Biological control for sustainable management of soybean gall midge, a new pest of soybean in the North Central Region

Commodities

• Agronomic: soybeans

Practices

• Pest Management: biological control

Title: Biological control for sustainable management of soybean gall midge, a new pest of soybean in the North Central Region.

This research-based project aims to advance implementation of biological control for soybean gall midge, Resseliella maxima (Diptera: Cecidomyiidae). Soybean gall midge is a new pest posing a significant threat to soybean production in the North Central Region. This pest infests the stems of soybean plants and has caused considerable yield reductions in multiple states. Research is urgently needed to understand the potential for biological control, specifically the community composition, dynamics and impacts of parasitic wasps on soybean gall midge populations. Over three field seasons, soybean fields of cooperating farmers will be sampled for this pest and its natural enemies. Parasitic wasps (parasitoids) will be identified through rearing from field-collected soybean gall midge larvae in the laboratory, and molecular methods to quantify parasitism of field-collected soybean gall midge larvae. Data will be analyzed to examine the spatiotemporal dynamics of the communities of parasitic wasps and their relationship to surrounding habitats. This knowledge on biological control of soybean gall midge will be essential for the implementation of sustainable IPM programs for this pest. A primary near-term outcome (upon completion of the project) will be knowledge of what species of parasitic wasps attack soybean gall midge across the region and what levels of biological control they provide. An additional near-term outcome (upon completion of the project) will be knowledge of the spatial and temporal dynamics of parasitism of soybean gall midge. Spatial models will be developed to allow identification of landscape features associated with high and low levels of potential biological control. Temporal models will be developed to determine the seasonal abundance (phenology) of the pest and parasitic wasps. A longer-term outcome will be improved knowledge for rearing the parasitic wasps that attack this pest, which could lead to development of future programs universities or government agencies to produce these parasitic wasps for release against this pest (2-4 years after completion of the project). Results of this research will be disseminated to growers across the North Central Region through active extension programming. Soybean farmers and the associated agricultural community will benefit from the knowledge that this project will provide, allowing them to adjust agricultural practices to improve or incorporate biological control for more sustainable management of this pest.

Objective 1: Characterize the community of parasitic wasps associated with soybean gall midge.

Objective 2: Evaluate the spatial-temporal dynamics of parasitism of soybean gall midge.

Objective 3: Develop models to identify fields with low or high potential for biological control of soybean gall midge and periods of the growing season when disruptions to fields should be avoided.

Learning outcomes of this project will focus on increasing knowledge of farmers and agricultural professionals about biological control for soybean gall midge. Action outcomes of this project will lead to improved integrated pest management by determining likelihood for biological control across the landscape.