Corn Nematodes and Soybean Cyst Nematode: Similar But Very Different

March 30, 2010
ICM News

By Greg Tylka, Department of Plant Pathology

Corn nematodes and the soybean cyst nematode (SCN) are microscopic, plant-parasitic worms that live in the soil and feed on plant roots. Iowa crop producers and agribusiness professionals generally are aware of the soybean cyst nematode and its biology, scouting and management.  But many people want to learn more about the biology, scouting and management of corn nematodes.

There are some similarities but also many major differences in various aspects of corn nematodes and the soybean cyst nematode. Keeping these similarities and differences in mind is important when trying to determine the most economical and effective way to manage these pests.

general aspects of nematodes

biology of nematodes chart

symptoms and scouting nematodes

nematode management chart

The information above is for most commonly found corn nematode species. But some of the generalizations are not true for the needle and sting nematodes. Following are specific exceptions to the generalizations listed in the table for needle and sting nematodes.

• only found in soils that are more than 70 percent sand

• sample spring or fall, not mid season

• extremely high damage potential; damage threshold is one per 100 cubic centimeters soil

• narrow host range

• nonhost crops for management include alfalfa and soybean

A printer friendly version of the article and charts can be downloaded.


Greg Tylka is a professor of plant pathology with extension and research responsibilities in management of plant-parasitic nematodes.


needle nematode damage

Symptoms of needle nematode damage to corn roots.

 swollen soybean cyst nematode female
Swollen soybean cyst nematode females on soybean root.

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on March 30, 2010. The information contained within may not be the most current and accurate depending on when it is accessed.


Greg Tylka Morrill Professor

Dr. Greg Tylka is a Morrill Professor in the Department of Plant Pathology and Microbiology at Iowa State University with extension and research responsibilities for management of plant-parasitic nematodes. The focus of Dr. Tylka's research program at Iowa State University is primarily the soybea...