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.
Wax covered egg mass left by a cottony grass scale.
Salmon-colored eggs inside.
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, Yard and Garden, 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 September 30, 2009. The information contained within may not be the most current and accurate depending on when it is accessed.