Since it's introduction into the United States in the past ten years, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), has been a damaging pest to soybean (Glycine max (L.) Merr.). Predicting their arrival in a soybean field on a year-by-year basis has been difficult as little is known as to what will cause an economic outbreak. During both 2008 and 2009, fields around central and north central Iowa experienced pockets of high soybean aphid populations. Yellow pan traps were placed in fields after planting along with lures which contained sex pheromones of the soybean aphid in 2009 or a plant volatile of the soybean plant and sex pheromones in 2008. Pan trap contents were collected weekly, and plant counts were also made. Aphids were identified, and soybean aphids were counted to determine if one chemical lure was more attractive to spring migrants than the others. In both years numbers of soybean aphids collected in pans with lures were not significantly different from each other or each other. It was observed that soybean aphids were present in soybean fields as early as June 23rd in 2008 and June 4th in 2009, and those populations do not always predict an outbreak.