Progress 01/01/24 to 12/31/24
Outputs
Target Audience:The outputs of our research objectives will advance our understanding of how biotic and abiotic stressors impact pollinators at the individual and population levels. Particularly, we will investigate how temperature increases interact with other stressors such as pathogens and pesticides. We will use the pollinator community of cucurbit cropping systems to address these questions. To achieve these research goals, we have recruited two graduate students and one postdoc over the past year. Our target audience includes pollinator scientists, conservationists, and growers of pollinator-dependent crops (with specific information for cucurbit growers). Changes/Problems:Some students will graduate and may not have enough time to work on the publications. Some of the research outputs may be delayed due to the amount of data included in those studies. The PIs will take leadership roles in the submission of those peer-reviewed publications. Additionally, we were unable to include experiments that incorporate pesticide exposure as a stressor. We investigated the role of interactive stressors in other ways (e.g., high humidity and heat, heat and pathogen infections) but due to limited time, we were unable to tackle those objectives. What opportunities for training and professional development has the project provided?We supported two graduate students and one postdoctoral researcher to work on this project. Both students graduated and completed their research projects. We hired one of the former graduate students as a technician to continue working on this project. How have the results been disseminated to communities of interest?We have four manuscripts ready for peer review, one accepted, and one published. We also wrote a blog post about the paper that was published. There was also a press release about this study. What do you plan to do during the next reporting period to accomplish the goals?We should have at least 3 of the four manuscripts in preparation submitted for publication. Additionally, this year, we are setting up a controlled comparative experiment to test the role of trypanosome infections on the thermal tolerance in bumble bees and squash bees. We will report on the findings of that study in the next reporting cycle.Here is a list of the manuscripts in preparation: Ivers NA, Gray HL, Lopez E, Peter BG, Neff JL, Longing S, López-Uribe MM, Jha S (Accepted) Pollination services to squash are insufficient despite abundant specialist bees. Agriculture, Ecosystems, and Environment Jones LJ, Youngsteadt EK, Jha S, Schilder RJ, López-Uribe MM. (In prep) The lower thermal limit of a solitary bee tracks its recent northward range expansion in North America. Global Change Biology Cruz JAM, Jha S, López-Uribe MM, Schilder RJ (In prep) The dangers of wet heat: interaction between heat waves and high humidity negatively affects Bombus impatiens fitness traits (Hymenoptera: Bombus). Journal of Experimental Biology. Ivers NA, Jha S, López-Uribe MM, Schilder RJ (In prep) Captive rearing mark-recapture allows characterization of metabolism across individuals' lifespan in a solitary ground-nesting bee. Conservation Physiology. Medina-Valencia A, Gutierrez GM, Turley NE, Jha S, Schilder RJ, López-Uribe MM. (In prep.) Phenology drives thermal tolerance traits in wild bees. Royal Society Open Science
Impacts
What was accomplished under these goals?
Objective 1. Quantify the interacting effects of pathogen pressure and pesticide exposure on individual-level heat tolerance, energetics, and fitness for social and solitary bee crop pollinators - We investigated the interactive effects of heat waves and humidity in bumble bees using microcolonies in the lab and full-size colonies in the field. The study results indicate that heat waves and high humidity conditions in isolation have neutral or even positive effects on bumble bee fitness. However, when bumble bees experience both conditions at the same time, there are severe negative effects on reproduction and survival. We investigated the role of phenological syndromes on heat tolerance variation across 17 bee species. We found that spring bees are more cold tolerant than summer bees by an average of 3.5ºC. Results from this study are currently being prepared for publication. We investigated how the metabolic rate of squash bees varies across their lifespan. This experiment was set up as a pilot study to assess our ability to use metabolic rate measurements in the field as a response variable that could measure an individual's stress. We found that squash bees at rest show two types of gas exchange (continuous and discontinuous) and that metabolism declines across an individual's lifespan. Our results indicate that this metric can be implemented in field settings to assess an individual's metabolism. Objective 2. Determine how microclimate variation, pathogen pressure, and pesticide exposure impact population-level thermal tolerance and fitness across heterogeneous agricultural landscapes - In Pennsylvania, we quantified pathogen loads and quantified the thermal tolerance of 418 individuals across 14 sites. Results from the interaction between infection levels and thermal tolerance were published (Jones et al 2024). A more comprehensive study showing the dynamics of squash bee pathogens in Pennsylvania is in the works. In Texas, we sampled 20 sites for bee pathogens. Pathogen quantifications are being worked on, and we should have results from this study by the next reporting cycle. Objective 3. Map stressors and population vulnerability across heterogeneous agricultural landscapes under varying climatic conditions We quantified the critical thermal limits of squash bee populations across a latitudinal gradient through sampling of populations in Texas, North Carolina, and Pennsylvania. We found that cold tolerance increases with latitude, while heat tolerance changes across sites but is not explained by latitude or local ambient temperatures. Using predictions from future temperatures across these sites, we found that squash bee populations in the southern part of their distribution are at risk of local extinction due to ambient temperatures likely exceeding their thermal tolerance capacity. This study is currently being prepared for Global Change Biology.
