Research HighlightsSoybean Entomology in the North Central Region: Management and Outreach for New and Existing Pests
By Julie Meyer, Lead PI: Kelley Tilmon (The Ohio State University)
The soybean team in this project is multi-disciplinary, with researchers in the fields of entomology, agronomy, and plant breeding. With checkoff funding provided by the North Central Soybean Research Program, the work is coordinated multi-state effort making the results applicable to a broad geographic area and creating greater research efficiencies through collaboration.
The benefit for soybean farmers is that coordinated, collaborative research and outreach is the most efficient way to address insect pest problems that affect their production and profitability.
Update on the soybean aphid
The soybean aphid breeding program continues to develop high yielding lines that have the resistance genes Rag1 and Rag2 stacked together. The program recently licensed a variety with this two-gene stack to a seed company and there is interest from other companies to license additional lines with this stack.
During the past six months, we have continued to develop experimental lines in a maturity group (MG) I and a MG II background that have all 32 combinations of resistance and susceptible alleles of five resistance genes: Rag1, Rag2, Rag3, Rag4, and Rag6. This represents a tremendous genetic resource that is being developed into advanced genetic lines.
Soybean aphid insecticide resistance
Previous work on the potential for insecticide resistance in aphids and tools to measure this resistance are now being used because the insecticide-resistant soybean aphids have been found in four states, with the problem spreading each year. An overview of the situation, and recommended strategies to prevent further aphid resistance is outlined in the publication Management of Insecticide-resistant Soybean Aphids.
In the 2019 season, an assessment of in-field efficacy of pyrethroid insecticides was conducted in six collaborating states by applying pyrethroid insecticides to soybean plots in large field experiments and measuring results using a standardized protocol.
Update on biological control of soybean aphid
An extensive network of collaborators sampled soybean fields for mummies of Aphelinus (a soybean aphid parasitoid) three times during the 2019 season —in late June, July, and August — and mailed the samples to the entomology lab at the University of Minnesota for processing. Last year aphids were found in all states but Missouri and Nebraska, and Aphelinus was found in the Dakotas, Minnesota, Wisconsin, Michigan and Ohio. We are also tracking seven additional hyperparasitoids from four genera.
Monitoring soybean aphids and other soybean insect pests in suction traps
The Suction Trap Network consisting of 33 suction traps operated this year from May 17 through October 18, 2019 (23 weeks). Samples were received on a weekly basis and the results posted the results to a public website: https://suctiontrapnetwork.org/data.
The website allows users to select any suction trap location and see a graph of the seasonal abundance for the eight most abundant aphid species. A feature manuscript about the Suction Trap Network was submitted to American Entomologist.
Role of pollinators in soybean fields
NCSRP research on pollinators in soybean has advanced to the point where we are ready to assess the value that honey bees may provide in soybean production (with some preliminary studies documenting the potential for substantial yield improvement).
This year hive equipment and honey bee colonies were installed in April and May on two soybean farms. The field were planted with soybean varieties which were selected so that floral attractiveness could also be evaluated. Data from this study are being analyzed.
Update on defoliators in soybean fields
Our goal is to maximize the efficiency of scouting and management of defoliating insects such as Japanese beetle, loopers and clover worm, and bean leaf beetle. The popular field guide, Stink Bugs on Soybean in the North Central Region, is now in it’s second printing. Bound copies are available from soybean checkoff associations within the North Central Region. It is also available as a free PDF download.
In the 2019 season, the value of remote-sensing technology such as satellite imagery or drones to spot defoliation damage was assessed in commercial fields and large production areas on research farms.
To find research related to this Research Highlight, please visit the National Soybean Checkoff Research Database.