Brief Summary of Minutes of Annual Meeting

Basic Information

• Project No. and Title: NE2332: Biological Control of Arthropod Pests and Weeds
• Period Covered: 10/01/2023 to 9/30/2024
• Date of Report: 02/25/2026
• Annual Meeting Date: 04/15/2025

Participants

Participants and visitors who attended (in person): Scott Salom (Virginia Tech); Liv Andrews (Scott Salom student, Virginia Tech); Harrison Miles (Scott Salom student, Virginia Tech.); Lisa Tewksbury (University of Rhode Island); Olga Kostromytska (University of Massachusetts); Jeremiah Foley (CT Agricultural Experiment Station); Dylan Parry (SUNY esf); David Harris (Dylan Parry student, SUNY esf); Max Ragozzino (Oregon Dept. of Agriculture)

Participants and visitors who attended (via zoom): Hannah Broadley (USDA APHIS); Christine Dodge (USDA APHIS); Samantha Wilden (Cornell); Elizabeth Long (Purdue); George Hamilton (Rutgers); Tory Hendry (Cornell)

Brief Summary of Minutes of Annual Meeting

Location: Annapolis, MD, in conjunction with the 2^nd National Forum on Biological Control

Date: April 15, 2025

Discussion points

• Need a new head of the project – Lisa Tewksbury (did not find one so Lisa Tewksbury is still acting head), Lisa has drafted a schedule of future chairs for each coming year, by participating institution
• Location of the next meeting – we will use a poll, ESA Eastern Branch is still a good option – it will be held in Saratoga Springs in 2026
• Work on a larger working group that includes federal partners in USDA ARS and APHIS
• Group is interested in encouraging more collaboration

Oral presentations and posters given at the 2^nd National Forum on Biological Control in Annapolis, MD (April 14-17, 2025) by NE2332 participants or other frequent visitors to our meetings and symposia (presenting author in bold) - no separate symposium held by NE2332.

Leveraging Augmentation Biological Control for Aquatic Weed Management Rodrigo Diaz¹, Ivan Grijalva¹ , Alex Gaffke² , Flaminia Mariani^{1 1}Louisiana State University, ²USDA-ARS CMAVE.

Biological Control of Emerald Ash Borer: A Sustainable Solution to Ash Recovery and Regeneration Jian J. Duan¹ , Toby Petrice² , and Therese Poland^{2 1}University of Delaware, ²USDA-Forest Service NRS.

Renewed Hope to Control Invasive Swallow-wort in North America with Chrysochus asclepiadeus. David C. Harris¹, René F.H. Sforza², Ghislaine Cortat^3, and Dylan Parry¹

¹ SUNY Environmental Science & Forestry, ² USDA-ARS EBC, ³ CABI Switzerland.

Understanding the Eradication and Restoration Potential of Sites Following the

Removal of Ailanthus altissima Using Biocontrol Harrison Miles, Jacob Barney, Scott Salom, Brian Strahm, and Carrie Fearer, Virginia Tech.

Extirpation of a Legacy Biocontrol Parasitoid Assemblage Following Arrival of an

Adventive Exotic Pathogen. Dylan Parry¹, Ann E. Hajek² , Patrick C. Tobin³, and Nathan W. Siegert⁴

¹SUNY Environmental Science & Forestry, ²Cornell University, ³University of Washington,

⁴ USDA-Forest Service SPTF

Accomplishments

1. Conserve existing natural enemies and enhance ecosystem function

At Cornell and NYSIPM: Efforts by Dr. Dunn and Dr. Lamb

            Our efforts during the report timeframe (3/10/24 – 4/15/25) have primarily focused on extending information to farmers and the general public, both about conserving insect natural enemies (biocontrol agents) in gardens and fields, and on releasing biocontrol agents augmentatively in greenhouses. See lists of accomplishments by relevant objective below. We completed our fifth year of insect monitoring at a research site in 2024 and are analyzing data for publication. Ongoing updates to the Cornell IPM (formerly NYSIPM) biocontrol webpages continue to support the use of augmentative and classical biocontrol as articles about specific biocontrol agents are added.

