Updated February 6, 2023:
Reporting period: Year 1 Final: October 1, 2021 to December 31, 2022
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
• In Year 1, adult gall midge emergence was monitored on 20 sites across NE, IA, SD, and MN
• Adult emergence from overwintering sites happed between June 7 and July 17, with continued capture of adults through September 12. This helps us establish the active window for adult activity and allows comparision among year.
• Collection of gall midge adults in our monitoring system in 2022 was less than 20% what we collected in 2021, showing that there can be large year to year variation in gall midge pressure.
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
• We tested 72 accession lines for gall midge resistance at seven locations across three states.
• This allowed us to assess injury which will inform the choice of accession lines for futher advancement in preparation for the 2023 field season.
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
• Mowing studies were conducted in MN and NE.
• August samples in Nebraska showed a greater number of larvae for unmowed treatments compared to mowed, though no yield difference were found.
• We conducted chisel and tandem disk tillage experiments with timings in fall, spring, and both fall+spring.
• We found few overwintering adults regardless of tillage timing or implement, probably because 2022 was a relatively low-pressure year in general.
• Data are inconclusive if tillage is a viable suppression tactic for overwintering populations, with futher research needed hopefully under higher-pressure situations.
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
• In 2022 there was one possible new state detection in ND, though this finding was inconclusive due to accidental sample destruction. Monitoring will continue in 2023.
• Gall midge was dected in 15 new counties in IA (8), SD (5), and NE (2) showing continued spread.
• Significant injury to soybean was observed in areas of east central and northeast NE as well as northwest IA.
• Preparations are underway for 2023 monitoring.
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
We conducted this experiment to develop sticky cards and phereomone lures for stink bug sampling. We had locations in 12 states. Data are being analyzed by PI Rice.
Program III. Soybean Aphid
3.1 Insecticide Resistance
Participants: Robert Koch* (University), with contributions from all team members *Project leader
• We conducted dose-response bioassays using Warrior, Sivanto, Transform and Sefina.
• In 2023 we will be ready to conduct dose-response bioassays with field populations.
• Three scientific journal papers have been published based on this project to date.
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
• Our goal for this project is to determine if a late season (R3) insecticide spray has any benefit to aphid resistant soybean (Rag1/Rag3).
• We conducted field trials in five states (ND, SD, NE, IA and OH). Results are being analyzed.
• Soybean aphids have been collected and being reared for phenotype/biotype diagnoses in the Michel lab.
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
• We monitored 27 suction traps during the 2022 field season, for insect pest of both soybean and corn.
• Data have been shared with several collaborators beyond the bounds of this working group, to help inform other projects.
• Also, the suction trap data have been shared with the public through https://suctiontrapnetwork.org/data/.
Program IV. Extension and Outreach
5.1 Extension Deliverables
Participants: Kelley Tilmon* (Ohio State University), with contributions from all team members *Project leader
We published a new, second edition of Stink Bugs of the North Central Region. This publication has been shared as a pdf with SRIN, and hard copies have been printed for distribution at winter extension events in each NCSRP member state.
Year 1 Summary
Though work on the objectives in this project are ongoing in Year 2, we learned several things in Year 1. For soybean gall midge, we obtained information on the timing of adult activity in the field, which extended from June 7 through September 12. Collection of gall midge adults in our monitoring system in 2022 was less than 20% what we collected in 2021, showing that there can be large year to year variation in gall midge pressure. Gall midge was possibly discovered in one new state (ND) though this will need to be confirmed in 2023. It was also found in 15 new counties in the region, showing that it continues to spread. For the breeding objective (gall-midge resistance) we tested 72 accession lines, some of which will be selected for advancement. For cultural controls, in the first year of testing so far neither mowing nor tillage shows strong control, but overall midge numbers were down in 2022 and work needs to be repeated in years with more gall midge pressure.
We began a project to develop sticky cards with pheromone lures (used to monitor stink bugs in orchards) as a sampling method for stink bugs in soybean. 12 states participated in this objective in 2022, with work to continue in Years 2 and 3.
We are testing four insecticides for the possibility of developing soybean aphid resistance (Warrior, Sivanto, Transform and Sefina). Methods were perfected using a lab colony, with work to begin on field populations in 2023.
In the quest for soybean varieties that are resistant to soybean aphid, our current goal is to determine if a late season (R3) insecticide spray has any benefit to aphid resistant soybean (Rag1/Rag3) by removing tolerant individuals from the population. This is an ongoing objective.
The suction trap network continues to provide region-wide data on insect pests of both corn and soybean that are useful to researchers both within this project and from beyond it. NCSRP funding pays only a portion of the operating costs of this monitoring system, with the full cost being made up from a variety of sources. All of the data from this network are made freely available to the public at https://suctiontrapnetwork.org/data/.
Our main extension deliverable in 2022 was a new, second edition of Stink Bugs of the North Central Region. This publication has been shared as a pdf with SRIN, and hard copies have been printed for distribution at winter extension events in each NCSRP member state.