Performing Department
Entomology; Ecology
Non Technical Summary
In August 2023 the first confirmed population of invasive, yellow-legged hornets (Vespa velutina) in the United States was detected by a Georgia beekeeper, near the major port of Savannah, GA. Yellow-legged hornets are a major predator of managed honey bees,Apis mellifera, where they can seriously weaken hives by intercepting returning foragers and deplete colony numbers. Yellow-legged hornets are a significant problem in other parts of their invasive range, for example France where estimates suggest that without control, up to 30% additional colony losses and €30million in direct annual losses to the beekeeping industry may be attributable to this invasive. The beekeeping industry is a critical part of Georgia's, and the United States', agricultural system, and is already embattled due to numerous threats. Further, yellow-legged hornets prey upon other non-Apisspecies including pollinators, threatening ecosystem function, conservation efforts, and pollination services. Control and eradication efforts are underway, led by the Georgia State Department of Agriculture. This project supports those efforts by generating invasion front forecasts, estimating possible range expansion limits, and providing economic damage assessments if control fails. Additionally, this project will begin genetically documenting the invasion biology and ecological impacts of this new invasive in Georgia, with a view to preparing for scenarios where containment fails. Finally, this project also directly supports the monitoring and eradication efforts by experimentally testing different bait-trap approaches to monitoring and nest triangulation, as well as establishing a beekeeper-led monitoring network of trained and prepared apiculturists, extension agents, and collaborating partners in neighboring states.
Animal Health Component
95%
Research Effort Categories
Basic
5%
Applied
95%
Developmental
0%
Goals / Objectives
Overall Goal:To protect US agriculture and apiculture by understanding, controlling, and eradicating the invasive yellow-legged hornet (YLH) oopulation in the United States.Objectives:Objective 11.1 Invasion Model1.2 Niche Model1.3 Economic Threat AssessmentObjective 22.0 Sample collection2.1.1 YLH Genetics - Wet Lab2.1.2 YLH Genetics - Analysis2.2.1 Metagenomics - Wet Lab2.2.2 Metagenomics - AnalaysisObjective 33.1 Establish Monitoring Network3.2 Creation & Revision of Education Materials3.3 Field Experiments3.4 Beekeeper Training3.5 Extension Agent Training
Project Methods
1.1 Invasion ModelAn invasion model will be made a top priority to inform the state Department of Agriculture response and develop targeted monitoring and training for objective 3. We anticipate using data from the various European invasion fronts (Spain, Italy, France, and the United Kingdom) of the YLH, which are well documented1.2 Niche ModelWe will pair our invasion modelling efforts with a niche model approach to try and determine the likely maximum range of the YLH across the US and the permissiveness of that range to expansion. Species distribution models, a type of niche model, are a commonly deployed ecological tool to understand the likely and maximum possible ranges occupied by focal species [16]. Their implementation is well studied, and numerous statistical and mechanistic modelling approaches can be used based on range data from other locations (for YLHs, those locations being Europe, Japan, Korea, and the native range elsewhere in Asia). We will explore these various options, recently outlined by Sillero et al. 20232.0 Sample collectionSamples and specimens will be collected for three major purposes. YLH larvae, pupae, larval frass pellet swabs, and YLH adults will be recovered as part of their controlled destruction. A majority of larval, pupal, and adult specimens will be placed individually in 2mL microcentrifuge tubes of suitable fixative (e.g. RNALater) and snap-frozen in liquid nitrogen where available, or failing the easy transport of liquid N2, supercooled ethanol and dry ice, to preserve DNA and RNA integrity long-term.A subset of these preserved samples will be processed for subobjectives 2.1 and 2.2. A second subset will be stored long-term at -80C for future work (for example, pathogen testing) as part of a pre-emptive effort to track the biology of the invasion.2.1 YLH GeneticsOne goal of this genetic testing is exploring the future development of sensitive, differential primers which allow for genetic sampling as part of detecting YLHs in the environment (for example, by swabbing honey bee hives, nectar sources such as hummingbird feeders, or deploying non-lethal bait traps)2.2 MetagenomicsTo characterize the diet of YLHs, we can concentrate on what they feed their developing larvae, as almost all active predation by vespids is in aid of feeding their growing, protein-hungry young. Metagenomics approaches used to characterize communities or the number of species a sample has been in contact with allow for this sort of testing when applied to larval frass pellets in wasp colonies , with pertinent examples in New Zealandand characterization of the diet of the invasive Vespa mandarina in Washington State using this approach. This technique has already been employed on V. velutina nests in Europe.3.1 Establish a Monitoring NetworkWe will continue our current efforts to establish a monitoring network of co-operation between beekeepers, Extension, the PI team, and the state Department of Agriculture to detect YLHs in apiaries across Georgia. We aim for this to extend into South Carolina, with a mirrored and collaborative effort led by Clemson University (see letters of collaboration).3.3 Field ExperimentsThese experiments will be simple - when YLHs are located, bait stations are deployed at multiple sites and those stations observed to ascertain the flight bearing of a fed forager returning to the nest; with multiple flight bearings, one triangulates the position of the nest. We will deploy multiple side-by-side bait stations as well as arrays of close, but separate, bait stations sporting different baits throughout the eradication effort and record the visit rate of different baits in a simple 'field choice' experiment.3.4 Beekeeper TrainingBeekeeper training will be delivered via club meetings, as well as centrally via the Georgia Beekeepers Association meetings (which happen in February and September each year). We will model this on our highly successful and long-established Master Beekeeping Program, delivered at these meetings, where the focus of training by the PI team will be on beekeepers in the affected region and training of beekeeping leaders, who can then train their local beekeeping neighbors and clubs (for example, club presidents and beekeepers at Journeyman accreditation). We already require an insect taxonomy test focusing on Hymenoptera at the Journeyman level, and will incorporate new emphasis on the YLH.3.5 Extension Agent TrainingExtension agents will be trained centrally, via the University of Georgia, by Co-PI Delaplane who holds an extension appointment and routinely delivers extension agent training. UGA has one of the most extensive and well-equipped extension systems in the United States - with dedicated extension offices and extension agents in every one of Georgia's 159 counties, arranged into 4 districts.