Soybean, Glycine max (L.), grown in Iowa and most of the north central region of the United States did not require regular insecticide usage before 2000. But the arrival of soybean aphid (Aphis glycines) has changed management practices because yield losses from direct plant feeding can reduce yield by 25 percent. Host plant resistance for soybean aphid is now commercially available and included for the first time in the efficacy evaluation.