Source: AGRICULTURAL RESEARCH SERVICE submitted to
ECOLOGY AND INTEGRATED MANAGEMENT OF AMBROSIA BEETLES IN EASTERN US ORCHARD AND ORNAMENTAL TREE CROPS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1027493
Grant No.
2021-51181-35863
Cumulative Award Amt.
$7,526,949.00
Proposal No.
2021-07812
Multistate No.
(N/A)
Project Start Date
Sep 1, 2021
Project End Date
Aug 31, 2026
Grant Year
2021
Program Code
[SCRI]- Specialty Crop Research Initiative
Recipient Organization
AGRICULTURAL RESEARCH SERVICE
1815 N University
Peoria,IL 61604
Performing Department
USDA ARS
Non Technical Summary
Exotic ambrosia beetles established in the U.S. are emerging as highly destructive pests in apple and pecan orchards and continue to be damaging insects of trees in ornamental nurseries. Infestations are a major source of revenue losses in these three commodity groups. Substantial losses have been reported throughout the eastern U.S. Ambrosia beetles are consistently ranked among the most concerning insect pests of horticultural tree crops in the eastern U.S. Rapid branch dieback and tree death on alarming scales are commonly observed following infestations due to their wood-boring behavior and association with symbiotic and secondary microorganisms. A multi-disciplinary team has been assembled to conduct field and laboratory research to maximize tree health and reduce tree vulnerability, optimize monitoring tactics, identify chemical and biological alternatives to broad-spectrum insecticides, determine the economic impacts of ambrosia beetles, and transfer new knowledge via outreach and extension to end-users. The expected accomplishments of this research include: (1) improving the understanding of stakeholders across the three commodity groups about ambrosia beetle monitoring and management; (2) implementing pest management tactics for ambrosia beetles beyond solely relying on preventive applications of broad-spectrum insecticides; (3) establishing and disseminating knowledge about the economic impact and cost:benefit ratio of managing ambrosia beetles; and (4) determining effective outreach avenues and expanding IPM tactics to reduce the risk of ambrosia beetle attacks.The collaborative nature of this project will facilitate cooperation among researchers, extension, and stakeholders resulting in productive outcomes to solving an emerging agricultural issue. Economic benefits will be realized by decreasing the negative economic impacts of ambrosia beetle through prevention of tree loss, increasing marketability of nursery trees, sustained orchard production, reduced management inputs by growers, and improved profitability. Social benefits from this project include improved knowledge and research-driven decision making for growers in their respective production systems. Furthermore, reducing applications of broad-spectrum insecticides, particularly during spring months, will reduce impacts on pollinating insects and end-users and enhance environmental stewardship within communities. Addressing these pest management issues can help enhance grower and farmworker health and quality of life by reducing exposures to harmful chemicals.
Animal Health Component
60%
Research Effort Categories
Basic
20%
Applied
60%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2031110113010%
2031211113010%
2032110113010%
2111110113010%
2111211113010%
2112110113010%
6011110113010%
6011211113010%
6012110113010%
9031119113010%
Knowledge Area
601 - Economics of Agricultural Production and Farm Management; 211 - Insects, Mites, and Other Arthropods Affecting Plants; 203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants; 903 - Communication, Education, and Information Delivery;

Subject Of Investigation
1119 - Deciduous tree fruits, general/other; 1110 - Apple; 2110 - Ornamental trees and shrubs; 1211 - Pecan;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
Exotic ambrosia beetlesestablished in the U.S. are emerging as highly destructive pests in apple and pecan orchards and continue to be damaging insects of trees in ornamental nurseries. Ambrosia beetle nfestations are a major source of revenue losses in these three commodity groups (i.e., apples, pecans, ornamentals). Infestations result in perforated stems, oozing sap, bark staining, branch dieback, and rapid tree death. Ambrosia beetlescan render trees unmarketable, decrease integrity of surviving trees, and make trees vulnerable to infection. This project will address the needs of stakeholders in the Eastern U.S., but will have applications to stakeholders across the U.S. where ambrosia beetles and horticultural tree crops overlap. Stakeholder needs were identified through the Ambrosia Beetle Working Group supported by the Southern IPM Center using a comprehensive stakeholder survey and in-person and virtual meetings attended by researchers, extension specialists, agents, and growers affiliated with eastern and southeastern US states. The goal of the proposed research and outreach activities align with the priorities of stakeholders to develop sustainable management practices for ambrosia beetles that maximize tree health and reduce tree vulnerability, optimize monitoring tactics, and identify chemical and biological alternatives to broad-spectrum insecticides. A systems approach will be used to achieve our overall goal of developing sustainable ambrosia beetle management strategies in our three commodity groups by integrating expertise on plant physiology, horticultural science, chemical ecology, plant pathology, insect-microbe interactions, engineering, applied insect ecology, biocontrol, economics, and social science.A multi-disciplinary team of experts has been assembled to address the following objectives:Objective 1) Predict the risk of infestations in orchard and nursery crop systems through improved understanding of ambrosia beetle biology and ecology. The following sub-objectives will be addressed:1a) Characterize abiotic stressors that induce ethanol production and ambrosia beetle attacks, 1b) Characterize biotic plant stress-related factors that influence ambrosia beetleattacks, 1c) Assess the pathogenicity and virulence of auxiliary and symbiotic fungi associated with ambrosia beetles to elucidate the basis for branch die-back and tree death, and 1d) Determine ambrosia beetle dispersal and attack patterns within agro-ecosystems and relate to landscape level factors.Objective 2) Develop novel tools to enhance the accuracy and precision of ambrosia beetleinfestation and monitoring tactics.The following sub-objectives will be addressed: 2a) Evaluate trapping tactics and lure release rates for species-specific monitoring of ambrosia beetlesand correlating trap captures with attacks, and 2b) Develop and compare existing and portable technologies to monitor tree ethanol production in orchard and nursery crop systems.Objective 3) Implement comprehensive management strategies. The following sub-objectiveswill be addressed:3a) Compare new and current insecticidal active ingredients at different timings and frequencies to reduce ambrosia beetleattacks, 3b) Test and integrate repellents and attractants into a push-pull strategy, 3c) Evaluate plant defense elicitors for promoting tree health and inhibiting ambrosia beetle attacks and/or colonization, and 3d) Assess antagonistic fungi and entomopathogenic nematodes against ambrosia beetles and their symbiotic fungi.Objective 4) Determine the economics of ambrosia beetle damage and control interventions on orchard and ornamental tree crop stakeholders. The following sub-objectiveswill be addressed:4a) Quantify the commodity-specific economic impact of ambrosia beetles, 4b) Determine the risk adjusted cost-benefit framework and feasibility of alternative management tactics for ambrosia beetles, and 4c) Identify social barriers for technology adoption and facilitators to enhance grower acceptance of improved strategies.Objective 5) Transfer research-based information to stakeholders. The following sub-objectives will be addressed: 5a) Developing a publicly accessible centralized website and project specific social media, 5b) Promote existing land grant Extension programs, 5c) Evaluating stakeholder reaction and utilization to Extension efforts, and 5d) Coordinate with other Regional IPM Centers to increase promotion of project outputs and calls for participation.
