Soybean Aphid

Soybean aphid. Click on image to view a larger version.

A good summary of what we know about aphid management and the cutting edge of aphid IPM research. Soybean Aphid Research Update. Read online (pdf) or order a free print copy by calling 1-800-383-1423).

See Soybean aphid-resistant soybean varieties for Iowa 2013. The listing includes varieties in late maturity group 0 and maturity groups 1, 2 and 3 (pdf)

The soybean aphid (Aphis glycines) is the only aphid in North America able to develop large colonies on soybeans. It was identified as a pest in North America in 2000. Since then, it has established itself in most soybean-growing areas and is a significant soybean pest in some years.

When the tiny, sap-sucking insects are present in large numbers (several hundred per plant), their feeding can cause stunting, puckered yellow leaves, reduced pod set, and smaller seed.

Agronomic impact

The risk of yield loss is greatest when aphid populations peak during the R1-to-R4 growth stages, when blooms and young pods are most suseptible to stress.

Damage from aphid feeding increases when growing conditions, especially soil moisture, are below optimum. 

Present and future tools to manage soybean aphids

Management of the soybean aphid is an active area of research in the north- central region. Growers now have a toolbox of strategies to work with, including.

• Well-established scouting procedures and an action threshold of 250 aphids/plant.
• Resistant soybean varieties - host plant resistance is a new and complementary tool to manage soybean aphid. Aphid-resistant varieties have the potential to simultaneously reduce insecticide usage
  and associated production costs, and preserve natural enemies in soybean. Host plant resistant genes for soybean aphid are prefixed with
  “Rag,” which is an abbreviation for “Resistant Aphis glycines.” The Rag1 gene expresses antibiosis -- a type of resistance where exposed insects do not live as long or produce as many offspring as they could on susceptible plants. About fifteen soybean varieties are available with Rag gene technology.
• Biological control - the soybean aphid would be a far more damaging pest were it not for biological control. Be aware of beneficials keeping aphids in check. A major regional research program is in progress with the goal of augmenting resident populations with specialist natural enemies.
• IPM - integrating aphid host resistance with biological control, scouting, insecticides, and crop management practices is the most effective strategy for aphid management. Read the Soybean Aphid Research Update for a good overview of soybean aphid IPM.