Research Project: Ecological Assessment and Mitigation Strategies to Reduce the Risks of Bees to Stressors in Southern Crop Ecosystems

Location: Pollinator Health in Southern Crop Ecosystems Research

2024 Annual Report

Objectives
1. Determine pesticide risks to honey bees, both by laboratory assays and field studies in southern cropping systems, including the mode of action of insecticides on bee pollinators and interactions with other pesticides. 2. Develop IPM systems to mitigate the effects of pesticides on bees in these systems. 3. Determine the role of non-crop vegetation in the health of bees in these systems, with a focus on enhancing bee forage habitat. 4. Conduct studies on native bee diversity and biology in southern cropping systems to improve the use of local bee species for pollination of regional crops such as squash and berries. 5. Conduct studies on aerial and ground application of pesticides, examining drift patterns and design equipment and spray adjuvants/dispensers that uses precision application to minimize off-target application onto adjacent non-cropping areas associated with bee habitat.

Approach
This new Research Unit will focus on how to improve both native and honey bee health as well as improving natural habitat and minimizing risk to stressors including pesticides and pests in a way that is beneficial to both beekeepers and farmers. The southern United States has traditionally been an area of high row crop agriculture with often high pest pressure than routinely needs synthetic pesticides to keep populations below economic injury levels. These areas are only now seeing the influx of commercial beekeepers that traditionally have been located in other areas of the U.S. Therefore, there is a need to determine ways to increase the health of both managed honey bees as well as native bees that are often needed for pollination services for farmers as well as producing honey for the commercial beekeeper. In addition, there is a lack of knowledge in the overall ecology of non-crop forage (i.e. weeds and native vegetation) to provide suitable habitat for bees as well as determining the risk of certain pesticides on bee health. Finding answers on which strategies increase bee health while being feasible and economical both to the farmer and commercial beekeeper is of the highest priority. Reducing pollinator losses by improving bee health is essential for consistently providing adequate bee populations for crop pollination and ensuring the productivity of U.S. crops that require bee pollination. Identification of particularly damaging chemical pesticides as well as improved application strategies that minimize impact on non-target organisms, such as bees, will inform exposure risks that may be mitigated. Conserving the diversity of non-Apis bees, including bumble bees, alfalfa leafcutter bees, and blue orchard bees, is essential for pollinating certain agricultural crops in addition to hundreds of species of native plants that can be forage for managed honey bees. Progress in NP305 will be accelerated by the information provided by this project. All information generated will be made available through various research publications outlets including outreach using University extension personnel. In addition, the new Unit will collaborate extensively with external partners including landgrant Universities and other federal agencies through outgoing NACAs and interagency agreements.