Project Methods
This project will be conducted usinga systems approach by integrating expertise on plant physiology, horticultural science, chemical ecology, plant pathology, insect-microbe interactions, engineering, applied insect ecology, biocontrol, economics, and social science. Field- and laboratory-based experiments will be used to predict the risk of infestations in orchard and nursery crop systems through improved understanding of ambrosia beetlebiology and ecology. Several experiments willimposeabioticand biotic stressors on potted trees, including water stress and pathogen infection. Lab experiments will use gas chromatography-mass spectrometry (GC-MS) to characterize physiological responses of trees to these stressors. Experiments with potted trees will be used to understand the diversity of fungi associated with beetles, and their capacity to induce branch dieback.Field experiments willbe conducted within orchards and nurseries to understanddispersal and attack patterns and relate to landscape level factors.Field experiments will also be conductedto evaluate monitoring tactics and correlations between attack rates and capture rates with the goal of improving monitoring and trapping strategies. Traps willbe used to characterize ambrosia beetledispersal into orchards and nurseries. Lab experiments andfield experiments will be used to developportable technologies to monitor tree ethanol production in orchard and nursery crop systems.Field and laboratory experiments will evaluate novel or untested insecticides, host tree defense elicitors, repellents, and microbial control agents. Under field settings, we will use stem sections (i.e. bolts) deployed in nurseries and orchards to compare attacks among treatments and understand insecticide residual longevity. Ultra performance liquid chromatography-mass spectrometry (UPLC-MS) will be used under lab conditions to quantify pesticide residues over time and correlate with ambrosia beetle attacks. Repellents and defense elicitors will be tested under field conditions using flood-stressed trees. Screening of microbial control agents will initially be conducted under laboratory conditions using petri dish assays. Treated and untreated bolts will then be deployed under field conditions to allow for ambrosia beetle attacks, after which they will be dissected under lab conditions.Grower surveys and analytical software will be used to determine the economics of ambrosia beetledamage and control interventions on orchard and ornamental tree crop stakeholders. These surveys will determine production costs for the three crops, commodity-specific losses to ambrosia beetles, willingness to adopt (WTA) and barriers to adoption of tactics, calculate consumer willingness to pay (WTP) for crops under different ambrosia beetlemanagement options, and given this price and cost information, calculate adoption rates and return on investment for different treatment tactics.Outreach and extension activities will be used to efficiently disseminate new tactics developed from the research findings of this project and aid with incorporating those tactics into management programs. Methods will include traditional in-person meetings, web-based approaches (blogs,YouTube, social media), outreach publications, a new centralized website on ambrosia beetles, and formal surveys.A large and diverse SAP has been assembled to provide feedback and help guide the research and outreach/extension activities. Surveys, virtual, and in-person meetings among the PDs, PIs, SAP, and additional key growers beyond the SAP will provide regular assessments throughout the duration of the project. As specified in Obj. 5 and the PMP, growers' existing and new knowledge about ambrosia beetles will be determined to assess the impact of our research and extension activities. Growers recognizing tree stressors and modifying production practices to reduce ambrosia beetlerisks will be considered an achievement resulting from research and outreach activities. Additional achievements will consist of stakeholders properly timing insecticide applications, repellents, and/or biological control agents based on the monitoring of ambrosia beetleactivity in near real-time in the eastern U.S. Growers learning about the economic impacts and risks of ambrosia beetleinfestations and cost-benefits of management will be an additional achievement. Growers adopting sustainable tactics that lead to a reduction in preventive applications of broad-spectrum insecticides will be an achievement. Overall, we intend the proposed research and extension activities will improve tree health and reduce crop losses.Short, medium, and long term metrics will initially be established by each participating PI sending a Gantt chart to PD Ranger that defines their lab specific activities and outputs for each objective for the duration of the funded project. These defined metrics will be used by the PD and Objective Leaders to evaluate progress of research and outreach activities. The PD and Objectives Leaders will use these metrics to identify research and outreach achievements and challenges that have arisen. PD Ranger and the Objective Leaders will prepare annual reports on these objective specific metrics to share with all co-PIs and the Stakeholder Advisory Panel for feedback. These annual reports will be discussed with the SAP to determine if research and outreach goals are following stakeholder expectations and needs. Short term goals and impacts related to ambrosia beetlerisks and management will be evaluated after years 1 and 2 through SAP surveys in conjunction with annual meetings. Intermediate goals will come after years 3 and 4 from SAP surveys plus feedback from growers beyond the SAP within the three commodity groups. Finally, long term goals of increased IPM adoption for ambrosia beetlemanagement in the three commodity groups will occur at the end of the five-year project resulting from broad regional outreach among the three commodity groups.The following are specific milestones that will be met over the duration of the project to establish ambrosia beetlemanagement and outreach resources in the three cropping systems: SAP meets annually to receive research and outreach updates; specific outreach activities will be demonstrated to SAP during the annual meeting; address SAP feedback to activities and adjust approach accordingly; ambrosia beetlemonitoring and management tactics established in all three cropping systems; establish the first level of traditional and social media outreach efforts about ambrosia beetlemanagement; IPM tactics; program process evaluated.The following are specific milestones that will be met to ensurestakeholder share accounts of implementing successful AB management programs: growers obtain new knowledge about successful ambrosia beetlemanagement from other growers:management practices adjusted; new knowledge transferred about ambrosia beetlemanagement specific to the three cropping systems; unique and overlapping ambrosia beetlemanagement established in the three cropping systems; grower knowledge and participation increased in all three cropping systems.The following are specific milestones that will be met to expand the outreach of ambrosia beetlemanagement within the three cropping systems:Southern IPM Center will educate growers with no prior ambrosia beetleissues about risks; S. IPM will disseminate knowledge on biology, ecology, and AB management; knowledge base about ambrosia beetlerisks, monitoring, and management will increase considerably across the three cropping systems.The following are specific milestones that will be met to demonstrate benefits from improved ambrosia beetlemanagement: economic benefits established and disseminated about impact of AB losses in the three cropping systems; IPM cost-benefit established for ambrosia beetlemanagement in the three cropping systems.

Progress 09/01/23 to 08/31/24

Outputs
Target Audience:The primary audience for this research is any grower who works with an agricultural commodity (e.g., nut trees, fruit trees, ornamentals) that are used as hosts for ambrosia beetle. Currently, insecticides are the primary method of ambrosia beetle management. The primary methods for sharing this research will be done through extension and outreach including grower meetings and publications that target these audiences (e.g., The Pecan Grower magazine). Target audiences reached by our efforts to improve the management of exotic ambrosia beetles include commercial and homeowner growers/producers of apple, peach and pecan crops in the Eastern, mid-Atlantic, and Southeastern U.S.; ornamental tree and shrub producers, and landscapers, in the Eastern, mid-Atlantic, and Southeastern U.S.; retail nurseries and garden centers; arborists, ground managers, and landscape care professionals; county and regional extension agents; pest management specialists; master gardeners; agrichemical industry representatives; and the scientific community, including entomologists, plant pathologists, biologists, economists, engineers, undergraduate students, graduate students, and postdoctoral researchers. Specifically, the apple grower stakeholders of NY collectively represent more than 600 farm business and 50,000 acres of commercial apples in six growing regions. Knowledge has also been transferred to avocado growers in Florida. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?PSU: The program technician and three summer student assistants participated in the project. USDA-ARS-OH: Two internships were completed during the review period. Training was provided in experimental design and data collection and analysis. An OSU graduate student was trained in rearing ambrosia beetles. A postdoc from USDA-ARS-NY, a graduate student from VT, and two postdocs from UGA separately visited to receive training in the analysis of plant volatiles using gas chromatography-mass spectrometry. A postdoc with our group visited VT for training in spatial analysis. A postdoc completed his program and is now employed by the Cleveland Metro Parks. UGA: A co-PI and graduate student worked together to train two temporary hourly employees (research assistants) and two undergraduate students on the deployment of trials and to help with the sorting of trap captures. A post-doc received training in identifying the ambrosia beetles to species during the SAP meeting in 2024. Clemson: Training on processing samples, field collection, and ambrosia beetle identification was provided to one technician. TSU: A doctoral student was trained on this project and has since graduated. One master's degree student graduated after completing ambrosia beetle projects from this agreement. A second graduate student participated in projects. One post-doc completed research projects on this agreement and presented the data at the annual stakeholder meeting. Multiple laboratory technicians, some of which are recent master's degree graduates, as well as two summer undergraduate interns from Middle Tennessee State University, participated in projects. Two summer interns participated in experiments. A postdoc also assisted with some projects. VT: Hosted a two-day visit for a postdoc from USDA-ARS-OH and a postdoc from NCSU. Both scientists received hands-on training in spatial interpolation and data visualization using ArcGIS. Trained one graduate student and two undergraduate students on insect identification, scouting techniques, and experimental design. UGA: Students and postdocs participated in the Pecan Field Day organized by Georgia Pecan Growers Association at King Springs Pecans, Hawkinsville, GA, on September 5, 2024. Participated in Grant Writing Seminar organized by Office of the Research, CAES, University of Georgia, Athens, on August 12, 2024. UF: An intern was trained in conducting greenhouse experiments and evaluating disease response in avocado seedlings. A postdoc attended and presented at the University of Florida's, Plant Pathology Research and Professional Development Symposium. An intern attended the Avocado grower's workshop in Homestead, FL. A doctoral student was hosted for three months to conduct in vitro trials in support of objective 3. A visiting scholar learned about tropical agriculture, plant pathology, and avocado research. A postdoc interacted and mentored a visiting scholar (PhD candidate) from Canada. USDA-ARS-NY: A postdoc received training in chemical ecology techniques used in ambrosia beetle systems from the Ranger Lab, Wooster, OH. A technician received training on beetle care, rearing, experimental techniques, and data collection. Co-PIs with the USDA-ARS in Ithaca, NY, continue co-mentoring a postdoctoral researcher in ambrosia beetle biology, mycology, molecular genetics, and insect pathology. This includes laboratory and field methods for bioassays. NCSU: A postdoc presented data at branch and national meetings of the Entomological Society of America. He recently started a new position as an assistant professor with the University of Tennessee. A post-doc and a research technician in NC received training in constructing and using the "open_irr" irrigation system developed by a USDA-ARS researcher. The system allowed homogeneous irrigation control for the experimental setup. A doctoral student graduated and began a new position with AgFirst Consulting in Hawkes Bay, New Zealand. How have the results been disseminated to communities of interest?During the rating period, students, postdocs, and co-PIs gave over 100 presentations to the scientific community and producers/stakeholders about ambrosia beetles. The presentations are listed under "other products" in this report. Co-PIs with Cornell Univeristy, USDA-ARS-GA, and USDA-ARS-OH organized a symposium at the annual meeting of the Entomological Society of America titled "Holistic Synthesis of Ambrosia Beetle-Microorganism-Host Interactions Affecting Horticultural Tree Crops". National Harbor, MD. Co-PIs on the SCRI grant participated in the symposium. A Co-PI and postdoc from Cornell University organized a symposium at the International