Activities & Short-term Outcomes

Gave 16 presentations reaching 403 people from elementary and high school students to adult gardeners and Christmas tree growers about conserving natural enemies and enhancing ecosystem function through habitat creation. This included a series of four presentations (three in English and one offered in English with simultaneous interpretation into Spanish) given as part of larger workshops that included the distribution of seeds for flowers that support insect natural enemies of pests. See details of presentations below.

In August 2024, the Cornell IPM Program partnered with local organizations to host a tabling display on three Saturdays at a farmer’s market/tourist stop in Geneva, NY. Over the three Saturdays, 338 people stopped by the table and received information about how to create habitat for insect biocontrol agents and pollinators, how to recognize these beneficial insects, and seeds for native perennial wildflowers that could provide that habitat. At these events, 70 people signed up to receive occasional email reminders about when and how to plant their seeds. They received four follow-up emails over the next year and were invited to share their experiences with the seeds they took home in an anonymous survey. Four people responded and estimated that they had planted 225 square feet with the seeds they brought home.

Ongoing monitoring of insects attracted to wildflower plots on the edges of a research field of Christmas trees compared to plots of mowed grass (through September 2024). Data analysis is ongoing.

Outputs

Dunn-Silver, A.R. 2025. Stratifying perennial wildflower seeds. Biocontrol Bytes blog. Cornell University, 22 January 2025. Accessed 1 October 2025.

Dunn-Silver, A.R. 2024. Fall is for planting perennial wildflower seeds. Biocontrol Bytes blog. Cornell University, 25 September 2024. Accessed 18 February 2025.

Presentations

            Dunn-Silver, A.R. (2024) Putting your garden to bed dos and don'ts. Professional                                 Development for Master Gardener Volunteers of CCE Schoharie & Otsego.                                    18 people in attendance. 5 October 2024.

            Dunn-Silver, A.R. (2024) Good bugs in the garden. Honeoye Community Garden                             Summer Program. 15 people in attendance. 26 August 2024.

            Dunn-Silver, A.R. (2024) Beneficial insects and Christmas trees. 2024 Christmas                              Tree IPM Field Day hosted by NYSIPM. 25 people in attendance. 15 August 2024.

            Dunn-Silver, A.R. (2024) Recognizing good bugs in the garden. Blueprint Geneva                             Summer Youth Program. 9 people in attendance. 15 August 2024.

            Dunn-Silver, A.R. (2024) Beneficial Insects – Recognizing and Feeding. 2024                              NYSIPM Annual Conference on Fruit IPM for the Home Garden and                                               Landscape hosted by NYSIPM. 45 people in attendance. 27 June 2024.

            Dunn-Silver, A.R. (2024) If you plant it, they will come. Sustainable Landscapes                              Lunch & Learn: Summer Ecological Gardening Practices hosted by Cornell                                                Cooperative Extension. 60 people in attendance. 26 June 2024.

            Dunn-Silver, A.R. (2024) Introduction to Integrated Pest Management. Gemini                              Environmental Science Class, Marcus Whitman Central School District. 10                                                people in attendance. 20 May 2024.

            Dunn-Silver, A.R. (2024) Recognizing Insect Natural Enemies of Pests. Home                              Gardening Webinar Lecture Series, CCE Westchester. 32 people in attendance.

            8 May 2024.

            Dunn-Silver, A.R. (2024) Identification: An essential step in IPM. Geneva High                              School Environmental Botany class. 13 people in attendance. 18 April                                        2024.

          At Virginia Tech: Efforts by Dr. Scott Salom

          Salom Project:   Use of a natural bioherbicide to remove Ailanthus stands       Ailanthus altissima (tree-of-heaven) is a non-native invasive tree that colonizes                disturbed sites and outcompetes native vegetation.  It is extremely difficult to       manage with traditional methods and herbicides.  With the recent introduction of               the spotted lanternfly (SLF) into Virginia, there is greater urgency to manage this          tree which is a critical host to SLF.  Verticillium nonalfalfae, a naturally occurring   fungus specific to Ailanthus, is a biological herbicide that rapidly (within            months) causes wilt and kills the tree, spreading clonally and affecting most of         the trees in a stand.   Sites where Ailanthus is removed are at risk of being       recolonized by different non-native plants.  We will remove Ailanthus using this               environmentally safe treatment and apply science-based restoration approaches                to these sites.  This work has important implications wherever Ailanthus grows             across the landscape, particularly on private and state-owned lands and where     SLF can spread.

