Indiana and Ohio.We continue to work with minority students in lab and field, focusing on their entomological training.We have continued to target students in classroom and lab instruction on bee decline issues. Community groups and K-12 students have been incorporated through targeted outreach presentations and activities on pollinator health in general, with a specific focus on bumble bees. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?We provided professional opportunities for the postdoc, RM Blazquez,who was hired recently at the University of Seville as key lab and bioinformatics personnel. In the past year the NIFA award has also facilitated the continued training and developmentin co-PI Sadd's lab for undergraduates(Audry Harrod, undergrad thesis "Investigating pathogen transmission potential upon fungicide co-exposure in bumble bees,"she is currently in the PhD program Univ of Georgia; Abraham Martinez, "Diet diversity and infection outcoms in a bumble bee and microsporidian system," currentlyin the PhD program Univ ofColorado); other non-thesisundergrads trained (Toby Bassingthwaite, Liv Cohen, Justin Palmer). Masters theses completed: Elyse McCormick (currently in PhD programU Mass Amherst), Austin Calhoun (currently in PhD programIllinois State). Many of these training opportunities have been extened to both underrepresented groups, including first in family andwomen. Most have given posters and presentations at national meetings, and been awardees of multiple awards both at conferences and from Illinois StateUniversity. How have the results been disseminated to communities of interest?Dissemination of results this year include one published paper in Scientific Reportsand a second paper including the integrated results across multiple species is near ready for submission.We havegiven scientific conference presentations on the final results of ourresearch. In addition, knowledge and expertise gained during the project has been used in communication with bumble bee conservation stakeholders, including the US Fish and Wildlife Service Rusty Patched Bumble Bee Recovery Implementation Strategy Science Support Team and NAPPC Imperiled Bombus Conservation Task Force. Further, a number of talks have been given to community and education groups that relate to the core bumble bee health focus of the grant, which have been informed by our findings. Lastly, we continue to work with BeeSpotter to enhance awareness of the plight of declining bumble bees. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
We investigated gene expression of Bombus impatiens (a non-declining species)larvae exposed through food provisions to two field-realistic imidacloprid concentrations (0.7 and 7.0 ppb). We hypothesized both concentrations would alter gene expression, but the higher concentration would have greater qualitative and quantitative effects. We found 678 genes differentially expressed under both imidacloprid exposures relative to controls, including mitochondrial activity, development, and DNA replication genes. However, more genes were differentially expressed with higher (7.0 ppb) imidacloprid exposure; uniquely differentially expressed genes included starvation response and cuticle genes. The former may partially result from reduced pollen use, monitored to verify food provision use and provide additional context to results. A smaller differentially expressed set only in lower concentration larvae, included neural development and cell growth genes. An important result if that imidacloprid impacts bumble bee healtheven at sublethal concentrations, as low as .07 ppb. These findings were published in Scientific Reports 2023 (listed under "Products"). Supplementary Informationavailable at https:// doi. org/10. 1038/ s41598- 023- 36232-y. Asecond manuscript is near completion for submission to Molecular Ecology this year: "Pathogens, pesticides and their interaction affect gene expression differently in declining and stable bumble bee species" Goal 1: determine differences in susceptibility to N. bombi, and examine any observed differences with respect to decline status Exposure of declining Bombus occidentalis larvae to Nosema bombi resulted in significantly higher overall gene expression (RNA-seq analysis) than that of the stable B. impatiens when exposed. N. bombi affected up- and down-regulation of 148 genes in B. occidentalis, including those with immune functions (up-regulation of defensin and down-regulation of spa?tzle) and lipid metabolism (down-regulation of lipase member H-A-like and putative fatty acyl-CoA reductase). Gene expression profiles of B. impatiens larvae exposed to the same spore concentration of N. bombi revealed only 62 differentially expressed genes, all of which were down-regulated, including integument component genes (larval cuticle protein A2B, integumentary mucin C1-like). Of note, the circadian clock-controlled protein gene was down-regulated in both species in response to N. bombi, suggesting the pathogen may generally disrupt timing of development. Based on GO term enrichment analysis of the differentially expressed gene sets of B. occidentalis, N. bombi affected chitin metabolism, lipid metabolism and immune system genes; in B. impatiens, N. bombi affected mostly integument-related genes. These results tentatively suggest that N. bombi may have more pronounced effects on the immune response system in declining B. occidentalis than in the stable B. impatiens. Goal 2: Compare the effects of exposure to the neonicotinoid imidacloprid between species, and examine any observed differences with respect to decline status Transcriptome profiles of B. impatiens larvae exposed to two different sublethal concentrations of imidacloprid, a typical field concentration (7.0 ppb) and a low concentration (0. 7 ppb), were significantly different. The higher concentration resulted in a higher number of differentially expressed genes (755) than the lower concentration (191), as might be expected. However, the fact that an order of magnitude lower concentration nonetheless had an effect indicates that even low concentrations of imidacloprid that could be encountered in the field can expression of important in growth and development in larvae relative to controls. Moreover, the number of overlapping differentially expressed genes in the high and low concentrations relative to controls was higher than expected, suggesting that a core of genes might be affected by imidacloprid independent of the concentration. We also found that B. impatiens larvae consumed less food when treated with the higher imidacloprid concentration than control larvae, and some of the gene expression responses under the higher concentration treatment likely resulted from this indirect effect. Experiments comparing expression responses of B. occidentalis (declining) and B. impatiens (stable) larvae to the higher imidacloprid