Congress of Entomology 2024 in Kyoto, Japan titled "Multi-trophic Interactions of Scolytinae in Näive Systems: Integrating Ecological Methods for Management." Co-PIs on the SCRI grant participated in the symposium. USDA-ARS-OH: The PD organized an in-person stakeholder advisory panel meeting to disseminate research findings. Information was exchanged and shared with research, extension, and agricultural producer stakeholders at the USDA-NIFA Specialty Crops Research Initiative Ecology and Integrated Management of Ambrosia Beetles in Eastern US Orchard and Ornamental Tree Crops Multistate Workshop hosted by Tennessee State University, Otis Floyd Nursery Research Center. The in-person and virtual meeting consisted of 24 presentations by students, postdocs, and co-PIs. UGA www.StopAB.org received 1,608 pageviews from 953 users during the project period. That is a 42% increase in page views and 116% increase in users compared to the same time period in the previous year. The results of the research and development of the ethanol sampling devices were disseminated to relevant communities of interest through several channels: Workshops and Presentations: Key findings have been shared with growers, industry stakeholders, and researchers through targeted stakeholder workshops in Tennessee. The sessions provided knowledge on the sampling devices and explained their practical applications in pest monitoring and volatile sampling in trees, particularly for beetle management in orchards and nurseries. Collaborations with Research Institutions: The devices have been distributed to major research labs, including USDA-ARS-OH and UT, for further testing and evaluation. These institutions are using the devices to compare their performance against traditional ethanol sampling techniques, such as gas chromatography, and the results will be shared in academic circles. Engagement with Graduate Students: The sampling devices have been introduced to graduate students working on beetle sampling in pecan trees, Tifton, University of Georgia. This allowed them to explore how the devices could enhance their research and contribute to improved pest-monitoring practices in pecan orchards. A survey was prepared by the economics team. The survey was distributed to stakeholders in all participating states for input from stakeholders. PSU: Hosted an Apple Tree Decline Summit at the Penn State Fruit Research and Extension Center in Biglerville, PA. Participants included all members of the industry in the United States and Canada (state, federal, academia, Extension, growers/packers, agrochemical industry, consultants, etc.). This all-day, free workshop covered various topics related apple tree decline, which included rapid apple decline, soilborne diseases, viruses, ambrosia beetles, winter injury, and herbicide injury. Post-survey responses from participants were very favorable, indicating knowledge gained after the workshop. The members of this grant who participated were PSU and NCSU. Clemson: Produced PestTalks newsletters in 2023 and 2024. The newsletter reached 27,487 subscribers throughout the US and internationally. Chong, J. H. 2024. Spring is for ambrosia beetles. PestTalks 3/11/2024. Available: https://www.growertalks.com/Newsletters/View/?article=4489 The entire newsletter is devoted to the monitoring, prevention, chemical treatment, and resources of ambrosia beetles. TSU: Southeastern Horticultural Inspection Society provided research program highlights, pathology, and insect display exhibits shared during laboratory tours of about 35 participants. Several inspectors from the Missouri Department of Agriculture stayed for extended discussions. The East Tennessee Extension Professionals group site visited to learn about research programs. During laboratory tours and interactive discussions, insect displays were also set up. Eight extension personnel attended. Environmental Science class received research program highlights and insect display exhibits on a tour of 5 students and their instruction. Tennessee Technology University Plant Science class received research program highlights and insect display exhibits on a tour of 7 students and their instruction. Consultation meeting with NCSU Nursery Extension about ambrosia beetle captures in their local traps and whether grower industry alerts should be issued with weather returning to cooler weather. Nursery industry pest alerts were issued (University of Tennessee extension) and the Otis Floyd Nursery grower database after beetle outbreaks were identified in redbuds at two nurseries.Information was also shared verbally at the Middle Tennessee Nursery Association monthly meeting. Consultation information was provided to University of Tennessee Extension Professional at the Plant Diagnostic Center about the destruction of ambrosia beetle-infested trees on homeowner properties to prevent additional beetle infestations. Cumberland County Ag in the Classroom Third Grader Event. Entomology and Chemical Ecology Programs provided insect displays and conversation with 600 students. Morrison Elementary School Reading Night--Entomology and Chemical Ecology programs provided insect displays and educational conversations with five groups of ~12 children plus parents. Buggy Day Camp by invitation of the Tennessee Department of Agriculture Division of Forestry. Entomology and Chemical Ecology programs and a summer intern student provided insect displays and educational conversations for 12 children and families. Insect Week Event: Entomology and Chemical Ecology programs provided insect displays and educational conversations for 3- to 5-year olds at the Brookside Headstart facility. VT: Text messages alerting ambrosia beetle densities were distributed to participating growers. Led two classes for 30 TCC Community College and Christopher Newport University students. The classes included a presentation on ambrosia beetle biology and management, as well as showing insect displays and a hands-on workshop on insect collection. Presented information on ambrosia beetles during the 13th Field Day at the HRAREC, and the annual field day organized by the Virginia Nursery and Landscape Association. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1 Co-PIs with USDA-ARS-OH determined that dogwoods and apples flooded for 7 days sustained more attacks than trees flooded for 3 days, with Xylosandrus germanus being predominant in spring and Anisandrus maiche in summer. The dogwoods tended to receive more attacks than the apples. NCSU, Cornell, PSU, and USDA-ARS-OH evaluated the potential of fire blight infection of apples to attract ambrosia beetles. In NC, fire blight infection induced fewer ambrosia beetle attacks than flooded trees. Fire blight infection did not result in attacks on trees deployed in OH. Data from PSU are being processed. Infected trees tested in NY by Cornell researchers were attractive to beetles. NCSU sequenced all loci for fungal isolates recovered from ambrosia beetles and stems. Fusarium spp. was most commonly isolated; phytopathogens of apple were infrequently isolated. Co-PIs with USDA-ARS-NY and Cornell finalized DNA identifications and compiled lists of auxiliary fungi associated with beetles. USDA-ARS-NY are sequencing the Ambrosiella genome. Assays on detached apple shoots and seedlings assessed the aggressiveness of Fusarium species and strains, revealing significant variability. Some Fusarium strains were more aggressive than Botryosphaeria and Diaporthe. USDA-ARS-OH deployed a grid of flood-stressed dogwoods at nurseries to characterize the distribution of attacked trees in relation to landscape factors. Trees closest to woodlands sustained the highest number of attacks. Spring-deployed trees were mainly infested by X. germanus, while summer-deployed trees were infested by A. maiche. TSU investigated ambrosia beetle outbreaks at two nurseries. Nine species of ambrosia beetles were recovered from infested redbuds. Most trees at the nursery sites were infected with vascular streak disease. A portable sampling device confirmed the emission of stress-induced ethanol associated with the infested trees. UGA characterized beetle dispersal and attack patterns within an apple orchard. Xylosandrus crassiusculus and X. germanus were the most abundant species. Trap captures of these two species were generally higher in deciduous woodlots than coniferous woodlots. Objective 2 UGA determined that low-release lures were equally effective compared to high-release lures for attracting ambrosia beetles. Colorless bottle traps were equally attractive to beetles as purple or green-colored traps. USDA-ARS-OH tested stem sections (i.e., bolts) soaked in dilutions of acetic acid and ethanol. The combinations of acetic and ethanol were usually more attractive to ambrosia beetles than either compound alone. Confining beetles to soaked bolts demonstrated tunneling, offspring, and adults were higher using acetic acid + ethanol solutions than ethanol alone. Gallery volume and surface area, measured using X-ray tomography, increased due to acetic acid and ethanol. TSU, UGA, USDA-ARS-OH, and USDA-ARS-MS tested ethanol release rates from filters representing varying pore sizes. There was a non-significant trend for the 2.5 mm pore size to have a higher numeric beetle catch for X. crassiusculus and A. maiche. Captures of C. mutilatus increased with pore sizes up to the maximum 3 mm opening. Attacks on balsawood bolts also increased as pore size and ethanol release rates increased. UGA designed lightweight, non-destructive 3D-printed chambers to sample ethanol from trees with portable detectors. TSU and USDA-ARS-OH are evaluating the sampling chambers. USDA-ARS-OH determined that a next-generation alcohol monitoring bracelet detects ethanol from stressed trees, allowing early detection of beetle attacks. Seasonal monitoring was conducted in SC (Clemson) in nurseries and PA (PSU) in apple orchards. Exotic species dominated the trap captures. NCSU determined that ambrosia beetle trap captures were higher in moist vs. dry sites and lower vs. high elevations. Exotic species dominated the trap captures. PSU deployed a grid of traps within orchards to characterize beetle dispersal relative to landscape factors. Objective 3 UGA, NCSU, TSU, UGA, and VT determined that bifenthrin, permethrin, nanocellulose + bifenthrin, or nanocellulose + permethrin reduced attacks. Ambrosia beetle attacks were lower for full and half-rate treatments of bifenthrin and permethrin. Indoxacarb and cyantraniliprole were ineffective. Cyhalothrin and bifenthrin were effective for up to 28 days. USDA-ARS-OH determined that verbenone + methyl salicylate as a "push" repellent and ethanol-baited traps as a "pull" attractant reduced attacks on flood-stressed dogwoods deployed in July but not in May. UGA also found reduced attacks on trees protected with the push-pull strategy. VT found that unprotected redbud trees had as many as four times more attacks than protected trees. However, UGA and Clemson did not find document efficacy associated with verbenone. Cornell, USDA-ARS-OH, and PSU deployed a push-pull trapping project in apple orchards. Data are being processed. TSU determined that stressed plants treated with the plant defense elicitors acibenzolar-S-methyl or acibenzolar-S-methyl + chlorothalonil were associated with reduced ambrosia beetle attacks. Cornell and the USDA-ARS-NY evaluated three entomopathogenic fungi and two mycoparasitic fungal biopesticides. The entomopathogenic fungi only slightly affected beetle mortality and brood production, and the mycoparasitic biopesticides were ineffective. UF assessed the fungicidal activity of Trichoderma strains against fungal mutualists. None of the strains had a fungicidal effect, but their inhibitory effect was comparable to some conventional fungicides. USDA-ARS-GA found significantly fewer ambrosia beetle attacks in trees with Metarhizium anisopliae as an endophyte than in untreated control trees. USDA-ARS-NY assays did not find the insect-killing fungus Beauveria out-competed fungal mutualists of ambrosia beetles. USDA-ARS-GA determined that strains of insect-killing, entomopathogenic nematodes were effective against two species of ambrosia beetles. However, directly injecting nematodes into beetle galleries did not result in significant mortality. USDA-ARS-GA evaluated an entomopathogenic nematode metabolite prepared from Xenorhabdus bacteria. Extracts from the three Xenorhabdus stains reduced the growth of ambrosia beetle fungal mutualists. Objective 4 UGA, Auburn, and UT implemented a national producer survey to assess awareness and damage from ambrosia beetle that examined producer awareness, pre- and post-ambrosia beetle infestation treatments, and treatment expenditures. A survey of U.S. producers showed that while most were aware of ambrosia beetles, control treatments varied widely. Many producers chose not to treat, which implies that many producers currently do not see a favorable benefit/cost to treat. The lack of treatment could be due to inconsistencies in ambrosia beetle infestations, as many producers indicated that ambrosia beetles were not a problem every year. This research provides stakeholders with information on preferred treatment methods and means to increase information dissemination about new ambrosia beetle treatments. For 2025, a consumer survey will be implemented to understand consumer responses to varying treatments, utilizing information from the producer survey. Objective 5 Details about disseminating results to communities of interest are described in the section below. UGA maintained the www.StopAB.org website, launched on November 1, 2022, and continues to house content for the website. Content is recruited at the monthly project team meetings. The site hosts 13 scientific publications, 2 extension resources, and 9 project reports and presentations. The website received 1,608 pageviews from 953 users during the project period, a 42% increase in page views and a 116% increase in users compared to the same time in the previous year.