          Objective 1. Assess plant re-colonization at sites where ailanthus has been          removed at least 5 years previously.

               The standing plant community and seedbank was quantified at several sites across VA 5 years after inoculation with V. nonalfalfae (Vna) to understand which species are present or being naturally recruited. A. altissima remained dominant in untreated areas but was nearly eradicated from the treatment plots. Other nonnative species made up a large portion of the plant community and seedbank across all study areas, with no differences in their respective cover and count  between treatments. While variability in plant community composition is high and  site-specific context is important for establishing effective management strategies,  planting native species and mitigating other invasives will be crucial to ensuring native species successfully establish in bioherbicide-treated areas.

2. Augmentation programs involving repeated rearing and release

At Cornell and NYSIPM: Efforts by Dr. Dunn and Dr. Lamb

Activities

               Ongoing updates to updated biocontrol pages host by Cornell IPM. A total of 45 articles about biocontrol agents including both classical and augmentative  biocontrol agents were published by March 2025. The following blog post was written to promote the articles to the approximately 370 subscribers at the time. In September 2024, a reddit post on r/whatsthisbug drove almost 10,000 people to the Hover Fly Biocontrol Fact Sheet on September 8 when someone responding to a reddit question included the link to the page in their answer. This demonstrates the utility of these articles as a resource for identifying and learning about biological control. 

               Dunn-Silver, A.R. 2024. Now available at the NYSIPM biocontrol website: Biocontrol agent profiles. Biocontrol Bytes blog. Cornell University, 10 October 2024. Accessed 18 February 2025.

               Presentations

               Dunn-Silver, A.R. and Peterson, H. (2024) Increasing access to practical biocontrol information through digital resources. IPM Toolbox Webinars hosted by NEIPMC. 40  people in attendance. 2 October 2024. (This presentation promoted the new articles added to the biocontrol website.)

               Dunn-Silver, A.R. (2024) Talking beneficial Bugs with your Customers. 2024 IPM In-Depth hosted by NYSIPM. 35 people in attendance. 22 July 2024.

       Introduction of new natural enemies against invasive plants 

1. Introduction of new natural enemies against invasive insects

      At Virginia Tech: Dr. Salom is releasing natural enemies for hemlock woolly adelgid

The Entomology Insectary at Virginia Tech has been rearing and releasing Laricobius beetles (Family: Derodontidae), specialist predators of hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae) on public lands in Virginia and all states north since 2003.  The beetles are well established throughout much of the range of HWA in the eastern U.S., except for being limited in the northern portion and newer expansion areas of HWA’s range.  The beetles have been shown to impact sistens ovisacs, but then drop to the soil to aestivate and, as a result, do not impact the progrediens generation enough to regulate HWA populations.  Leucotaraxis spp. silver flies are active in this later generation and have the potential to help regulate HWA populations in combination with the Laricobius beetles.  It is unknown if Leucotaraxis flies imported from western North America can establish in eastern hemlock stands.  Therefore, we propose to transition from Laricobius-only production, to a combination of Laricobius production at a reduced rate and increased processing and release of Leucotaraxis flies, from regular shipments of flies from western U.S.  We will continue to monitor and help assess Laricobius beetle recoveries.

Objective 1: Rear Laricobius beetles for release to land managers throughout the eastern U.S.

Laricobius beetle rearing and shipping summaries: 7,533 L. osakensis and 1,317 L. nigrinus adults were reared in 2023 in VT Insectary. Additional 2,851 L. nigrinus were reared from 2023 western collections. 5,413 L. osakensis beetles were shipped and released at 7 separate locations in the mid-Atlantic and New England states. 3,915 L. nigrinus beetles were shipped to 7 separate locations  in the mid-Atlantic and New England states.

Objective 2: Rear out Leucotaraxis flies from  HWA-infested western hemlock branches and distribute them throughout the eastern US.  