concentration (7.0 ppb) led to significant differences in gene expression profiles. In B. impatiens, we found 223 differentially expressed genes, including down-regulation of several cuticle protein genes and up-regulation of genes related to immune response (such as hymenoptaecin). B. occidentalis on the other hand appeared less affected by imidacloprid, exhibiting a total of only five differentially expressed genes, including the down-regulation of the circadian clock-controlled protein (involved in circadian rhythm and plays an important role in the timing of development), cyclin-dependent kinase inhibitor 1C (inhibitor of mitosis) and transient-receptor-potential-like protein (required for dark vision); there was an up- regulation of nose resistant to fluoxetine protein 6, which in C. elegans is involved in the uptake of lipids and xenobiotic compounds in the gut, and is also vital for embryo development. Goal 3: Determine if there are species and status specific interactive effects with imidacloprid and Nosema bombi When exposed to both stressors simultaneously, gene expression profiles changed differentially in both species: B. occidentalis down-regulated genes involved in regulation of the cell cycle (such as cyclin-dependent kinase inhibitor 1C, a mitosis inhibitor; or histone H4, a chromatin organization protein) and chitin-interacting proteins (such as collagen alpha chain protein, mucin-5AC and peritrophin-1). In B. impatiens, the combined treatment triggered down-regulation of proteases (including six carboxypeptidases involved in protein breakdown for either digestive, detoxification or regulatory purposes), cuticle proteins (eight in total, important for cuticle formation) and cytochromes P450 (three of them, involved in detoxification and redox regulation). We found up-regulated genes related to neurotransmitter reception (neuronal acetylcholine receptor subunit alpha-10-like and a metabotropic glutamate receptor involved in synaptic plasticity and neuroprotection), neuropeptide receptors (neuropeptide CCHamide-2 receptor-like, involved in appetite and feeding behavior, and cardioacceleratory peptide receptor, involved in ecdysis and heart rate regulation) and neurotransmitter metabolism (dopamine N- acetyltransferase, involved in serotonin and dopamine metabolism). Targeted qPCR of the 20 top differentially differentially expressed genes across all three test treatments (Nosema, imidacloprid and combined Nosema+imidacloprid) of B. impatiens and B. occidentalis larvae were tested for expression in larvae of the declining B. terricola (sister species to B. occidentalis) and stable B. griseocollis. Results were similar to comparisons of B. occidentalis and B. impatiens: gene expression appears to be species specific and independent of its decline status. We added an additional goal during 2023: this was to provide the scientific community with a fully assembled and well annotated whole genome of the bumble bee pathogen Nosema bombi (proposed genus name change, Vairimorpha; PI is in disagreement and plans to publish a response to this proposed name change). We accomplished this goal in full and are currently completing the analyses for a publication. The data are embargoed until a paper is in press. This was a collaborative effort with co-PI Sadd andKim Walden at the Institute for Genomic Biology at theUniversity of Illinois Urbana-Champaign.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Martin-Blazquez R, Calhoun AC, Sadd BM, Cameron SA. 2023. Gene expression in bumble bee larvae differs qualitatively between high and low concentration imidacloprid exposure levels. Scientific Reports doi: 10.1038/s41598-023-36232-y
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Martinez A, Calhoun AC, Sadd, BM. 2023. Investigating the influence of diet diversity on infection outcomes in a bumble bee (Bombus impatiens) and microsporidian (Nosema bombi) host-pathogen system. Frontiers in Insect Science, 3, 1207058.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
McCormick EC, Cohen OR, Dolezal AG, Sadd BM. 2023. Consequences of microsporidian prior exposure for virus infection outcomes and bumble bee host health. Oecologia 202: 325-335.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Rube?n Martin-Bla?zquez, Austin C Calhoun, Elyse C McCormick,
James P Strange, Sydney A Cameron, and Ben M Sadd. Imidacloprid-contaminated food consumption rates differ between four stable and declining North American bumble bee species. 2023 Ecoflor Annual Meeting, Seville, Spain.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
US Fish and Wildlife Survey, Rusty Patched Bumble Bee Virtual Science Webinar, 2023, Pathogens of Bombus affinis and understanding threats of multiple stressors using surrogate bumble bee species.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
McCormick E. (Author & Presenter), Cohen O, Sadd B. "Worse off together: consequences of microsporidian and virus co-infection for parasite dynamics and bumble bee host health," Lecture/Oral, Conference, Presented, Entomological Society of America Annual Meeting, Vancouver, Canada. Academic, International, New Scholarship, Refereed, Accepted. (November 2022).
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
McCormick E (Author & Presenter), Sadd B. "Worse off together: consequences of microsporidian and virus co-infection for parasite dynamics and bumble bee host health," Poster, Conference, Presented, Ecology and Evolution of Infectious Diseases 2022, Atlanta, GA. Academic, International, New Scholarship, Refereed, Accepted. (June 2022).
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Cameron SA. "A feeling for the organism," invited colloquium presentation, University of Illinois Urbana-Champaign.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Strange JP, Colla SR, Adams LD, Duennes MA, Evans EC, Figueroa LL, Lehmann DM, Moylett H, Richardson L, Sadd BM, Smith JW, Smith TA, Tripodi AD, Spevak EM, Inouye, DW. 2023. An evidence-based rationale for a North American commercial bumble bee clean stock certification program. Journal of Pollination Ecology 32: 1-13.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
*Figueroa LL, *Sadd BM, *Tripodi AD, Strange JP, Colla SR, Adams LD, Duennes MA, Evans EC, Lehmann DM, Moylett H, Richardson L, Smith JW, Smith TA, Spevak EM, Inouye DW. 2023. Endosymbionts that threaten commercially raised and wild bumble bees (Bombus spp.). Journal of Pollination Ecology 32: 14-36. (*Joint first authors)
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Evans EC, Strange JP, Sadd BM, Tripodi AD, Figueroa LL, Adams LD, Colla SR, Duennes MA, Lehmann DM, Moylett H, Richardson L, Smith JW, Smith TA, Spevak EM, Inouye DW. 2023. Ectoparasites, parasitoids, and hive products that are potentially deleterious to commercially raised and wild bumble bees (Bombus spp.). Journal of Pollination Ecology 32: 37-53.