Publications

  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Baniszewski, J.A., Barnett, J., Reding, M.E., and Ranger, C.M. 2024. Seasonal dominance of exotic ambrosia beetles compared to native species within deciduous and coniferous woodlots. Biological Invasions. 26: 1651-1668.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Tobin, K. N., S. Lizarraga, R. Acharya, A. K. Barman, B. D. Short, A. L. Acebes-Doria, and M. J. Rivera. 2024. Comparison of ethanol-baited trap designs for ambrosia beetles in orchards in the eastern United States. Journal of Economic Entomology. 117: 1476-1484.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Dzurenko, M., Ranger, C.M., Pavl�k, M., Reding, M.E. 2024. Influence of ethanol grade on captures of ambrosia beetles in tree fruit orchards, ornamental nurseries, and lumber yards. Insects. 15: 408.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Yilmaz, A.R., Santoiemma, G., Cavaletto, G., Barnett, J., Rassati, D., Reding, M.E., Ranger, C.M. 2024. Trap captures of invasive ambrosia beetles (Coleoptera: Curculionidae) as influenced by ethanol release rate. Agricultural and Forest Entomology. 26: 522-533.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Govindaraju, R., Hayter, J., Chong, J.H., Del Pozo?Valdivia, A.I., Cottrell, T.E., Walgenbach, J.F., Scheyer, T.W., Blaauw, B.R., Reding, M.E., Ranger, C.M. and Joseph, S.V., 2024. Influence of the Ethanol Lure and Concentration on Captures of Ambrosia Beetles in Tree Fruits and Ornamentals. Journal of Applied Entomology. 0:1-14.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Cambronero-Heinrichs, J.C., Santoiemma, G., Battisti, A., Cavaletto, G., Meggio, F., Ranger, C.M., Scabbio, E. and Rassati, D., 2024. Simulated flood-stress and X-ray tomography unveil susceptibility of different tree taxa to ambrosia beetles. Forest Ecology and Management, 568, p.122106.
  • Type: Peer Reviewed Journal Articles Status: Under Review Year Published: 2025 Citation: Parajuli, M., Oksel, C., Neupane, K., Ranger, C. M., and Baysal-Gurel, F. Xylosandrus ambrosia beetles preference of field nursery tree species for attacks and colonization under flood and drought stress. Journal of Insect Science. (Submitted)
  • Type: Peer Reviewed Journal Articles Status: Under Review Year Published: 2025 Citation: Cambronero-Heinrichs, J.C., Ranger, C.M, Santoiemma, G., Cavaletto, G., Carloni, F., Battisti, A., Meggio, F., Rassati, D. Host plant selection and performance of ambrosia beetles in flood-stressed versus ethanol-injected trees provide indications for management strategies. Journal of Economic Entomology.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Monterrosa, A., A. L. Acebes, B. Blaauw, and S. V. Joseph. 2024. Effects of biochar on ambrosia beetle attacks on redbud and pecan container trees. Florida Entomologist. 107: 20240036.
  • Type: Other Journal Articles Status: Awaiting Publication Year Published: 2025 Citation: Lizarraga, Tobin, K.N., van Zoeren, J., Rivera, M.J. 2024. A comparison of ambrosia beetle trap designs in apple orchards in New York State. New York Fruit Quarterly.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Milbrath, L.R. and Biazzo, J., 2024. Phenology, voltinism, and brood development of Xylosandrus (Coleoptera: Curculionidae) ambrosia beetles in New York. Journal of Insect Science, 24(5), p.6.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Milbrath, L.R., Biazzo, J. and Mudrak, E., 2024. In-gallery social behaviors of the ambrosia beetle, Xylosandrus germanus (Coleoptera: Curculionidae). Environmental Entomology, 53(1), pp.85-93.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Tobin, K.N., Moore, M.E., Lizarraga, S., Petzoldt, J., Reese, C., Lovett, B., and Rivera, M.J. 2024. First report of Anisandrus maiche (Coleoptera: Curculionidae: Scolytinae) infesting apple trees. Zootaxa. 5506: 261-271.


Progress 09/01/22 to 08/31/23

Outputs
Target Audience:The primary audience for this research is any grower who works with an agricultural commodity (e.g., nut trees, fruit trees, ornamentals) that are used as hosts for ambrosia beetle. Currently, insecticides are the primary method of ambrosia beetle management. The primary methods for sharing this research will be done through extension and outreach including grower meetings and publications that target these audiences (e.g., The Pecan Grower magazine). Target audiences reached by our efforts to improve the management of exotic ambrosia beetles include commercial and homeowner growers/producers of apple, crop consultants, peach and pecan crops in the Eastern, mid-Atlantic, and Southeastern U.S.; ornamental tree and shrub producers in the Eastern, mid-Atlantic, and Southeastern U.S.; avocado growers in the Southern U.S.; retail nurseries and garden centers; arborists, ground managers, and landscape care professionals; county and regional extension agents; pest management specialists; master gardeners; agrichemical industry representatives; and the scientific community, including entomologists, plant pathologists, biologists, economists, engineers, undergraduate students, graduate students, and postdoctoral researchers. Growers and the public were provided with information on ambrosia beetles. For example, Tennessee and other southeastern regional plant inspectors were trained in identification and management for ambrosia beetles. Scientists were presented with recent research findings. Our results reached a wider audience through extension activities such as the Tennessee State University Extension Publications and Tennessee Greentimes publications. The apple grower stakeholders of NY collectively represent more than 600 farm business and 50,000 acres of commercial apples in six growing regions. Target audiences include over 1,500 fruit growers in PA and equivalent numbers in the adjacent mid-Atlantic fruit growing regions of MD, VA, WV, NY, NJ, and NC. The website is targeted at academics working on ambrosia beetles, growers working in pecan, nursery, and tree fruit, and individuals wanting to better understand the outputs and impacts of this project. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Graduate (1) and undergraduate (3) students were trained by VT staff on insect identification, scouting techniques and experimental design. Growers, Extension agents, crop consultants, and agrichemical industry representatives attended "Apple Field Day" at the NCSU Mountain Horticultural Crops Research and Extension Center to learn about the impact and interactions of ambrosia beetles, associated auxiliary fungi, and water stress in apple trees USDA-ARS researchers in Wooster, Ohio are supervising two postdoctoral researchers being paid by the SCRI funding. Three undergraduate interns were supervised in spring/summer 2023, one of which formally participated in the Ohio Research Internship Program through The Ohio State University. The ORIP intern conducted research to compare the impact of drought stress and flood stress on ambrosia beetle host selection and colonization, along with the induction of stress-induced ethanol production. A USDA-ARS (Wooster, OH) lab technician provided training in (1) rearing ambrosia beetles to a PhD student from a Co-PIs lab at Cornell (October 24-25, 2023), (2) volatile sampling and analysis by SPME-GC-MS was provided to two postdocs and one PhD student visiting from a Co-PIs lab at NCSU (March 14-15, 2023), (3) ambrosia beetle rearing and identification to a technician from a co-PIs lab at Penn State Univ. (March 20-23, 2023), and (4) ambrosia beetle identification, setting up nematode field and lab efficacy bioassays (June 20-22, 2023). UGA staff participated in the 2023 Georgia Pecan Annual Conference at Georgia National Fairgrounds, Perry, GA, on March 28, 2023. Co-PI Apurba Barman attended 2-day Bark Beetle Academy help at University of Florida, Gainesville, FL from October 20-21, 2022 to learn about identification of different ambrosia beetle and related species. Co-PIs at TSU trained a summer intern and postdoctoral scientist in beetle behavior, identification, and management of ambrosia beetles. One PhD and two Master's students at TSU were trained in experimental design, data collection, analysis and scientific writing and presentations. A postdoc from USDA-ARS (Wooster, OH) was hosted by a co-PI at Virginia Tech to learn about light reflectance collection and imagery processing. The ARS postdoc in turn provided training to the VT staff about ambrosia beetle identification. An intern at UF was trained in plant husbandry, including the development and implementation of IPM management for greenhouse grown plants. The intern also attended and presented in the Florida Phytopathological Society meeting, May 17-19, Immokalee, FL, USA. UF postdoc attended and presented in the Florida Phytopathological Society meeting, May 17-19, Immokalee, FL, USA. The postdoc also attended the Laurel Wilt and Phytophthora root rot grower workshop, June 08, 2023, Homestead, FL, USA. The UF postdoc interacted with industry representatives through two visits to a co-PIs UF lab. One by Bioworks and one by IQ-Biotech, both companies produce Trichoderma-based products among other biopesticides. UF Intern attended the Laurel Wilt and Phytophthora root rot grower workshop, June 08, 2023, Homestead, FL, USA. UF co-PI presented at the Laurel Wilt and Phytophthora root rot grower workshop, June 08, 2023, Homestead, FL, USA; attended and presented at the Entomological Society of America Invasive Species Tour, September 13, 2023, Orlando, FL, USA; and attended and presented at the International Congress of Plant Pathology, August 21-25, 2023, Lyon, France. Members of a co-PIs UF lab hosted a co-PIs postdoc from the USDA-ARS (Byron, GA) for five days (10-15 July 2023) to