Iowa crop producers and agronomists are well aware of soybean cyst nematode (SCN), the plant-parasitic nematode that is widespread through the Midwest and can seriously reduce soybean yields. And many people are aware of other plant-parasitic nematodes that can cause significant yield reductions on corn. But most crop professionals probably are unaware that there is a corn cyst nematode that has been in the northeastern United States since 1981. And just recently, a new cyst nematode species that reproduces on corn was discovered in Tennessee.