|
Progress 05/01/21 to 04/30/22
Outputs
Target Audience: During 2021-2022 our activities have been very similar to prior years. We have continued to participate in citizen science efforts, including BeeSpotter and the National Pollinator Week BeeBlitz. BeeSpotter is our online interactive webpage targeting pollinator range distributions in Illinois, Missouri, Indiana and Ohio; we help to identify hundreds of bees from photographs sent in by citizens interested in wild bees. We have been involved in scientific support efforts for FWS Species Status Assessments of threatened species. We continue to work with minority students in the lab, focusing on their training. Other audiences have been scientists interested in bee pollinator decline issues and those specifically interested in pathogen and insecticide effects on bumble bees; we have communicated with these groups via national entomology meetings (Zoom meetings this last year) and invited seminars (also on Zoom). We have targeted students in classroom and lab instruction on bee decline issues. Community groups and K-12 students have been incorporated through targeted outreach presentations and activities on pollinator health in general, with a specific focus on bumble bees. In this year, this has included presentations to a 4th grade summer camp, four junior high science classes, and the Environmental Educators of Illinois group. We have provided specific locality data to the U.S. Forest Service and to the Vermont Agency of Natural Resources on Bombus terricola, a species that has undergone population decline in the northeastern U.S. PI Cameron has been assisting the U.S. Forest Service with their Species Status Assessment of the western bumble bee (B. occidentalis), which has declined precipitously over the last twenty-fiveyears in the western U.S. PI Sadd has been a consultant for the U.S. Fish and Wildlife Service as part of the Rusty Patched Bumble Bee Recovery Implementation Strategy Science Support Team. He has also provided consultation and materials for three groups using conservation dogs to assist in gaining knowledge about bumble bee nest locations and densities. PI Sadd has also been part of the North American Pollinator Protection Campaign (NAPPC) Imperiled Bombus Conservation Task Force. This resulted in the production of a white paper documenting pathogen threats to native bumble bees and recommending a clean stock program in commercial rearing and distribution of bumble bees. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?We provided professional opportunities for the postdoc, who was recently hired at the University of Seville as key lab and bioinformatics personnel. In the past year the NIFA award has also facilitated the continued training and development of undergraduates and a graduate student within the group of PI Sadd. One undergraduate and a graduate student successfully completed their respective honors and MS theses working on Nosema infection in bumble bees. These students gave presentations and local and national conferences, and the work from the MS thesis is currently in review at the journal Oikos. One undergraduate completed a honors thesis on Nosema infection, with a resulting publication in preparation. This student is now in a PhD program at the University of Colorado. Two other undergraduates were part of a now published study on the interactive effects of Nosema and a fungicide chlorothalonil on aspects of bumble bee health. They presented this work as a poster at a regional meeting. This work was predominantly the MS thesis of graduate student Austin Calhoun, and has been published this year, with all students as co-authors. Austin also presented this work at a virtual regional conference, where he received the top student presentation award. Austin Calhoun has now progressed to the PhD program at Illinois State University. How have the results been disseminated to communities of interest?We have submitted results to peer-reviewed journals and given scientific conference presentations on the goal related and associated results from our research. In addition, knowledge and expertise gained during the project has been used in communication with bumble bee conservation stakeholders, such as the U.S. Fish and Wildlife Service Rusty Patched Bumble Bee Recovery Implementation Strategy Science Support Team and NAPPC Imperiled Bombus Conservation Task Force. Further, a number of talks have been given to community and education groups that relate to the core bumble bee health focus of the grant, which have been informed by our findings. What do you plan to do during the next reporting period to accomplish the goals?Our emphasis over the next several months is to complete for publication our manuscript on the individual and interactive effects of Nosema bombi and imidacloprid exposure. In addition, associated manuscripts and already submitted papers will be completed.
Impacts
What was accomplished under these goals?
The major accomplishment this year is the completion of all analyses and the writing of two publications based on this research. We have submitted one publication to Scientific Reports for review and are writing a second manuscript at this time. Specifically, for each goal, we have done the following: Goal 1: Determine differences in susceptibility to N. bombi, and examine any observed differences with respect to decline status Exposure of declining Bombus occidentalis larvae to Nosema bombi resulted in significantly higher overall gene expression (RNA-seq analysis) than that of the stable B. impatiens when exposed. N. bombi affected up- and down-regulation of 148 genes in B. occidentalis, including those with immune functions (up-regulation of defensin and down-regulation of spatzle) and lipid metabolism (down-regulation of lipase member H-A-like and putative fatty acyl-CoA reductase). Gene expression profiles of B. impatiens larvae exposed to the same spore concentration of N. bombi revealed only 62 differentially expressed genes, all of which were down-regulated, including integument component genes (larval cuticle protein A2B, integumentary mucin C1-like). Of note, the circadian clock-controlled protein gene was down-regulated in both species in response to N. bombi, suggesting the pathogen may generally disrupt timing of development. Based on GO term enrichment analysis of the differentially expressed gene sets of B. occidentalis, N. bombi affected chitin metabolism, lipid metabolism and immune system genes; in B. impatiens, N. bombi affected mostly integument-related genes. These results tentatively suggest that N. bombi may have more pronounced effects on the immune response system in declining B. occidentalis than in the stable B. impatiens. Goal 2: Compare the effects of exposure to the neonicotinoid imidacloprid between species, and examine any observed differences with respect to decline status Transcriptome profiles of B. impatiens larvae exposed to two different sublethal concentrations of imidacloprid, a typical field concentration (7.0 ppb) and a low concentration (0. 7 ppb), were significantly different. The higher concentration resulted in a higher number of differentially expressed genes (755) than the lower concentration (191), as might be expected. However, the fact that an order of magnitude lower concentration nonetheless had an effect indicates that even low concentrations of imidacloprid that could be encountered in the field can expression of important in growth and development in larvae relative to controls. Moreover, the number of overlapping differentially expressed genes in the high and low concentrations relative to controls was higher than expected, suggesting that a core of genes might be affected by imidacloprid independent of the concentration. We also found that B. impatiens larvae consumed less food when treated with the higher imidacloprid concentration than control larvae, and some of the gene expression responses under the higher concentration treatment likely resulted from this indirect effect. Experiments comparing expression responses of B. occidentalis (declining) and B. impatiens (stable) larvae to the higher imidacloprid concentration (7.0 ppb) led to significant differences in gene expression profiles. In B. impatiens, we found 223 differentially expressed genes, including down-regulation of several cuticle protein genes and up-regulation of genes related to immune response (such as hymenoptaecin). B. occidentalis on the other hand appeared less affected by imidacloprid, exhibiting a total of only five differentially expressed genes, including the down-regulation of the circadian clock-controlled protein (involved in circadian rhythm and plays an important role in the timing of development), cyclin-dependent kinase inhibitor 1C (inhibitor of mitosis) and transient-receptor-potential-like protein (required for dark vision); there was an up- regulation of nose resistant to fluoxetine protein 6, which in C. elegans is involved in the uptake of lipids and xenobiotic compounds in the gut, and is also vital for embryo development. Goal 3: Determine if there are species and status specific interactive effects with imidacloprid and Nosema bombi When exposed to both stressors simultaneously, gene expression profiles changed differentially in both species: B. occidentalis down-regulated genes involved in regulation of the cell cycle (such as cyclin-dependent kinase inhibitor 1C, a mitosis inhibitor; or histone H4, a chromatin organization protein) and chitin-interacting proteins (such as collagen alpha chain protein, mucin-5AC and peritrophin-1). In B. impatiens, the combined treatment triggered down-regulation of proteases (including six carboxypeptidases involved in protein breakdown for either digestive, detoxification or regulatory purposes), cuticle proteins (eight in total, important for cuticle formation) and cytochromes P450 (three of them, involved in detoxification and redox regulation). We found up-regulated genes related to neurotransmitter reception (neuronal acetylcholine receptor subunit alpha-10-like and a metabotropic glutamate receptor involved in synaptic plasticity and neuroprotection), neuropeptide receptors (neuropeptide CCHamide-2 receptor-like, involved in appetite and feeding behavior, and cardioacceleratory peptide receptor, involved in ecdysis and heart rate regulation) and neurotransmitter metabolism (dopamine N- acetyltransferase, involved in serotonin and dopamine metabolism). Targeted qPCR of the twentytop differentially differentially expressed genes across all three test treatments (Nosema, imidacloprid and combined Nosema+imidacloprid) of B. impatiens and B. occidentalis larvae were tested for expression in larvae of the declining B. terricola (sister species to B. occidentalis) and stable B. griseocollis. Results were similar to comparisons of B. occidentalis and B. impatiens: Gene expression appeared to be species-specific and independent of whether a species is declining or not. Having said this, we are still in the midst of additional statistical analyses and therefore these final conclusions concerning the absence of a pattern based on the decline status of the bees are still are highly tentative. We are also completing experiments to examine variation in mortality (behavioral differences) across the four treatments described above. We are rearing colonies of the declining B. terricola and the stable B. impatiens for these tests.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2022
Citation:
Blazquez RM, Calhoun AC, Sadd BM and Cameron SA. 2022. Gene expression in bumble bee larvae differs qualitatively between high and low concentration imidacloprid exposure levels. Scientific Reports (Under Review).