learn about beneficial nematodes and their use as biological control agents of bark and ambrosia beetles. The UF staff learned how to propagate nematodes, isolate their symbiotic bacteria, and apply nematode-based products to bolts and rate the efficacy of the treatments. A technician at Clemson Univ. received training on processing samples, field collection and ambrosia beetle identification. Co-PIs with the USDA-ARS in Ithaca, NY hired and are co-mentoring a postdoctoral researcher in ambrosia beetle biology, mycology, molecular genetics, and insect pathology. This includes different laboratory rearing methods of the beetle, culturing a variety of fungi (symbiotic, entomopathogenic, mycoparasitic, and other species commonly associated with beetle cultures), molecular identification of isolates, and conducting bioassays with insect-killing fungi. The post-doc is investigating the efficacy of entomopathogenic and mycoparasitic fungal products against multiple ambrosia beetle species. Co-PIs at UGA trained a temporary hourly employee (a research assistant) to help with sorting ambrosia beetle trap contents. At PSU, two program technicians and three summer student assistants were actively involved in the project. During the winter 2022/2023 project entomology technician participated in hands-on training on ambrosia beetle identification intensive training provided by the project personnel from USDA lab in Wooster, OH. A postdoc with the USDA-ARS (Byron, GA) trained other individuals in ambrosia beetle identification and rearing techniques including technicians and undergraduate interns. How have the results been disseminated to communities of interest? 58 presentations given on ambrosia beetles to scientific and/or stakeholder audiences. (Full list under "Other Products") Co-PIs at NCSU Local apple growers and the general public were invited to the Mountain Horticultural Crop Research and Extension Center (MHCREC) to learn more about apple production, disease control, and insect control. Results from research being conducted at the MHCREC regarding habitat suitability and risk management were also shared via oral presentation and posters at the Field Day activities NCSU Apple Field Day, August 10, 2023. An ambrosia beetle management page specific to apple production was added to the StopAB.org website. VT co-PI Guided a tour of 20 Certified Arborists at the Hampton Road AREC and presented information on ambrosia beetle research projects. July 25, 2023. Virginia Beach, VA. VT co-PI led a class for 30 community college students from TCC. The class included a presentation on ambrosia beetle biology and management, as well as showing insect displays and a hands-on workshop on insect collection. September 6, 2023. Virginia Beach, VA. Communication with project team and stakeholders at Stakeholder advisory meeting. Website is delivering information to academics working on ambrosia beetles, growers working in pecan, nursery, and tree fruit, and individuals wanting to better understand the outputs and impacts of this project. Co-PI at Clemson Univ. disseminated information via the biweekly newsletter and made available via GrowerTalks (Ball Publishing). Current subscription to the newsletter is more than 27,800. Grower Field Day: 100 North Carolina nursery growers educated on 8 Sept. 2023; 80 nursery growers were educated on 23 Feb. 2023. Grower Information Shared: Pest alerts including ambrosia beetle recommendations were shared with Phillip Haar (East Tenn. Nursery Specialist) for an upcoming grower newsletter. 12 Apr. 2023. Youth Outreach: Warren County Third Grader Entomology Event: >200 students, 26 Sept. 2023; >700 students, 21 Sept. 2023; >60 students, 28 June 202; >150, 20 June 2023. Nursery pest information shared with NCSU Specialized Agent, Ornamental Nursery and Greenhouse Crops NC State Extension-Western Region, North Carolina State University) on management and trapping of camphor shot borer (a pest causing issues in NC nurseries) via a journal article and 1-hour zoom conference. 12 May 2023. Nursery Industry Ambrosia Beetle Alerts: Ambrosia beetle alerts were issued on 24 Mar. and 8 Apr. 2023 based on trap collections via Dr. Amy Fulcher (Univ. Tenn. Extension Specialist and Professor for Sustainable Ornamental Plant Production and Landscape) and Tennessee nursery associations. Consultation: Information was shared with a North Carolina peach tree grower pertaining to Xylosandrus ambrosia beetle tree attacks. 3 Mar. 2023. Nursery Association Newsletter: A short section on ambrosia beetles and the need to scout for early detection of damage was prepared for Tennessee Department of Agriculture Plant Inspector Gary Clendenon's Middle Tennessee Nursery Association Newsletter article. 9 Feb. 2023. Guided a tour of 20 Certified Arborists at the Hampton Road AREC and presented information on ambrosia beetle research projects. July 25, 2023. Virginia Beach, VA. Led a class for 30 community college students from TCC. The class included a presentation on ambrosia beetle biology and management, as well as showing insect displays and a hands-on workshop on insect collection. September 6, 2023. Virginia Beach, VA. Stakeholder meeting: Highlight of research being conducted by USDA-ARS-Application Technology Research Unit scientists. Hosted by The Ohio State University Extension's--Next Generation Nursery and Greenhouse Research Workshop. Co-PIs with the USDA-ARS (Ithaca, NY) provided informal training of extension agent to identify relevant ambrosia beetles in upstate New York. Informal training was also provided to NY apple growers on ambrosia beetles and their potential management using microbial products during site selection visits to four orchards. Co-PIs with the USDA-ARS (Byron, GA) published a report in a trade journal that reaches pecan growers across the U.S. (Pecan South) concerning ambrosia beetles and pecan. Additionally, pecan producers were reached during the Georgia Pecan Growers Field Day (about 250-300 attendees) where ambrosia beetles and pecan were discussed. Co-PI efforts at Cornell were made apparent at the LOF summer apple fruit tour in August 2023, Albion NY. There were 256 growers in attendance. Ambrosia beetles and research efforts have been presented by Co-PIs at Cornell on the scaffolds podcast https://podcasters.spotify.com/pod/show/scaffolds?%24web_only=true&_branch_match_id=1243604277815335201&utm_source=web&utm_campaign=web-share&utm_medium=sharing&_branch_referrer=H4sIAAAAAAAAA8soKSkottLXLy7IL8lMq0zMS87IL9ItT03SSywo0MvJzMvWT9UPMDMxsixMrAytTAIA6xqX6jAAAAA%3D Co-PIs with the USDA-ARS (Byron, GA) shared in-person presentations at the Entomological Society of America, Entomological Society of Canada, and Entomological Society of British Columbia Joint Annual Meeting (Vancouver, Canada), Southeastern Pecan Growers Conference (Gulf Shores, AL, Feb. 2023), Entomological Society of America Southeastern Branch Meeting (Little Rock, AR, March 2023), Georgia Pecan Growers Association Annual Conference and Trade Show (Perry, GA, March 2023, Georgia Entomological Society (Helen, GA, April 2023), Society for Invertebrate Pathology (College Park, MD, Aug. 2023), and Georgia Pecan Growers Association Fall Field Day (Byron, GA, Sept. 2023), Western Pecan Growers conference (Las Cruces, NM, March 2023), Oklahoma Pecan Growers meeting (Tulsa, OK, June 2023). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1) Predict the risk of infestations in orchard and nursery crop systems through improved understanding of ambrosia beetle biology and ecology. Co-PIs at NCSU determined the effect of the interaction between apple rootstocksand water stress on soil and plant water status, leaf gas exchange, and ambrosia beetle (AB) colonization. 'G-41' trees tended to have higher transpiration, stomatal conductance, and assimilation rate than 'B-9' and 'EMLA-7' trees. Co-PIs at NCSU, USDA-ARS (OH), and TSU conducted a series ofstudies to determine main effects and interactions of water stress on plant stress, ethanol production, and AB attack. In short, flood stress, but not drought stress, lead to mass attacks by ABs. Co-PIs at NCSU and Cornell isolated auxiliary and symbiotic fungi from ABs.Fusarium andTrichodermaspp. were commonly recovered from beetles and galleries. Phytopathogens of apple were rare. Fusarium spp., but not AB symbionts, exhibited pathogenicity to apple shoots. Fire blight (shoot blight) experiments were deployed in OH, NY, PA, and NC to evaluate the potential of fire blight infection of apple to attract ABs and produce ethanol in potted apple trees. In PA, OH, and NC, fire blight infection resulted in fewer AB attacks than flood stress. Co-PIs with the USDA-ARS (Wooster, OH) demonstrated that ethanol and acetic acid in host tree tissues increases the attraction of ABs, burrowing, and offspring production. A study was initiated to learn more about habitat suitability and beetle distribution based on landscape factors such as elevation, species composition of woodlots adjacent to tree fruit production areas, and flood risk. Results indicate that AB species respond differently to the observed landscape factors. Objective 2) Develop novel tools to enhance the accuracy and precision of ambrosia beetle infestation and monitoring tactics. Co-PIs at Cornell Univ. compared trap types for ABs. After two years of our trap comparison study,clear sticky traps with ethanol bait captures more beetles than the other trap types tested. Co-PIs at UGA, USDA-ARS (OH and GA), NCSU, and VT deployed expansive grids of traps within cooperating commercial nurseries, apple orchards, and pecan groves to characterize dispersal patterns of ABs. ABs disperse from woodlots into neighboring nurseries and will fly at least 100 m into the interior of nurseries. Co-PIs at TSU, UGA, and USDA-ARS (Wooster, OH) conducted experiments to evaluate portable devices for detecting the emission of ethanol from stressed trees. A 3-D printed sensor mounting device for housing a commercially available sensor has been developed. The sensor mounting device is moderately successful. Co-PIs compared low vs high release rates for ethanol using baited traps and cored bolts filled with ethanol. Higher release rates from lures generally captured more beetles than lower release rates. Similarly, cored bolts filled with 90% ethanol are generally more attractive to ABs than 10% ethanol. 