This proposal is a request for a Year 3 renewal on the three-year project plan first submitted in May 2021. This proposal has programs related to several insect pest problems of emerging importance in the North Central Region. Our objectives are based on professionally-organized focus group sessions with farmers and crop consultants. Farmer priorities include the emerging threat of soybean gall midge, lack of threshold use for several reasons, but in part because of the time and effort needed to scout, the need for pest monitoring and alerts especially for emerging pests, and the importance of communicating unbiased, research-based pest management information to farmers. These priorities informed this proposal with objectives on soybean gall midge (alert network, germplasm screening, tillage/mowing for management, new detection efforts); stink bugs (pheromone-baited traps for scouting); soybean aphid (tolerant varieties in public/private partnership with Corteva; regional monitoring/reporting); and extension deliverables. In addition, this year we are adding a new objective in response to a new emerging pest first identified in Minnesota: soybean tentiform leafminer. This pest has the capacity to significantly impact soybean yield and this objective is to provide new information on its biology and management. Another new effort this year will be to use the NCSRP funds (if awarded) for soybean gall midge and soybean leafminer as match for the federal grant program USDA-FFAR-ROAR (Rapid Outcomes from Agricultural Research). This program funds time-sensitive research on emerging pests and requires match from non-federal sources. We have made a proposal to this USDA program in conjunction with this proposal, with complementary objectives (review pending). If this is successful it will be an excellent way to leverage checkoff dollars for additional impact. All of the objectives in this proposal will contribute to best-practice pest management in soybean, and contribute positively to farmers’ bottom lines.

Program I. Soybean Gall Midge
1.1 Soybean Gall Midge Alert Network
1.2 Midge-Resistant Soybean Germplasm
1.3 Tillage and Mowing as Control Strategies for Soybean Gall Midge
1.4 New Detection/Injury Survey

Program II. Easier Scouting Methods
2.1 Pheromone-Baited Traps for Stink Bug Monitoring and Thresholds

Program III. Soybean Aphid
3.1 Aphid-Resistant Varieties
3.1.1 Impact of growing resistant varieties without insecticide
3.1.2 Frequency and modeling of virulent aphid biotypes
3.2 Suction Trap Network for Monitoring Aphids and Thrips

Program IV. Extension and Outreach
5.1 Extension Deliverables

Soybean Gall Midge Deliverables
• Publication with six years of adult emergence data
• Gall midge alert network
• Gall midge information website
• Resistant germplasm report and manuscript for publication
• Tillage/mowing: prepare reports and paper submitted for tillage and mowing
• Updated distribution maps with any new gall midge detections

Soybean Tentiform Leafminer Deliverables

• Report of first-year findings
• Grant proposal submitted to USDA

Stink Bug Performance Deliverables
• Extension publication on stink bug trapping/monitoring

Soybean Aphid Deliverables
- 3-year summary on frequency of virulence in the North Central Region
- Final assessment on benefits of spraying Rag plots
- Final report

Suction Trap Network Deliverables
- Make data publicly available through Suction Trap Network website
- Provide annual summary of soybean pest abundance

Extension Deliverables
•Develop extension deliverables based on Year 2 results – printing will be deferred to another project-year because of budget cuts to Year 3 funding

Update:
Program I. Soybean Gall Midge

1.1 Soybean Gall Midge Alert Network
Participants: Justin McMechan,* Thomas Hunt, Robert Wright (University of Nebraska); Erin Hodgson (Iowa State University); Bruce Potter, Bob Koch (University of Minnesota); Adam Varenhorst (South Dakota State University). *Project leader
• As of March 30th, 600 subscribers across 8 states and 2 Canadian provinces are on the Soybean Gall Midge (SGM) Alert Network.
• At least 10 sites across four states have been identified for adult monitoring. Three sites in Nebraska contain the stem burial project, which will be monitored as well. Cages will be placed in the field in Nebraska by May 10th, and the other states will place their cages shortly after that.