Progress Report
This is the final report for this project. It has been replaced by bridging project 6066-30500-001-000D pending completion of research review. Objective 1: ARS researchers in Stoneville, Mississippi, continued studies exploring the toxicity of synthetic pesticides to non-target organisms such as honey bees and developing alternate chemicals for pest control. as these are of significant to ensure safe farming in the Mississippi delta region. Essential oils and other plant components have been considered as alternatives to toxic synthetic chemical insecticides not only for crop pest control, but also for the control of Varroa mites, the most destructive pest of honey bees. However, for these potential biopesticides to be widely accepted, their risks to pollinating bees needs to be determined. ARS researchers are assessing the risks and benefits of essential oils to adult honey bees. The commercially available essential oil mixture showed no measurable effects, and the four essential oil components tested elicited varied responses. In conclusion, the essential oils studied did not pose a significant danger to honey bees and appear to be a safer alternative to certain synthetic pesticides. Building on the findings of the current projects on honey bee health, ARS researchers in Stoneville, Mississippi, in collaborations with other ARS researchers, established a honey bee cell line (AmE-711) as a model to study the toxicity of pesticides and pesticide adjuvants. The results from these cells are consistent with the results from studies on adult honey bees, making these cells a promising model for honey bee toxicological studies that can also be used in conjunction with honey bee nutrition studies. Objective 2: Research on developing Integrated Pest Management (IPM) systems to mitigate the effects of pesticides on honey bees continued. The combination of bee nutrition and exposure to neonicotinoid insecticides are factors that may interact synergistically to impact bee health. In this collaborative study, ARS researchers demonstrated that adult honey bees receiving diets supplemented with proteins lived longer than control. Adding proteins and lipids to artificial diets improved honey bee physiology but natural pollen from plants, with its complex mixture of macro-and micronutrients was found to be the best for pesticide detoxification. Objective 3: ARS researchers in Stoneville, Mississippi, continued exploring the nutritional content of pollen from different sources, as relevant to honey bees. Pollen samples collected from flowers in clover-mix cover crops grown under different tillage treatments, were analyzed for the nutritional content. In addition, pollen and nectar from flowering soybean crops and weedy plants within the intensive agricultural landscape of the Mississippi Delta, and from cotton plants in a greenhouse study, were analyzed for nutritional content. In addition, the availability of pollen in the environment was determined by monitoring bloom times to establish a calendar for when plants provide pollen (pollen phenology) to honey bees in the southeastern United States (US). The data are currently being analyzed to provide a detailed understanding of available nutritional sources for honey bees and other pollinators in the Mississippi delta. Objective 4: Research on native bee diversity and biology in southern agroecosystems continued. Samples were collected using a combination of different collection techniques including modified pan traps (bee bowls), malaise traps, vane traps, and net sampling. All specimens have been cleaned, pinned, mounted, and entered to a database. Specimens of species new to Mississippi or of significance for conservation have been deposited with regional, national, and international entomological collections. Photographic documentation of all local species are in progress for future use. This baseline information will be used to examine potential impacts of local agricultural production practices on these insects and compare across production practices and pollinator communities. ARS Researchers from Stoneville, Mississippi, along with >14 USDA ARS research units and university collaborators are participating in the collaborative Beenome100 project prioritizing, collecting, and sequencing over 100 bee species from across the US. Many of the species submitted for sequencing have been collected by ARS researchers in PHSCERU from the local Mississippi Delta area and beyond. Objective 5: Research continued to develop safe strategies for aerial and ground application of pesticides. Some of the existing commercially available pesticide adjuvants, inert material in pesticide tank mixes, are toxic to pollinators. ARS researchers are testing several plant-based polymers, including an algae-based polymer, as safer adjuvants with potential drift-reducing properties. Preliminary results from experiments using cell lines in the lab and direct pesticide spray bioassays in the field demonstrate that the algae-based polymer may be a less toxic adjuvant to honey bees and is compatible with commonly used herbicides and insecticides in the Mississippi Delta for controlling pests in row crops. This new adjuvant also shows promise to control off-target drift in ground-based and drone-based aerial applications. The physical and chemical properties of the three plant-based polymers - sodium alginate (from algae), fenugreek polymer, and an okra polymer - are being characterized. The viscosity and dynamic surface tension seem to provide a mechanistic basis for how these polymers can reduce pesticide spray drift in the field. Researchers also collected vegetation samples (leaves and flowers) from field studies to explore the impact on the nearby crops. Trials were conducted by placing potted corn, oats, tomatoes, wildflower plants and canola. Additional research includes testing 15 different medium-sized droplet spray nozzles in ground-based chemical applications to identify nozzles with the least drifting of chemicals. Potted plants were used as part of a bioassay to determine the distance to which off-target drift can travel during herbicide application. Satisfactory progress on subordinate projects 6066-21000-001-002S and 6066-21000-001-003S were achieved by cooperators. Scientists and extension specialists were hired to complement the existing strengths of the ARS. Sub-ordinate projects 6066-21000-001-6S, 6066-21000-001-009S, 6066-21000-001-019S and 6066-21000-001-024S demonstrated satisfactory progress. Researchers developed simple 3D printed structures (metamaterials) capable of considerably enhancing the sound emitted by a targeted insect in the presence of background noise and thus researchers can record the presence of the targeted species eliminating the need for post processing and machine learning. The developed technology allows for customizing the design to detect various insect types and their health conditions. Progress on the subordinate projects 6066-21000-001-004S and 6066-21000-001-007S were marginal due to retirements and failed hirings that did not allow the stated tasks to be accomplished.

Accomplishments
1. The Giant Resin Bee, an introduced species, exhibits changes in life history traits in its new range. ARS Researchers in Stoneville, Mississippi, along with collaborators from several museums and universities across Europe, collected data on the Giant Resin Bee, across its new range in North America and Europe and demonstrated that bees in the new range emerge approximately a month earlier than those in the native range. Understanding the invasion success of this species provides critical information about the spread and management of future introduced bee species.

2. A global bee occurrence dataset and R software package. Species occurrence data are foundational for research, conservation, and science communication. However, limited availability and accessibility of reliable data represents a major obstacle, particularly for insects, whose global populations are facing increasing challenges to remain viable. ARS researchers in Stoneville, Mississippi, and Logan, Utah, collaborated with a worldwide group of collaborators on BeeBDC (a new R software package) and a global bee occurrence dataset to address this issue. By publishing reproducible workflows and globally cleaned datasets, the accessibility and reliability of downstream analyses are increased. Understanding the biodiversity and distribution of wild bees around the world provides critical information for future research and conservation efforts.

3. A pollinator-friendly, drift-reducing pesticide adjuvant. Commercially available pesticide adjuvants, inert material in pesticide tank mixes, are known to be toxic to pollinators. Of the 15 different nozzles tested, a few nozzles with the least drifting medium-droplet spray were identified, allowing crop producers to make informed decisions and chemical production companies to suggest the best nozzles for chemical applications. ARS researchers in Stoneville, Mississippi, also demonstrated the farthest off-target drift occurrence in ground-based chemical applications helping the delineation of buffer zones near crop fields where sensitive beneficial insects and pollinators are likely to be found.

4. Macronutrients in honey bee diet interact with sublethal concentrations of a pesticide to impact physiology and gene expression. Nutritious and balanced pollen and nectar diet is critical for the health and performance of honey bee colonies. ARS researchers in Stoneville, Mississippi, demonstrated that different diets interact with sublethal concentrations of a commonly used neonicotinoid, clothianidin, impacting honey bee health. Macronutrients in artificial diets improved bee physiology and health metrics but did not upregulate the genes involved with immunity and pesticide detoxification compared to natural pollen.

