Updated February 4, 2020:
Progress Report (Year 1 through December 2019)

Note: Year 1 funds were extended until December 31, 2019

Program I. Extension/Outreach and Farmer Feedback
1.1 Extension coordination and deliverables
Participants: Kelley Tilmon* (Ohio State University), with contributions all team members *Project leader
During the reporting period we published an updated soybean aphid insecticide resistance factsheet including an updated distribution map of the problem and new insecticide products registered for soybean aphid. Partering with the Ohio Soybean Council, NCSRP results were used to publish a Pollinators of Soybean fact-card for specimens found in Ohio. Copies from the new print run of Stink Bugs of the North Central Region were sent to 12 states for distribution to farmers at various extension programs.
1.2 Determining farmer needs and priorities
Participants: Tom Hunt* (University of Nebraska), Kevin Rice* (University of Missouri) *Project leaders
Progress. A professional facilitator, Dr. Mary Anne Casey, was contracted to advise on and conduct the farmer needs assessment focus groups. Question development was initiated. These will not be simple questions with short answers, but questions intended to initiate group discussion. An information-rich participant pool was initiated – farmers/consultants that are likely to enter in discussion.

Program II. Insect Management and Profitability
2.1 Management guidelines for defoliating insects
Participants: Nick Seiter* (University of Illinois), Erin Hodgson (Iowa State), Brian McCornack (Kansas State), Chris DiFonzo (Michigan State), Christian Krupke (Purdue), Kelley Tilmon (Ohio State). *Project leader
Progress. 27 soybean fields in 6 states were sampled following a common protocol to (1) estimate the extent and spatial distribution of soybean defoliation, (2) compare those estimates to measurements taken with a smartphone app, and (3) collect images of canopy defoliation with known levels of defoliation. We are still seeking a graduate student to coordinate data analysis and publication of these results; however, the project remains on schedule. Insect defoliation throughout most of the sampled region was relatively low in 2019 (far less than established economic thresholds in every field we sampled). Defoliators collected through sweep net sampling included bean leaf beetles, Japanese beetles, green cloverworm, thistle caterpillars, and flea beetles. Data for 2019 are currently being compiled. Defoliation estimates will be conducted again in 2020, with the sampling procedure modified based on our 2019 experience. Additional efforts will focus on verifying that typical levels of defoliation are not reducing yields.

2.2 Cover crops: pest and beneficial insects in cereal rye to soybean transition systems
Participants: Justin McMechan* (University of Nebraska), Shawn Conley (University of Wisconsin), Louis Hesler and Shannon Osborne (USDA ARS South Dakota), Thomas Hunt (University of Nebraska), Bruce Potter (University of Minnesota), Kevin Rice (University of Missouri), Nick Seiter (University of Illinois); Kelley Tilmon (Ohio State University), and Robert Wright (University of Nebraska). *Project leader
Progress. Arthropod collection from pitfall traps and injury estimates on soybean were completed at all sites. Identification of arthropods is currently in progress or completed. Soybean harvest is in progress. So far there is no indication of significant of arthropod injury to soybean with cover crop treatment. Beneficial insect activity was reported at a number of sites. Cereal rye cover crop have already been planted in a few states in late September, however, some sites are experiencing delays due to wet weather.

2.3 Pollinators to improve soybean yield
Participants: Reed Johnson*, Chia Lin, and Kelley Tilmon (Ohio State University) *Project leader
Progress. We placed honey bee colonies in three large soybean fields during soybean bloom, and are currently hand-harvesting plants at three distances in relation to the hive location, as three “pollination treatments” in each field:(1) Pollination by honey bees (near bee hives, far from field edges); (2) Pollination by local bees (near field edge, where wild bees have easy access to field); (3) Minimal pollination (mid-point between bee hive and field edges, which is the farthest point to either pollinator groups. The number of pods and seeds per plant will be counted in October and November to evaluate any treatment effect on soybean yield. A second experiment where pollinator-exclusion cages were placed in a field where three soybean varieties (AG34X6, AG39X7, and 38A98X) were planted side-by-side and 10 honey bee colonies were placed to boost pollination. The three varieties differ in sugar concentrations in nectar (16 - 30%) and show different attractiveness to honey bees according to the grower’s previous observation. The plants have been harvested and the effects of pollinator boosting vs. exclusion on seed production in these varieties will be evaluated. We measured nectar during peak bloom in approximately 160 soybean varieties planted by Laura Lindsey’s team. Preliminary results indicate significant variation in nectar quantity and sugar concentration among varieties. Up to 0.5 microliter of nectar produced by single flowers and sugar concentration 39% have been observed, while many varieties produced very little or no nectar. We will analyze the data to evaluate correlations with pollinator visitation and seed quality parameters when the data become available after harvest.

