If you haven't started thinking about scouting your soybean fields for aphids yet, Marlin Rice, Iowa State University (ISU) Extension entomologist, urges you to get ready to start checking your fields by the end of June.
"Aphids often occur in soybeans in northeastern Iowa around mid June, but they are difficult to find, and infestations rarely reach the economic threshold of 250 aphids per plant during June. However, this year aphids were found earlier than expected in northeastern Iowa. Therefore, I recommend that producers start scouting the last week of June, or the first week of July at the very latest. Scouting can provide information on the presence of aphids and by scouting for several weeks, it can be determined whether the population is increasing or decreasing," he said.
Read the full story at http://www.extension.iastate.edu/news/2005/jun/072101.htm