Scout for Soybean Aphids in MN Fields

Soybean Aphid Resistance 
Figure 1. Soybean aphids infesting a soybean leaf. (Photo courtesy of R. Kock, University of Minnesota)

Figure 2. Counties with reported failures of pyrethroids for control of soybean aphid. Red-shaded counties indicate those from which Extension entomologists received reports of failures. (Maps courtesy of B. Potter, University of Minnesota)
Management of Insecticide-resistant Soybean Aphids
North Dakota State University
Robert Koch, University of Minnesota; Erin Hodgson, Iowa State University; Janet Knodel, North Dakota State University; Adam Varenhorst, South Dakota State University
Soybean aphid populations are highly variable again this year.  Locally at the Stanton, MN, Agronomy in Action site aphid populations are nearing the 250 threshold in soybean demonstration plots. Favorable weather for rapid reproduction is in the works. 

Farmers looking to accelerate the scouting process, can turn to the University of Minnesota Extension, speed scouting methods.

Historically, we’ve been able to rely on insecticide applications to manage soybean aphids. Our reliance on only a few insecticide groups in combination with their biology & persistence has led them to develop resistance to the pyrethroid mode of action.  
  • If you choose to spray, be mindful of product labels and spray instructions.  After application, continue to scout closely for at least 2 weeks.
  • If your initial treatment doesn’t work, it’s unlikely that applying it a second time will be effective. Rule out other causes for error and rotate to a different insecticide group.
  • Maintain application setbacks from permanent water bodies to protect surface water from runoff, drift or leaching.
For more information on soybean aphid management in your area, get in touch with your Golden Harvest Seed Advisor.

Syngenta hereby disclaims liability for third-party websites.
Share This Article


Name is required
Please enter a valid email address
Please enter a valid zip code
Sign Up

Your submission has been received, thanks!


You are viewing from

Thank you for visiting the Golden Harvest website. We understand how important it is for you to find agronomic and product information pertinent to your local area. Please enter your zip code or select your area below to ensure you are seeing the information that matters most to you.
Learn more about regions >


We’re sorry. Golden Harvest is not available in this area. Please try another zip code or contact a Golden Harvest Seed Advisor for more information.