Your local cooperative extension office is a very valuable and seriously under used source of all things plant-bug-turf-... related. To locate your's start by looking on your city's web site or call their offices. They will know how to contact them. The Co-op office has a vast data base to draw from. In Michigan ours is connected with Michigan State University. You could contact them as well. http://www.msue.msu.edu/portal/ = This is a link to their extention home page.