We are starting to get more reports of spider mites damaging corn and soybeans in Nebraska. Because many other things can cause similar discoloration, it is important to check leaves closely to make sure mites are actually causing the damage.
Recommendations for managing spider mites in corn and soybean, including treatment thresholds, insecticides as well as discussions on the potential impact of beneficial insects, diseases, and insecticide applications.
The infestations appear to have occurred recently, as the aphids were only observed on leaves that had not yet expanded completely. The economic threshold for late vegetative through R5 stage soybeans is 250 aphids per plant with 80% of the plants infested and populations increasing.
The current economic threshold for soybean aphids is 250 aphids per plant with 80% of the plant infested and populations increasing. The article discusses the basis for this threshold and two scouting methods, including a speed scouting app, and management guidelines.