Here is an interesting lawn problem that is quite rare, but seems to come up almost every spring here in Iowa. People will call and say that they appear to have cigarette papers all over their lawn. They usually do not see an insect associated with the problem and the question is, “what could possibly cause this?”
The problem is caused by an insect called the Burrowing Webworm. It is in the genus Acrolophus. Other common names include Cigarette paper webworm or tube moth. There are reportedly 65 species within the genus. Like the more common Sod Webworm, the larvae live in a web-lined burrow just under the surface of the lawn. In the case of the Burrowing webworm, birds feeding on the larvae pull out the webbing, consume the larvae and leave the cigarette paper-like webbing on the surface. It is not usual to see hundreds of these on the lawn after birds have been there. They disappear very quickly with moisture and the larvae are generally not seen because the birds ate them.
While the larvae can feed on turf, they rarely do any serious damage to lawns. Most common insecticides for surface feeders will kill them. However, most of them are generally gone because of bird feeding when the paper-like burrow is observed and insecticides would not be recommended.
I would like some more pictures of the papers. If any one sees them, send the pictures to Nick Christians at email@example.com.
Picture of Cigarette paper-like burrow lining. Courtesy of Laura Iles of the Plant and Insect Diagnosis Clinic at Iowa State University.
Picture of adult Burrowing Webworm from the web. It is from New Hampshire Public Television.
I received the following pictures from Gary McVay. They are from St. Charles Ia, south of Des Moines. They were taken the week of June 19, 2017.
In this picture the hole from which the larvae and paper were taken by birds is visible.
Here are a couple more from the Boone, Ia area from 6/23/17.
Here are two new ones from the Ames area, 6/27/17
Here are a few more from 6/27/17. These are from Ida County.
Yet another one from the North side of Ames on 7/5/17