Brief Summary of Minutes of Annual Meeting

The previous year provided unprecedented challenges to green industry professionals and university personnel throughout the country.  Many of the challenges were addressed as best as possible through new practices such as social distance priorities, few (if any) in-person interactions, and increased importance of using technology in delivering outputs to stakeholders.  A primary use of technology this year was remote learning through Zoom or similar software for workshops, meetings, or other events.  Our meeting was supposed to occur between 10 – 15 December 2020; however, due to scheduling, technical difficulties, and other issues we were unable to find a time that synced well for everyone.  Some members that had planned to attend the in-person meeting sent state reports they had prepared and are shared in the rest of this report.

Short-term outcomes:  Members of the group were productive during 2020 despite challenges presented by the pandemic.  Most of the short-term outcomes reflect the adoption and use of social media or conferencing software packages.

• Social media was used by most universities to inform stakeholders of upcoming pest issues of concern. Twitter, blogs, Instagram, and podcasts were used to disseminate knowledge about new invasive pests, upcoming workshops, and management strategies for economically important pests.  For example, the University of Florida used Twitter to send out “Pest-Alerts” to stake-holders.  These alerts increased stakeholder learning and reduced costs for managing some pests.
• Zoom or similar software was heavily used to conduct workshops or collaborative meetings. For example, Purdue University provided bi-weekly outreach programs and the University of Delaware conducted identification workshops with stakeholders.

Output:  The group was able to maintain dynamic research programs despite pandemic challenges throughout the year.  The group contributed to understanding of the biology and management of insect and disease pests which is reflected in the publication record included with this report. 

Objective 1:  New & Emerging Pests

• Research led by the University of Nebraska-Lincoln found the cause of Aspen running canker – a fungus called Neodothiora populina.
• Research results have been shared with stakeholders in each state via trade journals, webinars, workshops and weekly to bi-weekly newsletters (depending on state). For example, Purdue University was awarded 2020 Outstanding Educational Materials Award by The American Society for Horticultural Science – Extension Division for their bi-weekly blog and newsletter.
• A collaborative multi-state research team formed under this working group continues to document the diversity and seasonal activity of elm bark beetles in South Carolina. Only Scolytus multistriatus and quadrispinosus occur in the coastal plain and piedmont regions of South Carolina. No banded elm bark beetle, which is the target of this surveying effort, was detected in 2018 through 2020.
• A paper has been published on the most diagnosed scale insect species in the United States. The paper was developed based on a survey of all diagnosis records deposited at the National Plant Diagnosis Network database, and listed the top armored scale, soft scale, mealybug, and other scale insect species most diagnosed by diagnosticians. This resource will help guide the development of resources to assists nursery growers, landscape care professionals, arborists, diagnosticians, extension agents, and other in identifying, understanding, and managing scale insects on ornamental plants.
• Early detection of plant diseases, prior to symptom development, can allow for targeted and more proactive disease management. The objective of this study was to evaluate the use of near-infrared (NIR) spectroscopy combined with machine learning for early detection of rice sheath blight (ShB), caused by the fungus Rhizoctonia solani. We collected NIR spectra from leaves of ShB-susceptible rice (Oryza sativa ) cultivar, Lemont, growing in a growth chamber one day following inoculation with R. solani, and prior to the development of any disease symptoms. Support vector machine (SVM) and random forest, two machine learning algorithms, were used to build and evaluate the accuracy of supervised classification-based disease predictive models. Sparse partial least squares discriminant analysis was used to confirm the results. The most accurate model was SVM-based and had an overall testing accuracy of 86.1% (N = 72) when mock-inoculated and inoculated plants were compared; whereas, when control, mock-inoculated, and inoculated plants were compared the most accurate SVM model had an overall testing accuracy of 73.3% (N = 105). These results suggest that machine learning models could be developed into tools to diagnose infected but asymptomatic plants based on spectral profiles at early stages of disease development. While testing and validation in field trials are still needed, this technique holds promise for application in the field for disease diagnosis and management.
• Maintenance and restoration of forest ecosystems will be key to achieving necessary carbon sequestration goals, protecting biodiversity, and supporting healthy economies and societies. Forest ecosystems are increasingly threatened by non-native forest insects and pathogens. A portion of these pests can overcome prevention and containment efforts and become established in naïve ecosystems. Once established these pests pose a long-term large-scale threat to forest ecosystems, which current policy and response frameworks are poorly equipped to address. We propose the creation of a federal Center for Forest Pest Control and Prevention to implement end-to-end responses to forest pest invasions using an ecologically informed framework that fully integrates host tree resistance development and deployment.
• European ash is a significant tree commercially, ecologically, and culturally. It is currently threatened by two invasive species, the fungus that causes ash dieback and the emerald ash borer (EAB) beetle. We showed that saplings of European ash are much less susceptible to EAB than black ash, which has suffered severe damage in North America, but have similar resistance to Manchurian ash, which coexists with EAB in East Asia. Selecting ash with stronger resistance to dieback is unlikely to decrease its resistance to EAB. As we do not know what the combined effect of ash dieback and EAB will be on European ash, biosecurity measures are needed to exclude EAB from Western Europe.
• Plant interactions with herbivores and pathogens are among the most widespread ecological relationships and show many congruent properties. Despite these similarities, general models describing how plant defenses function in ecosystems, and the prioritization of responses to emerging challenges such as climate change, invasive species, and habitat alteration, often differ markedly between entomologists and plant pathologists. We posit that some fundamental distinctions between how insects and pathogens interact with plants underlie these differences. We propose a conceptual framework to help incorporate these distinctions into robust models and research priorities. The most salient distinctions include features of host-searching behavior, evasion of plant defenses, plant tolerance to utilization, and sources of insect and microbial population regulation. Collectively, these features lead to relatively more diffuse and environmentally mediated plant–insect interactions, and more intimate and genetically driven plant–pathogen interactions. Specific features of insect vs pathogen life histories can also yield different patterns of spatiotemporal dynamics. These differences can become increasingly pronounced when scaling from controlled laboratory to open ecological systems. Integrating these differences alongside similarities can foster improved models and research approaches to plant defense, trophic interactions, coevolutionary dynamics, food security and resource management, and provide guidance as traditional departments increase collaborations, or merge into larger units.