2.4 Insecticide-resistant soybean aphids
Participants: Robert Koch* (University of Minnesota), Ana Vélez (University of Nebraska), Janet Knodel (North Dakota State University); with contributions from other NCSRP participants including Andy Michel (Ohio State University), Erin Hodgson (Iowa State University), Adam Varenhorst (South Dakota State University), Louis Hesler (USDA ARS South Dakota), and Tom Hunt (University of Nebraska) *Project leader
Progress. Clonal lines of soybean aphid are being established for on-plant assessment of resistance to thiamethoxam. To assess the magnitude and scale of pyrethroid resistance in soybean aphid, the standardized protocol for coupled field efficacy trials and glass-vial bioassays was implemented in Minnesota, South Dakota and Iowa, at 3, 1 and 1 sites, respectively. Aphid populations in other cooperating states (and at the South Dakota site) were extremely low. In preparation for the efforts to assess potential fitness costs of pyrethroid resistance in soybean aphid, several insecticide-resistant populations were identified and laboratory colonies were established for upcoming research. These were detected in a broader effort that assessed at least 23 aphid populations (approximately 18 in MN, 2 in IA, 1 in ND and 1 in SD). This work has been the source of four new extension publications.

Program III. Aphid Resistant Varieties and Aphid Virulence Management
3.1 Advancing aphid resistant soybeans through a public-private partnership
Participants: Matt O’Neal* (Iowa State University), Andy Michel* (Ohio State University), Mauricio Urrutia* (Corteva), David Onstad* (Corteva), Kelley Tilmon (Ohio State University), Thomas Hunt (University of Nebraska), Deirdre Prischmann (North Dakota State University), Adam Varenhorst (South Dakota State University), Louis Hesler (USDA ARS South Dakota). *Project leaders
Progress. For the project on field testing aphid resistant soybean varieties for commercialization: we obtained and executed legal agreements with Corteva Agriscience, and planted full experimental design in 6 locations (5 states). We collected aphid population data at least 2 times per month throughout the growing season. We provided aphids for insect resistance management study (sub-objective 3.1.2), and provided field efficacy data and aphids for insecticide resistance study (Objective 2.4). For the project on insect resistance management for aphid-resistant soybeans: aphids collected from sub-objective 3.1.1 fields are undergoing screening/phenotyping for virulence; individual clonal lineages have been established. The legal agreement for IRM modeling is still in the works.

3.2 Soybean breeding for aphid resistance
Participants: Brian Diers* (University of Illinois), Glen Hartman* and Doris Lago-Kutz (USDA-ARS) *Project leaders
Progress. In the soybean aphid resistance breeding objective we completed the development of the isolines with all five resistance genes and we will have seed available of them soon. The University of Illinois completed the development of isogenic lines that have all 32 combinations of Rag1, Rag2, Rag3, Rag4, and Rag6 in the backgrounds of a MG I and a MG II cultivar. A few pounds of seed will be harvested this fall from each line, which includes lines that have all five resistance genes. Seed of these lines will be made available to the research community. We have continued to develop cultivars with Rag1 and Rag2 and the stack of the two genes. Several experimental lines with the Rag1 and Rag2 stack are being increased this year by seed companies. Assuming the lines continue to perform well, the companies plan to commercialize them. The phenotyping test of five lines with Rag genes 1 and 2 (Rag1/2): LD14-4098a, LD16-4429a, LD16-4471a, LD15-5170a and LD16-5724a, and three checks: LD14-8033 (R,S,S), LD14-8034 (S,S,S) and LD14-8037 (S,R,S) is in progress. The phenotype information is being generated to compare to with the marker-assisted selection.

Program IV. Insect Monitoring
4.1 Biological control of soybean aphid
Participants: George Heimpel*, with contributions from other project team members *Project leader
Progress. Aphelinus parasitoid numbers were low this year (as were soybean aphid numbers), with most states reporting no mummies found. In August Aphelinus were at moderate densities of 0.5 to 1.5 per plant in Minnesota, Wisconsin, and Illinois, and lower numbers were detected in North Dakota, Iowa, and Michigan. Despite low aphid numbers, we found a surprisingly high number of tan braconid mummies, which are Lysiphlebus testaceipes. In late June an aphid-infested plant on the Saint Paul, Minnesota, campus produced more than 40 tan mummies. In early July, Michigan sent 118 tan mummies. Iowa sent 141 tan mummies in late August, Wisconsin sent 5, and Indiana sent 24. Hyperparasitism was undetected in most sites. From Indiana we received black mummies from which emerged 3 Syrphophagus aphidivorus. Within Minnesota we sampled more extensively and found dozens of Alloxysta as well as 2 or 3 Asaphes sp. and S. aphidivorus. No hyperparasitoids were observed emerging from L. testaceipes mummies.