5. Knowledge gaps exist in the pollinator nutritional landscape in agroecosystems. The knowledge of the nutritional properties of crop pollen and nectar available to pollinators was lacking in reports on attractiveness of agricultural crops to pollinating bees. ARS researchers in Stoneville, Mississippi, and university scientists compiled data on the nutritional profile of pollen and nectar from a variety of crops. Including those that represent a significant portion of United States agriculture, some of which are undervalued in the context of pollinator nutrition and health.

Review Publications
Fornhoff, F., Lanner, J., Orr, M.C., Xie, T., Guo, S., Guariento, E., Tuerlings, T., Smagghe, G., Parys, K.A., Cetkovic, A., Dubaic, J.B., Geslin, B., Scharnhorst, V., Pachinger, B., Klein, A., Meimberg, H. 2024. Home-and-away comparisons of life history traits indicate enemy release and founder effects of the solitary bee, Megachile sculpturalis. Basic and Applied Ecology. https://doi.org/10.1016/j.baae.2024.02.008.
Zhang, W., Reddi, K.K., Shahrabi-Farahani, S., Anderson, K.M., Liu, M., Rose, L., Kakhniashvili, D., Wang, X., Zhang, Y. 2024. Tetraspanin CD82 Regulates S100A7 Expression in Oral Squamous Cell Carcinoma. Cancer Cell International. 25(5)/2569. https://doi.org/10.3390/ijms25052659.
Dorey, J.B., Fischer, E.E., Chesshire, P.R., Nava-Bolanos, A.N., O'Rielly, R.L., Bossert, S., Collins, S.M., Lichtenberg, E.M., Tucker, E.M., Smith-Pardo, A., Falcon-Brindis, A., Guevara, D.A., Ribeiro, B., De Pedro, D., Pickering, J., Hung, K.J., Parys, K.A., McCabe, L.M., Rogan, M.S., Minckley, R.L., Velzco, J.E., S., Griswold, T.L., Zarillo, T.A., Jetz, W., Sica, Y.V., Orr, M.C., Guzman, L.M., Ascher, J.S., Hughes, A.C., Cobb, N.S. 2023. A globally synthesized and flagged bee occurrence dataset and cleaning workflow. Scientific Data - Nature. 10(747):2023. https://doi.org/10.1038/s41597-023-02626-w.
Rangel, J., Lau, P.W., Strauss, B., Hildinger, E., Hernandez, B., Rodriguez, S., Bryant, V., Tarone, A.M. 2023. Pollen associated with a Texas population of blowflies (Diptera: Calliphoridae) highlights underappreciated aspects of their biology. Ecological Entomology. https://doi.org/10.1111/een.13298.
Zhang, W., Lee, J., Husami, A., Kadri, F., Yarlagadda, S., Moon, C., Mun, K., Zhang, K., Arora, K., Naren, A.P., Brewington, J., Clancy, J.P. 2023. Using a Personalized Medicine Approach to Develop Care for an Atypical Cystic Fibrosis Patient. Pediatrics. 59/229-232. https://doi.org/10.1002/ppul.26719.
Zhu, Y., Du, Y., Liu, X.F., Portilla, M., Chen, J. 2024. Microarray and functional pathway analyses revealed significantly elevated gene expressions associated with metabolic resistance to oxamyl (vydate) in lygus lineolaris. Toxics. 12(3). Article 188. https://doi.org/10.3390/toxics12030188.
Lau, P.W., Esquivel, I.L., Parys, K.A., Hung, J., Chakrabarti, P. 2023. The nutritional landscape in agroecosystems: A review on how resources and management practices can shape pollinator health in agricultural environments. Annals of the Entomological Society of America. https://doi.org/10.1093/aesa/saad023.
Kannan, N. 2023. An analysis of the climate change effects on pesticide vapor drift from ground-based pesticide applications to cotton. Scientific Reports. 13/1-12. https://doi.org/10.1038/s41598-023-36941-4.
Powell, E.J., Lau, P.W., Rangel, J., Arnott, R., Dejong, T., Moran, N.A. 2023. The microbiome and gene expression of honey bee workers are affected by a diet containing pollen substitutes. PLOS ONE. https://doi.org/10.1371/journal.pone.0286070.
Kannan, N., Huggins, C.L. 2023. Opportunities to mitigate particle drift from ground-based preemergent herbicide applications. Applied Engineering in Agriculture. https://doi.org/10.13031/aea.15307.
Abou-Shaara, H.F., Amiri, E., Parys, K.A. 2022. Tracking the effects of climate change on the distribution of Plecia nearctica (Diptera, Bibionidae) in the USA using MaxEnt and GIS. Diversity. 14(8):690 (11pgs). https://doi.org/10.3390/d14080690.
Lau, P.W., Sgolostra, F., Williams, G., Straub, L. 2023. Editorial: Insect pollinators in the Anthropocene: How multiple environmental stressors are shaping pollinator health. Frontiers in Ecology and Evolution. 11:1279774. https://doi.org/10.3389/fevo.2023.1279774.