263 reports from 10 reporters were added to the online AB monitoring system shown on StopAB.org through EDDMapS. Total data set now includes 2,099 records of AB activity from 20 reporters. Co-PIs at UGA initiated a study to determine the risk of AB emergence patterns from pine-dominated and mixed pine-hard wood woodlots in Georgia. Objective 3) Implement comprehensive management strategies. Insecticide efficacy trials were conducted by co-PIs at multiple locations. Permethrin and bifenthrin were consistently the only active ingredients that reduced AB attacks. Surfactants were not effective at enhancing insecticide activity. Co-PIs at the UGA also evaluated the residual longevity of bifenthrin and found that 0- and 7-day bifenthrin treated bolts had significantly lower attacks compared to control, 28-, 21-, and 14-day bolts. Steinernema riobravewas the most effective strain against the granulate AB (X. crassiusculus), whileS. carpocapsaewas the most effective strain against the black stem borer (X. germanus). Co-PIs at multiple locations evaluated integrating repellents and attractants into a push-pull strategy for protecting vulnerable trees. The "push-pull" strategy testing verbenone + methyl salicylate (push) and ethanol-baited traps (pull) significantly reduced attacks on flood stressed dogwood trees deployed in ornamental nurseries in Ohio and other locations. Yet, results were inconsistent at other locations and the push-pull strategy continues to be elusive. Co-PIs at TSU tested a stress reducer treatment. Dogwoods were pre-treated with foliar sprays 7 days prior to flooding with three reported stress mitigating products: Regalia (biofungicide extract ofReynoutria sachalinensis), Reliant (fungicide/fertilizer phosphorous acid) and Axiom (harpin protein). None of the products reduced attacks to acceptable levels and in at least one trial, Axiom had more attacks than the flooded control. Co-PIs at the UF conducted a first screening of their assembledTrichodermacollection. Twenty-three strains were included in the metabolitein vitroassay to test their antagonistic effect against the laurel wilt pathogen (the ambrosia fungusHarringtonia lauricola). SixTrichodermastrainsproduced metabolites that inhibit the growth (>75%) of the laurel wilt pathogen. A protocol for inoculating avocado seeds with potential antagonistic and endophyticTrichodermawas also developed. Co-PIs at the USDA-ARS (Ithaca, NY) challenged three species of AB with three commercially available insect-killing fungi. All three fungi could kill all three beetle species at the highest dose, but at lower doses, beetle survival differed. Co-PIs with the USDA-ARS (Byron, GA) evaluated the efficacy of nematodes. Steinernema carpocapsae was the most effective strain of nematodes against the AB Xylosandrus germanus; S. riobrave was most effective against X. crassiusculus. Objective 4) Determine the economics of ambrosia beetle damage and control interventions on orchard and ornamental tree crop stakeholders. Agricultural economists with the UGA, Auburn Univ., and UTenn have developed producer and consumer surveys. The grower survey has been developed and will identify the economic impact of AB on production. The end customer survey to identify end consumer familiarity with and response to ABs has been developed and IRB approval obtained with a target launch in early 2024. In the next reporting period the bulk of objective 4 will be completed. During the next reporting period, the economics team will launch the survey using a panel of green industry stakeholders to assess the perceived current and potential economic impact of ABs on their operations and the industry. Objective 5) Transfer research-based information to stakeholders. A total of 58 presentations were given to stakeholders representing growers, producers, and the scientific community. Publications in peer-reviewed journals, trade articles, and theses/dissertations are listed under Products and Other Products. The websitehttps://stopab.org/(established in 2022) provides the first level of outreach efforts. The site targets academics working with ABs, growers working in pecan, nursery, or tree fruit, and individuals wanting to know more about the project activities and impacts. AB monitoring and management tactics have been established in all three cropping systems. AB flight seasonal activity is available in near real time through the website to provide growers and extension agents with activity. Pages on how ABs are managed in apple and about AB fungi have been released (https://stopab.org/management/apple/andhttps://stopab.org/about/about-ambrosia-fungi/). Overall,www.stopab.orghas received 1,130 page views from 417 users. Two stakeholder advisory panel meeting videos, three research manuscripts, an extension fact sheet, and a popular press article were also published on the site.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Dzurenko, M., Galko, J., Kulfan, J., V�?ka, J., Holec, J., Saniga, M., Z�brik, M., Vakula, J., Ranger, C.M., Skuhrovec, J., Jauschov�, T., Zach, P. 2022. Can the invasive ambrosia beetle Xylosandrus germanus withstand an unusually cold winter in the West Carpathian forest in Central Europe? Folia Oecologica. 49: 1-8.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Gugliuzzo, A., Kreuzwieser, J., Ranger, C.M., Tropea Garzia, G., Biondi, A., Biedermann, P.H.W. 2023. Volatiles of fungal cultivars act as cues for host-selection in the fungus-farming ambrosia beetle Xylosandrus germanus. Frontiers in Microbiology. 14: 1151078
  • Type: Other Status: Published Year Published: 2023 Citation: Halliday, P., A. Monterrosa, A. Acebes-Doria, J. Oliver, and C. Ranger. 2023. Field guide to ambrosia beetles of agricultural importance in the eastern and southern United States. (https://extension.uga.edu/publications/detail.html?number=C1239). Univ. of Georgia Extension Circular 1239. (Aug. 2023).
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Parajuli, M., C. Oksel, K. Neupane, C.M. Ranger, J.B. Oliver, K.M. Addesso, and F. Baysal-Gurel. 2023. Acibenzolar-S-methyl induces resistance against ambrosia beetle attacks in dogwoods exposed to simulated flood stress. Journal of Insect Science. 23(4): 12; 1-8.
  • Type: Other Status: Published Year Published: 2023 Citation: Poudel, A., A. Gautam, K. Addesso, J. Oliver, and G. Roper. 2023. Ambrosia beetles important to Tennessee nurseries. Tenn. State Univ. Cooperative Extension Publ. ANR-ENT-02-2023 (TSU-23-148(B)-15c-13515). 31 Jan. 2023.
  • Type: Theses/Dissertations Status: Published Year Published: 2023 Citation: Poudel, A. 2023. Ecology and Integrated Management of Ambrosia Beetles in Ornamental Nursery Trees. Masters Thesis. Tennessee State University, Nashville, TN.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Ranger, C.M., Parajuli, M., Gresham, S., Barnett, J., Villani, S., Walgenbach, J., Baysal-Gurel, F., Owen, J., and M. E. Reding. 2023. Type and duration of water stress influences host selection and colonization by exotic ambrosia beetles (Coleoptera: Curculionidae). Frontiers in Insect Science. doi.org/10.3389/finsc.2023.1219951
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Sutherland, R., Meurisse, N., Pugh, A.R., Ranger, C.M., Reding, M.E., Kerr, J.L., Russell, J., Withers, T.M. 2023. Phenological observations and trapping tactics for the granulate ambrosia beetle Xylosandrus crassiusculus (Coleoptera: Curculionidae, Scolytinae) in New Zealand. Agricultural and Forest Entomology. doi: 10.1111/afe.12558
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Williamson, Z. V., Blaauw, B. R., & Joseph, S. V. (2023). Effects of permethrin on ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in ornamental nurseries. Journal of Insect Science, 23(4), 4.
  • Type: Other Status: Published Year Published: 2023 Citation: Barman, A. and A. Sawyer. 2023. 2023 Ambrosia beetle update. UGA Pecan Extension (A website from UGA Cooperative Extension). https://site.extension.uga.edu/pecan/2023/02/2023-ambrosia-beetle-update/
  • Type: Other Status: Published Year Published: 2023 Citation: Cottrell, T., Barman, A., and W. Hudson. 2023. Keeping up with ambrosia beetles. Pecan South Magazine. Vol. 56 (2): 6-13. https://www.pecansouthmagazine.com/magazine/article/keeping-up-with-ambrosia-beetles/
  • Type: Other Status: Published Year Published: 2023 Citation: Parajuli, M., C. Oksel, J. B. Oliver, K. M. Addesso, and F. Baysal-Gurel1. 2023. Integration of control strategies for management of Phytophthora root rot and ambrosia beetles in nursery trees. Tennessee Greentimes (Mar. 2023) https://issuu.com/leadingedgepubs/docs/tn-greentimes-2023-spring/s/21599813
  • Type: Other Status: Published Year Published: 2023 Citation: Slusher, E.K. and D. Shapiro-Ilan (2023) Use of entomopathogenic nematodes as a management tactic for weevil pests in Pecan. Pecan South Magazine. May 2023 (56:3): 30-37.
  • Type: Theses/Dissertations Status: Published Year Published: 2023 Citation: Gresham, S. 2023. Association of Xyleborine ambrosia beetles and phytopathogens with declining apple trees in North Carolina. Disseration submitted to the Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC.