Objective II:  Pesticide technology development:  Evaluate effectiveness of reduced-risk pesticides, biopesticides, new and novel chemistries, and application of technologies for control of key disease and arthropod pests of landscapes, nurseries, and Christmas tree farms.

• The University of Delaware and Maryland collaborated on research projects focused on management of root aphids and root mealybugs using biological control, reduced-risk insecticides and biopesticides.
• Research trials led by Clemson evaluated reduced-risk insecticides, miticides, novel chemistries and biopesticides against sweet potato whitefly, western flower thrips, citrus mealybug, magnolia scale, redheaded flea beetle, rose rosette mites and two spotted spider mites which was then shared with green industry professionals via workshops and publications.

Activities:

• University laboratories (diagnostic clinics associated with National Plant Diagnostic Clinics) continue to provide diagnosis of various insect and disease samples.
• A MS student at Clemson has a project investigating the compatibility between chordotonal organ TRPV channel modulator insecticides (IRAC Group 9) and the minute pirate bug, Orius insidiosus has been completed and thesis preparation is currently underway. This research team is also investigating the effectiveness of pre-planting cutting dip of different Beauveria bassiana products against sweetpotato whiteflies on poinsettias, and the compatibility of these products with fungicides used during cutting propagation and rooting.
• A collaborative project between the Mosquito Control Association and University of Delaware is investigating the impacts of barrier sprays on non-target arthropods.

Milestones:

• Members of the group continue to develop novel ways to detect diseases and disease resistance in trees which opens new avenues to plant breeding and disease management.
• Members continue to investigate the biology of new invasive pests, evaluate new management tools or products, and educate green industry professionals.
• Members continue to build collaborative networks addressing important pests between industry professionals, growers and research laboratories at universities.
• Members continue to publish research results in trade or peer-reviewed journals and share information with stakeholders via workshops, conference networking software, and social media.

Adams, G. and L. Winton.  2020.  Aspen running canker.  https://www.fs.usda.gov/detailfull/r10/forest-grasslandhealth/?cid=FSEPRD536250&width=full#AlaskaForestHealth

Bonello P, Campbell FT, Cipollini D, Conrad AO, Farinas C, Gandhi KJ, Hain FP, Parry D, Showalter DN, Villari C and Wallin KF.  2020.  Invasive tree pests devastate ecosystems – A proposed new response framework.  Frontiers in Forests and Global Change - Pests, Pathogens, and Invasions – DOI: 10.3389/ffgc.2020.00002.

