Progress 09/15/23 to 09/14/24
Outputs Target Audience:Over 5500 beekeepers and other stakeholders received60oral presentations made in 18 states by members of the team on varroa mite control in honey bee colonies.Topics included the basics of mite control andmore specialized presentations on pesticide regulation, miticide resistance and improved mite control approaches. Beekeepers at all levels, from hobbyist to commercial, are the primary target audience for these communication activities as all beekeepers continue to struggle with effective varroa mite management. Other target audiences reached includeveterinarians incorporating bee health into their practice and state-level pesticide control officials responsible for enforcing pesticide law. Changes/Problems:The dissolution of one of the project partners, the Bee Informed Partnership (BIP) resulted in the removal of Steinhauer and Fauvel from the project. Most work to be performed by BIP under these objectives have been taken up by other team members. The national beekeeper survey (Obj. A2) incorporating questions on Varroa management is being conducted by Williams (Auburn) and partners. Promotion of this survey is being coordinated by the Mullica and the HBHC. Coordination with beekeepers to identify amitraz resistant Varroa mites and collect wax samples for miticide residue analysis (Obj. B2) will be conducted by Rinkevich (USDA-ARS, Baton Rouge) who is developing miticide resistance assays and has many collaborations with commercial beekeepers throughout the US. The team has not yet identified a way to conduct demonstration trials (Obj. C1) in Year 3 and 4 without the assistance of the BIP Tech Teams. The beekeeping cost and returns study was delayed due to Goodrich's transition from UC Davis to the University of Illinois at Urbana-Champaign. However, Goodrich will have a Master's student fully funded by this project in the spring of 2025 to begin interviews and working on the study. What opportunities for training and professional development has the project provided?Five postdoctoral researchers or staff scientists led components of the field miticide testing and gained experience in leading research teams. Ten graduate students, both M.S. and Ph.D.were trained in the work of testing miticides in laboratory or field settings. Components of this research will appear in their dissertations or theses. Eleven undergraduate students assisted with miticide research. Two of these students presented their work at the Annual Meeting of the Entomological Society of America in Maryland in November 2023 and five students presented to bee scientists and beekeepers at the American Bee Research Conference in New Orleans in January 2024. How have the results been disseminated to communities of interest?Mulica (HBHC) released an updated list of approved bee medications for US and Canadian beekeepers in April 2024 and was downloaded 40 times. The Honey Bee Health Coalition Tools for Varroa Management Guide was downloaded approximately 8000 times from Sept. 2023-Aug. 2024 (Obj. C3). Work informed by the work of this project was used to train of veterinarians through the 2024 Honey Bee Veterinary Consortium meeting where Bartlett and Tokach (Ph.D. Student at Auburn). State apiary inspectors and state pesticide control personnel were informed about miticide use and varroa resistance by Johnson at the Pesticide Inspector Residential Training Program in North Carolina in July. Additionally, members of the project presented work to over 5500 beekeepers at at over 40 beekeeper conferences and meetings at local, regional and national levels. Members of this project (Bartlett and Shannon [Ph.D. student at Ohio]) were also featured on the popular "Two Bees in a Podcast" out of the University of Florida. Work under Objective A will identify beekeepers' preferred means of learning and, following interviews conducted in 2024 and 2025, we will prioritize and develop dissemination methods using the media beekeepers identify as preferred. What do you plan to do during the next reporting period to accomplish the goals?Beekeepers participating in Rinkevich's resistance monitoring and wax sampling work (Obj. B1-2) will be interviewed using the survey developed by Ballen and Williams to both determine how beekeepers prefer to gain new information about beekeeping and varroa mites as well as an assessment of their current mite control practices (Obj. A1-3). Goodrich will contact these and other beekeepers to conduct interviews to determine the cost-return of beekeepers and assess the financial impact of varroa (Obj. A4). Varroa management questions will again appear in the US Beekeeping survey conducted by Williams and team to allow assessment of stakeholder behavior change over the course of the project (Obj. C5). New miticides suggested by colleagues in industry and other sources will continue to be explored using lab assays (Obj B3.1 and B3.2) Jack (Florida) will test carbamate compounds. Among the potential miticidal compounds tested under Obj, B, Beauvaria bassiana shows the most promise and will be tested in field trials in 2025 by Johnson (Ohio) and Cook (USDA-ARS Beltsville). Nasr (Saskatchewan) will test miticide active ingredients with existing registration for non-bee uses in a low-density plastic formulation (Obj. B3.3). Oxalic acid is already registered and is currently the most important alternative to the failing miticide amitraz. Jack (Florida), Nasr (Saskatchewan), Williams (Auburn) and Bartlett (Georgia) will continue to evaluate the efficacy of different oxalic acid delivery methods (vaporization temperature) and formulations (Varroxsan, OA+glycerin) (Obj. B4). Varroa Management Decision Support Tools managed by Mulica and the Honey Bee Health Coalition will be updated to incorporate findings on oxalic acid delivery methods and formulations (Obj. C3). Additional communication through methods identified in beekeeper interviews (e.g. podcasts or short form video) will also be developed to promote communication of the Best Management Practices identified by team members and other researchers (Obj. C2)
Impacts What was accomplished under these goals?