Publications
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Jones LJ, Miller D, Schilder RJ, L�pez-Uribe MM. (2024) Body mass, temperature, and pathogen intensity differentially affect the critical thermal maxima and its population-level variance in a solitary bee. Ecology and Evolution 14(2): e10945.
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Progress 01/01/23 to 12/31/23
Outputs
Target Audience:The outputs of our research objectives will advance our understanding of how biotic and abiotic stressors impact pollinators at the individual and population levels. Particularly, we will investigate how temperature increases interact with other stressors such as pathogens and pesticides. We will use the pollinator community of cucurbit cropping systems to address these questions. To achieve these research goals, we have recruited two graduate students and one postdoc over the past year. Our target audience includes pollinator scientists, conservationists, and growers of pollinator-dependent crops (with specific information for cucurbit growers). Changes/Problems:Some students will graduate and may not have enough time to work on the publications. Some of the research outputs may be delayed due to the amount of data included in those studies. The PIs will take leadership roles in the submission of those peer-reviewed publications. What opportunities for training and professional development has the project provided?We supported two graduate students (both URM in STEM) and we hired a postdoctoral researcher to work on this project. These students and postdocs have presented their work at national conferences. How have the results been disseminated to communities of interest?We have three manuscripts ready for peer review. Students have presented talks about their work at the National Entomological Society of America Conference. What do you plan to do during the next reporting period to accomplish the goals?We have several manuscripts in the works: (1) Two manuscripts on squash bee pathogen dynamics in Pennsylvania and Texas; (2) the effects of heat waves and high humidity on bumble bee fitness; (3) the role of phenology on wild bee tolerance. We are setting up a controlled experiment in hoop houses to test our ability to keep squash bees alive in a controlled environment and measure metabolic rates throughout their lives. We will report the results of these experiments next year.
Impacts
What was accomplished under these goals?
Objective 1. Quantify the interacting effects of pathogen pressure and pesticide exposure on individual-level heat tolerance, energetics, and fitness for social and solitary bee crop pollinators - We investigated the interactive effects of heat waves and humidity in bumble bees using microcolonies in the lab and full-size colonies in the field. The study results indicate that heat waves and high humidity conditions in isolation have neutral or even positive effects on bumble bee fitness. However, when bumble bees experience both conditions at the same time, there are severe negative effects on reproduction and survival. Additionally, we are investigating the role of phenological syndromes on heat tolerance variation across bee species. Results from this study are currently being prepared for publication. Objective 2. Determine how microclimate variation, pathogen pressure, and pesticide exposure impact population-level thermal tolerance and fitness across heterogeneous agricultural landscapes - We sampled squash floral visitors across more than 20 Cucurbita farms in both Pennsylvania and Texas. Results have been partially published through descriptive papers, but a more comprehensive study from Pennsylvania is still in the works. Samples for the bee pathogens from Texas are currently being analyzed. Objective 3. Map stressors and population vulnerability across heterogeneous agricultural landscapes under varying climatic conditions - NA
Publications
- Type:
Other
Status:
Other
Year Published:
2023
Citation:
Medina-Valencia A, Gutierrez G, Schilder RJ, L�pez-Uribe MM. Phenology is Associated with Thermal Tolerance in Bees. (Poster presentation). Entomological Society of America Meeting, National Harbor, MD, USA (November 2023)
- Type:
Other
Status:
Other
Year Published:
2023
Citation:
Cruz JM, L�pez-Uribe MM, Schilder RJ. Effects of heat waves and high humidity on colony and individual fitness in bumble bees. (Oral Presentation). Entomological Society of America Meeting, National Harbor, MD USA (November, 2023)
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Progress 01/01/22 to 12/31/22
Outputs
