Little to no information is available on soybean gall midge or its interactions with soybean pathogens. No information is available on the economic losses with either or both being present on the same plant. The rapid and widespread infestation of this pest in soybeans throughout four key soybean-producing states (Nebraska, Iowa, South Dakota and Minnesota) has raised major concerns about what management practices are needed to mitigate losses. Field observations and communications with growers, consultants, and ag professionals have shown there are a number of questions surrounding the interactions between soybean gall midge and plant disease both in terms of infestation potential and yield loss relationships. Applications of fungicides can cost from $18 to $30 dollars per acre and as a result, they require careful consideration of their value for crop protection. Information provided in this project regarding the
importance of the disease component will guide future decisions relative the use of fungicides in mitigating yield losses associated with soybean gall midge.

The objective of this proposal are to evaluate soybean gall midge infestation potential in soybean throughout the entire growing season and evaluate the presence of plant diseases with these infestations using plants grown in a greenhouse and exposed to the field for brief periods.
The second objective is to evaluate a combination of pesticide tactics such insecticide and fungicide applications for management of soybean gall midge and its interactions with plant diseases under field conditions.

This 3-yr project would increase efforts to assess the timing of emergence of soybean gall midge adults and expand this effort to evaluate the potential infestation period over the growing season. Furthermore, interactions between soybean gall midge and plant diseases will also be determined. Sentinel plants would be exposed to a field for a period of one-week beginning in early spring through late August and evaluated for the presence of the midge and plant diseases. Sites would be adjacent to areas with high pressure from soybean gall midge the previous season. In addition, sites would consist of field plots with insecticide, fungicide and combination treatments to evaluate the role and interactions between fungal pathogens and soybean gall midge. Updates on this study would be provided during the growing season via UNL CropWatch and Twitter. Findings will also be disseminated through field days, conferences, as well as extension and research publications. Results from this study would provide farmers with an understanding of the risk period for infestation from soybean gall midge and its yield loss interactions with plant diseases.

Updated May 19, 2023:

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The lack of interactions to date is important to the overall management strategy for soybean gall midge. Using the research generated to date, growers should not apply fungicides as a management strategy for soybean gall midge. Such results simply the management, increasing the opportunity for more standard control methods that target the pest. In addition, the use of fungicides is expense, removing them as a potential strategy can save farmers money.

- Provides farmers with a window of the season at which their crop is at risk to soybean gall midge infestation
- Provides insight into potential economic impacts occur after spray dates during early vegetative stages
- Provides a basis for future management practices.
- Provides an understanding of the potential of other strategies that are not designed directly for soybean gall midge to mitigate losses
- Regardless of the results, the data would allow growers to make informed decisions about soybean gall midge management