The cottony grass scale is not a common problem in Iowa. This insect is noticed in the fall when small white tufts that look like a cotton-swab are noticed clinging to grass blades. The puffs that are so noticeable are actually the eggs of the scale covered by a waxy protective covering. We think that it is probably the eggs that overwinter in Iowa and hatch in the spring. However, we do not know enough about the scale to know if there is one or two generations and when the crawlers are present.
Although we still lack a lot of basic information about the cottony grass scale, indications are that it does not cause much damage to healthy turf. Discoloration of the turf seems to appear later in the summer and reports are that it seems to be more noticeable in some years and not at all in others. At this point we are not recommending any insecticidal sprays because lawns recover, and we do not have good information on when to spray.
For more information and pictures of the damage to turf please see this article from the University of Minnesota Yard and Garden News.

Wax covered egg mass left by a cottony grass scale.
 

Salmon-colored eggs inside.