The BICF’s capacity to house western hemlock foliage and rear Leucotaraxis spp. has increased since 2023 with the addition of two more cages, totaling 14 cages for 2024 rearing. Seven separate shipments of western hemlock foliage were received in 2024.  A total of 30,470 Leucotaraxis spp. flies and were collected from cages.  ). It was observed that the predominant species collected this year was Le. piniperda. That is, we collected 21,492 identified Le. piniperda versus 666 Le. argenticollis. An additional 8,312 flies were collected but not distinguished between the two species and were stored and shipped as “mix.” A total of 20,085 flies were shipped to cooperators in NC, VA, PA, MD, TN, NH, and RI for release. We recorded 7,661 flies that died in holding containers and calculated approximately 25.7% mortality on average per holding container. 

At the University of Rhode Island: Efforts by Lisa Tewksbury

 Introduction of New Natural Enemies Against Invasive Insects

Biological control of spotted lanternfly:

 URI has been collaborating with the USDA FPML lab in Buzzards Bay, MA since 2020, providing native hoppers for no-choice and choice host specificity testing  URI has provided many insects for this testing for classical biocontrol of spotted lanternfly. The first organism tested was the egg parasitoid, Anastatus orientalis and due to broad host choice in this species, it is currently not being evaluated further.  In 2023 the lab began host specificity testing of a larval parasitoid, Dryinus sinicus.  This species has demonstrated narrow host

 Biological control of Spotted wing drosophila

Spotted wing drosophila (SWD) is an invasive fruit fly from Southeast Asia that lays its eggs in ripening berry crops, which results in losses in fruit quality and yield. The parasitoid wasp Ganaspis kimorum is a natural enemy from Southeast Asia that parasitizes SWD larvae and was permitted for release in the US as a classical biological control agent for SWD. A biocontrol program using G. kimorum was started in Rhode Island to help RI farmers minimize SWD damage. We maintained colonies of SWD and G. kimorum in the lab with the goal of releasing G. kimorum at berry farms in Rhode Island. After releases, berries were collected from these farms to monitor for the presence of spotted wing drosophila and to determine parasitism rates of SWD larvae post G. kimorum release.

Presentations:

Publications

            Dietschler, NJ, Bittner, TD, Jubb, CS, Salom, SM, Whitmore, M. 2024. Observation of key phenological stages of hemlock woolly adelgid: Using citizen science as a tool to inform research and management. Short Communication, J. Econ. Entomol. 117 (3):1185-1191.

     Dunn-Silver, AR and Lamb, EM, Growing perennial wildflowers from seed. Biocontrol Bytes blog post. 19 March 2024. blogs.cornell.edu/biocontrolbytes/2024/03/19/growing-perennial-    wildflowers-from-seed/

     Endriss, SB, Nuzzo, V and Blossey, B. 2025. Return of diversity: Wetland plant community recovery following purple loosestrife biocontrol. Ecological Applications.  

     Fulcher, M.R.; Larkin, R.; Johnson, A.; Tewksbury, L.; Tancos, M.A. 2025.     A foliar disease of invasive black swallow-wort (Vincetoxicum nigrum) caused by Boeremia exigua. Plant Disease. https://doi.org/10.1094/PDIS-03-25-0684-SC

     Grevstad, F.S.; Andersen, J.C.; Oderkirk, N.C.; Andreas, J.; Tewksbury, L.; Detweiler, C.; Price, J.; Blossey, B.; Reardon, R. 2025. Limited establishment from widespread releases of the knotweed  psyllid Aphalara itadori, a biological control agent for knotweeds in the USA. Biocontrol.         https://doi.org/10.1007/s10526-025-10362-w

     Indermauer, E.J.; Fulcher, M.R.; Szarka, D.; Johnson, A.; Tewksbury, L.; Tancos, M.A.; Smart, C.D. 2026. A new species of Didymella from the eastern United States is a pathogen of invasive Reynoutria japonica. Plant Disease.  https://doi.org/10.1094/PDIS-05-25-1125-RE

     Miles, HH; Salom, S; Shively, TJ; Bielski, JT; McAvoy, TJ; Fearer, CJ. 2025. A review of potential biological controls for Ailanthus altissima. Annals of the Entomological Society of America.  118(2): 101-109. https://doi.org/10.1093/aesa/saae041

      Shively, Timothy, Jacob Barney, Leighton Reid, and Scott Salom.  2024. The bioherbicide Verticillium nonalfalfae effectively removes Ailanthus altissima but leaves many other  nonnative plants. (Invasive Plant Science and Management – (Online DOI:      10.1017/inp.2024.27).