  • Type: Other Status: Published Year Published: 2023 Citation: Barman, A. and A. Sawyer. 2023. Tiny insect, but big impact: should we be concerned with ambrosia beetles? The Pecan Grower. Vol. 35(1): 46-51.


Progress 09/01/21 to 08/31/22

Outputs
Target Audience:The primary audience for this research is any grower who works with an agricultural commodity (e.g., nut trees, fruit trees, ornamentals) that are used as hosts for ambrosia beetle. Currently, insecticides are the primary method of ambrosia beetle management. The primary methods for sharing this research will be done through extension and outreach including grower meetings and publications that target these audiences (e.g., The Pecan Grower magazine). Target audiences reached by our efforts to improve the management of exotic ambrosia beetles include commercial and homeowner growers/producers of apple, peach and pecan crops in the Eastern, mid-Atlantic, and Southeastern U.S.; ornamental tree and shrub producers in the Eastern, mid-Atlantic, and Southeastern U.S.; retail nurseries and garden centers; arborists, ground managers, and landscape care professionals; county and regional extension agents; pest management specialists; master gardeners; agrichemical industry representatives; and the scientific community, including entomologists, plant pathologists, biologists, economists, engineers, undergraduate students, graduate students, and postdoctoral researchers. Specifically, the apple grower stakeholders of NY collectively represent more than 600 farm business and 50,000 acres of commercial apples in six growing regions. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Co-PIs at TSU are training a master's degree student in entomology. A master's degree student, doctoral student, and a postdoctoral researcher are also being training in plant pathology. All four positions are addressing research outlined in the SCRI proposal involving field and lab research for ambrosia beetles. Co-PIs at UGA have hired one master's degree student training in entomology, one postdoctoral researcher, one doctoral student training in engineering, and one doctoral student training in agricultural economics to address research outlined in the SCRI grant. Co-PIs atClemson hired a technician and have provided training on field collection and ambrosia beetle identification. Summer interns from Hobart and William Smith Colleges and Saint John Fisher University participated in a two day informal workshop on establishing a potted planting of apple trees as part research activities at Cornell University. Students worked one on one with PIs to learn about the horticultural practices of establishing an orchard to be used in scientific field experiments. Training was provided on experimental design and practice data analyses. A PhD student at Cornell training in entomology and funded by the SCRI grant visited a PD lab with the USDA-ARS in Wooster, OH to receive training in ambrosia beetle rearing. A co-PI at the UF and an intern participated of the Bark Beetle Academy, October 19-23, 2022: Gainesville, FL, USA. Intern Carlos Sendoya received training in processing ambrosia beetle for fungi. AUF intern and postdoc participated of the International Technical Course Laurel Wilt of Avocado. Laboratory technicians and summer employees at PSU received training and became familiar with the project activities and gained necessary experience to obtain project objectives in the coming years. Co-PIs with the USDA-ARS in Wooster, OH hired and have started training two postdoctoral researchers in entomology. One of the postdocs is characterizing the dispersal patterns of ambrosia beetles into cropping systems. The other postdoc is optimizing repellent and attractant tactics for use in a 'push-pull' strategy against ambrosia beetles. Three undergraduate student interns werehired and received training in experimental design and ambrosia beetle identification during the spring and summer of 2022. A post-doc with the USDA-ARS in Byron, GA learned how to rear both ambrosia beetles and nematodes in a laboratory setting. Ambrosia beetle training involved visiting the USDA-ARS in Wooster, OH lab for a week to learn and develop rearing techniques. In addition, the postdoc has also gained experience in culture, bioassay techniques, and application of EPNs. Co-PIs atNCSU hired and began training a postdoctoral researcher in entomology to support SCRI research objectives. NCSU researchers also transferred knowledge by participating in the International Tree Fruit Association Conference in Hershey PA. A student at Texas A & M (Kelman Scholars Internship Program) hosted at NCSU conducted research on the effect of ambrosia beetles and opportunistic fungi on young apple trees. Growers, Extension agents, crop consultants, and agrichemical industry representatives attended "Apple Field Day" at the NCSU Mountain Horticultural Crops Research and Extension Center to learn about the impact of ambrosia beetles in apple trees and the initiative that are being undertaken with the SCRI project. How have the results been disseminated to communities of interest? The www.stopAB.org was launched in FY22. It includes a database of ambrosia beetle flight activity in participating regions of the U.S. The stakeholder advisory panel was formed. A virtual presentation was held on January 27, 2022 to update the SAP on administrative and research activities. PDs and co-PIs gave 15 minute presentations followed by questions and feedback from the SAP. A Box folder was created that stores documents, presentations, photos, etc. supporting the USDA-NIFA-SCRI project. The folder includes presentations of monthly meetings (Nov. 2021 - present) organized and led by PD Ranger. Presentations Addesso, K. M. 2022. Pests in the landscape - preparing for spring. Middle Tennessee Nursery Association Horticultural Expo. McMinnville, TN. Addesso, K. and J. Oliver. 2021. Pest management in landscape trees. Extension Service Fall Lawn and Landscape Training. Rutherford Co. Addesso, K. and J. Oliver. 2022. Middle Tenn. State Univ. Nursery Production Class tour of TSU Nursery Research Center and entomology / chemical ecology laboratories. McMinnville, TN. Addesso, K. and J. Oliver. 2022. Warren County TN Third Grader Agricultural Day Display and Education Event. Addesso, K. and J. Oliver. 2022. Cumberland County Extension Youth Outreach. Addesso, K. and J. Oliver. Tenn. Tech Univ. Nursery Plant Class tour of TSU Nursery Research Center. Addesso, K. and J. Oliver. 2022. Southern Division of American Phytopathological Society field and nursery tour at the TSU Nursery Research Center. Addesso, K. and J. Oliver. Media Publicity: Phone interview with Tash Lemley (Multimedia Producer for "This is Nashville WPLN - Nashville Public Radio) to discuss invasive species issues. Blaauw, B. 2022. Apple insect pest management update. North Georgia Apple Production Meeting. Ellijay, GA. Cottrell, T. 2022. Managing insect pests across the season. Annual Meeting of the Southeast Pecan Growers Association. Cox, K. and Rivera, M. 2022. Lake Ontario Fruit Program - Cornell University: Announcement of USDA-NIFA-SCRI ambrosia beetle research efforts. Del-Pozo, A., D. Calpo and P. Schultz. 2021. Documenting the changes in species composition through time of ambrosia beetles in Virginia. ESA annual meeting. Del-Pozo, A. 2022. Managing ornamental pests. Virginia Cooperative Extension. Pesticide Recertification Meeting. Winchester, VA. Del-Pozo, A. 2022. Managing ornamental pests. Virginia Turf Council. Pesticide Recertification Meeting. Virginia Beach, VA. Del-Pozo, A. 2022. Managing ornamental pests. Virginia Cooperative Extension. Pesticide Recertification Meeting. Painter, VA. Del-Pozo, A., E. Hopkins, D. Calpo, J. Brindley and P. Schultz. 2022. Improving monitoring efforts for ambrosia beetles in Virginia. ESA Eastern Branch. Philadelphia, PA. Del-Pozo, A. 2022. A research update on relevant pests for Virginia nurseries. ESA Eastern Branch. Philadelphia, PA. Del-Pozo, A., E. Hopkins, D. Calpo, J. Brindley and P. Schultz. Improving monitoring efforts for ambrosia beetles in Virginia. 22nd Ornamental Workshop. Raleigh, NC. Del-Pozo, A. 2022. Expanding the toolbox: applied research for improving IPM in specialty crops. Iowa State University. Entomology Department. Gresham, S., Villani, S.M., and Walgenbach J. 2022. Pathogenicity of fungi associated with ambrosia beetles attacking apple trees. 2022 American Phytopathological Society. Pittsburgh, PA. Gresham, S.D. 2022. Unraveling the relationship between ambrosia beetles and rapid apple decline. 2022 Apple Field Day. Mills River, NC. Neupane, K., Ojha, V., Oliver, J., Addesso, K., Baysal-Gurel, F. 2022. Comparative efficacy of integrated fungicide, insecticide and blocking agent to manage Phytophthora root rot and Ambrosia beetles in flood stressed flowering dogwoods. 3rd Association of Nepalese Agricultural Professionals of Americas (NAPA)Biennial International Scientific Conference. Atlanta, GA. Neupane, K., V. Ojha, J.B. Oliver, K.M. Addesso, and F. Baysal-Gurel. 2022. Efficacy of fungicides, insecticides and crop protectants to manage Phytophthora root rot and ambrosia beetles in a simulated flooding condition. Southern Division American Phytopathological Society 99th Annual Meeting. Chattanooga, TN. Neupane, K., Ojha, V., Oliver, J., Addesso, K., Baysal-Gurel, F. 2022. Integrated management of ambrosia beetles and Phytophthora root rot of flowering dogwoods in a simulated flooding condition. 2022 joint Southeastern branch & APS-CD Meeting. San Juan, Puerto Rico. Neupane, K. 2022. Three minute thesis. MANRRS National Competition. Masters Division 1st Place. Oliver, J., K Addesso, A. Witcher, N. Youssef, P. O'Neal, A. Morrison, S. King, D. Oi, R. Weeks, and L. Alexander. 2022. Fire ant update and other important woody ornamental insect updates. Tennessee Green Industry Field Day. Hosted by Tenn. State Univ. and Tenn. Nursery & Landscape Assoc. 25 Aug. 2022. McMinnville, TN. Oliver, J., K. Addesso, C. Ranger, M. Reding, F. Baysal-Gurel, N. Youssef, P. O'Neal, M. Brown, V. Ojha, K. Neupane, C. Werle, A. Bray, J. Saroli, P. Schultz, and B. Sampson. 2022. Managing insect pests of nursery and landscape: ambrosia Beetle. Gulf States Horticultural Expo. Parajuli, M. 2022. Plant defense elicitor reduces ambrosia beetle attacks in flowering dogwoods exposed to simulated flood stress condition. 