Here is an interesting question from Diane Tewes, a former turf student here at ISU. Diane currently lives at near the Harvester golf course by Marshalltown, IA.
I was wondering if you would know what caused this silky, web-like stuff on the yard? We moved to the Harvester last October and I spotted this a couple of Sundays ago. It was partially in our yard, all of my neighbors and the next. I had never seen anything like it before.
It looked like spider webs to me, but I also checked with our local expert, Dr. Donald Lewis of the ISU Entomology Department. Here is Don's response.
Hi Diane and Nick:
Thank you for your message. Your experience with a lawn covered in spider webs puts you in a very small group of people lucky enough to see this phenomenon. The webs come from a huge, simultaneous hatch of harmless spiders.
Here is a previous article on the topic: http://www.ipm.iastate.edu/ipm/hortnews/2009/7-15/spiderwebs.html
May we have permission to use your photo on our websites?
Hopefully this will be of use, particularly to those of you in lawn care who often get questions on this phenomenon.