Social Science and Outreach Objectives (A and C) Williams (Auburn) conducted the 2023-2024 US Beekeeping survey of annual honey bee colony losses, which includes questions related to effective varroa management. Mulica (HBHC) assisted in contacting beekeeper participants and promoting this survey (Obj. A2). This broad online survey of beekeepers includes questions on varroa management that will form the baseline against which to compare beekeeper knowledge gains and behavior changes (Obj. C5). Ballen and Williams (Auburn) have developed and modified a questionnaire that addresses the following: (1) obtains basic demographic information about beekeepers such as their age and reason for keeping bees, (2) their perceptions of the threat of varroa, (3) how they treat varroa annually, (4) their limitations to treating varroa with specific methods, (5) how they monitor their treatments, (6) where they obtain sources of information for varroa treatment, (7) how they prefer to receive information. This survey has been submitted to the Institutional Review Board and should gain an exemption allowing surveys to be conducted Natural Science Objectives (B) Rinkevich (USDA-ARS, Baton Rouge) conducted miticide bioassays with fluvalinate and coumaphos to establish baseline LC50 for a miticide susceptible population. Resistance tests with Apistan (fluvalinate) were completed at different temperatures and surface area of Apistan strips in the container tests. Results showed there was no significant effect of temperature or surface area size on the efficacy of Apistan, but the test population demonstrated some resistance to this compound. CheckMite (coumaphos) tests have not been possible as this product is no longer available. Development of resistance monitoring tests for oxalic acid has been unsuccessful as Aluen CAP causes few mites to drop in cage tests -- this test will need to be redesigned for longer exposure periods or higher concentrations of oxalic acid (Obj. B1). Beekeepers have provided Varroa mites and wax samples from 60 apiaries for genotyping and pesticide testing to Rinkevich. Varroa from 26 samples have been genotyped and they have high levels of amitraz resistance genetics (92% avg, 53-100%). This is concerning as resistance is being observed in operations that have never used amitraz. Miticide residue analysis of all 60 wax samples is being conducted by Roger Simmonds at USDA-AMS in Gastonia, NC (Obj. B2). Cook (USDA-ARS Beltsville), Bartlett (Georgia) and Johnson (Ohio) conducted laboratory trials to identify new miticides using spray adjuvant constituents, including ethoxylates and organosilicones, falcarinol, several plant extracts, organic acids and the entomopathogenic fungus Beauvaria basssiana (Obj. B3.1 and B3.2). Field testing by Johnson indicated that a novel extended release oxalic acid formulation incorporating an adjuvant was more effective than oxalic acid alone (Obj. B3.3). This formulation was patented by OSU and licensed to the an existing registrant for oxalic acid, Chemicals Laif, and may incorporated into a commercially available for beekeepers. Nasr (Saskatchewan) field tested two active ingredients that are registered as miticides for non-beekeeping uses in small experimental colonies. A bee-safe and effective dose for these compounds was identified (Obj B3.3). Jack (Florida) performed experiments and published an article comparing the efficacy of oxalic acid vaporization, fogging and dribble (Obj. B4.3). Efficacy of the only currently available extended release oxalic acid product, Varroxsan, was compared with a new registered amitraz formulation, Amiflex, in 65 full-sized colonies in a Southern climate by Bartlett (Georgia) and Williams (Auburn). The efficacy and colony-level effects of Varroxsan at different doses (½-1 ½) was tested in a Northern climate by Nasr (Saskatchewan). Nasr also tested the efficacy of using repeated vaporization of oxalic acid to control varroa (Obj. B4) along with characterizing the distribution of oxalic acid vapor within the colony (Obj. B4.2).