- Type:
Websites
Status:
Published
Year Published:
2022
Citation:
Strange, JP, Colla, SR, Duennes, M, Evans, E, Figueroa, LL, Inouye, DW, Lehmann, DM, Moylett, H, Richardson, L, Sadd, BM, Smith, JW, Tripodi, AD and Adams, LD. 2022. Developing a commercial bumble bee clean stock certification program: A white paper of the North American Pollinator Protection Campaign Bombus Task Force. North American Pollinator Protection Campaign (NAPPC). https://www.pollinator.org/nappc/imperiled-bombus-conservation.
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2022
Citation:
Audrey Harrod. 2022. Investigating pathogen transmission potential upon fungicide co-exposure in bumble bees. Undergraduate Honors Thesis, Illinois State University.
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2022
Citation:
Elyse McCormick. 2022. Consequences of microsporidian prior exposure for
virus infection outcomes and bumble bee host health. MS Thesis, Illinois State University.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2022
Citation:
McCormick, EC, Cohen, L, Dolezal, A and Sadd, BM. 2022. Consequences of microsporidian prior exposure for virus infection outcomes and bumble bee host health. Oikos (Under Review).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
McCormick, E. and Sadd, B.M. 2022. Worse off together: Consequences of microsporidian and virus co-infection for parasite dynamics and bumble bee host health. Phi Sigma Biological Sciences Student Association Conference (Poster).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
McCormick, E. and Sadd, B.M. 2022. Worse off together: Consequences of microsporidian and virus co-infection for parasite dynamics and bumble bee host health. Illinois State University Research Symposium (Poster).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
Audrey Harrod. 2022. Investigating pathogen transmission potential upon fungicide co-exposure in bumble bees. Illinois State University Research Symposium (Poster).
|
Progress 05/01/20 to 04/30/21
Outputs
Target Audience:This year we have been especially involved in citizen science efforts (BeeSpotter; BeeBlitz) and offered scientific support to government agencies and their conservation efforts. BeeSpotter is our online interactive webpage targeting pollinator range distributions in Illinois, Missouri and Indiana; we help to identify hundreds of bees from photographs sent in by citizens interested in wild bees. We have also worked with minority students in the lab, focusing on their training. Other audiences have been scientists interested in bee pollinator decline issues and those specifically interested in pathogen and insecticide effects on bumble bees; we have communicated with these groups via national entomology meetings (Zoom meetings this last year) and invited seminars (also on Zoom). We have targeted students in classroom and lab instruction on bee decline issues. Community groups and K-12 students have been incorporated through targeted outreach presentations and activities on pollinator health in general, with a specific focus on bumble bees. In this year, this has included the production of a video for a local Children's Discovery Museum (Normal, Illinois) and insect structure and function adaptions and a half day workshop at a 4th grade summer camp. We have provided specific locality data to the U.S. Forest Service and to the Vermont Agency of Natural Resources on Bombus terricola, a species that has undergone population decline in the northeastern U.S. PI Cameron has been assisting the U.S. Forest Service with their Species Status Assessment of the western bumble bee (B. occidentalis), which has declined precipitously over the last 25 years in the western U.S. PI Sadd has been a consultant for the U.S. Fish and Wildlife Service as part of the Rusty Patched Bumble Bee Recovery Implementation Strategy Science Support Team. He has also provided consultation and materials for three groups using conservation dogs to assist in gaining knowledge about bumble bee nest locations and densities. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?We continue to provide professional opportunities for the postdoc, including attending genomic workshops and meetings. In the coming November the postdoc plans a presentation at the Entomological Society of America meeting inDenver, Coloradoon some of the results presented here. In the past year the NIFA award has also facilitated the continued training and development of undergraduates and a graduate student within the group of PI Sadd. One undergraduate completed an honors thesis on Nosema infection, with a resulting publication in preparation. This student is now in a PhD program at the University of Colorado. Two other undergraduates were part of a now published study on the interactive effects of Nosema and a fungicide chlorothalonil on aspects of bumble bee health. They presented this work as a poster at a regional meeting. This work was predominantly the MS thesis of graduate student Austin Calhoun, and has been published this year, with all students as co-authors. Austin also presented this work at a virtual regional conference, where he received the top student presentation award. Austin Calhoun has now progressed to the PhD program at Illinois State University. How have the results been disseminated to communities of interest?Results during this COVID-19 year were constrained due to dangers of exposure to the virus. However, we continue to publish results in peer-reviewed journals. Of direct relevance to the hypothesis of interactive effects of pathogen and pesticide exposures, we have published a study investigating co-exposure to Nosema bombi and the fungicide chlorothalonil in Bombus impatiens. In an earlier landscape study, chlorothalonil use had been found to be a positive predictor of Nosema prevalence in declining bumble bee species. However, there had been no causal link established. Our study shows that B. impatiens is relatively tolerant to N. bombi infections, there is no interactive effect of the stressors in terms of survival or condition of bees. However, co-exposure with chlorothalonil increases the production of transmissible spore stages, which could have implications for disease spread in natural communities. Work partly funded by this award has also been presented by PI Sadd in a keynote seminar at the Midwest Ecology and Evolution Conference 2021 and at Indiana State University. In addition, knowledge and expertise gained during the project has been used in communication with bumble bee conservation stakeholders, such as the U.S. Fish and Wildlife Service Rusty Patched Bumble bee Recovery Implementation Strategy Science Support Team, which PI Sadd is a member of. What do you plan to do during the next reporting period to accomplish the goals?We are initiating mortality experiments to add biological insights to the results of the gene expression analyses. These experiments are designed to determine if the four treatments given to larvae (Nosema, imidacloprid, combined and controls) result in differences in adult mortality. The other principal activity over the next reporting period is to write two major manuscripts for publication. We have begun working on both of these.