Chong, J. H. 2020. These guys suck! pp. 6-7. In 2020 Grower Talks Insecticide, Miticide & Fungicide Guide. https://www.growertalks.com/pdf/2020_IMF_Guide.pdf

Chong, J. H. 2020. Soft scale crawlers, Bt and herbicide crop safety summaries. PestTalks 8 May 2020.

Chong, J. H. 2020. Mites and bittercress; Grotto fungicide; adelgid-resistant hemlock. PestTalks 21 April 2020.

Chong, J. H. 2020. What the … ?; Oxalis efficacy; Neonicotinoid reviews; Women rule over bugs. PestTalks 24 February 2020.

Chong, J., H. 2020. Scale insect management. Eastern North Carolina Nursery IPM Workshop, Wilson, NC.

Chong, J. H. 2020. Untangling the relationship among pollinators, flowering plants, and systemic insecticides. AFE Webinar.

Conrad AO, Li W, Lee D-Y, Wang G-L, Rodriguez-Saona L, Bonello P (2020).  Machine learning-based presymptomatic detection of rice sheath blight using spectral profiles.  Plant Phenomics – DOI:10.34133/2020/8954085.

Conrad AO, Villari C, Sherwood P, Bonello P (2020).  Phenotyping Austrian pine for resistance using Fourier-transform infrared spectroscopy.  Arboriculture and Urban Forestry 46: 276–286.

Chong, J. H. 2019. Nematodes vs flea beetles; Boxwood health workshop and hemp pesticides. 26 December 2019.

Chong, J. H. 2019. Hungry, hungry caterpillars. GrowerTalks November 2019. https://www.growertalks.com/Article/?articleid=24398

Chong, J. H. 2019. What the … ?; Efficacy against scales and mealybugs, and Orkestra Intrinsic. PestTalks 8 November 2019.

Gill, S., and B.A. Kunkel.  Management of Two Major Below Ground Feeding Plant Pests - Root Mealybug, Rhizoecus sp. and Root Aphid, Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Pseudococcidae and Aphididae) in nurseries (J Environmental Hort, in prep)

Klingeman, W. E., J. H. Chong, C. Harmon, L. Ames, A. V. LeBude, and P. Chandran. 2020. Scale insect records from ornamental plants help to prioritize plant health resource development. Plant Health Progress 21: 278-287.

Klingeman, W. E., J. H. Chong, C. Harmon, L. Ames, A. LeBude, P. Chandran. 2019. The most commonly diagnosed scale insects on ornamental plants in the United States. International Symposium on the Studies of Scale Insects (ISSIS).

Raffa KF, Bonello P, Orrock JL (2020).  Why do entomologists and plant pathologists approach trophic relationships so differently?  Identifying biological distinctions to foster synthesis.  New Phytologist 225: 609-620. DOI: 10.1111/nph.16181.

Showalter DN, Saville RJ, Orton ES, Buggs RJA, Bonello P, Brown JKM.  2020.  Resistance of European ash (Fraxinus excelsior) saplings to larval feeding by the emerald ash borer (Agrilus planipennis). Plants, People, Planet 2:41-46. DOI: 10.1002/ppp3.10077.

(Notable/relevant) Scientific and Outreach Oral Presentations:

Chong, J. H. 2019. Comparison of chordotonal organ modulators for their efficacies against aphids on greenhouse

ornamentals. Member Symposium: New Discoveries and Practical Approaches to Greenhouse Insect Management. Annual meeting of the Entomological Society of America (ESA).

Chong, J. H. 2019. Insect pest identification and management. UpState IPM Workshop, Spartanburg, SC.

Chong, J. H. 2019. Challenges and progress in thrips management. ProFlora, Bogota, Colombia.

Gill, S., and B.A. Kunkel.  2020.  Control of Root Mealybug and Root Aphid in Ornamental Plants in Greenhouse and High Tunnels.  Greenhouse Arthropod Management: Encompassing Past Experiences and Challenging Future Expectations (On Demand).  Annual meeting of the Entomological Society of America (ESA).

Kunkel, B.A. 2020.  Redheaded flea beetle: the native invasive.  North Carolina State University Cooperative Extension Webinar Series

Kunkel, B.A.  2020.  Wow!  These Suck! Options for Managing Scales.  Pen-Del Chapter International Society of Arboriculture Meeting, Lancaster, PA.