4.2 Monitoring soybean aphids and other soybean insect pests in suction traps
Participants: Glen Hartmant* and Doris Lagos-Kutz (USDA-ARS/ University of Illinois) and Nick Seiter (University of Illinois), with contributions from other project team members *Project leader
Progress. Our collaborators (33 located in 10 states with one new location in Nebraska, UNL Haskell Ag Lab led by Thomas Hunt) have been sending suction trap samples to the USDA Laboratory in Urbana weekly starting from May 17th, 2019. The samples have been processed (drain the antifreeze and water, and store the samples in ethanol at -20 C) up to September 20, 2019. The sampling will continue until October 18th. Data has been entered in excel files up to September 13 and shared with our collaborators and extension personnel. Also, the suction trap data have been shared through https://suctiontrapnetwork.org/data/.

1.1 Extension coordination and deliverables
During the reporting period we published an updated soybean aphid insecticide resistance factsheet including an updated distribution map of the problem and new insecticide products registered for soybean aphid. Partering with the Ohio Soybean Council, NCSRP results were used to publish a Pollinators of Soybean fact-card for specimens found in Ohio. Copies from the new print run of Stink Bugs of the North Central Region were sent to 12 states for distribution to farmers at various extension programs.

1.2 Determining farmer needs and priorities
A professional facilitator, Dr. Mary Anne Casey, was contracted to advise on and conduct the farmer needs assessment focus groups. Question development was initiated. These will not be simple questions with short answers, but questions intended to initiate group discussion. An information-rich participant pool was initiated – farmers/consultants that are likely to enter in discussion.

2.1 Management guidelines for defoliating insects
27 soybean fields in 6 states were sampled following a common protocol to (1) estimate the extent and spatial distribution of soybean defoliation, (2) compare those estimates to measurements taken with a smartphone app, and (3) collect images of canopy defoliation with known levels of defoliation. We are still seeking a graduate student to coordinate data analysis and publication of these results; however, the project remains on schedule. Insect defoliation throughout most of the sampled region was relatively low in 2019 (far less than established economic thresholds in every field we sampled). Defoliators collected through sweep net sampling included bean leaf beetles, Japanese beetles, green cloverworm, thistle caterpillars, and flea beetles. Data for 2019 are currently being compiled. Defoliation estimates will be conducted again in 2020, with the sampling procedure modified based on our 2019 experience. Additional efforts will focus on verifying that typical levels of defoliation are not reducing yields.

2.2 Cover crops: pest and beneficial insects in cereal rye to soybean transition systems
Arthropod collection from pitfall traps and injury estimates on soybean were completed at all sites. Identification of arthropods is currently in progress or completed. Soybean harvest is in progress. So far there is no indication of significant of arthropod injury to soybean with cover crop treatment. Beneficial insect activity was reported at a number of sites. Cereal rye cover crop have already been planted in a few states in late September, however, some sites are experiencing delays due to wet weather.

2.3 Pollinators to improve soybean yield
We placed honey bee colonies in three large soybean fields during soybean bloom, and are currently hand-harvesting plants at three distances in relation to the hive location, as three “pollination treatments” in each field:(1) Pollination by honey bees (near bee hives, far from field edges); (2) Pollination by local bees (near field edge, where wild bees have easy access to field); (3) Minimal pollination (mid-point between bee hive and field edges, which is the farthest point to either pollinator groups. The number of pods and seeds per plant will be counted in October and November to evaluate any treatment effect on soybean yield. A second experiment where pollinator-exclusion cages were placed in a field where three soybean varieties (AG34X6, AG39X7, and 38A98X) were planted side-by-side and 10 honey bee colonies were placed to boost pollination. The three varieties differ in sugar concentrations in nectar (16 - 30%) and show different attractiveness to honey bees according to the grower’s previous observation. The plants have been harvested and the effects of pollinator boosting vs. exclusion on seed production in these varieties will be evaluated. We measured nectar during peak bloom in approximately 160 soybean varieties planted by Laura Lindsey’s team. Preliminary results indicate significant variation in nectar quantity and sugar concentration among varieties. Up to 0.5 microliter of nectar produced by single flowers and sugar concentration 39% have been observed, while many varieties produced very little or no nectar. We will analyze the data to evaluate correlations with pollinator visitation and seed quality parameters when the data become available after harvest.