1.2 Midge-Resistant Soybean Germplasm
Participants: George Graef,* Justin McMechan (University of Nebraska); Erin Hodgson (Iowa State University); Adam Varenhorst (South Dakota State University) *Project leader
• 50 accession lines spanning maturity groups 0 to 3 have been chosen for testing this year across three sites.
• These lines will be planted with blank rows around each plot to enhance pressure from SGM
• In addition, 13 elite lines from the Nebraska breeding program will be tested with and without hilling in NE and SD.
1.3 Tillage and Mowing as Control Strategies for Soybean Gall Midge
Participants: Justin McMechan,* Tom Hunt (University of Nebraska); Erin Hodgson (Iowa State University); Bruce Potter, Bob Koch (University of Minnesota); Adam Varenhorst (South Dakota State University) *Project leader
• The border for the mowing study in NE was planted to Oats in early April to ensure an adequate presence of dense vegetation is available for the project.
• Bruce Potter has retired, so this project will not be conducted in MN this year.
• As a result, NE will increase its effort and put in a tillage treatment in addition to mowing. The tillage portion of the project showed some promising results last year.
• Stem burials were hilled last fall at one site, and cages will be placed in the next two weeks to monitor for adult emergence.
1.4 New Detection/Injury Survey
Participants: Justin McMechan* (University of Nebraska); Janet Knodel (North Dakota State University); Brian McCornack (Kansas State University); Kevin Rice (University of Missouri), Bryan Jensen (University of Wisconsin); Nicholas Seiter (University of Illinois) *Project leader

• High risk sites will be selected via CropLand Cross for all participating states.
• Dr. Kevin Rice is no longer with MSU but Dr. Ivair Valmorbida has agreed to conduct a survey in MO.

Program II. Easier Scouting Methods

2.1 Pheromone-Baited Traps for Stink Bug Monitoring and Thresholds
Participants: Kevin Rice* (University of Missouri); Kelley Tilmon (Ohio State University); Robert Wright (University of Nebraska); Janet Knodel, Deirdre Prischmann-Voldseth (North Dakota State University); Matt O’Neal (Iowa State University); Robert Koch (University of Minnesota); Brian McCornack (Kansas State University); Nicholas Seiter (University of Illinois); Shawn Conley (University of Wisconsin); Raul Villanueva (University of Kentucky); Christina DiFonzo (Michigan State University); John Tooker (Penn State University) *Project leader

• The group met recently and discussed the data for the project. They developed a plan for the analysis of the project that will compare the stink bug captures with sweep nets using a single species comparison.
• Heat maps will be generated for species abundance and field locations to determine edge effects and correlations between trap captures and sweet nets will be examined to determine the effects of field size.
• Bob Koch from MN has developed a small protocol to evaluate the time of day on stink bug abundance with sweep nets in soybean to add to the data for this project in 2024.

Program III. Soybean Aphid

3.1 Insecticide Resistance
Participants: Robert Koch* (University), with contributions from all team members *Project leader

• Results were analyzed and summarized from dose-response bioassays performed on a laboratory population of soybean aphid with the insecticides Transform, Sefina and Sivanto.
• In summer of 2023, six field-collected populations of soybean aphid were established as greenhouse colonies. These were reduced to three colonies that will be used for dose-response bioassays with Transform, Sefina and Sivanto, which are just beginning now.
• Results from this NCSRP-funded work focused on insecticide resistance will be presented in extension meetings in the winter of 2023-2024.

3.2 Aphid-Resistant Varieties
Participants: Andy Michel* (Ohio State University); Matt O’Neal* (Iowa State university); Louis Hesler (USDA-ARS South Dakota); Deirdre Prischmann-Voldseth (North Dakota State University) *Project leaders

• Sweep samples are being analyzed for the project.
• Plans for the 2024 season are underway

3.3 Suction Trap Network for Monitoring Aphids and Thrips
Participants: Nick Seiter* and Doris Lagos-Kutz (University of Illinois); Glen Hartman (USDA-ARS Illinois); with cooperation from other team members *Project leader

• Materials for the 2024 have been acquired and will be distributed to the participating states.
• Plans are to continue monitoring for soybean thrips and soybean vein necrosis virus through the suction trap network.
• 2023 data showed that nearly 100% of subsamples caught in suction traps were positive for SVNV in soybean thrips. In contrast, eastern flowers thrips were negative for SVNV. This will provide important information on virus detection across the midwest and potentially identiify overwintering sites.

