Hmm... well, I never did anything specific to "treat" the spittlebugs, but I can say since it has been in the mid-90s for about a month, I haven't seen a single ball of spittlebug "foam" ANYWHERE recently. I did put down the GrubEx about 5 weeks ago, however. You have a good point, but none of these spots have anything going on (visibly) but weird-looking zoysia.
There is very little going on within my zoysia that I don't notice. I'm literally the guy who crawls around the yard on my knees, pulling weeds by hand for several hours per week. I know there is still rust here and there on some of the blades. I know the shaded areas of the lawn seem fairly unhealthy and wispy. Other than that, things are good..... except for these weird patches.