Impacts
What was accomplished under these goals?
Goal 1: Determine differences in susceptibility to N. bombi,and examine any observed differences with respect to decline status Exposure of declining Bombus occidentalis larvae to Nosema bombi resulted in significantly higher overall gene expression (RNA-seq analysis) than that of the stable B. impatiens when exposed. N. bombi affected up- and down-regulation of 148 genes in B. occidentalis, including those with immune functions (up-regulation of defensin and down-regulation of spätzle) and lipid metabolism (down-regulation of lipase member H-A-like and putative fatty acyl-CoA reductase). Gene expression profiles of B. impatiens larvae exposed to the same spore concentration of N. bombi revealed only 62 differentially expressed genes, all of which were down-regulated, including integument component genes (larval cuticle protein A2B, integumentary mucin C1-like). Of note, the circadian clock-controlled protein gene was down-regulated in both species in response to N. bombi, suggesting the pathogen may generally disrupt timing of development. Based on GO term enrichment analysis of the differentially expressed gene sets of B. occidentalis, N. bombi affected chitin metabolism, lipid metabolism and immune system genes; in B. impatiens, N. bombi affected mostly integument-related genes. These results tentatively suggest that N. bombi may have more pronounced effects on the immune response system in declining B. occidentalis than in the stable B. impatiens. Goal 2: Compare the effects of exposure to the neonicotinoidimidacloprid between species, and examine any observed differences with respect to decline status Transcriptomeprofiles of B. impatiens larvae exposed to two different sublethal concentrations of imidacloprid, a typical field concentration (7.0 ppb) and a low concentration (0. 7 ppb), were significantly different. The higher concentration resulted in a higher number of differentially expressed genes (132) than the lower concentration (46), as might be expected. However, the fact that an order of magnitude lower concentration nonetheless had an effect indicates that even extremely low concentrations of imidacloprid can affect gene expression in larvae relative to controls. Moreover, the number of overlapping differentially expressed genes in the high and low concentrations relative to controls was higher than expected, suggesting that a core of genes might be affected by imidacloprid independent of the concentration. We also found that B. impatiens larvae consumed less food when treated with the higher imidacloprid concentration than control larvae. Experiments comparing expression responses of B. occidentalis (declining) and B. impatiens (stable) larvae to the higher imidacloprid concentration (7.0 ppb) led to significant differences in gene expression profiles. In B. impatiens, we found 223 differentially expressed genes, including down-regulation of several cuticle protein genes and up-regulation of genes related to immune response (such as hymenoptaecin). B. occidentalis on the other hand appeared less affected by imidacloprid, exhibiting a total of only five differentially expressed genes, includingthe down-regulation of the circadian clock-controlled protein (involved in circadian rhythm and plays an important role in the timing of development), cyclin-dependent kinase inhibitor 1C (inhibitor of mitosis) and transient-receptor-potential-like protein (required for dark vision); there was an up-regulation of nose resistant to fluoxetine protein 6, which in C. elegans is involved in the uptake of lipids and xenobiotic compounds in the gut,andis also vital for embryo development. Goal 3: Determine if there are species and status specific interactive effects with imidacloprid and Nosema bombi When exposed to both stressors simultaneously, gene expression profiles changed differentially in both species: B. occidentalis down-regulated genes involved in regulation of the cell cycle (such as cyclin-dependent kinase inhibitor 1C, a mitosis inhibitor; or histone H4, a chromatin organization protein) and chitin-interacting proteins (such as collagen alpha chain protein, mucin-5AC and peritrophin-1).In B. impatiens, the combined treatment triggered down-regulation of proteases (including six carboxypeptidases involved in protein breakdown for either digestive, detoxification or regulatory purposes), cuticle proteins (eight in total, important for cuticle formation) and cytochromes P450 (three of them, involved in detoxification and redox regulation). We found up-regulated genes related to neurotransmitter reception (neuronal acetylcholine receptor subunit alpha-10-likeand a metabotropic glutamate receptorinvolved in synaptic plasticity and neuroprotection), neuropeptide receptors (neuropeptide CCHamide-2 receptor-like, involved in appetite and feeding behaviour,and cardioacceleratory peptide receptor, involved in ecdysis and heart rate regulation) and neurotransmitter metabolism (dopamine N-acetyltransferase, involved inserotonin and dopamine metabolism). Targeted qPCR of the twentytop differentiallydifferentially expressed genes across all three test treatments (Nosema, imidacloprid and combined Nosema+imidacloprid) of B. impatiens and B. occidentalis larvae were tested for expression in larvae of the declining B. terricola (sister species to B. occidentalis) and stable B. griseocollis. Results were similar to comparisons of B. occidentalis and B. impatiens: Gene expression appeared to be species-specific and independent of whether a species is declining or not. Having said this, we are still in the midst of additional statistical analyses and therefore these final conclusions concerning the absence of a pattern based on the decline status of the bees are still are highly tentative. We are also currently preparing for experimentsto examine variation in mortality (behavioral differences) across the four treatments describedd above. We are rearing colonies of the declining B. terricola and the stable B. impatiens for these tests.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Sadd, B.M. 2021. What kills the buzz in the meadow? An evolutionary ecology approach to bumble bee health and declines. Midwest Ecology and Evolution Conference, USA (Oral).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Calhoun, A.C. and Sadd, B.M. 2021. Testing the multiple stressor hypothesis: Chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health. Phi Sigma Biological Sciences Student Association Conference (Oral).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Calhoun, A.C., Harrod, A.E. (Presenter), Bassingthwaite, T.A. (Presenter) and Sadd, B.M. 2021. Testing the multiple stressor hypothesis: Chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health. Phi Sigma Biological Sciences Student Association Conference (Poster).
