YES, they are real. The week of the DNC they were spraying like crazy here and I live in the middle of nowhere.
http://www.youtube.com/watch?v=7VmAQqi3OJc
What no one has suggested is calling the sylphs. Sounds crazy, but I saw it work. After 3 days of spraying, I called the sylphs and they decimated the trails. Now anytime I see a trail I call them.
Picture of sylph over my house: