re: Sod web worms

Use a pyrethroid like I posted earlier. It's extremely effective and safe around pets. Dursban and chlordane are both organophosphate and very toxic to mammals. Lowes of tractor supply probably have a dozen choices to use. The insect isn't a webworm. It's an armyworm named that way because that just March through an area destroying everything. If you have st Augustine add a fungicide to prevent brown spot while you are at it.

Illegal where I live.

I would say 7-10 applications. They are do hard to see it's tough to judge when is the best time to spray. Biggest egg lay will be around the full moon which was Friday so if you were seeing moths big hatchout should be mid week. If you are trying to treat the dying spots remember the bulk of the worms will actually be on the edge of those areasand in the grass that looks unaffected. Usually 2 apps is enough but that has more to do with the weather. If we could get a little cool front in here that should end the problem.