Pyrethroid resistant soybean aphids continues to threaten effective pest management of soybean aphids in eastern ND. The first goal of this research is to provide soybean growers with ‘updated’ insecticide efficacy for successful management of pyrethroid resistant soybean aphids in their fields, and to mitigate the development of resistance to other insecticides. By understanding which insecticides manage pyrethroid resistant soybean aphids, soybean yields can be maximized. We will evaluate a broad range of registered and experimental insecticides with different modes of action. The second goal of this research is to continue survey work for the invasive soybean gall midge, a new economic insect pest of soybeans. Soybean gall midge was recently discovered in Sargent County, ND in 2022 (pending DNA analyses). In summary, this research will identify the best management practices for pyrethroid resistant soybean aphids and determine the pest status of soybean gall midge in ND. By understanding the producer’s increasing risk of insecticide resistant soybean aphids, management of soybean aphids can be optimized through Integrated Pest Management (IPM) and maximize soybean profits. Survey work for the invasive and destructive soybean gall midge is crucial so that soybean producers are aware of its current distribution and pest density in ND.

1) To determine which insecticides and mode of actions are the best tools for management of pyrethroid resistant soybean aphids.
2) To continue survey work for the detection of the invasive soybean gall midge.
3) To develop extension outreach material on soybean insect pests for NSDC and growers.

• Results will be published in NDSC reports and trade magazines, NDSC podcasts and NDSU Extension’s Crop & Pest Report.
• Results also will be posted on the NDSU Extension Entomology and IPM websites.
• Results will be presented at soybean extension and commodity meetings / field.
• New soybean insect outreach materials will be provided to NDSC for soybean growers.

Update:

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Objective 1: We propose to be proactive in detecting developing insecticide resistance in populations of soybean aphids in eastern North Dakota. Insecticide resistance in populations of soybean aphids will complicate control decisions for producers, and potentially increase costs and decrease net returns. Producers need to know which insecticide products will control pyrethroid resistant soybean aphids, since economic aphid populations are known to cause significant yield losses of over 50% if not managed.

For the 2nd objective, a survey will be conducted in southeastern ND to determine if the soybean gall midge is expanding its distribution and prevalence in ND soybean fields.

The 3rd objective will provide a ‘new’ soybean insect pest publication for use by the NDSC, soybean growers and NDSU Extension. The outdated NDSU Extension Soybean Aphid IPM publication will be updated with new research information.

An Integrated Pest Management (IPM) approach will benefit the ND soybean industry by minimizing pesticide costs, soybean pest damage, and risks of pests developing pesticide resistance, thereby increasing soybean productivity.