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2020
Citation:
Abraham Martinez. 2020. Diet diversity and infection outcomes in a bumble bee and microsporidian system. Undergraduate Honors Thesis, Illinois State University.
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2020
Citation:
Austin Calhoun. 2020. Testing the multiple stressor hypothesis: Chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health. MS Thesis, Illinois State University.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Calhoun, A.C., Harrod, A.E., Bassingthwaite, T.A. and Sadd, B.M. 2021. Testing the multiple stressor hypothesis: Chlorothalonil exposure alters transmission potential of a bumblebee pathogen but not individual host health. Proceedings of the Royal Society B: Biological Sciences, 288, 20202922.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Sadd, B.M. 2021. What kills the buzz in the meadow? An evolutionary ecology approach to bumble bee health and declines. Indiana State University, USA (Oral).
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Progress 05/01/19 to 04/30/20
Outputs
Target Audience:We have targeted scientists through publications resulting from research funded by this project; citizen scientists and especially BeeSpotter, our online interactive webpage targeting pollinator distributions in Illinois, Missouri and Indiana; minority students who have worked in the lab have been a focus. Other audiences have been scientists interested in bee pollinator decline issues and those specifically interested in pathogen and insecticide effects on bumble bees, targeted through focalBombusmeetings, national entomology meetings and invited seminars. We have targeted students in classroom and lab instruction of issues and protocols. Community groups and K-12 students have been incorporated through targeted outreach presentations and activities on pollinator health in general, with a specific focus on bumble bees.Dr. Strange helped organize the Bombuss. 2.0 workshop, held in Toronto Oct. 2019, and both Drs. Sadd and Cameron were invited participants. We have alsoprovided information to the US Forest Service, Willamette National Forest, regarding bumble bee population health for collections of spring queens we conducted as part of this work. We have done the same in Vermont for the Vermont Agency of Natural Resources vis a vis our collection of Bombus terricola, which has been shown to have declined in the northeastern US. Co-PIs Sadd and Strange were invited as speakers and PI Cameron as a participant in a Rusty-Patched Bumble Bee IUCN and SSC Conservation Planning Specialist Group Workshop in Minnesota. Changes/Problems:The only problem we encountered since the last report is the COVID-19 pandemic, which began to hit the US hard in March. Our state of Illinois mandated stay-at-home regulationsand university travel was suspended. This prevented us from collecting a key species in our research, Bombus terricola. We plan to collect this species next spring to complete our research. We are hoping to keep the postdoc beyond the original two years proposed in our budget. What opportunities for training and professional development has the project provided?We have continued training of the postdoc, Ruben Blazquez, and Masters graduate student,Austin Calhoun. Numerous undergraduates and a new Masters student, Elyse McCormick, have been working closely with Dr. Sadd; Austin has segued into Dr. Sadd's lab as a PhD student this spring. The grad students and postdoc have presented research results at the national meetings, including the Entomological Society of America. How have the results been disseminated to communities of interest?We have disseminated results of this year's research at both national meetings and through the indicated journal publications. In particular, Cameron and Sadd published a global reviewof bumble bee health and threats in theAnnual Review of Entomology. This paper is acomprehensive and timely review summarizing current data on bumble bee declines globally. This review also compiles and assesses the evidence for the role of putative causal factors in these declines, and presents testable hypotheses and future directions relating to bumble bee conservation and understanding the threats to bumble bees worldwide. What do you plan to do during the next reporting period to accomplish the goals?Over the next and final year of the project, we will add the final declining species, Bombus terricola,and the stable species, B. griseocollis, to the four-treatment experiments (Nosema only exposure, imidacloprid only, Nosema and imidacloprid combined, and controls). This will allow us to complete the comparative gene expression analysis of all species included in the grant-- two declining and two stable species. We will also collect mortality data on at least one declining and one stable species under the same 4-treatment experimental conditions as we've presented the bees for the RNA-seq (gene expression) analysis. We are already beginning to write a preliminary manuscript on the first two of the four species included in our experiments.We will continue with the training of postdoc and students.
Impacts
What was accomplished under these goals?
Diet diversity and Nosema bombi infection To further our understanding of factors influencing N. bombi infection outcomes, this study investigated how adult pollen consumption, pollen type, and pollen diversity influence survival and infection in B. impatiens. Experimental infections during the larval stage were performed in microcolonies and newly emerged adult workers were given one of five pollen diet treatments: (i) monofloral green, (ii) monofloral orange, (iii) monofloral yellow, (iv) polyfloral, or (v)no pollen. Workers were assessed for size, pollen consumption, infection eight days following adult-eclosion, survival, and the presence of extracellular spores of the microsporidian at the time of death. We found that infected workers were smaller and had reduced survival. In addition, we demonstrate that adult pollen deprivation also decreases survival. However, we saw no effects of provisioning with pollen, pollen type, nor pollen diet diversity on infection, and infection and pollen diet treatment independently affected survival. Although infection outcomes were not altered by pollen diet in our study, it highlights that both parasite infection and pollen availability are important for bumble bee health, and these factors may interact at different stages of bumble bee development, at the colony level, or under different dietary regimes. This work resulted in an undergraduate honors thesis (Martinez, A. 2020. Investigating the influence of diet diversity on infection outcomes in a bumble bee and microsporidian host-parasite system. Illinois State University) and is currently being prepared for submission to Ecological Entomology.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Cameron, S.A. and Sadd, B.M. 2020. Global trends in bumble bee health. Annual Review of Entomology 65:209-232.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Tobin, K.B., Calhoun, A.C., Hallahan, M.F., Martinez, A. and Sadd, B.M. 2019. Infection outcomes are robust to thermal variability in a bumble bee hostparasite system. Integrative and Comparative Biology, 59(4), 1103-1113.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Sadd, B.M. 2019. Rusty-Patched Bumble Bee (IUCN and SSC Conservation Planning Specialist Group, Minnesota, USA, 2020) I am sick of this: considering disease in bumble bee captive rearing.
