Not sure what these patches are; they started to appear around 3-4 weeks ago. It's been very hot and humid and we havn't had a good soaking rain in about a month. I've been on a good yearly program using all Lesco stuff including Merit and Talstar. I've puilled on the turf in and around these areas and it is all good and rooted (no grubs). Also, I don't see any bugs or have little moths flying up when I mow. I hope that's enough information for you guys to help me. It sucks, because my lawn has looked great since I planted it all 6 years ago, and now what the *#@! Thanks in advance for your help!