As soybean fields enter seed set throughout the state, we continue to get questions about how long to scout for soybean aphid. This year, aphid populations have been extremely variable with a limited number of fields exceeding the economic threshold (250 aphids per plant with increasing populations on 80 percent of the plants) in late July. In August, however, there have been more reports of increased aphid activity throughout the state (i.e., some fields were clean until last week). Many of the extension field agronomists also indicate winged aphids are showing up in fields. This correlates well with current aphid captures in the Regional Aphid Trapping Network (Figure 1).
Iowa State University
Hodgson, Erin W. and O'Neal, Matthew E., "Aphids Are on the Move, Remember to Scout in August!" (2009). Integrated Crop Management News. 561.
The Iowa State University Digital Repository provides access to Integrated Crop Management News for historical purposes only. Users are hereby notified that the content may be inaccurate, out of date, incomplete and/or may not meet the needs and requirements of the user. Users should make their own assessment of the information and whether it is suitable for their intended purpose. For current information on integrated crop management from Iowa State University Extension and Outreach, please visit https://crops.extension.iastate.edu/.