|
Progress 05/01/18 to 04/30/19
Outputs
Target Audience:We have targeted scientists through publications resulting from research funded by this project; citizen scientists and especially BeeSpotter, our online interactive webpage targeting pollinator distributions in Illinois, Missouri and Indiana; minority students who have worked in the lab have been a focus. Other audiences have been scientists interested in bee pollinator decline issues and those specifically interested in pathogen and insecticide effects on bumble bees, targeted through focalBombusmeetings, national entomology meetings, and invited seminars. We have targeted students in classroom and lab instruction of issues and protocols. Community groups and K-12 students have been incorporated through targeted outreach presentations and activities on pollinator health in general, with a specific focus on bumble bees.Dr. Strange helped organize the Bombuss. 2.0 workshop, held in Toronto in October of 2019, and both Drs. Sadd and Cameron were invited participants. We have alsoprovided information to the US Forest Service, Willamette National Forest, regarding bumble bee population health for collections of spring queens we conducted as part of this work. We have done the same in Vermont for the Vermont Agency of Natural Resources vis a vis our collection of Bombus terricola, which has been shown to have declined in the northeastern U.S. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Multiple undergraduate, graduate, and postdoctoral training has been accomplished this year, with the addition of a new graduate student, which brings the number of PhD students to two. The grad students have presented results of this research at national meetings and given posters. The postdoc, from Spain, has had his first opportunity to present a talk at the national ESA meeting on our research results to date. How have the results been disseminated to communities of interest?We have disseminated results of this year's research at both national meetings and through the indicated journal publications. In particular, Cameron and Sadd have reviewedof status of bumble bee global health and threats, submitted to the Annual Review of Entomology. This paper is acomprehensive and timely review summarizing current data on bumble bee declines globally. This review also compiles and assesses the evidence for the role of putative causal factors in these declines, and presents testable hypotheses and future directions relating to bumble bee conservation and understanding the threats to bumble bees worldwide. Cameron, S.A. andSadd, B.M. (Accepted) Global trends in bumble bee health.Annual Review of Entomology. What do you plan to do during the next reporting period to accomplish the goals?Beyond refining our RNA-seq results andmining the data for clear and robust patterns of differential gene expression. we plan to repeat all experiments with twoadditional species, the declining Bombus terricola and the stable Bombus griseocollis. We have learned how to rear B. terricola over the last couple of summers and expect to be able to have a significantly larger number of experimental colonies with which to carry out our stressor treatment experiments. Currently, we have larvae from two B. terricola colonies, four micro-colonies from each colony, treated, according to our standard experimental design, with Nosema, imidacloprid, and acombination of the two. We intend to analyze the RNA-seq data obtained from those larvae over the winter. In spring we will rear new colonies of both B. terricola and B. impatiens for our final summer season of treatment experiments.
Impacts
What was accomplished under these goals?
Optimization of infection delivery protocols: Illinois State University graduate student Austin Calhoun, advised by co-PI Sadd, has further optimized the delivery ofNosemaspores to achieve regular infections. For consistency, this has required direct delivery of spore solutions to larvae. Multiple stressors experiment in microcolonies: Pesticides and parasites:Results based on spore counts suggest that infections are indeed higher when bees are co-exposed to the pesticide, consistent with the multiple stressor hypothesis. However, unexpectedly, bee survival was not reduced in the co-exposed group. Currently, qPCR that will include quantification of intracellular Nosema and measures of condition, such as lipid, protein, and carbohydrate reserves, are being carried out. These assays may resolve the existing seemingly paradoxical results. RNA-seq analysis of differential gene expression: To analyze differential gene expression in declining and stable species of Bombus exposed toNosema, imidacloprid, orcombination of both of these potential stressors, our postdoc, Ruben Blazquez,obtained 24 larvae from two colonies ofB. terricola, 48 larvae from four colonies ofB. impatiens, and 48 larvae from four colonies ofB. occidentalis.Microcolonies of the three species were treated with N. bombi, or with a sublethal dose of imidacloprid, or with both N. bombi and imidacloprid combined. Gene expression profiles were analyzed from RNA-seq data for B. occidentalis and B. impatiens, indicatingdifferent sets of genes were differentially expressed between species in response to the treatments. These experiments and analyses will be ongoing over the winter and spring of 2020.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2020
Citation:
Cameron, S.A. and B.M. Sadd. 2020. Global trends in bumble bee health. Annual Review of Entomology (In Press).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Tobin, K.B., Martinez, A. and Sadd, B.M 2019. Negative effects of heatwaves on bumble bee immunity and parasite resistance. SACNAS Conference, Honolulu, Hawaii.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Calhoun, C and Sadd, B.M. 2019. The influence of multiple stressors of a fungicide and microsporidian parasite on bumble bee health. BOMBUSS 2.0: Building Our Methods by Using Sound Science: Next Steps in North American Bumble Bee Monitoring and Conservation. York University, Toronto, CA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Tobin, K.B., Martinez, A. and Sadd, B.M. 2019. Negative effects of heatwaves on bumble bee immunity and parasite resistance. Midwest LSAMP Conference, Lisle, USA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Cameron, S.A. 2019. Getting to know the organism. BOMBUSS 2.0: Building Our Methods by Using Sound Science: Next Steps in North American Bumble Bee Monitoring and Conservation. York University, Toronto, CA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Martin-Blazquez, R., Calhoun, A.C., Strange, J.P., Sadd, B.M. and Cameron, S.A 2019. Transcriptomic differences between stable and declining bumble bee (Bombus) species exposed to neonicotinoid pesticides and Nosema bombi pathogens. Entomological Society of America Annual Meeting, St Louis, Missouri.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Mullins, J.L., Strange, J.P. and Tripodi, A.D. 2019. Why are queens broodless? Failed nest initiation not linked to parasites, mating status or ovary development in two bumble bee species of Pyrobombus (Hymenoptera: Apidae: Bombus). Journal of Economic Entomology doi: 10.1093/jee/toz330.
