Source: Iowa State University

The soybean cyst nematode has been known to exist in Iowa since 1978. The first Iowa finding was in Winnebago County. In the 1980s and 1990s, SCN was found for the first time in many different Iowa counties. By 2000, SCN had not yet been found in only nine Iowa counties. By the end of 2007, it had not yet been found or officially confirmed in only three Iowa counties