2.4 Insecticide-resistant soybean aphids
Clonal lines of soybean aphid are being established for on-plant assessment of resistance to thiamethoxam. To assess the magnitude and scale of pyrethroid resistance in soybean aphid, the standardized protocol for coupled field efficacy trials and glass-vial bioassays was implemented in Minnesota, South Dakota and Iowa, at 3, 1 and 1 sites, respectively. Aphid populations in other cooperating states (and at the South Dakota site) were extremely low. In preparation for the efforts to assess potential fitness costs of pyrethroid resistance in soybean aphid, several insecticide-resistant populations were identified and laboratory colonies were established for upcoming research. These were detected in a broader effort that assessed at least 23 aphid populations (approximately 18 in MN, 2 in IA, 1 in ND and 1 in SD). This work has been the source of four new extension publications.

3.1 Advancing aphid resistant soybeans through a public-private partnership
For the project on field testing aphid resistant soybean varieties for commercialization: we obtained and executed legal agreements with Corteva Agriscience, and planted full experimental design in 6 locations (5 states). We collected aphid population data at least 2 times per month throughout the growing season. We provided aphids for insect resistance management study (sub-objective 3.1.2), and provided field efficacy data and aphids for insecticide resistance study (Objective 2.4). For the project on insect resistance management for aphid-resistant soybeans: aphids collected from sub-objective 3.1.1 fields are undergoing screening/phenotyping for virulence; individual clonal lineages have been established. The legal agreement for IRM modeling is still in the works.

3.2 Soybean breeding for aphid resistance
In the soybean aphid resistance breeding objective we completed the development of the isolines with all five resistance genes and we will have seed available of them soon. The University of Illinois completed the development of isogenic lines that have all 32 combinations of Rag1, Rag2, Rag3, Rag4, and Rag6 in the backgrounds of a MG I and a MG II cultivar. A few pounds of seed will be harvested this fall from each line, which includes lines that have all five resistance genes. Seed of these lines will be made available to the research community. We have continued to develop cultivars with Rag1 and Rag2 and the stack of the two genes. Several experimental lines with the Rag1 and Rag2 stack are being increased this year by seed companies. Assuming the lines continue to perform well, the companies plan to commercialize them. The phenotyping test of five lines with Rag genes 1 and 2 (Rag1/2): LD14-4098a, LD16-4429a, LD16-4471a, LD15-5170a and LD16-5724a, and three checks: LD14-8033 (R,S,S), LD14-8034 (S,S,S) and LD14-8037 (S,R,S) is in progress. The phenotype information is being generated to compare to with the marker-assisted selection.

4.1 Biological control of soybean aphid
Aphelinus parasitoid numbers were low this year (as were soybean aphid numbers), with most states reporting no mummies found. In August Aphelinus were at moderate densities of 0.5 to 1.5 per plant in Minnesota, Wisconsin, and Illinois, and lower numbers were detected in North Dakota, Iowa, and Michigan. Despite low aphid numbers, we found a surprisingly high number of tan braconid mummies, which are Lysiphlebus testaceipes. In late June an aphid-infested plant on the Saint Paul, Minnesota, campus produced more than 40 tan mummies. In early July, Michigan sent 118 tan mummies. Iowa sent 141 tan mummies in late August, Wisconsin sent 5, and Indiana sent 24. Hyperparasitism was undetected in most sites. From Indiana we received black mummies from which emerged 3 Syrphophagus aphidivorus. Within Minnesota we sampled more extensively and found dozens of Alloxysta as well as 2 or 3 Asaphes sp. and S. aphidivorus. No hyperparasitoids were observed emerging from L. testaceipes mummies.

4.2 Monitoring soybean aphids and other soybean insect pests in suction traps
Our collaborators (33 located in 10 states with one new location in Nebraska, UNL Haskell Ag Lab led by Thomas Hunt) have been sending suction trap samples to the USDA Laboratory in Urbana weekly starting from May 17th, 2019. The samples have been processed (drain the antifreeze and water, and store the samples in ethanol at -20 C) up to September 20, 2019. The sampling will continue until October 18th. Data has been entered in excel files up to September 13 and shared with our collaborators and extension personnel. Also, the suction trap data have been shared through https://suctiontrapnetwork.org/data/.