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Progress 05/01/17 to 04/30/18
Outputs
Target Audience:The target audience for this reporting periodhas include citizen scientists andminority students who have worked in the lab, Other audiences have been scientists interested in bee pollinator decline issues andthose specifically interested in pathogen and insecticide effects on bumble bees. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The PI and collaborators have together mentored two postdocs (Drs. Ruben Blazquez and Amber Tripodi), multiple graduate students and undergraduates in the rearing of bumble bee colonies for experiments, different pathogens affecting the health of bumble bees (Nosema bombi, Crithidia bombi) and different pesticides potentially affecting the health of bumble bees, including imidacloprid and chlorothalonil. One of the graduate students, K. Tobin, received his masters degree and is continuing on with this research as he has been accepted into thePhD program. How have the results been disseminated to communities of interest?These are the outreach communities we have interacted with: llinois State University Summer Child Care Group (August 2018): Learning about Insects half-day visit (pre-school group). Parklands Foundation (local conservation land protection group): Consultation and presentations relating to pollinator health, particularly bumble bees. Included an information table at the annual Parklands Foundation day in Summer 2018. Chiddix Junior High, Normal: Presentations on interactions between bees, their microbes, and us. Fall 2018. Normal Ecology Action Center: Yard smart garden walk keynote presentation on pollinators. Fall 2018. ScoutReach: Educational exhibit and exercises on bees and insect evolution. Spring 2019. Working dogs for conservation - Forensics and Field Specialists: Consultant and supplier of materials for a NGO using dogs in conservation, including to identify bumble bee nests. Program Organizer, Science Technology Engineering and Mathematics (STEM) Social for Underrepresented Minority Students (August 2017 - Present). This is essentially a career outreach/retention evening event with current ISU students, students from surrounding colleges, and high school students thinking about college. BeeSpotter citizen scientist interaction, identifying photographs sent in by the spotters; BeeBlitz 2018 organized by BeeSpotter, which brings in interested citizens who wish to learn about bee biology and ecology. What do you plan to do during the next reporting period to accomplish the goals?During the oncoming summer season we are geared up to begin major experiments to test the genomic and behavioral effects of pathogens, pesticides and combined stressors on four or fivespecies of bumble bees: two to three declining species (B. terricola, B. occidentalis and possiby B. pensylvanicus). We have colonies at the early brood stage of all three of these declining species; we also have colonies near the first generation of adults for the non-declining species B. griseocollis and B. impatiens. All colonies are being reared from spring queens. When the colonies are large enough we will be performing the comparative experiments, introducing 2nd and 3rd instar larvae to pathogens Nosema bombi alone, imidacloprid alone, both combined and a control. The goal is to compare gene expression patterns for each of these foursamples to determine any genomic level effects on gene expression. That work should be completed by January of 2020.
Impacts
What was accomplished under these goals?
Optimization of infection delivery protocols Illinois State University graduate student Austin Calhoun, advised by co-PI Sadd, has optimized the delivery ofNosemaspores to achieve regular infections. For consistency, this has required direct delivery of spore solutions to larvae. Multiple stressors experiment in microcolonies: Pesticides and parasites Related to the main aims of the grant, Austin Calhoun has been investigating experimentally an association between the fungicide chlorothalonil andNosema bombiinfection reported in an earlier landscape ecology study. This has involved a fully crossed design of exposure or not ofBombus impatiensmicrocolonies to the pesticide and/orNosema. Treatments have been completed in 76 microcolonies, derived from eight original colonies of origin. Responses measured include survival, infection loads, adult size, and measures of condition, such as lipid, protein, and carbohydrate reserves. Additionally, a preference experiment was carried out that demonstrated adult bumble bees do not show any preference for chlorothalonil-laced sugar water. Multiple stressors experiment: Environmental temperature and parasite resistance Linked to the main aims of the grant concerning bumble bee health and responses to multiple stressors encountered in the environment, a graduate student at Illinois State University partially funded from this grant, Kerrigan Tobin, has completed work on the interaction between thermal variation and immunity and parasite infection inBombus impatiens. A first study investigated if variation in temperatures within the normal experienced range of workers during summer conditions could lead to increased susceptibility to experimental infection by a trypanosome parasite. Parasite strains differed in infectivity and host colonies in their resistance, but it was shown that acclimation temperatures and fluctuations to performance temperatures within the range of 21-29 degrees C did not alter infection outcomes. In addition tothe thesis of the graduate student, this is published at the journal Integrative and Comparative Biology. The manuscript for a second study demonstrating effects of a naturally relevant simulated heatwave on antibacterial immunity and parasite resistance individual bumble bee workers is currently in preparation. RNAseq Postdoc Ruben Blazquez has worked out the protocols and data analysis pipelines for analysis of the differential gene expression analysis. We have preliminary data on imidacloprid-exposed larvae (2nd and 3rd instar) with two different concentrations, high (field-realistic, sublethal) and low (below field-realistic dose), as described in the "products from this research" section. Completion of Masters Thesis: KB Tobin(2018) The Influence of Heatwaves on Bumble Bee Immunity and Parasite Infection. Master's Thesis, Illinois State University.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Cameron, S.A. and Whitfield, J.,B. 2019. Shift in temporal and spatial expression of Hox gene explains color mimicry in bees. NAS June 11, 2019 116 (24) 11573-11574.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Tripodi, A.D. and Strange, J.P. 2019. No second chances for pollen-laden queens? Insectes Sociaux, pp.1-6.
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2018
Citation:
Tobin, K. 2018. The influence of heatwaves on bumble bee immunity and parasite infection. Masters Thesis, Illinois State University.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Tobin, K.B., Calhoun, A.C., Hallahan, M.F., Martinez, A. and Sadd, B.M. 2019. Infection outcomes are robust to thermal variability in a bumble bee host-parasite system. Integrative and Comparative Biology. Online early.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Calhoun, C and Sadd, B.M. 2019. The influence of multiple stressors of a fungicide and microsporidian parasite on bumble bee health. Ecology and Evolution of Infectious Disease Meeting, Princeton, New Jersey.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Calhoun, C. and Sadd, B.M. 2019. The influence of multiple stressors of a fungicide and microsporidian parasite on bumble bee health. Society for Integrative and Comparative Biology, Tampa, Florida.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Sadd, B.M. and Tobin, K. 2019. In the heat of the moment: Host immunity and parasite resistance in the face of thermal shifts and stress. Society for Integrative and Comparative Biology, Tampa, Florida.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Tobin, K., Hallahan, M., Martinez, A., Mandes, R. and Sadd, B.M. 2018. Bumble bee immunity and parasite infection in the face of thermal variability and heatwaves. IUSSI Congress, Guaruja, Brazil.
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2018
Citation:
Bumble bee pathogens.
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