3rdAssociation of Nepalese Agricultural Professionals of Americas (NAPA)Biennial International Scientific Conference. Parajuli, M., Oksel, C., Neupane, K., Ranger, C.M., Oliver, J.B., Addesso, K.M., Baysal-Gurel, F. 2022. Plant defense elicitor reduces ambrosia beetle attacks in flowering dogwoods exposed to simulated flood stress condition. 2022 Tennessee Academy of Science Meeting. Nashville, TN. Peter, K. 2022. Overview of rapid/sudden apple decline (RAD/SAD)in Pennsylvania (and elsewhere in the U.S.). Fundazione Edmund Mach, San Michele d'Aldige, Trento, Italy. Special seminar via Zoom. Poudel, A., Oliver, J. B., Perkovich, C., O' Neal, P. A., Mafra-Neto, A., Saroli, J., Addesso, K.M. Assessment of ambrosia beetle attack using repellents in ethanol infused bolts to facilitate its effective management. Tennessee Entomological Society. Knoxville, TN. Ranger, C.M. 2022. Exotic ambrosia beetles as wood-boring insect pests in nurseries and orchards. AmericanHort Cultivate '22. Columbus, OH. Ranger, C.M. 2022. Biology and management of wood-boring ambrosia beetles. 2022 Green Industry Field Day, University of Tennessee. Ranger, C.M., Villani, S., Joseph, S., Chong, J., Campbell, B., and J. LaForest. 2022. Ecology and integrated management of ambrosia beetles in Eastern US orchard and ornamental tree crops. 1st Annual Meeting with the USDA-NIFA-SCRI Stakeholder Advisory Panel. Ranger, C.M. Monitoring and reporting in near real-time the flight activity of ambrosia beetles in tree orchards and nurseries. Annual meeting of the ESA. Reding, M. and Ranger, C. 2021. Seasonal vulnerability of trees to colonization by ambrosia beetles. Annual meeting of the Entomological Society of America. Villani, S.M. 2022. Ambrosia beetles, borers, and interactions with RAD/SAD incidence. 2022 International Tree Fruit Association Meeting in Hershey, PA. Walgenbach, J. 2022. Research update. Blue Ridge Apple Growers Winter Conference. Flat Rock, NC. Weber, A. and Gresham, S. 2022. Unraveling the relationship between ambrosia beetles and trunk disease in apple. Presented at the 2022 Apple Field Day in Mills River, NC. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1) Predict the risk of infestations in orchard and nursery crop systems through improved understanding of ambrosia beetle biology and ecology. Co-PIs at TSU conducted experiments to compare the impact of flooding and drought on tree attractiveness to ambrosia beetles. The influence of Phytophthora cinnamomi infection on tree suitability to ambrosia beetles was also examined. The presence of stress-induced ethanol within stems was also quantified. Data are being processed. Co-PIs at NCSU inoculated apple trees with fireblight to determine the impact of infection of tree attractiveness to ambrosia beetles and ethanol production. Data are being processed. Co-PIs at Cornell Univ. isolated cultures of fire blight for inoculating trees in field experiments in 2023. Co-PIs at NCSU, PSU, USDA-ARS (OH, NY) collected ambrosia beetles in traps and/or dissected from ethanol-soaked stem sections (i.e., bolts) to culture auxiliary and symbiotic fungi associated with the beetles. Extraction of DNA is being conducted to confirm identifications. Co-PIs at VT characterized an ambrosia beetle infestation in a commercial nursery to improve our understanding of their host selection. A commercial block with ornamental trees was selected and the number of ambrosia beetle attacks were counted along with tree characteristics. Data are being processed. Objective 2) Develop novel tools to enhance the accuracy and precision of ambrosia beetle infestation and monitoring tactics. Co-PIs at Clemson Univ., NCSU, PSU, TSU, UGA, USDA-ARS (OH, NY), and VT evaluated trapping tactics to improve the monitoring of ambrosia beetle. Researchers evaluated high vs. low ethanol release lures, and ethanol-baited traps vs. ethanol-infused bolts. The high release ethanol lures generally performed better than the low release lures and the ethanol-infused bolts. Co-PIs at TSU tested wooden dowels infused with ethanol to monitor ambrosia beetle tunneling. Data are being processed but a type/species of wood was preferred by beetles. Co-PIs at Cornell tested five different traps for ambrosia beetles and a clear sticky trap consistently captured the highest number of beetles. Co-PIs at UGA, USDA-ARS (GA, OH), and VT deployed expansive grids of traps within cooperating commercial nurseries and orchards to characterize dispersal patterns of ambrosia beetles in relation to landscape factors and tree crops. Data are being processed. Co-PIs at UGA, TSU, and USDA-ARS (OH) conducted experiments to evaluate portable devices for detecting the emission of ethanol from stressed trees. Co-PI at UGA developed a 3-D printed sensor mounting device for housing a commercially available sensor. The sensor mounting device was tested and the basic design was moderately successful. Co-PIs at TSU tested a commercially available ethanol detector and alcohol enzyme strips for detecting ethanol. The ethanol detector performed well but the enzyme strips were less reliable. Researchers with the USDA-ARStested a handheld air sampling device for detecting the emission of ethanol from flood-stressed trees. Ethanol was detected at 5 and 8 days after initiating flooding, but the technique is not sensitive enough to detect ethanol before ambrosia beetles begin infesting the trees. Objective 3) Implement comprehensive management strategies: Co-PIs at Clemson, NCUSU, UGA, USDA-ARS (GA), and VT evaluated several insecticides against ambrosia beetles. Among all products tested, only bifenthrin and permethrin achieved a significant reduction of attacks. Other formulations were ineffective or partially effective. Co-PIs at the USDA-ARS (OH) and the UGA evaluated verbenone, methyl salicylate, and a proprietary formulation for interrupting the attraction of ambrosia beetles to ethanol. Verbenone and the proprietary formulation almost completely interrupted the attraction of beetles to ethanol. Methyl salicylate alone provided a slight reduction in trap captures, but verbenone + methyl salicylate was not more effective than verbenone alone. A complementary study determined that an ethanol release rate of 1 g/d was optimal for attracting ambrosia beetles. These results will be used to improve the repellent and attractant tactics for ambrosia beetles when tested as part of a push-pull strategy in FY23. Co-PIs at TSU tested four putative repellent products. The proprietary product resulted in a near complete shutdown of beetle attraction to ethanol-baited traps. The proprietary formulation was slightly less effective when traps became more attractive due to increased ethanol release rate. Co-PIs at TSU tested a plant defense elicitor (acibenzolar-S-methyl; ASM) against ambrosia beetle tunneling. Tunneling was significantly reduced in trees treated with ASM (drench or foliar) compared to the control. Drench application gave superior control of ambrosia beetle over foliar application. Only the plant tissues collected from the flooded plants produced ethanol. To test antagonistic fungi, a co-PI with UF established a collection of ambrosia fungi and potential antagonistic fungal strains. Selected strains will be tested in bioassays and for their ability to be incorporated into living trees to disrupt establishment of the ambrosia beetle fungal symbiont. The in vitro protocol to test the antagonistic effect of Trichoderma other strains against the ambrosia beetle fungal symbionts. Co-PIs at USDA-ARS (GA) assessed the effectiveness of different strains of commercially available entomopathogenic (insect-killing) nematodes on the granulate ambrosia beetle (Xylosandrus crassiusculus) and black stem borer (Xylosandrus germanus). This involved learning how to create a diet for rearing ambrosia beetles in the lab to produce colonies for experiments. Four commercial strains of nematodes were tested. Differences in efficacy were detected among the strains, and all of the strains produced higher mortality than the control group. Objective 4) Determine the economics of ambrosia beetle damage and control interventions on orchard and ornamental tree crop stakeholders. Agricultural economists with the UGA, Auburn Univ., and University of Tennessee have begun developing the producer and consumer surveys and they will be launched during Spring 2023 to assess economic impact associated with ambrosia beetles infesting ornamental and orchard tree crops. Objective 5) Transfer research-based information to stakeholders. An information brochure and newsletter article were prepared and distributed by Clemson University. A total of 32 presentations were given to stakeholders representing growers, producers, and the scientific community. The website https://stopab.org/ was established to provide the first level of outreach efforts. A content manager was hired to gather information from the different objective leaders, get feedback on website design, and collect news and products from the existing land-grant Extension programs. The site targets academics working with ambrosia beetles, growers working in pecan, nursery, or tree fruit, and individuals wanting to know more about the project activities and impacts. AB monitoring and management tactics have been established in all three cropping systems. Ambrosia beetle flight seasonal activity is available in near real time through the website to provide growers and extension agents with activity. Survey questions regarding importance of different types of content and communication methods with the different audiences have been developed and will be distributed to stakeholders with the survey sent in objective 4.

Publications

  • Type: Other Status: Published Year Published: 2022 Citation: Chong, J. 2022. How to prevent attacks of ornamental trees and shrubs by ambrosia beetles. Clemson University Cooperative Extension. (A trifold brochure for growers and retail nurseries.)
  • Type: Other Status: Published Year Published: 2022 Citation: Chong, J. H. 2022. New management strategies to be developed for ambrosia beetles. Newsletter of the SC Green Industry Association. February 2022.