The soybean aphid (Aphis glycines Matsumura) was discovered infesting soybean fields in southern Wisconsin in July of 2000. This was the first time aphids had been found colonizing soybeans in Wisconsin. A host range study was performed on this aphid the following winter to determine whether or not the aphid was utilizing plants other than soybean for reproductive purposes. Virus transmission experiments were also conducted with the soybean aphid.