SDSU IPM: Soybean Aphids

About Soybean Aphids

The soybean aphid, Aphis glycines, has emerged in recent years as the most important new insect pest of Midwestern soybeans. This aphid (from Asia) was first detected in North America in 2000. Crop losses from this pest have been estimated in the billions of dollars, nationally. Though there can be great field-to-field variability in infestation, widespread outbreaks of the soybean aphid are common throughout the Midwest.

We have conducted work in South Dakota funded by the North Central Soybean Research Program and the South Dakota Soybean Research and Promotion Council (grower-funded organizations that invest soybean checkoff funds regionally and in South Dakota) to refine the economic thresholds for soybean aphid for this state. The economic injury level – how many aphids it takes to cause economic loss, is on average around 675 aphids/plant. The economic threshold in the Midwestern region is 250 aphids/plant, based on research conducted in Minnesota, Iowa, Nebraska, North Dakota, Michigan, Wisconsin, and in South Dakota.

Other SDSU research has been to assess the level of background soybean aphid suppression being provided by the natural enemies we already have in South Dakota. For a video summary of natural enemies often found in soybeans, listen to talk #4 at the following link: http://www.ncipmc.org/teleconference/soybean2007/videos/

A good all-purpose website for information about the history of the soybean aphid in the US, its biology, and management can be found at:

http://www.soybeans.umn.edu/crop/insects/aphid/aphid.htm

See also the following site. This is an information site of the North Central Soybean Research Program (NCSRP). This organization invests some of the checkoff funds generated by soybean producers in many states into regional research programs designed to benefit the producers in these states:

http://www.planthealth.info/aphids_basics.htm

SDSU Soybean Aphids Research

Soybean Aphid Economic Threshold Research

South Dakota Cooperative Extension Service Factsheet: Soybean Aphids in South Dakota