Northeast Research and Demonstration Farm
Soybean grown in Iowa has historically used low amounts of insecticide. However, an invasive insect pest has threatened soybean production in Iowa, with the arrival of the soybean aphid (Aphis glycines Matsumura). The soybean aphid causes yield losses from direct plant feeding, and has been shown to transmit several plant viruses. In Iowa, soybean aphids colonize soybean fields beginning in June and have produced outbreaks in July and August capable of reducing yields by nearly 25 percent. We know that the presence of the aphid is not enough to warrant the application of an insecticide; populations above 600 aphids/plant are needed to produce measurable yield losses. We have developed a recommendation that incorporates an economic threshold of 250 aphids/plant. However, we continue to be asked, “What products offer the most consistent control of soybean aphids?”
Iowa State University
Johnson, Kevin and O'Neal, Matthew E., "2008 Insecticide Trials for Aphid Control" (2009). Iowa State Research Farm Progress Reports. 567.