Soybean cyst nematode (SCN) is an important, widespread soybean pest in Iowa that often goes undetected. To date, the nematode has been discovered in all but Adams, Allamakee, Ida, and Lyon counties in Iowa. The only consistent and reliable sign of an SCN infestation in the field during the growing season is the presence of adult SCN females and cysts (dead females) on the roots of infected soybean plants. Adult SCN females and cysts are small, round, and white to yellow, each approximately the size of a period at the end of a sentence.