Look for the following signs: 

• Moderate to high insect activity

• Lower than expected yields

• Mottled seed  

• Green stem plants at harvest maturity 

• No yield response to insecticides applied for soybean aphid control

• Presence of mottled, crinkled leaf symptoms typical of virus infection.  

• View a photo gallery of virus symptoms

Virus symptoms will be most apparent during times of rapid growth and cooler weather. Mottled and crinkled leaves can also be caused by herbicide injury or nutrient deficiencies.	Scout for insects: soybean aphid, bean leaf beetle and thrips	Mottled seed can indicate virus infection. However mottling can also be caused by insect feeding and physiological causes.