Target Audience:The outputs of our research objectives will advance our understanding of how biotic and abiotic stressors impact pollinators at the individual and population levels. Particularly, we will investigate how temperature increases interact with other stressors such as pathogens and pesticides. We will use the pollinator community of cucurbit cropping systems to address these questions. To achieve these research goals, we have recruited two graduate students and one postdoc over the past year. Our target audience includes pollinator scientists, conservationists, and growers of pollinator-dependent crops (with specific information for cucurbit growers). Changes/Problems:Recruiting graduate students and postdocs to work on this project took about 8 months of the first year of the grant, so our proposed activities are delayed. We are confident that with the new students and postdocs brought on board on the project, we will be able to accomplished all the proposed activities of the proposal. What opportunities for training and professional development has the project provided?We are currently supporting two graduate students (both URM in STEM) and we just hired a postdoctoral researcher this spring. We will be hiring another postdoc this summer. Another graduate student who contributed to work on this project is graduating this summer and secured a postdoctoral position to continue with her research on pollinator-pathogen interactions. How have the results been disseminated to communities of interest?We published one peer-review open-access article reporting two main findings (1) novel trypanosome species in squash bees; and (2) high host specificity among trypanosomes with different parasite species infecting different bee species. What do you plan to do during the next reporting period to accomplish the goals?We have two ongoing experiments: (1) controlled experiment investigating the colony-level fitness consequences of high humidity and high temperature conditions in bumble bee colonies; and (2) broad characterization of thermal tolerance of bee species with different phenological syndromes (spring, summer, and broad, which pollinate different crops across the year). We will report the results of these experiments next year. Additionally, we will present the preliminary results of our research during the Mid-Atlantic Vegetable Grower Conference in February 2024.
Impacts
What was accomplished under these goals?
Objective 1. Quantify the interacting effects of pathogen pressure and pesticide exposure on individual-level heat tolerance, energetics, and fitness for social and solitary bee crop pollinators - NA Objective 2. Determine how microclimate variation, pathogen pressure, and pesticide exposure impact population-level thermal tolerance and fitness across heterogeneous agricultural landscapes - We sampled squash floral visitors across more than 20 cucurbita farms in both Pennsylvania and Texas. We have just completed pollinator identification for our Texas sites. For our Pennsylvania sites, we finished pollinator identification and quantified the prevalence and intensity of 5 common parasites in the main pollinator species: honey bees, squash bees and bumble bees. For squash bees, we found that individual infected with high levels of trypanosome parasites exhibit lower thermal tolerance (Jones et al in prep). Additionally, we found that specialist pollinators, such as squash bees, are the main host driving parasite dynamics in crop systems (Jones et al in review). Our results will provide recommendations to farmers on what type of farm modification (e.g., plantings) they can incorporate to reduce parasite intensity in crop pollinators. Objective 3. Map stressors and population vulnerability across heterogeneous agricultural landscapes under varying climatic conditions - NA
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Jones LJ, Singh A, Schilder RJ, L�pez-Uribe MM. Squash bees host high diversity and prevalence of parasites in the northeastern United States. Journal of invertebrate pathology. 2022 Nov 1;195:107848.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2023
Citation:
Jones LJ, Rom�n-Echevarr�a G, Schilder RJ, L�pez-Uribe MM. (In review) Parasite ecology and landscape context shape transmission dynamics in a pollinator community dominated by a diet specialist. Proceedings of the Royal Society B: Biological Sciences.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2023
Citation:
Gray H.L., Lopez-Uribe M.M. & S. Jha (in review) Floral changes induced by early-season herbivory. American Journal of Botany
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