Larvae are dark grey to brown above with faint lighter stripes. Skin has strongly convex, rounded granules of varying sizes (like sandpaper).

Foliage feeder in early stages, cuts plant off below ground in later stages.

May through June (primarily eastern 1/3 of state, along Missouri River)

Count wilting or cut plants in 20 feet of row in several spots in the field.

Treat when 5% of plants are damaged or cut, and larvae are < 1/2" long