By Robert Koch, Extension Entomologist
On June 11, 2013, we found soybean aphids on soybean at the Rosemount Research and Outreach Center near Rosemount, MN. Not many beans were out of the ground there, but in the two fields we sampled, we found aphids. We sampled one commercial soybean field at the VC growth stage (unifoliate leaves unfolded) and found 7.5% of plants infested with 1 to 9 aphids on each infested plant. The other field we sampled was a small plot trial, also at the VC growth stage, and had 10% of plants infested with 2 to 3 aphids on each plant.
This find is in line with what is being seen in neighboring states. Last week, soybean aphids were found on soybean in Wisconsin and northeastern Iowa. It is far too early to be worrying about aphid control; however, you may want to begin checking your fields for aphids, especially when we get into late June.
By the way, I am the new soybean entomologist. I have a research and extension appointment and I am stationed on the St. Paul campus. You can find out more about me on my webpage.
I look forward to working with you.