Soybean aphid populations are continuing to persist and increase in South Dakota. Hot spots can be observed from the Southeast to the Northeast corners of the state. For this reason, scouting should continue and extra attention should be given to fields that are close to the 250 aphid/plant threshold.
The majority of soybean that were scouted this week are between the R3-R5 growth stages. Once soybean reach the R6 growth stage management of soybean aphid management does not typically result in any yield benefits.
Refer to this fact sheet for a product list of pyrethroid alternative insecticides.