Publications
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Lewis J Bartlett, Christian Baker, Selina Bruckner, Keith S Delaplane, Ethan J Hackmeyer, Chama Phankaew, Geoffrey R Williams, Jennifer A Berry, No evidence to support the use of glyceroloxalic acid mixtures delivered via paper towel for controlling Varroa destructor (Mesostigmata: Varroidae) mites in the Southeast United States, Journal of Insect Science, Volume 23, Issue 6, November 2023.
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Lewis J Bartlett, Michael Boots, Berry J Brosi, Keith S Delaplane, Travis L Dynes, Jacobus C de Roode, Faster-growing parasites threaten host populations via patch-level population dynamics and higher virulence; a case study in Varroa mites (Mesostigmata: Varroidae) and honey bees (Hymenoptera: Apidae), Journal of Insect Science, Volume 24, Issue 3, May 2024.
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Jennifer A Berry, S Kris Braman, Keith S Delaplane, Lewis J Bartlett, Inducing a summer brood break increases the efficacy of oxalic acid vaporization for Varroa destructor (Mesostigmata: Varroidae) control in Apis mellifera (Hymenoptera: Apidae) colonies, Journal of Insect Science, Volume 23, Issue 6, November 2023.
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Cody Prouty, Hossam F Abou-Shaara, Branden Stanford, James D Ellis, Cameron Jack, Oxalic acid application method and treatment intervals for reduction of Varroa destructor (Mesostigmata: Varroidae) populations in Apis mellifera (Hymenoptera: Apidae) colonies, Journal of Insect Science, Volume 23, Issue 6, November 2023.
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Cameron J Jack, Humberto Boncristiani, Cody Prouty, Daniel R Schmehl, James D Ellis, Evaluating the seasonal efficacy of commonly used chemical treatments on Varroa destructor (Mesostigmata: Varroidae) population resurgence in honey bee colonies, Journal of Insect Science, Volume 24, Issue 3, May 2024.
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Cook, S.C., Johnson, J.D., Rogers, C.W., Sachs, I.E., Feng, X., Plettner, E. The efficacy of 1-allyloxy-4-propoxybenzene against Varroa destructor mites in honey bee colonies from Maryland, USA. J. Ins. Sci., 24(3): 9
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Shannon B, Jeon H, Johnson RM. 2023. Review: the risks of spray adjuvants to honey bees. J. Insect Sci. 23(6).
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Frank D Rinkevich, Robert G Danka, Thomas E Rinderer, Joseph W Margotta, Lewis J Bartlett, Kristen B Healy, Relative impacts of Varroa destructor (Mesostigmata:Varroidae) infestation and pesticide exposure on honey bee colony health and survival in a high-intensity corn and soybean producing region in northern Iowa, Journal of Insect Science, Volume 24, Issue 3, May 2024
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Lewis J Bartlett, Suleyman Alparslan, Selina Bruckner, Deborah A Delaney, John F Menz, Geoffrey R Williams, Keith S Delaplane, Neonicotinoid exposure increases Varroa destructor (Mesostigmata: Varroidae) mite parasitism severity in honey bee colonies and is not mitigated by increased colony genetic diversity, Journal of Insect Science, Volume 24, Issue 3, May 2024,
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