Program IV. Extension and Outreach

5.1 Extension Deliverables
Participants: Kelley Tilmon* (Ohio State University), with contributions from all team members *Project leader
• A soybean gall midge regional webinar was held on April 5th with over 250 registred and 175 live attendees. Recording for the webinar have been processed and will be posted to the soybean gall midge website before May 1st.
• We produced a new edition of the field guide “Stink Bugs of the North Central Region.” During the reporting period, a print run of 3,800 guides was made and copies distributed to 13 Land Grant universities and 15 state checkoff boards. A pdf is also available online at SRIN.
• In Ohio we tested audiences using the “Guide to Defoliation” keychain set and info card at extension meetings, and found that users were on average 30% more accurate at diagnosing soybean defoliation using the guide. This tool can contribute to good scouting for insect defoliation, leading to more accurate management decisions.
• The following is an example of the power of leveraging/teamwork to extend project outcomes. Cate Newburg of NCSRP used our “Guide to Defolation” design to print 30,000 leaf set copies for distribution to QSSBs around the country. It is the most asked-for item at farmer events. It has also been featured in checkoff ads, postcards, and signage. A QR code with the material leads clients to the project database for our entomology project, which has received 2740 views, helping to further disseminate information about NCSRP-funded projects.
Layman’s Summary
Soybean gall midge projects for the 2024 season are underway, and at least 10 monitoring sites have been identified. Three of these sites contain stem burials to potentially enhance the timing and capture of adults this spring. Farmers and ag professionals rely heavily on the alert network as it is the first indication that the pest is active in the field. The network continues to grow, with over 600 subscribers from 8 States and 2 Canadian provinces. Germplasm lines for 2024 have been selected with the plan to generate a high-pressure field test to validate resistant lines. Additional tests are being conducted on elite lines with and without hilling to determine the ability of those lines to protect yield under soybean gall midge pressure. Mowing and tillage studies are already underway, and enhancements have been made to both projects to increase the likelihood of detecting differences. Monitoring for SGM in states where it has been detected will begin with the selection of at least 20 high-risk sites per state based on data from USDA Cropland Cross. Participating states will check these and other random sites in late July.
Stinkbug monitoring analyses are underway on the previous two years of data. An additional project will be conducted in those same states to monitor the time of day for stink bug activity. Aphid resistance testing plans are set for the 2024 season, and sweep net samples from 2023 are analyzed. The suction trap network continues to provide valuable data. Several extension outputs are planned for the 2024 season. A regional soybean gall midge webinar was held on April 5th with over 175 live participants. All of the current NCSRP soybean gall midge projects were presented in that webinar.

View uploaded report

All of the objectives in this proposal will contribute to best-practice pest management in soybean, and contribute positively to farmers’ bottom lines. Soybean gall midge is an emerging pest in the North Central Region and this project will provide monitoring and new county detection information, an informational website, preliminary data on possible sources of resistant germplasm, and information on whether tillage and mowing might provide management strategies. Soybean tentiform leafminer is also a new, emerging pest and this project will provide preliminary information in insecticide efficacy, life cycles, and leafminer genetics that will inform future research. Stink bugs are difficult to scout late in the season when they are most damaging, and this project will provide a new scouting method using pheromone lures that will make detection and management decisions easier. The project will provide information on whether there is a benefit to spraying for soybean aphids in aphid-resistant varieties. And finally, the aphid suction trap network provides a publicly available monitoring tool for regional aphid trends.